diff --git a/thirdparty/libpng/CHANGES b/thirdparty/libpng/CHANGES new file mode 100644 index 00000000..95350873 --- /dev/null +++ b/thirdparty/libpng/CHANGES @@ -0,0 +1,278 @@ +CHANGES - changes for libpng + +version 0.2 + added reader into png.h + fixed small problems in stub file +version 0.3 + added pull reader + split up pngwrite.c to several files + added pnglib.txt + added example.c + cleaned up writer, adding a few new tranformations + fixed some bugs in writer + interfaced with zlib 0.5 + added K&R support + added check for 64 KB blocks for 16 bit machines +version 0.4 + cleaned up code and commented code + simplified time handling into png_time + created png_color_16 and png_color_8 to handle color needs + cleaned up color type defines + fixed various bugs + made various names more consistant + interfaced with zlib 0.71 + cleaned up zTXt reader and writer (using zlib's Reset functions) + split transformations into pngrtran.c and pngwtran.c +version 0.5 + interfaced with zlib 0.8 + fixed many reading and writing bugs + saved using 3 spaces instead of tabs +version 0.6 + added png_large_malloc() and png_large_free() + added png_size_t + cleaned up some compiler warnings + added png_start_read_image() +version 0.7 + cleaned up lots of bugs + finished dithering and other stuff + added test program + changed name from pnglib to libpng +version 0.71 [June, 1995] + changed pngtest.png for zlib 0.93 + fixed error in libpng.txt and example.c +version 0.8 + cleaned up some bugs + added png_set_filler() + split up pngstub.c into pngmem.c, pngio.c, and pngerror.c + added #define's to remove unwanted code + moved png_info_init() to png.c + added old_size into png_realloc() + added functions to manually set filtering and compression info + changed compression parameters based on image type + optimized filter selection code + added version info + changed external functions passing floats to doubles (k&r problems?) + put all the configurable stuff in pngconf.h + enabled png_set_shift to work with paletted images on read + added png_read_update_info() - updates info structure with + transformations +version 0.81 [August, 1995] + incorporated Tim Wegner's medium model code (thanks, Tim) +version 0.82 [September, 1995] + [unspecified changes] +version 0.85 [December, 1995] + added more medium model code (almost everything's a far) + added i/o, error, and memory callback functions + fixed some bugs (16 bit, 4 bit interlaced, etc.) + added first run progressive reader (barely tested) +version 0.86 [January, 1996] + fixed bugs + improved documentation +version 0.87 [January, 1996] + fixed medium model bugs + fixed other bugs introduced in 0.85 and 0.86 + added some minor documentation +version 0.88 [January, 1996] + fixed progressive bugs + replaced tabs with spaces + cleaned up documentation + added callbacks for read/write and warning/error functions +version 0.89 [July, 1996] + added new initialization API to make libpng work better with shared libs + we now have png_create_read_struct(), png_create_write_struct(), + png_create_info_struct(), png_destroy_read_struct(), and + png_destroy_write_struct() instead of the separate calls to + malloc and png_read_init(), png_info_init(), and png_write_init() + changed warning/error callback functions to fix bug - this means you + should use the new initialization API if you were using the old + png_set_message_fn() calls, and that the old API no longer exists + so that people are aware that they need to change their code + changed filter selection API to allow selection of multiple filters + since it didn't work in previous versions of libpng anyways + optimized filter selection code + fixed png_set_background() to allow using an arbitrary RGB color for + paletted images + fixed gamma and background correction for paletted images, so + png_correct_palette is not needed unless you are correcting an + external palette (you will need to #define PNG_CORRECT_PALETTE_SUPPORTED + in pngconf.h) - if nobody uses this, it may disappear in the future. + fixed bug with Borland 64K memory allocation (Alexander Lehmann) + fixed bug in interlace handling (Smarasderagd, I think) + added more error checking for writing and image to reduce invalid files + separated read and write functions so that they won't both be linked + into a binary when only reading or writing functionality is used + new pngtest image also has interlacing and zTXt + updated documentation to reflect new API +version 0.90 [January, 1997] + made CRC errors/warnings on critical and ancillary chunks configurable + libpng will use the zlib CRC routines by (compile-time) default + changed DOS small/medium model memory support - needs zlib 1.04 (Tim Wegner) + added external C++ wrapper statements to png.h (Gilles Dauphin) + allow PNG file to be read when some or all of file signature has already + been read from the beginning of the stream. ****This affects the size + of info_struct and invalidates all programs that use a shared libpng**** + fixed png_filler() declarations + fixed? background color conversions + fixed order of error function pointers to match documentation + current chunk name is now available in png_struct to reduce the number + of nearly identical error messages (will simplify multi-lingual + support when available) + try to get ready for unknown-chunk callback functions: + - previously read critical chunks are flagged, so the chunk handling + routines can determine if the chunk is in the right place + - all chunk handling routines have the same prototypes, so we will + be able to handle all chunks via a callback mechanism + try to fix Linux "setjmp" buffer size problems +version 0.95 [March, 1997] + fixed bug in pngwutil.c allocating "up_row" twice and "avg_row" never + fixed bug in PNG file signature compares when start != 0 + changed parameter type of png_set_filler(...filler...) from png_byte + to png_uint_32 + added test for MACOS to ensure that both math.h and fp.h are not #included + added macros for libpng to be compiled as a Windows DLL (Andreas Kupries) + added "packswap" transformation, which changes the endianness of + packed-pixel bytes (Kevin Bracey) + added "strip_alpha" transformation, which removes the alpha channel of + input images without using it (not neccesarily a good idea) + added "swap_alpha" transformation, which puts the alpha channel in front + of the color bytes instead of after + removed all implicit variable tests which assume NULL == 0 (I think) + changed several variables to "png_size_t" to show 16/32-bit limitations + added new pCAL chunk read/write support + added experimental filter selection weighting (Greg Roelofs) + removed old png_set_rgbx() and png_set_xrgb() functions that have been + obsolete for about 2 years now (use png_set_filler() instead) + added macros to read 16- and 32-bit ints directly from buffer, to be + used only on those systems that support it (namely PowerPC and 680x0) + With some testing, this may become the default for MACOS/PPC systems. + only calculate CRC on data if we are going to use it + added macros for zTXt compression type PNG_zTXt_COMPRESSION_??? + added macros for simple libpng debugging output selectable at compile time + removed PNG_READ_END_MODE in progressive reader (Smarasderagd) + more description of info_struct in libpng.txt and png.h + more instructions in example.c + more chunk types tested in pngtest.c + renamed pngrcb.c to pngset.c, and all png_read_ functions to be + png_set_. We now have corresponding png_get_ + functions in pngget.c to get infomation in info_ptr. This isolates + the application from the internal organization of png_info_struct + (good for shared library implementations). +version 0.96 [May, 1997] + fixed serious bug with < 8bpp images introduced in 0.95 + fixed 256-color transparency bug (Greg Roelofs) + fixed up documentation (Greg Roelofs, Laszlo Nyul) + fixed "error" in pngconf.h for Linux setjmp() behaviour + fixed DOS medium model support (Tim Wegner) + fixed png_check_keyword() for case with error in static string text + added read of CRC after IEND chunk for embedded PNGs (Laszlo Nyul) + added typecasts to quiet compiler errors + added more debugging info +version 0.97 [January, 1998] + removed PNG_USE_OWN_CRC capability + relocated png_set_crc_action from pngrutil.c to pngrtran.c + fixed typecasts of "new_key", etc. (Andreas Dilger) + added RFC 1152 [sic] date support + fixed bug in gamma handling of 4-bit grayscale + added 2-bit grayscale gamma handling (Glenn R-P) + added more typecasts. 65536L becomes (png_uint_32)65536L, etc. (Glenn R-P) + minor corrections in libpng.txt + added simple sRGB support (Glenn R-P) + easier conditional compiling, e.g. define PNG_READ/WRITE_NOT_FULLY_SUPPORTED; + all configurable options can be selected from command-line instead + of having to edit pngconf.h (Glenn R-P) + fixed memory leak in pngwrite.c (free info_ptr->text) (Glenn R-P) + added more conditions for png_do_background, to avoid changing + black pixels to background when a background is supplied and + no pixels are transparent + repaired PNG_NO_STDIO behaviour + tested NODIV support and made it default behaviour (Greg Roelofs) + added "-m" option and PNGTEST_DEBUG_MEMORY to pngtest (John Bowler) + regularized version numbering scheme and bumped shared-library major + version number to 2 to avoid problems with libpng 0.89 apps (Greg Roelofs) +version 0.98 [January, 1998] + cleaned up some typos in libpng.txt and in code documentation + fixed memory leaks in pCAL chunk processing (Glenn R-P and John Bowler) + cosmetic change "display_gamma" to "screen_gamma" in pngrtran.c + changed recommendation about file_gamma for PC images to .51 from .45, + in example.c and libpng.txt, added comments to distinguish between + screen_gamma, viewing_gamma, and display_gamma. + changed all references to RFC1152 to read RFC1123 and changed the + PNG_TIME_RFC1152_SUPPORTED macro to PNG_TIME_RFC1123_SUPPORTED + added png_invert_alpha capability (Glenn R-P -- suggestion by Jon Vincent) + changed srgb_intent from png_byte to int to avoid compiler bugs +version 0.99 [January 30, 1998] + free info_ptr->text instead of end_info_ptr->text in pngread.c (John Bowler) + fixed a longstanding "packswap" bug in pngtrans.c + fixed some inconsistencies in pngconf.h that prevented compiling with + PNG_READ_GAMMA_SUPPORTED and PNG_READ_hIST_SUPPORTED undefined + fixed some typos and made other minor rearrangement of libpng.txt (Andreas) + changed recommendation about file_gamma for PC images to .50 from .51 in + example.c and libpng.txt, and changed file_gamma for sRGB images to .45 + added a number of functions to access information from the png structure + png_get_image_height(), etc. (Glenn R-P, suggestion by Brad Pettit) + added TARGET_MACOS similar to zlib-1.0.8 + define PNG_ALWAYS_EXTERN when __MWERKS__ && WIN32 are defined + added type casting to all png_malloc() function calls +version 0.99a [January 31, 1998] + Added type casts and parentheses to all returns that return a value.(Tim W.) +version 0.99b [February 4, 1998] + Added type cast png_uint_32 on malloc function calls where needed. + Changed type of num_hist from png_uint_32 to int (same as num_palette). + Added checks for rowbytes overflow, in case png_size_t is less than 32 bits. + Renamed makefile.elf to makefile.lnx. +version 0.99c [February 7, 1998] + More type casting. Removed erroneous overflow test in pngmem.c. + Added png_buffered_memcpy() and png_buffered_memset(), apply them to rowbytes. + Added UNIX manual pages libpng.3 (incorporating libpng.txt) and png.5. +version 0.99d [February 11, 1998] + Renamed "far_to_near()" "png_far_to_near()" + Revised libpng.3 + Version 99c "buffered" operations didn't work as intended. Replaced them + with png_memcpy_check() and png_memset_check(). + Added many "if (png_ptr == NULL) return" to quell compiler warnings about + unused png_ptr, mostly in pngget.c and pngset.c. + Check for overlength tRNS chunk present when indexed-color PLTE is read. + Cleaned up spelling errors in libpng.3/libpng.txt + Corrected a problem with png_get_tRNS() which returned undefined trans array +version 0.99e [February 28, 1998] + Corrected png_get_tRNS() again. + Add parentheses for easier reading of pngget.c, fixed "||" should be "&&". + Touched up example.c to make more of it compileable, although the entire + file still can't be compiled (Willem van Schaik) + Fixed a bug in png_do_shift() (Bryan Tsai) + Added a space in png.h prototype for png_write_chunk_start() + Replaced pngtest.png with one created with zlib 1.1.1 + Changed pngtest to report PASS even when file size is different (Jean-loup G.) + Corrected some logic errors in png_do_invert_alpha() (Chris Patterson) +version 0.99f [March 5, 1998] + Corrected a bug in pngpread() introduced in version 99c (Kevin Bracey) + Moved makefiles into a "scripts" directory, and added INSTALL instruction file + Added makefile.os2 and pngos2.def (A. Zabolotny) and makefile.s2x (W. Sebok) + Added pointers to "note on libpng versions" in makefile.lnx and README + Added row callback feature when reading and writing nonprogressive rows + and added a test of this feature in pngtest.c + Added user transform callbacks, with test of the feature in pngtest.c +version 0.99g [March 6, 1998, morning] + Minor changes to pngtest.c to suppress compiler warnings. + Removed "beta" language from documentation. +version 0.99h [March 6, 1998, evening] + Minor changes to previous minor changes to pngtest.c + Changed PNG_READ_NOT_FULLY_SUPPORTED to PNG_READ_TRANSFORMS_NOT_SUPPORTED + and added PNG_PROGRESSIVE_READ_NOT_SUPPORTED macro +version 1.00 [March 7, 1998] + Changed several typedefs in pngrutil.c + Added makefile.wat (Pawel Mrochen), updated makefile.tc3 (Willem van Schaik) + replaced "while(1)" with "for(;;)" + added PNGARG() to prototypes in pngtest.c and removed some prototypes + updated some of the makefiles (Tom Lane) + changed some typedefs (s_start, etc.) in pngrutil.c + fixed dimensions of "short_months" array in pngwrite.c + Replaced ansi2knr.c with the one from jpeg-v6 +version 1.0.0 [March 8, 1998] + Changed name from 1.00 to 1.0.0 (Adam Costello) + Added smakefile.ppc (with SCOPTIONS.ppc) for Amiga PPC (Andreas Kleinert) +version 1.0.1 [March 9, 1998] + Fixed three bugs in pngrtran.c to make gamma+background handling consistent + (Greg Roelofs) + Changed format of the PNG_LIBPNG_VER integer to xyyyzzzz instead of xyz + for major, minor, and bugfix releases. This is 10000001L. (Adam Costello) diff --git a/thirdparty/libpng/INSTALL b/thirdparty/libpng/INSTALL new file mode 100644 index 00000000..bc9f5f02 --- /dev/null +++ b/thirdparty/libpng/INSTALL @@ -0,0 +1,87 @@ + +Installing libpng version 1.0.1 March 9, 1998 + +Before installing libpng, you must first install zlib. zlib +can usually be found wherever you got libpng. zlib can be +placed in another directory, at the same level as libpng. +Note that your system might already have a preinstalled +zlib, but you will still need to have access to the +zlib.h and zconf.h include files that correspond to the +version of zlib that's installed. + +You can rename the directories that you downloaded (they +might be called "libpng-1.0.1 or "lpng100" and "zlib-1.1.1" +or "zlib111") so that you have directories called "zlib" and "libpng". + +Your directory structure should look like this: + + .. (the parent directory) + libpng (this directory) + INSTALL (this file) + README + *.h + *.c + scripts + makefile.* + pngtest.png + etc. + zlib + README + *.h + *.c + contrib + etc. + +First enter the zlib directory and follow the instructions +in zlib/README. Then come back here and choose the +appropriate makefile.sys in the scripts directory. +The files that are presently available in the scripts directory +include + + descrip.mms => VMS makefile for MMS or MMK + makefile.std => Generic UNIX makefile + makefile.knr => Archaic UNIX Makefile that converts files with ansi2knr + makefile.dec => DEC Alpha UNIX makefile + makefile.sgi => Silicon Graphics IRIX makefile + makefile.sun => Sun makefile + makefile.s2x => Solaris 2.X makefile (gcc, creates libpng.so.2.1.0) + makefile.lnx => Linux/ELF makefile (gcc, creates libpng.so.2.1.0) + makefile.mip => MIPS makefile + makefile.aco => Acorn makefile + makefile.ama => Amiga makefile + smakefile.ppc => AMIGA smakefile for SAS C V6.58/7.00 PPC compiler + (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc) + makefile.atr => Atari makefile + makefile.bor => Borland makefile + build.bat => MS-DOS batch file for Borland compiler + makefile.dj2 => DJGPP 2 makefile + makefile.msc => Microsoft C makefile + makefile.tc3 => Turbo C 3.0 makefile + makefile.os2 => OS/2 Makefile (gcc and emx, requires pngos2.def) + pngos2.def => OS/2 module definition file used by makefile.os2 + makefile.wat => Watcom 10a+ Makefile, 32-bit flat memory model + makevms.com => VMS build script + +Copy the file (or files) that you need from the +scripts directory into this directory, for example + + MSDOS example: copy scripts\makefile.msd makefile + UNIX example: cp scripts/makefile.std makefile + +Read the makefile to see if you need to change any source or +target directories to match your preferences. + +Then read pngconf.h to see if you want to make any configuration +changes. + +Then just run "make test" which will create the libpng library in +this directory and run a quick test that reads the "pngtest.png" +file and writes a "pngout.png" file that should be identical to it. + +Most of the makefiles will allow you to run "make install" to +put the library in its final resting place (if you want to +do that, run "make install" in the zlib directory first if necessary). + +Further information can be found in the README and libpng.txt +files, in the individual makefiles, and in png.h, and the manual +pages libpng.3 and png.5. diff --git a/thirdparty/libpng/README b/thirdparty/libpng/README new file mode 100644 index 00000000..ea463cd9 --- /dev/null +++ b/thirdparty/libpng/README @@ -0,0 +1,194 @@ +README for libpng 1.0.1 (shared library 2.1) +See the note about version numbers near the top of png.h + +See INSTALL for instructions on how to install libpng. + +This is the first official release of libpng. Don't let the fact that +it's the first release fool you. The libpng library has been in +extensive use and testing for about two and a half years. However, it's +finally gotten to the stage where there haven't been significant +changes to the API in some time, and people have a bad feeling about +libraries with versions < 1.0. + +**** +Note that some of the changes to the png_info structure render this +version of the library binary incompatible with libpng-0.89 or +earlier versions if you are using a shared library. The type of the +"filler" parameter for png_set_filler() has changed from png_byte to +png_uint_32, which will affect shared-library applications that use +this function. + +To avoid problems with changes to the internals of png_info_struct, +new APIs have been made available in 0.95 to avoid direct application +access to info_ptr. These functions are the png_set_ and +png_get_ functions. These functions should be used when +accessing/storing the info_struct data, rather than manipulating it +directly, to avoid such problems in the future. + +It is important to note that the APIs do not make current programs +that access the info struct directly incompatible with the new +library. However, it is strongly suggested that new programs use +the new APIs (as shown in example.c), and older programs be converted +to the new format, to facilitate upgrades in the future. +**** + +Additions since 0.90 include the ability to compile libpng as a +Windows DLL, and new APIs for accessing data in the info struct. +Experimental functions include the ability to set weighting and cost +factors for row filter selection, direct reads of integers from buffers +on big-endian processors that support misaligned data access, faster +methods of doing alpha composition, and more accurate 16->8 bit color +conversion. + +The additions since 0.89 include the ability to read from a PNG stream +which has had some (or all) of the signature bytes read by the calling +application. This also allows the reading of embedded PNG streams that +do not have the PNG file signature. As well, it is now possible to set +the library action on the detection of chunk CRC errors. It is possible +to set different actions based on whether the CRC error occurred in a +critical or an ancillary chunk. + +The changes made to the library, and bugs fixed are based on discussions +on the PNG implementation mailing list +and not on material submitted to Guy. + +For a detailed description on using libpng, read libpng.txt. For +examples of libpng in a program, see example.c and pngtest.c. For usage +information and restrictions (what little they are) on libpng, see +png.h. For a description on using zlib (the compression library used by +libpng) and zlib's restrictions, see zlib.h + +I have included a general makefile, as well as several machine and +compiler specific ones, but you may have to modify one for your own needs. + +You should use zlib 1.0.4 or later to run this, but it MAY work with +versions as old as zlib 0.95. Even so, there are bugs in older zlib +versions which can cause the output of invalid compression streams for +some images. You will definitely need zlib 1.0.4 or later if you are +taking advantage of the MS-DOS "far" structure allocation for the small +and medium memory models. You should also note that zlib is a +compression library that is useful for more things than just PNG files. +You can use zlib as a drop-in replacement for fread() and fwrite() if +you are so inclined. + +zlib should be available at the same place that libpng is. +If not, it should be at ftp.uu.net in /graphics/png +Eventually, it will be at ftp.uu.net in /pub/archiving/zip/zlib + +You may also want a copy of the PNG specification. It is available +as an RFC and a W3C Recommendation. Failing +these resources you can try ftp.uu.net in the /graphics/png directory. + +This code is currently being archived at ftp.uu.net in the +/graphics/png directory, and on CompuServe, Lib 20 (PNG SUPPORT) +at GO GRAPHSUP. If you can't find it in any of those places, +e-mail me, and I'll help you find it. + +If you have any code changes, requests, problems, etc., please e-mail +them to me. Also, I'd appreciate any make files or project files, +and any modifications you needed to make to get libpng to compile, +along with a #define variable to tell what compiler/system you are on. +If you needed to add transformations to libpng, or wish libpng would +provide the image in a different way, drop me a note (and code, if +possible), so I can consider supporting the transformation. +Finally, if you get any warning messages when compiling libpng +(note: not zlib), and they are easy to fix, I'd appreciate the +fix. Please mention "libpng" somewhere in the subject line. Thanks. + +This release was created and will be supported by myself (of course +based in a large way on Guy's and Andreas' earlier work), and the PNG group. + +randeg@alumni.rpi.edu +png-implement@dworkin.wustl.edu + +You can't reach Guy, the original libpng author, at the addresses +given in previous versions of this document. He and Andreas will read mail +addressed to the png-implement list, however. + +Please do not send general questions about PNG. Send them to +the address in the specification (png-group@w3.org). At the same +time, please do not send libpng questions to that address, send them to me +or to png-implement@dworkin.wustl.edu. I'll +get them in the end anyway. If you have a question about something +in the PNG specification that is related to using libpng, send it +to me. Send me any questions that start with "I was using libpng, +and ...". If in doubt, send questions to me. I'll bounce them +to others, if necessary. + +Please do not send suggestions on how to change PNG. We have +been discussing PNG for three years now, and it is official and +finished. If you have suggestions for libpng, however, I'll +gladly listen. Even if your suggestion is not used for version +1.0, it may be used later. + +Files in this distribution: + + CHANGES => Description of changes between libpng versions + README => This file + TODO => Things not implemented in the current library + ansi2knr.1 => Manual page for ansi2knr + ansi2knr.c => Converts files to K&R style function declarations + build.bat => MS-DOS batch file for Borland compiler + descrip.mms => VMS project file + example.c => Example code for using libpng functions + libpng.3 => manual page for libpng + libpng.txt => Description of libpng and its functions + libpngpf.3 => manual page for libpng's private functions + png.5 => manual page for the PNG format + png.c => Basic interface functions common to library + png.h => Library function and interface declarations + pngconf.h => System specific library configuration + pngerror.c => Error/warning message I/O functions + pngget.c => Functions for retrieving info from struct + pngmem.c => Memory handling functions + pngpread.c => Progressive reading functions + pngread.c => Read data/helper high-level functions + pngrio.c => Lowest-level data read I/O functions + pngrtran.c => Read data transformation functions + pngrutil.c => Read data utility functions + pngset.c => Functions for storing data into the info_struct + pngtest.c => Library test program + pngtest.png => Library test sample image + pngtrans.c => Common data transformation functions + pngwio.c => Lowest-level write I/O functions + pngwrite.c => High-level write functions + pngwtran.c => Write data transformations + pngwutil.c => Write utility functions + scripts => Directory containing scripts for building libpng: + descrip.mms => VMS makefile for MMS or MMK + makefile.std => Generic UNIX makefile + makefile.knr => Archaic UNIX Makefile that converts files with ansi2knr + makefile.dec => DEC Alpha UNIX makefile + makefile.sgi => Silicon Graphics IRIX makefile + makefile.sun => Sun makefile + makefile.s2x => Solaris 2.X makefile (gcc, creates libpng.so.2.1.0) + makefile.lnx => Linux/ELF makefile (gcc, creates libpng.so.2.1.0) + makefile.mip => MIPS makefile + makefile.aco => Acorn makefile + makefile.ama => Amiga makefile + smakefile.ppc => AMIGA smakefile for SAS C V6.58/7.00 PPC compiler + (Requires SCOPTIONS, copied from scripts/SCOPTIONS.ppc) + makefile.atr => Atari makefile + makefile.bor => Borland makefile + build.bat => MS-DOS batch file for Borland compiler + makefile.dj2 => DJGPP 2 makefile + makefile.msc => Microsoft C makefile + makefile.tc3 => Turbo C 3.0 makefile + makefile.os2 => OS/2 Makefile (gcc and emx, requires pngos2.def) + makefile.wat => Watcom 10a+ Makefile, 32-bit flat memory model + pngos2.def => OS/2 module definition file used by makefile.os2 + makevms.com => VMS build script + +Good luck, and happy coding. + +-Glenn Randers-Pehrson + Internet: randeg@alumni.rpi.edu + Web: http://www.rpi.edu/~randeg/index.html + +-Andreas Eric Dilger + Internet: adilger@enel.ucalgary.ca + Web: http://www-mddsp.enel.ucalgary.ca/People/adilger/ + +-Guy Eric Schalnat + (formerly of Group 42, Inc) + Internet: gschal@infinet.com diff --git a/thirdparty/libpng/TODO b/thirdparty/libpng/TODO new file mode 100644 index 00000000..21f963a8 --- /dev/null +++ b/thirdparty/libpng/TODO @@ -0,0 +1,21 @@ +TODO - list of things to do for libpng + +fix problem with C++ and EXTERN "C" +add "grayscale->palette" transformation and "palette->grayscale" detection +improved dithering +multi-lingual error and warning message support +sPLT chunk handling +cHRM transformation +complete sRGB transformation (presently it simply uses gamma=0.45) +man pages for function calls +high-level API for reading images +final bug fixes +better documentation +better filter selection + (counting huffman bits/precompression? filter inertia? filter costs?) +optional palette creation +histogram creation +support for application-defined chunk handlers +keep up with public chunks +better C++ wrapper/full C++ implementation? +text conversion between different code pages (Latin-1 -> Mac and DOS) diff --git a/thirdparty/libpng/ansi2knr.1 b/thirdparty/libpng/ansi2knr.1 new file mode 100644 index 00000000..f9ee5a63 --- /dev/null +++ b/thirdparty/libpng/ansi2knr.1 @@ -0,0 +1,36 @@ +.TH ANSI2KNR 1 "19 Jan 1996" +.SH NAME +ansi2knr \- convert ANSI C to Kernighan & Ritchie C +.SH SYNOPSIS +.I ansi2knr +[--varargs] input_file [output_file] +.SH DESCRIPTION +If no output_file is supplied, output goes to stdout. +.br +There are no error messages. +.sp +.I ansi2knr +recognizes function definitions by seeing a non-keyword identifier at the left +margin, followed by a left parenthesis, with a right parenthesis as the last +character on the line, and with a left brace as the first token on the +following line (ignoring possible intervening comments). It will recognize a +multi-line header provided that no intervening line ends with a left or right +brace or a semicolon. These algorithms ignore whitespace and comments, except +that the function name must be the first thing on the line. +.sp +The following constructs will confuse it: +.br + - Any other construct that starts at the left margin and follows the +above syntax (such as a macro or function call). +.br + - Some macros that tinker with the syntax of the function header. +.sp +The --varargs switch is obsolete, and is recognized only for +backwards compatibility. The present version of +.I ansi2knr +will always attempt to convert a ... argument to va_alist and va_dcl. +.SH AUTHOR +L. Peter Deutsch wrote the original ansi2knr and +continues to maintain the current version; most of the code in the current +version is his work. ansi2knr also includes contributions by Francois +Pinard and Jim Avera . diff --git a/thirdparty/libpng/ansi2knr.c b/thirdparty/libpng/ansi2knr.c new file mode 100644 index 00000000..4e05fc2d --- /dev/null +++ b/thirdparty/libpng/ansi2knr.c @@ -0,0 +1,693 @@ +/* ansi2knr.c */ +/* Convert ANSI C function definitions to K&R ("traditional C") syntax */ + +/* +ansi2knr is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY. No author or distributor accepts responsibility to anyone for the +consequences of using it or for whether it serves any particular purpose or +works at all, unless he says so in writing. Refer to the GNU General Public +License (the "GPL") for full details. + +Everyone is granted permission to copy, modify and redistribute ansi2knr, +but only under the conditions described in the GPL. A copy of this license +is supposed to have been given to you along with ansi2knr so you can know +your rights and responsibilities. It should be in a file named COPYLEFT. +[In the IJG distribution, the GPL appears below, not in a separate file.] +Among other things, the copyright notice and this notice must be preserved +on all copies. + +We explicitly state here what we believe is already implied by the GPL: if +the ansi2knr program is distributed as a separate set of sources and a +separate executable file which are aggregated on a storage medium together +with another program, this in itself does not bring the other program under +the GPL, nor does the mere fact that such a program or the procedures for +constructing it invoke the ansi2knr executable bring any other part of the +program under the GPL. +*/ + +/* +---------- Here is the GNU GPL file COPYLEFT, referred to above ---------- +----- These terms do NOT apply to the JPEG software itself; see README ------ + + GHOSTSCRIPT GENERAL PUBLIC LICENSE + (Clarified 11 Feb 1988) + + Copyright (C) 1988 Richard M. Stallman + Everyone is permitted to copy and distribute verbatim copies of this + license, but changing it is not allowed. You can also use this wording + to make the terms for other programs. + + The license agreements of most software companies keep you at the +mercy of those companies. By contrast, our general public license is +intended to give everyone the right to share Ghostscript. To make sure +that you get the rights we want you to have, we need to make +restrictions that forbid anyone to deny you these rights or to ask you +to surrender the rights. Hence this license agreement. + + Specifically, we want to make sure that you have the right to give +away copies of Ghostscript, that you receive source code or else can get +it if you want it, that you can change Ghostscript or use pieces of it +in new free programs, and that you know you can do these things. + + To make sure that everyone has such rights, we have to forbid you to +deprive anyone else of these rights. For example, if you distribute +copies of Ghostscript, you must give the recipients all the rights that +you have. You must make sure that they, too, receive or can get the +source code. And you must tell them their rights. + + Also, for our own protection, we must make certain that everyone finds +out that there is no warranty for Ghostscript. If Ghostscript is +modified by someone else and passed on, we want its recipients to know +that what they have is not what we distributed, so that any problems +introduced by others will not reflect on our reputation. + + Therefore we (Richard M. Stallman and the Free Software Foundation, +Inc.) make the following terms which say what you must do to be allowed +to distribute or change Ghostscript. + + + COPYING POLICIES + + 1. You may copy and distribute verbatim copies of Ghostscript source +code as you receive it, in any medium, provided that you conspicuously +and appropriately publish on each copy a valid copyright and license +notice "Copyright (C) 1989 Aladdin Enterprises. All rights reserved. +Distributed by Free Software Foundation, Inc." (or with whatever year is +appropriate); keep intact the notices on all files that refer to this +License Agreement and to the absence of any warranty; and give any other +recipients of the Ghostscript program a copy of this License Agreement +along with the program. You may charge a distribution fee for the +physical act of transferring a copy. + + 2. You may modify your copy or copies of Ghostscript or any portion of +it, and copy and distribute such modifications under the terms of +Paragraph 1 above, provided that you also do the following: + + a) cause the modified files to carry prominent notices stating + that you changed the files and the date of any change; and + + b) cause the whole of any work that you distribute or publish, + that in whole or in part contains or is a derivative of Ghostscript + or any part thereof, to be licensed at no charge to all third + parties on terms identical to those contained in this License + Agreement (except that you may choose to grant more extensive + warranty protection to some or all third parties, at your option). + + c) You may charge a distribution fee for the physical act of + transferring a copy, and you may at your option offer warranty + protection in exchange for a fee. + +Mere aggregation of another unrelated program with this program (or its +derivative) on a volume of a storage or distribution medium does not bring +the other program under the scope of these terms. + + 3. You may copy and distribute Ghostscript (or a portion or derivative +of it, under Paragraph 2) in object code or executable form under the +terms of Paragraphs 1 and 2 above provided that you also do one of the +following: + + a) accompany it with the complete corresponding machine-readable + source code, which must be distributed under the terms of + Paragraphs 1 and 2 above; or, + + b) accompany it with a written offer, valid for at least three + years, to give any third party free (except for a nominal + shipping charge) a complete machine-readable copy of the + corresponding source code, to be distributed under the terms of + Paragraphs 1 and 2 above; or, + + c) accompany it with the information you received as to where the + corresponding source code may be obtained. (This alternative is + allowed only for noncommercial distribution and only if you + received the program in object code or executable form alone.) + +For an executable file, complete source code means all the source code for +all modules it contains; but, as a special exception, it need not include +source code for modules which are standard libraries that accompany the +operating system on which the executable file runs. + + 4. You may not copy, sublicense, distribute or transfer Ghostscript +except as expressly provided under this License Agreement. Any attempt +otherwise to copy, sublicense, distribute or transfer Ghostscript is +void and your rights to use the program under this License agreement +shall be automatically terminated. However, parties who have received +computer software programs from you with this License Agreement will not +have their licenses terminated so long as such parties remain in full +compliance. + + 5. If you wish to incorporate parts of Ghostscript into other free +programs whose distribution conditions are different, write to the Free +Software Foundation at 675 Mass Ave, Cambridge, MA 02139. We have not +yet worked out a simple rule that can be stated here, but we will often +permit this. We will be guided by the two goals of preserving the free +status of all derivatives of our free software and of promoting the +sharing and reuse of software. + +Your comments and suggestions about our licensing policies and our +software are welcome! Please contact the Free Software Foundation, +Inc., 675 Mass Ave, Cambridge, MA 02139, or call (617) 876-3296. + + NO WARRANTY + + BECAUSE GHOSTSCRIPT IS LICENSED FREE OF CHARGE, WE PROVIDE ABSOLUTELY +NO WARRANTY, TO THE EXTENT PERMITTED BY APPLICABLE STATE LAW. EXCEPT +WHEN OTHERWISE STATED IN WRITING, FREE SOFTWARE FOUNDATION, INC, RICHARD +M. STALLMAN, ALADDIN ENTERPRISES, L. PETER DEUTSCH, AND/OR OTHER PARTIES +PROVIDE GHOSTSCRIPT "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER +EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED +WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE +ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF GHOSTSCRIPT IS WITH +YOU. SHOULD GHOSTSCRIPT PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL +NECESSARY SERVICING, REPAIR OR CORRECTION. + + IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW WILL RICHARD M. +STALLMAN, THE FREE SOFTWARE FOUNDATION, INC., L. PETER DEUTSCH, ALADDIN +ENTERPRISES, AND/OR ANY OTHER PARTY WHO MAY MODIFY AND REDISTRIBUTE +GHOSTSCRIPT AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING +ANY LOST PROFITS, LOST MONIES, OR OTHER SPECIAL, INCIDENTAL OR +CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE +(INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED +INACCURATE OR LOSSES SUSTAINED BY THIRD PARTIES OR A FAILURE OF THE +PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS) GHOSTSCRIPT, EVEN IF YOU +HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES, OR FOR ANY CLAIM +BY ANY OTHER PARTY. + +-------------------- End of file COPYLEFT ------------------------------ +*/ + +/* + * Usage: + ansi2knr input_file [output_file] + * If no output_file is supplied, output goes to stdout. + * There are no error messages. + * + * ansi2knr recognizes function definitions by seeing a non-keyword + * identifier at the left margin, followed by a left parenthesis, + * with a right parenthesis as the last character on the line, + * and with a left brace as the first token on the following line + * (ignoring possible intervening comments). + * It will recognize a multi-line header provided that no intervening + * line ends with a left or right brace or a semicolon. + * These algorithms ignore whitespace and comments, except that + * the function name must be the first thing on the line. + * The following constructs will confuse it: + * - Any other construct that starts at the left margin and + * follows the above syntax (such as a macro or function call). + * - Some macros that tinker with the syntax of the function header. + */ + +/* + * The original and principal author of ansi2knr is L. Peter Deutsch + * . Other authors are noted in the change history + * that follows (in reverse chronological order): + lpd 96-01-21 added code to cope with not HAVE_CONFIG_H and with + compilers that don't understand void, as suggested by + Tom Lane + lpd 96-01-15 changed to require that the first non-comment token + on the line following a function header be a left brace, + to reduce sensitivity to macros, as suggested by Tom Lane + + lpd 95-06-22 removed #ifndefs whose sole purpose was to define + undefined preprocessor symbols as 0; changed all #ifdefs + for configuration symbols to #ifs + lpd 95-04-05 changed copyright notice to make it clear that + including ansi2knr in a program does not bring the entire + program under the GPL + lpd 94-12-18 added conditionals for systems where ctype macros + don't handle 8-bit characters properly, suggested by + Francois Pinard ; + removed --varargs switch (this is now the default) + lpd 94-10-10 removed CONFIG_BROKETS conditional + lpd 94-07-16 added some conditionals to help GNU `configure', + suggested by Francois Pinard ; + properly erase prototype args in function parameters, + contributed by Jim Avera ; + correct error in writeblanks (it shouldn't erase EOLs) + lpd 89-xx-xx original version + */ + +/* Most of the conditionals here are to make ansi2knr work with */ +/* or without the GNU configure machinery. */ + +#if HAVE_CONFIG_H +# include +#endif + +#include +#include + +#if HAVE_CONFIG_H + +/* + For properly autoconfiguring ansi2knr, use AC_CONFIG_HEADER(config.h). + This will define HAVE_CONFIG_H and so, activate the following lines. + */ + +# if STDC_HEADERS || HAVE_STRING_H +# include +# else +# include +# endif + +#else /* not HAVE_CONFIG_H */ + +/* Otherwise do it the hard way */ + +# ifdef BSD +# include +# else +# ifdef VMS + extern int strlen(), strncmp(); +# else +# include +# endif +# endif + +#endif /* not HAVE_CONFIG_H */ + +#if STDC_HEADERS +# include +#else +/* + malloc and free should be declared in stdlib.h, + but if you've got a K&R compiler, they probably aren't. + */ +# ifdef MSDOS +# include +# else +# ifdef VMS + extern char *malloc(); + extern void free(); +# else + extern char *malloc(); + extern int free(); +# endif +# endif + +#endif + +/* + * The ctype macros don't always handle 8-bit characters correctly. + * Compensate for this here. + */ +#ifdef isascii +# undef HAVE_ISASCII /* just in case */ +# define HAVE_ISASCII 1 +#else +#endif +#if STDC_HEADERS || !HAVE_ISASCII +# define is_ascii(c) 1 +#else +# define is_ascii(c) isascii(c) +#endif + +#define is_space(c) (is_ascii(c) && isspace(c)) +#define is_alpha(c) (is_ascii(c) && isalpha(c)) +#define is_alnum(c) (is_ascii(c) && isalnum(c)) + +/* Scanning macros */ +#define isidchar(ch) (is_alnum(ch) || (ch) == '_') +#define isidfirstchar(ch) (is_alpha(ch) || (ch) == '_') + +/* Forward references */ +char *skipspace(); +int writeblanks(); +int test1(); +int convert1(); + +/* The main program */ +int +main(argc, argv) + int argc; + char *argv[]; +{ FILE *in, *out; +#define bufsize 5000 /* arbitrary size */ + char *buf; + char *line; + char *more; + /* + * In previous versions, ansi2knr recognized a --varargs switch. + * If this switch was supplied, ansi2knr would attempt to convert + * a ... argument to va_alist and va_dcl; if this switch was not + * supplied, ansi2knr would simply drop any such arguments. + * Now, ansi2knr always does this conversion, and we only + * check for this switch for backward compatibility. + */ + int convert_varargs = 1; + + if ( argc > 1 && argv[1][0] == '-' ) + { if ( !strcmp(argv[1], "--varargs") ) + { convert_varargs = 1; + argc--; + argv++; + } + else + { fprintf(stderr, "Unrecognized switch: %s\n", argv[1]); + exit(1); + } + } + switch ( argc ) + { + default: + printf("Usage: ansi2knr input_file [output_file]\n"); + exit(0); + case 2: + out = stdout; + break; + case 3: + out = fopen(argv[2], "w"); + if ( out == NULL ) + { fprintf(stderr, "Cannot open output file %s\n", argv[2]); + exit(1); + } + } + in = fopen(argv[1], "r"); + if ( in == NULL ) + { fprintf(stderr, "Cannot open input file %s\n", argv[1]); + exit(1); + } + fprintf(out, "#line 1 \"%s\"\n", argv[1]); + buf = malloc(bufsize); + line = buf; + while ( fgets(line, (unsigned)(buf + bufsize - line), in) != NULL ) + { +test: line += strlen(line); + switch ( test1(buf) ) + { + case 2: /* a function header */ + convert1(buf, out, 1, convert_varargs); + break; + case 1: /* a function */ + /* Check for a { at the start of the next line. */ + more = ++line; +f: if ( line >= buf + (bufsize - 1) ) /* overflow check */ + goto wl; + if ( fgets(line, (unsigned)(buf + bufsize - line), in) == NULL ) + goto wl; + switch ( *skipspace(more, 1) ) + { + case '{': + /* Definitely a function header. */ + convert1(buf, out, 0, convert_varargs); + fputs(more, out); + break; + case 0: + /* The next line was blank or a comment: */ + /* keep scanning for a non-comment. */ + line += strlen(line); + goto f; + default: + /* buf isn't a function header, but */ + /* more might be. */ + fputs(buf, out); + strcpy(buf, more); + line = buf; + goto test; + } + break; + case -1: /* maybe the start of a function */ + if ( line != buf + (bufsize - 1) ) /* overflow check */ + continue; + /* falls through */ + default: /* not a function */ +wl: fputs(buf, out); + break; + } + line = buf; + } + if ( line != buf ) + fputs(buf, out); + free(buf); + fclose(out); + fclose(in); + return 0; +} + +/* Skip over space and comments, in either direction. */ +char * +skipspace(p, dir) + register char *p; + register int dir; /* 1 for forward, -1 for backward */ +{ for ( ; ; ) + { while ( is_space(*p) ) + p += dir; + if ( !(*p == '/' && p[dir] == '*') ) + break; + p += dir; p += dir; + while ( !(*p == '*' && p[dir] == '/') ) + { if ( *p == 0 ) + return p; /* multi-line comment?? */ + p += dir; + } + p += dir; p += dir; + } + return p; +} + +/* + * Write blanks over part of a string. + * Don't overwrite end-of-line characters. + */ +int +writeblanks(start, end) + char *start; + char *end; +{ char *p; + for ( p = start; p < end; p++ ) + if ( *p != '\r' && *p != '\n' ) + *p = ' '; + return 0; +} + +/* + * Test whether the string in buf is a function definition. + * The string may contain and/or end with a newline. + * Return as follows: + * 0 - definitely not a function definition; + * 1 - definitely a function definition; + * 2 - definitely a function prototype (NOT USED); + * -1 - may be the beginning of a function definition, + * append another line and look again. + * The reason we don't attempt to convert function prototypes is that + * Ghostscript's declaration-generating macros look too much like + * prototypes, and confuse the algorithms. + */ +int +test1(buf) + char *buf; +{ register char *p = buf; + char *bend; + char *endfn; + int contin; + + if ( !isidfirstchar(*p) ) + return 0; /* no name at left margin */ + bend = skipspace(buf + strlen(buf) - 1, -1); + switch ( *bend ) + { + case ';': contin = 0 /*2*/; break; + case ')': contin = 1; break; + case '{': return 0; /* not a function */ + case '}': return 0; /* not a function */ + default: contin = -1; + } + while ( isidchar(*p) ) + p++; + endfn = p; + p = skipspace(p, 1); + if ( *p++ != '(' ) + return 0; /* not a function */ + p = skipspace(p, 1); + if ( *p == ')' ) + return 0; /* no parameters */ + /* Check that the apparent function name isn't a keyword. */ + /* We only need to check for keywords that could be followed */ + /* by a left parenthesis (which, unfortunately, is most of them). */ + { static char *words[] = + { "asm", "auto", "case", "char", "const", "double", + "extern", "float", "for", "if", "int", "long", + "register", "return", "short", "signed", "sizeof", + "static", "switch", "typedef", "unsigned", + "void", "volatile", "while", 0 + }; + char **key = words; + char *kp; + int len = endfn - buf; + + while ( (kp = *key) != 0 ) + { if ( strlen(kp) == len && !strncmp(kp, buf, len) ) + return 0; /* name is a keyword */ + key++; + } + } + return contin; +} + +/* Convert a recognized function definition or header to K&R syntax. */ +int +convert1(buf, out, header, convert_varargs) + char *buf; + FILE *out; + int header; /* Boolean */ + int convert_varargs; /* Boolean */ +{ char *endfn; + register char *p; + char **breaks; + unsigned num_breaks = 2; /* for testing */ + char **btop; + char **bp; + char **ap; + char *vararg = 0; + + /* Pre-ANSI implementations don't agree on whether strchr */ + /* is called strchr or index, so we open-code it here. */ + for ( endfn = buf; *(endfn++) != '('; ) + ; +top: p = endfn; + breaks = (char **)malloc(sizeof(char *) * num_breaks * 2); + if ( breaks == 0 ) + { /* Couldn't allocate break table, give up */ + fprintf(stderr, "Unable to allocate break table!\n"); + fputs(buf, out); + return -1; + } + btop = breaks + num_breaks * 2 - 2; + bp = breaks; + /* Parse the argument list */ + do + { int level = 0; + char *lp = NULL; + char *rp; + char *end = NULL; + + if ( bp >= btop ) + { /* Filled up break table. */ + /* Allocate a bigger one and start over. */ + free((char *)breaks); + num_breaks <<= 1; + goto top; + } + *bp++ = p; + /* Find the end of the argument */ + for ( ; end == NULL; p++ ) + { switch(*p) + { + case ',': + if ( !level ) end = p; + break; + case '(': + if ( !level ) lp = p; + level++; + break; + case ')': + if ( --level < 0 ) end = p; + else rp = p; + break; + case '/': + p = skipspace(p, 1) - 1; + break; + default: + ; + } + } + /* Erase any embedded prototype parameters. */ + if ( lp ) + writeblanks(lp + 1, rp); + p--; /* back up over terminator */ + /* Find the name being declared. */ + /* This is complicated because of procedure and */ + /* array modifiers. */ + for ( ; ; ) + { p = skipspace(p - 1, -1); + switch ( *p ) + { + case ']': /* skip array dimension(s) */ + case ')': /* skip procedure args OR name */ + { int level = 1; + while ( level ) + switch ( *--p ) + { + case ']': case ')': level++; break; + case '[': case '(': level--; break; + case '/': p = skipspace(p, -1) + 1; break; + default: ; + } + } + if ( *p == '(' && *skipspace(p + 1, 1) == '*' ) + { /* We found the name being declared */ + while ( !isidfirstchar(*p) ) + p = skipspace(p, 1) + 1; + goto found; + } + break; + default: + goto found; + } + } +found: if ( *p == '.' && p[-1] == '.' && p[-2] == '.' ) + { if ( convert_varargs ) + { *bp++ = "va_alist"; + vararg = p-2; + } + else + { p++; + if ( bp == breaks + 1 ) /* sole argument */ + writeblanks(breaks[0], p); + else + writeblanks(bp[-1] - 1, p); + bp--; + } + } + else + { while ( isidchar(*p) ) p--; + *bp++ = p+1; + } + p = end; + } + while ( *p++ == ',' ); + *bp = p; + /* Make a special check for 'void' arglist */ + if ( bp == breaks+2 ) + { p = skipspace(breaks[0], 1); + if ( !strncmp(p, "void", 4) ) + { p = skipspace(p+4, 1); + if ( p == breaks[2] - 1 ) + { bp = breaks; /* yup, pretend arglist is empty */ + writeblanks(breaks[0], p + 1); + } + } + } + /* Put out the function name and left parenthesis. */ + p = buf; + while ( p != endfn ) putc(*p, out), p++; + /* Put out the declaration. */ + if ( header ) + { fputs(");", out); + for ( p = breaks[0]; *p; p++ ) + if ( *p == '\r' || *p == '\n' ) + putc(*p, out); + } + else + { for ( ap = breaks+1; ap < bp; ap += 2 ) + { p = *ap; + while ( isidchar(*p) ) + putc(*p, out), p++; + if ( ap < bp - 1 ) + fputs(", ", out); + } + fputs(") ", out); + /* Put out the argument declarations */ + for ( ap = breaks+2; ap <= bp; ap += 2 ) + (*ap)[-1] = ';'; + if ( vararg != 0 ) + { *vararg = 0; + fputs(breaks[0], out); /* any prior args */ + fputs("va_dcl", out); /* the final arg */ + fputs(bp[0], out); + } + else + fputs(breaks[0], out); + } + free((char *)breaks); + return 0; +} diff --git a/thirdparty/libpng/example.c b/thirdparty/libpng/example.c new file mode 100644 index 00000000..bc86aed6 --- /dev/null +++ b/thirdparty/libpng/example.c @@ -0,0 +1,688 @@ + +/* example.c - an example of using libpng */ + +/* This is an example of how to use libpng to read and write PNG files. + * The file libpng.txt is much more verbose then this. If you have not + * read it, do so first. This was designed to be a starting point of an + * implementation. This is not officially part of libpng, and therefore + * does not require a copyright notice. + * + * This file does not currently compile, because it is missing certain + * parts, like allocating memory to hold an image. You will have to + * supply these parts to get it to compile. For an example of a minimal + * working PNG reader/writer, see pngtest.c, included in this distribution. + */ + +#include "png.h" + +/* Check to see if a file is a PNG file using png_sig_cmp(). Returns + * non-zero if the image is a PNG, and 0 if it isn't a PNG. + * + * If this call is successful, and you are going to keep the file open, + * you should call png_set_sig_bytes(png_ptr, PNG_BYTES_TO_CHECK); once + * you have created the png_ptr, so that libpng knows your application + * has read that many bytes from the start of the file. Make sure you + * don't call png_set_sig_bytes() with more than 8 bytes read or give it + * an incorrect number of bytes read, or you will either have read too + * many bytes (your fault), or you are telling libpng to read the wrong + * number of magic bytes (also your fault). + * + * Many applications already read the first 2 or 4 bytes from the start + * of the image to determine the file type, so it would be easiest just + * to pass the bytes to png_sig_cmp() or even skip that if you know + * you have a PNG file, and call png_set_sig_bytes(). + */ +#define PNG_BYTES_TO_CHECK 4 +int check_if_png(char *file_name, FILE **fp) +{ + char buf[PNG_BYTES_TO_CHECK]; + + /* Open the prospective PNG file. */ + if ((*fp = fopen(file_name, "rb")) != NULL); + return 0; + + /* Read in the signature bytes */ + if (fread(buf, 1, PNG_BYTES_TO_CHECK, *fp) != PNG_BYTES_TO_CHECK) + return 0; + + /* Compare the first PNG_BYTES_TO_CHECK bytes of the signature. */ + return(png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK)); +} + +/* Read a PNG file. You may want to return an error code if the read + * fails (depending upon the failure). There are two "prototypes" given + * here - one where we are given the filename, and we need to open the + * file, and the other where we are given an open file (possibly with + * some or all of the magic bytes read - see comments above). + */ +#ifdef open_file /* prototype 1 */ +void read_png(char *file_name) /* We need to open the file */ +{ + png_structp png_ptr; + png_infop info_ptr; + unsigned int sig_read = 0; + png_uint_32 width, height; + int bit_depth, color_type, interlace_type; + FILE *fp; + + if ((fp = fopen(file_name, "rb")) == NULL) + return; +#else no_open_file /* prototype 2 */ +void read_png(FILE *fp, unsigned int sig_read) /* file is already open */ +{ + png_structp png_ptr; + png_infop info_ptr; + png_uint_32 width, height; + int bit_depth, color_type, interlace_type; +#endif no_open_file /* only use one prototype! */ + + /* Create and initialize the png_struct with the desired error handler + * functions. If you want to use the default stderr and longjump method, + * you can supply NULL for the last three parameters. We also supply the + * the compiler header file version, so that we know if the application + * was compiled with a compatible version of the library. REQUIRED + */ + png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, + (void *)user_error_ptr, user_error_fn, user_warning_fn); + + if (png_ptr == NULL) + { + fclose(fp); + return; + } + + /* Allocate/initialize the memory for image information. REQUIRED. */ + info_ptr = png_create_info_struct(png_ptr); + if (info_ptr == NULL) + { + fclose(fp); + png_destroy_read_struct(&png_ptr, (png_infopp)NULL, (png_infopp)NULL); + return; + } + + /* Set error handling if you are using the setjmp/longjmp method (this is + * the normal method of doing things with libpng). REQUIRED unless you + * set up your own error handlers in the png_create_read_struct() earlier. + */ + if (setjmp(png_ptr->jmpbuf)) + { + /* Free all of the memory associated with the png_ptr and info_ptr */ + png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); + fclose(fp); + /* If we get here, we had a problem reading the file */ + return; + } + + /* One of the following I/O initialization methods is REQUIRED */ +#ifdef streams /* PNG file I/O method 1 */ + /* Set up the input control if you are using standard C streams */ + png_init_io(png_ptr, fp); + +#else no_streams /* PNG file I/O method 2 */ + /* If you are using replacement read functions, instead of calling + * png_init_io() here you would call: + */ + png_set_read_fn(png_ptr, (void *)user_io_ptr, user_read_fn); + /* where user_io_ptr is a structure you want available to the callbacks */ +#endif no_streams /* Use only one I/O method! */ + + /* If we have already read some of the signature */ + png_set_sig_bytes(png_ptr, sig_read); + + /* The call to png_read_info() gives us all of the information from the + * PNG file before the first IDAT (image data chunk). REQUIRED + */ + png_read_info(png_ptr, info_ptr); + + png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, + &interlace_type, NULL, NULL); + +/**** Set up the data transformations you want. Note that these are all + **** optional. Only call them if you want/need them. Many of the + **** transformations only work on specific types of images, and many + **** are mutually exclusive. + ****/ + + /* tell libpng to strip 16 bit/color files down to 8 bits/color */ + png_set_strip_16(png_ptr); + + /* Strip alpha bytes from the input data without combining with th + * background (not recommended). + */ + png_set_strip_alpha(png_ptr); + + /* Extract multiple pixels with bit depths of 1, 2, and 4 from a single + * byte into separate bytes (useful for paletted and grayscale images). + */ + png_set_packing(png_ptr); + + /* Change the order of packed pixels to least significant bit first + * (not useful if you are using png_set_packing). */ + png_set_packswap(png_ptr); + + /* Expand paletted colors into true RGB triplets */ + if (color_type == PNG_COLOR_TYPE_PALETTE) + png_set_expand(png_ptr); + + /* Expand grayscale images to the full 8 bits from 1, 2, or 4 bits/pixel */ + if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) + png_set_expand(png_ptr); + + /* Expand paletted or RGB images with transparency to full alpha channels + * so the data will be available as RGBA quartets. + */ + if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) + png_set_expand(png_ptr); + + /* Set the background color to draw transparent and alpha images over. + * It is possible to set the red, green, and blue components directly + * for paletted images instead of supplying a palette index. Note that + * even if the PNG file supplies a background, you are not required to + * use it - you should use the (solid) application background if it has one. + */ + + png_color_16 my_background, *image_background; + + if (png_get_bKGD(png_ptr, info_ptr, &image_background)) + png_set_background(png_ptr, image_background, + PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); + else + png_set_background(png_ptr, &my_background, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); + + /* Some suggestions as to how to get a screen gamma value */ + + /* Note that screen gamma is (display_gamma/viewing_gamma) */ + if (/* We have a user-defined screen gamma value */) + { + screen_gamma = user-defined screen_gamma; + } + /* This is one way that applications share the same screen gamma value */ + else if ((gamma_str = getenv("SCREEN_GAMMA")) != NULL) + { + screen_gamma = atof(gamma_str); + } + /* If we don't have another value */ + else + { + screen_gamma = 2.2; /* A good guess for a PC monitors in a dimly + lit room */ + screen_gamma = 1.7 or 1.0; /* A good guess for Mac systems */ + } + + /* Tell libpng to handle the gamma conversion for you. The second call + * is a good guess for PC generated images, but it should be configurable + * by the user at run time by the user. It is strongly suggested that + * your application support gamma correction. + */ + + int intent; + + if (png_get_sRGB(png_ptr, info_ptr, &intent)) + png_set_sRGB(png_ptr, intent, 0); + else + if (png_get_gAMA(png_ptr, info_ptr, &image_gamma)) + png_set_gamma(png_ptr, screen_gamma, image_gamma); + else + png_set_gamma(png_ptr, screen_gamma, 0.50); + + /* Dither RGB files down to 8 bit palette or reduce palettes + * to the number of colors available on your screen. + */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + png_uint_32 num_palette; + png_colorp palette; + + /* This reduces the image to the application supplied palette */ + if (/* we have our own palette */) + { + /* An array of colors to which the image should be dithered */ + png_color std_color_cube[MAX_SCREEN_COLORS]; + + png_set_dither(png_ptr, std_color_cube, MAX_SCREEN_COLORS, + MAX_SCREEN_COLORS, NULL, 0); + } + /* This reduces the image to the palette supplied in the file */ + else if (png_get_PLTE(png_ptr, info_ptr, &palette, &num_palette)) + { + png_color16p histogram; + + png_get_hIST(png_ptr, info_ptr, &histogram); + + png_set_dither(png_ptr, palette, num_palette, + max_screen_colors, histogram, 0); + } + } + + /* invert monocrome files to have 0 as white and 1 as black */ + png_set_invert_mono(png_ptr); + + /* If you want to shift the pixel values from the range [0,255] or + * [0,65535] to the original [0,7] or [0,31], or whatever range the + * colors were originally in: + */ + if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sBIT)) + { + png_color8p sig_bit; + + png_get_sBIT(png_ptr, info_ptr, &sig_bit); + png_set_shift(png_ptr, sig_bit); + } + + /* flip the RGB pixels to BGR (or RGBA to BGRA) */ + png_set_bgr(png_ptr); + + /* swap the RGBA or GA data to ARGB or AG (or BGRA to ABGR) */ + png_set_swap_alpha(png_ptr); + + /* swap bytes of 16 bit files to least significant byte first */ + png_set_swap(png_ptr); + + /* Add filler (or alpha) byte (before/after each RGB triplet) */ + png_set_filler(png_ptr, 0xff, PNG_FILLER_AFTER); + + /* Turn on interlace handling. REQUIRED if you are not using + * png_read_image(). To see how to handle interlacing passes, + * see the png_read_row() method below: + */ + number_passes = png_set_interlace_handling(png_ptr); + + /* Optional call to gamma correct and add the background to the palette + * and update info structure. REQUIRED if you are expecting libpng to + * update the palette for you (ie you selected such a transform above). + */ + png_read_update_info(png_ptr, info_ptr); + + /* Allocate the memory to hold the image using the fields of info_ptr. */ + + /* The easiest way to read the image: */ + png_bytep row_pointers[height]; + + for (row = 0; row < height; row++) + { + row_pointers[row] = malloc(png_get_rowbytes(png_ptr, info_ptr)); + } + + /* Now it's time to read the image. One of these methods is REQUIRED */ +#ifdef entire /* Read the entire image in one go */ + png_read_image(png_ptr, row_pointers); + +#else no_entire /* Read the image one or more scanlines at a time */ + /* The other way to read images - deal with interlacing: */ + + for (pass = 0; pass < number_passes; pass++) + { +#ifdef single /* Read the image a single row at a time */ + for (y = 0; y < height; y++) + { + png_bytep row_pointers = row[y]; + png_read_rows(png_ptr, &row_pointers, NULL, 1); + } + +#else no_single /* Read the image several rows at a time */ + for (y = 0; y < height; y += number_of_rows) + { +#ifdef sparkle /* Read the image using the "sparkle" effect. */ + png_read_rows(png_ptr, row_pointers, NULL, number_of_rows); + +#else no_sparkle /* Read the image using the "rectangle" effect */ + png_read_rows(png_ptr, NULL, row_pointers, number_of_rows); +#endif no_sparkle /* use only one of these two methods */ + } + + /* if you want to display the image after every pass, do + so here */ +#endif no_single /* use only one of these two methods */ + } +#endif no_entire /* use only one of these two methods */ + + /* read rest of file, and get additional chunks in info_ptr - REQUIRED */ + png_read_end(png_ptr, info_ptr); + + /* clean up after the read, and free any memory allocated - REQUIRED */ + png_destroy_read_struct(&png_ptr, &info_ptr, (png_infopp)NULL); + + /* close the file */ + fclose(fp); + + /* that's it */ + return; +} + +/* progressively read a file */ + +int +initialize_png_reader(png_structp *png_ptr, png_infop *info_ptr) +{ + /* Create and initialize the png_struct with the desired error handler + * functions. If you want to use the default stderr and longjump method, + * you can supply NULL for the last three parameters. We also check that + * the library version is compatible in case we are using dynamically + * linked libraries. + */ + *png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, + (void *)user_error_ptr, user_error_fn, user_warning_fn); + + if (*png_ptr == NULL) + { + *info_ptr = NULL; + return ERROR; + } + + *info_ptr = png_create_info_struct(png_ptr); + + if (*info_ptr == NULL) + { + png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL); + return ERROR; + } + + if (setjmp((*png_ptr)->jmpbuf)) + { + png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL); + return ERROR; + } + + /* this one's new. You will need to provide all three + * function callbacks, even if you aren't using them all. + * These functions shouldn't be dependent on global or + * static variables if you are decoding several images + * simultaneously. You should store stream specific data + * in a separate struct, given as the second parameter, + * and retrieve the pointer from inside the callbacks using + * the function png_get_progressive_ptr(png_ptr). + */ + png_set_progressive_read_fn(*png_ptr, (void *)stream_data, + info_callback, row_callback, end_callback); + + return OK; +} + +int +process_data(png_structp *png_ptr, png_infop *info_ptr, + png_bytep buffer, png_uint_32 length) +{ + if (setjmp((*png_ptr)->jmpbuf)) + { + /* Free the png_ptr and info_ptr memory on error */ + png_destroy_read_struct(png_ptr, info_ptr, (png_infopp)NULL); + return ERROR; + } + + /* This one's new also. Simply give it chunks of data as + * they arrive from the data stream (in order, of course). + * On Segmented machines, don't give it any more than 64K. + * The library seems to run fine with sizes of 4K, although + * you can give it much less if necessary (I assume you can + * give it chunks of 1 byte, but I haven't tried with less + * than 256 bytes yet). When this function returns, you may + * want to display any rows that were generated in the row + * callback, if you aren't already displaying them there. + */ + png_process_data(*png_ptr, *info_ptr, buffer, length); + return OK; +} + +info_callback(png_structp png_ptr, png_infop info) +{ +/* do any setup here, including setting any of the transformations + * mentioned in the Reading PNG files section. For now, you _must_ + * call either png_start_read_image() or png_read_update_info() + * after all the transformations are set (even if you don't set + * any). You may start getting rows before png_process_data() + * returns, so this is your last chance to prepare for that. + */ +} + +row_callback(png_structp png_ptr, png_bytep new_row, + png_uint_32 row_num, int pass) +{ +/* this function is called for every row in the image. If the + * image is interlacing, and you turned on the interlace handler, + * this function will be called for every row in every pass. + * Some of these rows will not be changed from the previous pass. + * When the row is not changed, the new_row variable will be NULL. + * The rows and passes are called in order, so you don't really + * need the row_num and pass, but I'm supplying them because it + * may make your life easier. + * + * For the non-NULL rows of interlaced images, you must call + * png_progressive_combine_row() passing in the row and the + * old row. You can call this function for NULL rows (it will + * just return) and for non-interlaced images (it just does the + * memcpy for you) if it will make the code easier. Thus, you + * can just do this for all cases: + */ + + png_progressive_combine_row(png_ptr, old_row, new_row); + +/* where old_row is what was displayed for previous rows. Note + * that the first pass (pass == 0 really) will completely cover + * the old row, so the rows do not have to be initialized. After + * the first pass (and only for interlaced images), you will have + * to pass the current row, and the function will combine the + * old row and the new row. + */ +} + +end_callback(png_structp png_ptr, png_infop info) +{ +/* this function is called when the whole image has been read, + * including any chunks after the image (up to and including + * the IEND). You will usually have the same info chunk as you + * had in the header, although some data may have been added + * to the comments and time fields. + * + * Most people won't do much here, perhaps setting a flag that + * marks the image as finished. + */ +} + +/* write a png file */ +void write_png(char *file_name /* , ... other image information ... */) +{ + FILE *fp; + png_structp png_ptr; + png_infop info_ptr; + + /* open the file */ + fp = fopen(file_name, "wb"); + if (fp == NULL) + return; + + /* Create and initialize the png_struct with the desired error handler + * functions. If you want to use the default stderr and longjump method, + * you can supply NULL for the last three parameters. We also check that + * the library version is compatible with the one used at compile time, + * in case we are using dynamically linked libraries. REQUIRED. + */ + png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, + (void *)user_error_ptr, user_error_fn, user_warning_fn); + + if (png_ptr == NULL) + { + fclose(fp); + return; + } + + /* Allocate/initialize the image information data. REQUIRED */ + info_ptr = png_create_info_struct(png_ptr); + if (info_ptr == NULL) + { + fclose(fp); + png_destroy_write_struct(&png_ptr, (png_infopp)NULL); + return; + } + + /* Set error handling. REQUIRED if you aren't supplying your own + * error hadnling functions in the png_create_write_struct() call. + */ + if (setjmp(png_ptr->jmpbuf)) + { + /* If we get here, we had a problem reading the file */ + fclose(fp); + png_destroy_write_struct(&png_ptr, (png_infopp)NULL); + return; + } + + /* One of the following I/O initialization functions is REQUIRED */ +#ifdef streams /* I/O initialization method 1 */ + /* set up the output control if you are using standard C streams */ + png_init_io(png_ptr, fp); +#else no_streams /* I/O initialization method 2 */ + /* If you are using replacement read functions, instead of calling + * png_init_io() here you would call */ + png_set_write_fn(png_ptr, (void *)user_io_ptr, user_write_fn, + user_IO_flush_function); + /* where user_io_ptr is a structure you want available to the callbacks */ +#endif no_streams /* only use one initialization method */ + + /* Set the image information here. Width and height are up to 2^31, + * bit_depth is one of 1, 2, 4, 8, or 16, but valid values also depend on + * the color_type selected. color_type is one of PNG_COLOR_TYPE_GRAY, + * PNG_COLOR_TYPE_GRAY_ALPHA, PNG_COLOR_TYPE_PALETTE, PNG_COLOR_TYPE_RGB, + * or PNG_COLOR_TYPE_RGB_ALPHA. interlace is either PNG_INTERLACE_NONE or + * PNG_INTERLACE_ADAM7, and the compression_type and filter_type MUST + * currently be PNG_COMPRESSION_TYPE_BASE and PNG_FILTER_TYPE_BASE. REQUIRED + */ + png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, PNG_COLOR_TYPE_???, + PNG_INTERLACE_????, PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE); + + /* set the palette if there is one. REQUIRED for indexed-color images */ + palette = (png_colorp)png_malloc(png_ptr, 256 * sizeof (png_color)); + /* ... set palette colors ... */ + png_set_PLTE(png_ptr, info_ptr, palette, 256); + + /* optional significant bit chunk */ + /* if we are dealing with a grayscale image then */ + sig_bit.gray = true_bit_depth; + /* otherwise, if we are dealing with a color image then */ + sig_bit.red = true_red_bit_depth; + sig_bit.green = true_green_bit_depth; + sig_bit.blue = true_blue_bit_depth; + /* if the image has an alpha channel then */ + sig_bit.alpha = true_alpha_bit_depth; + png_set_sBIT(png_ptr, info_ptr, sig_bit); + + + /* Optional gamma chunk is strongly suggested if you have any guess + * as to the correct gamma of the image. + */ + png_set_gAMA(png_ptr, info_ptr, gamma); + + /* Optionally write comments into the image */ + text_ptr[0].key = "Title"; + text_ptr[0].text = "Mona Lisa"; + text_ptr[0].compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr[1].key = "Author"; + text_ptr[1].text = "Leonardo DaVinci"; + text_ptr[1].compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr[2].key = "Description"; + text_ptr[2].text = ""; + text_ptr[2].compression = PNG_TEXT_COMPRESSION_zTXt; + png_set_text(png_ptr, info_ptr, text_ptr, 2); + + /* other optional chunks like cHRM, bKGD, tRNS, tIME, oFFs, pHYs, */ + /* note that if sRGB is present the cHRM chunk must be ignored + * on read and must be written in accordance with the sRGB profile */ + + /* Write the file header information. REQUIRED */ + png_write_info(png_ptr, info_ptr); + + /* Once we write out the header, the compression type on the text + * chunks gets changed to PNG_TEXT_COMPRESSION_NONE_WR or + * PNG_TEXT_COMPRESSION_zTXt_WR, so it doesn't get written out again + * at the end. + */ + + /* set up the transformations you want. Note that these are + * all optional. Only call them if you want them. + */ + + /* invert monocrome pixels */ + png_set_invert_mono(png_ptr); + + /* Shift the pixels up to a legal bit depth and fill in + * as appropriate to correctly scale the image. + */ + png_set_shift(png_ptr, &sig_bit); + + /* pack pixels into bytes */ + png_set_packing(png_ptr); + + /* swap location of alpha bytes from ARGB to RGBA */ + png_set_swap_alpha(png_ptr); + + /* Get rid of filler (OR ALPHA) bytes, pack XRGB/RGBX/ARGB/RGBA into + * RGB (4 channels -> 3 channels). The second parameter is not used. + */ + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); + + /* flip BGR pixels to RGB */ + png_set_bgr(png_ptr); + + /* swap bytes of 16-bit files to most significant byte first */ + png_set_swap(png_ptr); + + /* swap bits of 1, 2, 4 bit packed pixel formats */ + png_set_packswap(png_ptr); + + /* turn on interlace handling if you are not using png_write_image() */ + if (interlacing) + number_passes = png_set_interlace_handling(png_ptr); + else + number_passes = 1; + + /* The easiest way to write the image (you may have a different memory + * layout, however, so choose what fits your needs best). You need to + * use the first method if you aren't handling interlacing yourself. + */ + png_byte row_pointers[height][width]; + + /* One of the following output methods is REQUIRED */ +#ifdef entire /* write out the entire image data in one call */ + png_write_image(png_ptr, row_pointers); + + /* the other way to write the image - deal with interlacing */ + +#else no_entire /* write out the image data by one or more scanlines */ + /* The number of passes is either 1 for non-interlaced images, + * or 7 for interlaced images. + */ + for (pass = 0; pass < number_passes; pass++) + { + /* Write a few rows at a time. */ + png_write_rows(png_ptr, row_pointers, number_of_rows); + + /* If you are only writing one row at a time, this works */ + for (y = 0; y < height; y++) + { + png_bytep row_pointers = row[y]; + png_write_rows(png_ptr, &row_pointers, 1); + } + } +#endif no_entire /* use only one output method */ + + /* You can write optional chunks like tEXt, zTXt, and tIME at the end + * as well. + */ + + /* It is REQUIRED to call this to finish writing the rest of the file */ + png_write_end(png_ptr, info_ptr); + + /* if you malloced the palette, free it here */ + free(info_ptr->palette); + + /* if you allocated any text comments, free them here */ + + /* clean up after the write, and free any memory allocated */ + png_destroy_write_struct(&png_ptr, (png_infopp)NULL); + + /* close the file */ + fclose(fp); + + /* that's it */ + return; +} + diff --git a/thirdparty/libpng/libpng.3 b/thirdparty/libpng/libpng.3 new file mode 100644 index 00000000..1226d789 --- /dev/null +++ b/thirdparty/libpng/libpng.3 @@ -0,0 +1,2408 @@ +.TH LIBPNG 3 "March 9, 1998" +.SH NAME +libpng \- Portable Network Graphics (PNG) Reference Library +.SH SYNOPSIS + +#include + +int png_check_sig (png_bytep sig, int num); + +void png_chunk_error (png_structp png_ptr, png_const_charp +error); + +void png_chunk_warning (png_structp png_ptr, png_const_charp +message); + +void png_convert_from_struct_tm (png_timep ptime, struct tm FAR +* ttime); + +void png_convert_from_time_t (png_timep ptime, time_t ttime); + +png_charp png_convert_to_rfc1123 (png_structp png_ptr, +png_timep ptime); + +png_infop png_create_info_struct (png_structp png_ptr); + +png_structp png_create_read_struct (png_const_charp +user_png_ver, voidp error_ptr, png_error_ptr error_fn, +png_error_ptr warn_fn); + +png_structp png_create_write_struct (png_const_charp +user_png_ver, voidp error_ptr, png_error_ptr error_fn, +png_error_ptr warn_fn); + +void png_debug_free (png_structp png_ptr, png_voidp ptr); + +png_voidp png_debug_malloc (png_structp png_ptr, png_uint_32 +size); + +void png_destroy_info_struct (png_structp png_ptr, png_infopp +info_ptr_ptr); + +void png_destroy_read_struct (png_structpp png_ptr_ptr, +png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr); + +void png_destroy_write_struct (png_structpp png_ptr_ptr, +png_infopp info_ptr_ptr); + +void png_error (png_structp png_ptr, png_const_charp error); + +void png_free (png_structp png_ptr, png_voidp ptr); + +png_byte png_get_bit_depth (png_structp png_ptr, png_infop +info_ptr); + +png_uint_32 png_get_bKGD (png_structp png_ptr, png_infop +info_ptr, png_color_16p *background); + +png_byte png_get_channels (png_structp png_ptr, png_infop +info_ptr); + +png_uint_32 png_get_cHRM (png_structp png_ptr, png_infop +info_ptr, double *white_x, double *white_y, double *red_x, +double *red_y, double *green_x, double *green_y, double +*blue_x, double *blue_y); + +png_byte png_get_color_type (png_structp png_ptr, png_infop +info_ptr); + +png_byte png_get_compression_type (png_structp png_ptr, +png_infop info_ptr); + +png_voidp png_get_error_ptr (png_structp png_ptr); + +png_byte png_get_filter_type (png_structp png_ptr, png_infop +info_ptr); + +png_uint_32 png_get_gAMA (png_structp png_ptr, png_infop +info_ptr, double *file_gamma); + +png_uint_32 png_get_hIST (png_structp png_ptr, png_infop +info_ptr, png_uint_16p *hist); + +png_uint_32 png_get_image_height (png_structp png_ptr, +png_infop info_ptr); + +png_uint_32 png_get_image_width (png_structp png_ptr, png_infop +info_ptr); + +png_byte png_get_interlace_type (png_structp png_ptr, png_infop +info_ptr); + +png_voidp png_get_io_ptr (png_structp png_ptr); + +png_uint_32 png_get_IHDR (png_structp png_ptr, png_infop +info_ptr, png_uint_32 *width, png_uint_32 *height, int +*bit_depth, int *color_type, int *interlace_type, int +*compression_type, int *filter_type); + +png_uint_32 png_get_oFFs (png_structp png_ptr, png_infop +info_ptr, png_uint_32 *offset_x, png_uint_32 *offset_y, int +*unit_type); + +png_uint_32 png_get_pCAL (png_structp png_ptr, png_infop +info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1, +int *type, int *nparams, png_charp *units, png_charpp *params); + +png_uint_32 png_get_pHYs (png_structp png_ptr, png_infop +info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int +*unit_type); + +float png_get_pixel_aspect_ratio (png_structp png_ptr, +png_infop info_ptr); + +png_uint_32 png_get_pixels_per_meter (png_structp png_ptr, +png_infop info_ptr); + +png_voidp png_get_progressive_ptr (png_structp png_ptr); + +png_uint_32 png_get_PLTE (png_structp png_ptr, png_infop +info_ptr, png_colorp *palette, int *num_palette); + +png_uint_32 png_get_rowbytes (png_structp png_ptr, png_infop +info_ptr); + +png_uint_32 png_get_sBIT (png_structp png_ptr, png_infop +info_ptr, png_color_8p *sig_bit); + +png_bytep png_get_signature (png_structp png_ptr, png_infop +info_ptr); + +png_uint_32 png_get_sRGB (png_structp png_ptr, png_infop +info_ptr, int *intent); + +png_uint_32 png_get_text (png_structp png_ptr, png_infop +info_ptr, png_textp *text_ptr, int *num_text); + +png_uint_32 png_get_tIME (png_structp png_ptr, png_infop +info_ptr, png_timep *mod_time); + +png_uint_32 png_get_tRNS (png_structp png_ptr, png_infop +info_ptr, png_bytep *trans, int *num_trans, png_color_16p +*trans_values); + +png_uint_32 png_get_valid (png_structp png_ptr, png_infop +info_ptr, png_uint_32 flag); + +png_uint_32 png_get_x_offset_microns (png_structp png_ptr, +png_infop info_ptr); + +png_uint_32 png_get_x_offset_pixels (png_structp png_ptr, +png_infop info_ptr); + +png_uint_32 png_get_x_pixels_per_meter (png_structp png_ptr, +png_infop info_ptr); + +png_uint_32 png_get_y_offset_microns (png_structp png_ptr, +png_infop info_ptr); + +png_uint_32 png_get_y_offset_pixels (png_structp png_ptr, +png_infop info_ptr); + +png_uint_32 png_get_y_pixels_per_meter (png_structp png_ptr, +png_infop info_ptr); + +void png_info_init (png_infop info_ptr); + +void png_init_io (png_structp png_ptr, FILE *fp); + +png_voidp png_malloc (png_structp png_ptr, png_uint_32 size); + +voidp png_memcpy (png_voidp s1, png_voidp s2, png_size_t size); + +png_voidp png_memcpy_check (png_structp png_ptr, png_voidp s1, +png_voidp s2, png_uint_32 size); + +voidp png_memset (png_voidp s1, int value, png_size_t size); + +png_voidp png_memset_check (png_structp png_ptr, png_voidp +s1, int value, png_uint_32 size); + +void png_process_data (png_structp png_ptr, png_infop info_ptr, +png_bytep buffer, png_size_t buffer_size); + +void png_progressive_combine_row (png_structp png_ptr, +png_bytep old_row, png_bytep new_row); + +void png_read_destroy (png_structp png_ptr, png_infop info_ptr, +png_infop end_info_ptr); + +void png_read_end (png_structp png_ptr, png_infop info_ptr); + +void png_read_image (png_structp png_ptr, png_bytepp image); + +void png_read_info (png_structp png_ptr, png_infop info_ptr); + +void png_read_row (png_structp png_ptr, png_bytep row, +png_bytep display_row); + +void png_read_rows (png_structp png_ptr, png_bytepp row, +png_bytepp display_row, png_uint_32 num_rows); + +void png_read_update_info (png_structp png_ptr, png_infop +info_ptr); + +void png_set_background (png_structp png_ptr, png_color_16p +background_color, int background_gamma_code, int need_expand, +double background_gamma); + +void png_set_bgr (png_structp png_ptr); + +void png_set_bKGD (png_structp png_ptr, png_infop info_ptr, +png_color_16p background); + +void png_set_cHRM (png_structp png_ptr, png_infop info_ptr, +double white_x, double white_y, double red_x, double red_y, +double green_x, double green_y, double blue_x, double blue_y); + +void png_set_compression_level (png_structp png_ptr, int +level); + +void png_set_compression_mem_level (png_structp png_ptr, int +mem_level); + +void png_set_compression_method (png_structp png_ptr, int +method); + +void png_set_compression_strategy (png_structp png_ptr, int +strategy); + +void png_set_compression_window_bits (png_structp png_ptr, int +window_bits); + +void png_set_crc_action (png_structp png_ptr, int crit_action, +int ancil_action); + +void png_set_dither (png_structp png_ptr, png_colorp palette, +int num_palette, int maximum_colors, png_uint_16p histogram, +int full_dither); + +void png_set_error_fn (png_structp png_ptr, png_voidp +error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn); + +void png_set_expand (png_structp png_ptr); + +void png_set_filler (png_structp png_ptr, png_uint_32 filler, +int flags); + +void png_set_filter (png_structp png_ptr, int method, int +filters); + +void png_set_filter_heuristics (png_structp png_ptr, int +heuristic_method, int num_weights, png_doublep filter_weights, +png_doublep filter_costs); + +void png_set_flush (png_structp png_ptr, int nrows); + +void png_set_gamma (png_structp png_ptr, double screen_gamma, +double default_file_gamma); + +void png_set_gAMA (png_structp png_ptr, png_infop info_ptr, +double file_gamma); + +void png_set_gray_to_rgb (png_structp png_ptr); + +void png_set_hIST (png_structp png_ptr, png_infop info_ptr, +png_uint_16p hist); + +int png_set_interlace_handling (png_structp png_ptr); + +void png_set_invert_alpha (png_structp png_ptr); + +void png_set_invert_mono (png_structp png_ptr); + +void png_set_IHDR (png_structp png_ptr, png_infop info_ptr, +png_uint_32 width, png_uint_32 height, int bit_depth, int +color_type, int interlace_type, int compression_type, int +filter_type); + +void png_set_oFFs (png_structp png_ptr, png_infop info_ptr, +png_uint_32 offset_x, png_uint_32 offset_y, int unit_type); + +void png_set_packing (png_structp png_ptr); + +void png_set_packswap (png_structp png_ptr); + +void png_set_pCAL (png_structp png_ptr, png_infop info_ptr, +png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int +nparams, png_charp units, png_charpp params); + +void png_set_pHYs (png_structp png_ptr, png_infop info_ptr, +png_uint_32 res_x, png_uint_32 res_y, int unit_type); + +void png_set_progressive_read_fn (png_structp png_ptr, +png_voidp progressive_ptr, png_progressive_info_ptr info_fn, +png_progressive_row_ptr row_fn, png_progressive_end_ptr +end_fn); + +void png_set_PLTE (png_structp png_ptr, png_infop info_ptr, +png_colorp palette, int num_palette); + +void png_set_read_fn (png_structp png_ptr, png_voidp io_ptr, +png_rw_ptr read_data_fn); + +void png_set_read_status_fn (png_structp png_ptr, png_read_status_ptr + read_row_fn); + +void png_set_read_user_transform_fn (png_structp png_ptr, + png_user_transform_ptr read_user_transform_fn); + +void png_set_rgb_to_gray (png_structp png_ptr); + +void png_set_sBIT (png_structp png_ptr, png_infop info_ptr, +png_color_8p sig_bit); + +void png_set_shift (png_structp png_ptr, png_color_8p +true_bits); + +void png_set_sig_bytes (png_structp png_ptr, int num_bytes); + +void png_set_sRGB (png_structp png_ptr, png_infop info_ptr, int +intent); + +void png_set_sRGB_gAMA_and_cHRM (png_structp png_ptr, png_infop +info_ptr, int intent); + +void png_set_strip_16 (png_structp png_ptr); + +void png_set_strip_alpha (png_structp png_ptr); + +void png_set_swap (png_structp png_ptr); + +void png_set_swap_alpha (png_structp png_ptr); + +void png_set_text (png_structp png_ptr, png_infop info_ptr, +png_textp text_ptr, int num_text); + +void png_set_tIME (png_structp png_ptr, png_infop info_ptr, +png_timep mod_time); + +void png_set_tRNS (png_structp png_ptr, png_infop info_ptr, +png_bytep trans, int num_trans, png_color_16p trans_values); + +void png_set_write_fn (png_structp png_ptr, png_voidp io_ptr, +png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn); + +void png_set_write_status_fn (png_structp png_ptr, png_write_status_ptr + write_row_fn); + +void png_set_write_user_transform_fn (png_structp png_ptr, + png_user_transform_ptr write_user_transform_fn); + +int png_sig_cmp (png_bytep sig, png_size_t start, png_size_t +num_to_check); + +void png_start_read_image (png_structp png_ptr); + +void png_warning (png_structp png_ptr, png_const_charp +message); + +void png_write_chunk (png_structp png_ptr, png_bytep +chunk_name, png_bytep data, png_size_t length); + +void png_write_chunk_data (png_structp png_ptr, png_bytep data, +png_size_t length); + +void png_write_chunk_end (png_structp png_ptr); + +void png_write_chunk_start (png_structp png_ptr, png_bytep +chunk_name, png_uint_32 length); + +void png_write_destroy (png_structp png_ptr); + +void png_write_destroy_info (png_infop info_ptr); + +void png_write_end (png_structp png_ptr, png_infop info_ptr); + +void png_write_flush (png_structp png_ptr); + +void png_write_image (png_structp png_ptr, png_bytepp image); + +void png_write_info (png_structp png_ptr, png_infop info_ptr); + +void png_write_row (png_structp png_ptr, png_bytep row); + +void png_write_rows (png_structp png_ptr, png_bytepp row, +png_uint_32 num_rows); + +.SH DESCRIPTION +The +.I libpng +library supports encoding, decoding, and various manipulations of +the Portable Network Graphics (PNG) format image files. It uses the +.IR zlib(3) +compression library. +Following is a copy of the libpng.txt file that accompanies libpng. +.SH LIBPNG.TXT +libpng.txt - A description on how to use and modify libpng + + libpng version 1.0.1 March 9, 1998 + Updated and distributed by Glenn Randers-Pehrson + + Copyright (c) 1998, Glenn Randers-Pehrson + For conditions of distribution and use, see copyright + notice in png.h. + + based on: + + libpng 1.0 beta 6 version 0.96 May 28, 1997 + Updated and distributed by Andreas Dilger + Copyright (c) 1996, 1997 Andreas Dilger + + libpng 1.0 beta 2 - version 0.88 January 26, 1996 + For conditions of distribution and use, see copyright + notice in png.h. Copyright (c) 1995, 1996 Guy Eric + Schalnat, Group 42, Inc. + + Updated/rewritten per request in the libpng FAQ + Copyright (c) 1995 Frank J. T. Wojcik + December 18, 1995 && January 20, 1996 + +.SH I. Introduction + +This file describes how to use and modify the PNG reference library +(known as libpng) for your own use. There are five sections to this +file: introduction, structures, reading, writing, and modification and +configuration notes for various special platforms. In addition to this +file, example.c is a good starting point for using the library, as +it is heavily commented and should include everything most people +will need. We assume that libpng is already installed; see the +INSTALL file for instructions on how to install libpng. + +Libpng was written as a companion to the PNG specification, as a way +of reducing the amount of time and effort it takes to support the PNG +file format in application programs. The PNG specification is available +as RFC 2083 and as a +W3C Recommendation . Some +additional chunks are described in the special-purpose public chunks +documents at . Other information +about PNG can be found at the PNG home page, . + +Most users will not have to modify the library significantly; advanced +users may want to modify it more. All attempts were made to make it as +complete as possible, while keeping the code easy to understand. +Currently, this library only supports C. Support for other languages +is being considered. + +Libpng has been designed to handle multiple sessions at one time, +to be easily modifiable, to be portable to the vast majority of +machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy +to use. The ultimate goal of libpng is to promote the acceptance of +the PNG file format in whatever way possible. While there is still +work to be done (see the TODO file), libpng should cover the +majority of the needs of its users. + +Libpng uses zlib for its compression and decompression of PNG files. +The zlib compression utility is a general purpose utility that is +useful for more than PNG files, and can be used without libpng. +See the documentation delivered with zlib for more details. +You can usually find the source files for the zlib utility wherever you +find the libpng source files. + +Libpng is thread safe, provided the threads are using different +instances of the structures. Each thread should have its own +png_struct and png_info instances, and thus its own image. +Libpng does not protect itself against two threads using the +same instance of a structure. + + +.SH II. Structures + +There are two main structures that are important to libpng, png_struct +and png_info. The first, png_struct, is an internal structure that +will not, for the most part, be used by a user except as the first +variable passed to every libpng function call. + +The png_info structure is designed to provide information about the +PNG file. At one time, the fields of png_info were intended to be +directly accessible to the user. However, this tended to cause problems +with applications using dynamically loaded libraries, and as a result +a set of interface functions for png_info was developed. The fields +of png_info are still available for older applications, but it is +suggested that applications use the new interfaces if at all possible. + +The png.h header file is an invaluable reference for programming with libpng. +And while I'm on the topic, make sure you include the libpng header file: + +#include + +.SH III. Reading + +Reading PNG files: + +We'll now walk you through the possible functions to call when reading +in a PNG file, briefly explaining the syntax and purpose of each one. +See example.c and png.h for more detail. While Progressive reading +is covered in the next section, you will still need some of the +functions discussed in this section to read a PNG file. + +You will want to do the I/O initialization(*) before you get into libpng, +so if it doesn't work, you don't have much to undo. Of course, you +will also want to insure that you are, in fact, dealing with a PNG +file. Libpng provides a simple check to see if a file is a PNG file. +To use it, pass in the first 1 to 8 bytes of the file, and it will +return true or false (1 or 0) depending on whether the bytes could be +part of a PNG file. Of course, the more bytes you pass in, the +greater the accuracy of the prediction. + +If you are intending to keep the file pointer open for use in libpng, +you must ensure you don't read more than 8 bytes from the beginning +of the file, and you also have to make a call to png_set_sig_bytes_read() +with the number of bytes you read from the beginning. Libpng will +then only check the bytes (if any) that your program didn't read. + +(*): If you are not using the standard I/O functions, you will need +to replace them with custom functions. See the discussion under +Customizing libpng. + + + FILE *fp = fopen(file_name, "rb"); + if (!fp) + { + return; + } + fread(header, 1, number, fp); + is_png = png_check_sig(header, 0, number); + if (!is_png) + { + return; + } + + +Next, png_struct and png_info need to be allocated and initialized. In +order to ensure that the size of these structures is correct even with a +dynamically linked libpng, there are functions to initialize and +allocate the structures. We also pass the library version, optional +pointers to error handling functions, and a pointer to a data struct for +use by the error functions, if necessary (the pointer and functions can +be NULL if the default error handlers are to be used). See the section +on Changes to Libpng below regarding the old initialization functions. + + png_structp png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (void *)user_error_ptr, + user_error_fn, user_warning_fn); + if (!png_ptr) + return; + + png_infop info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, + (png_infopp)NULL, (png_infopp)NULL); + return; + } + + png_infop end_info = png_create_info_struct(png_ptr); + if (!end_info) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return; + } + + +The error handling routines passed to png_create_read_struct() are only +necessary if you are not using the libpng supplied error handling +functions. When libpng encounters an error, it expects to longjmp back +to your routine. Therefore, you will need to call setjmp and pass the +jmpbuf field of your png_struct. If you read the file from different +routines, you will need to update the jmpbuf field every time you enter +a new routine that will call a png_ function. + +See your documentation of setjmp/longjmp for your compiler for more +handling in the Customizing Libpng section below for more information on +the libpng error handling. If an error occurs, and libpng longjmp's +back to your setjmp, you will want to call png_destroy_read_struct() to +free any memory. + + if (setjmp(png_ptr->jmpbuf)) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + fclose(fp); + return; + } + +Now you need to set up the input code. The default for libpng is to +use the C function fread(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. If you wish to handle reading data in another +way, you need not call the png_init_io() function, but you must then +implement the libpng I/O methods discussed in the Customizing Libpng +section below. + + png_init_io(png_ptr, fp); + +If you had previously opened the file and read any of the signature from +the beginning in order to see if this was a PNG file, you need to let +libpng know that there are some bytes missing from the start of the file. + + png_set_sig_bytes(png_ptr, number); + +At this point, you can set up a callback function that will be +called after each row has been read, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void read_row_callback(png_ptr, png_uint_32 row, int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "read_row_callback") + +To inform libpng about your function, use + + png_set_read_status_fn(png_ptr, read_row_callback); + +In PNG files, the alpha channel in an image is the level of opacity. +If you need the alpha channel in an image to be the level of transparency +instead of opacity, you can invert the alpha channel (or the tRNS chunk +data) after it's read, so that 0 is fully opaque and 255 (in 8-bit or +paletted images) or 65535 (in 16-bit images) is fully transparent, with + + png_set_invert_alpha(png_ptr); + +This has to appear here rather than later with the other transformations +because the tRNS chunk data must be modified in the case of paletted images. +If your image is not a paletted image, the tRNS data (which in such cases +represents a single color to be rendered as transparent) won't be changed. + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_read_user_transform_fn(png_ptr, + read_transform_fn); + +You must supply the function + + void read_transform_fn(png_ptr ptr, row_info_ptr + row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +after all of the other transformations have been processed. + +You are now ready to read all the file information up to the actual +image data. You do this with a call to png_read_info(). + + png_read_info(png_ptr, info_ptr); + +Functions are used to get the information from the info_ptr: + + png_get_IHDR(png_ptr, info_ptr, &width, &height, + &bit_depth, &color_type, &interlace_type, + &compression_type, &filter_type); + + width - holds the width of the image + in pixels (up to 2^31). + height - holds the height of the image + in pixels (up to 2^31). + bit_depth - holds the bit depth of one of the + image channels. (valid values are + 1, 2, 4, 8, 16 and depend also on + the color_type. See also + significant bits (sBIT) below). + color_type - describes which color/alpha channels + are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + filter_type - (must be PNG_FILTER_TYPE_BASE + for PNG 1.0) + compression_type - (must be PNG_COMPRESSION_TYPE_BASE + for PNG 1.0) + interlace_type - (PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7) + Any or all of interlace_type, compression_type, of + filter_type can be + NULL if you are not interested in their values. + + channels = png_get_channels(png_ptr, info_ptr); + channels - number of channels of info for the + color type (valid values are 1 (GRAY, + PALETTE), 2 (GRAY_ALPHA), 3 (RGB), + 4 (RGB_ALPHA or RGB + filler byte)) + rowbytes = png_get_rowbytes(png_ptr, info_ptr); + rowbytes - number of bytes needed to hold a row + + signature = png_get_signature(png_ptr, info_ptr); + signature - holds the signature read from the + file (if any). The data is kept in + the same offset it would be if the + whole signature were read (i.e. if an + application had already read in 4 + bytes of signature before starting + libpng, the remaining 4 bytes would + be in signature[4] through signature[7] + (see png_set_sig_bytes())). + + + width = png_get_image_width(png_ptr, + info_ptr); + height = png_get_image_height(png_ptr, + info_ptr); + bit_depth = png_get_bit_depth(png_ptr, + info_ptr); + color_type = png_get_color_type(png_ptr, + info_ptr); + filter_type = png_get_filter_type(png_ptr, + info_ptr); + compression_type = png_get_compression_type(png_ptr, + info_ptr); + interlace_type = png_get_interlace_type(png_ptr, + info_ptr); + + +These are also important, but their validity depends on whether the chunk +has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_) and +png_get_(png_ptr, info_ptr, ...) functions return non-zero if the +data has been read, or zero if it is missing. The parameters to the +png_get_ are set directly if they are simple data types, or a pointer +into the info_ptr is returned for any complex types. + + png_get_PLTE(png_ptr, info_ptr, &palette, + &num_palette); + palette - the palette for the file + (array of png_color) + num_palette - number of entries in the palette + + png_get_gAMA(png_ptr, info_ptr, &gamma); + gamma - the gamma the file is written + at (PNG_INFO_gAMA) + + png_get_sRGB(png_ptr, info_ptr, &srgb_intent); + srgb_intent - the rendering intent (PNG_INFO_sRGB) + The presence of the sRGB chunk + means that the pixel data is in the + sRGB color space. This chunk also + implies specific values of gAMA and + cHRM. + + png_get_sBIT(png_ptr, info_ptr, &sig_bit); + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, + red, green, and blue channels, + whichever are appropriate for the + given color type (png_color_16) + + png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, + &trans_values); + trans - array of transparent entries for + palette (PNG_INFO_tRNS) + trans_values - transparent pixel for non-paletted + images (PNG_INFO_tRNS) + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + png_get_hIST(png_ptr, info_ptr, &hist); + (PNG_INFO_hIST) + hist - histogram of palette (array of + png_color_16) + + png_get_tIME(png_ptr, info_ptr, &mod_time); + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_get_bKGD(png_ptr, info_ptr, &background); + background - background color (PNG_VALID_bKGD) + + num_text = png_get_text(png_ptr, info_ptr, &text_ptr); + text_ptr - array of png_text holding image + comments + text_ptr[i]->key - keyword for comment. + text_ptr[i]->text - text comments for current + keyword. + text_ptr[i]->compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE + or PNG_TEXT_COMPRESSION_zTXt + num_text - number of comments + + png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, + &unit_type); + offset_x - positive offset from the left edge + of the screen + offset_y - positive offset from the top edge + of the screen + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, + &unit_type); + res_x - pixels/unit physical resolution in + x direction + res_y - pixels/unit physical resolution in + x direction + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + +The data from the pHYs chunk can be retrieved in several convenient +forms: + + res_x = png_get_x_pixels_per_meter(png_ptr, + info_ptr) + res_y = png_get_y_pixels_per_meter(png_ptr, + info_ptr) + res_x_and_y = png_get_pixels_per_meter(png_ptr, + info_ptr) + aspect_ratio = png_get_pixel_aspect_ratio(png_ptr, + info_ptr) + + (Each of these returns 0 [signifying "unknown"] if + the data is not present or if res_x is 0; + res_x_and_y is 0 if res_x != res_y) + +For more information, see the png_info definition in png.h and the +PNG specification for chunk contents. Be careful with trusting +rowbytes, as some of the transformations could increase the space +needed to hold a row (expand, filler, gray_to_rgb, etc.). +See png_read_update_info(), below. + +A quick word about text_ptr and num_text. PNG stores comments in +keyword/text pairs, one pair per chunk, with no limit on the number +of text chunks, and a 2^31 byte limit on their size. While there are +suggested keywords, there is no requirement to restrict the use to these +strings. It is strongly suggested that keywords and text be sensible +to humans (that's the point), so don't use abbreviations. Non-printing +symbols are not allowed. See the PNG specification for more details. +There is also no requirement to have text after the keyword. + +Keywords should be limited to 79 Latin-1 characters without leading or +trailing spaces, but non-consecutive spaces are allowed within the +keyword. It is possible to have the same keyword any number of times. +The text_ptr is an array of png_text structures, each holding pointer +to a keyword and a pointer to a text string. Only the text string may +be null. The keyword/text pairs are put into the array in the order +that they are received. However, some or all of the text chunks may be +after the image, so, to make sure you have read all the text chunks, +don't mess with these until after you read the stuff after the image. +This will be mentioned again below in the discussion that goes with +png_read_end(). + +After you've read the header information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +The colors used for the background and transparency values should be +supplied in the same format/depth as the current image data. They +are stored in the same format/depth as the image data in a bKGD or tRNS +chunk, so this is what libpng expects for this data. The colors are +transformed to keep in sync with the image data when an application +calls the png_read_update_info() routine (see below). + +Data will be decoded into the supplied row buffers packed into bytes +unless the library has been told to transform it into another format. +For example, 4 bit/pixel paletted or grayscale data will be returned +2 pixels/byte with the leftmost pixel in the high-order bits of the +byte, unless png_set_packing() is called. 8-bit RGB data will be stored +in RGBRGBRGB format unless png_set_filler() is called to insert filler +bytes, either before or after each RGB triplet. 16-bit RGB data will +be returned RRGGBBRRGGBB, with the most significant byte of the color +value first, unless png_set_strip_16() is called to transform it to +regular RGBRGB triplets. + +The following code transforms grayscale images of less than 8 to 8 bits, +changes paletted images to RGB, and adds a full alpha channel if there is +transparency information in a tRNS chunk. This is most useful on +grayscale images with bit depths of 2 or 4 or if there is a multiple-image +viewing application that wishes to treat all images in the same way. + + if (color_type == PNG_COLOR_TYPE_PALETTE && + bit_depth <= 8) png_set_expand(png_ptr); + + if (color_type == PNG_COLOR_TYPE_GRAY && + bit_depth < 8) png_set_expand(png_ptr); + + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_tRNS)) png_set_expand(png_ptr); + +PNG can have files with 16 bits per channel. If you only can handle +8 bits per channel, this will strip the pixels down to 8 bit. + + if (bit_depth == 16) + png_set_strip_16(png_ptr); + +The png_set_background() function tells libpng to composite images +with alpha or simple transparency against the supplied background +color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), +you may use this color, or supply another color more suitable for +the current display (e.g., the background color from a web page). You +need to tell libpng whether the color is in the gamma space of the +display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file +(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one +that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't +know why anyone would use this, but it's here). + +If, for some reason, you don't need the alpha channel on an image, +and you want to remove it rather than combining it with the background +(but the image author certainly had in mind that you *would* combine +it with the background, so that's what you should probably do): + + if (color_type & PNG_COLOR_MASK_ALPHA) + png_set_strip_alpha(png_ptr); + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit +files. This code expands to 1 pixel per byte without changing the +values of the pixels: + + if (bit_depth < 8) + png_set_packing(png_ptr); + +PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels +stored in a PNG image have been "scaled" or "shifted" up to the next +higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] to +8 bits/sample in the range [0, 255]). However, it is also possible to +convert the PNG pixel data back to the original bit depth of the image. +This call reduces the pixels back down to the original bit depth: + + png_color_16p sig_bit; + + if (png_get_sBIT(png_ptr, info_ptr, &sig_bit)) + png_set_shift(png_ptr, sig_bit); + +PNG files store 3-color pixels in red, green, blue order. This code +changes the storage of the pixels to blue, green, red: + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_bgr(png_ptr); + +PNG files store RGB pixels packed into 3 bytes. This code expands them +into 4 bytes for windowing systems that need them in this format: + + if (bit_depth == 8 && color_type == + PNG_COLOR_TYPE_RGB) png_set_filler(png_ptr, + filler, PNG_FILLER_BEFORE); + +where "filler" is the number to fill with, and the location is +either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether +you want the filler before the RGB or after. This transformation +does not affect images that already have full alpha channels. + +If you are reading an image with an alpha channel, and you need the +data as ARGB instead of the normal PNG format RGBA: + + if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_swap_alpha(png_ptr); + +For some uses, you may want a grayscale image to be represented as +RGB. This code will do that conversion: + + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(png_ptr); + +If you have a grayscale and you are using png_set_expand() to change to +a higher bit-depth you must indicate if the supplied background gray +is supplied in the original file bit depth (need_expand = 1) or in the +expanded bit depth (need_expand = 0). Similarly, if you are reading +a paletted image, you must indicate if you have supplied the background +as a palette index that needs to be expanded (need_expand = 1). You can +also specify an RGB triplet that isn't in the palette when setting your +background for a paletted image. + + png_color_16 my_background; + png_color_16p image_background; + + if (png_get_bKGD(png_ptr, info_ptr, + &image_background)) + png_set_background(png_ptr, image_background), + PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); + else + png_set_background(png_ptr, &my_background, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); + +To properly display PNG images on any kind of system, the application needs +to know what the display gamma is. Ideally, the user will know this, and +the application will allow them to set it. One method of allowing the user +to set the display gamma separately for each system is to check for the +DISPLAY_GAMMA and VIEWING_GAMMA environment variables or for a SCREEN_GAMMA +environment variable, which will hopefully be correctly set. + +Note that display_gamma is the gamma of your display, while screen_gamma is +the overall gamma correction required to produce pleasing results, +which depends on the lighting conditions in the surrounding environment. +Screen_gamma is display_gamma/viewing_gamma, where viewing_gamma is +the amount of additional gamma correction needed to compensate for +a (viewing_gamma=1.25) environment. In a dim or brightly lit room, no +compensation other than the display_gamma is needed (viewing_gamma=1.0). + + if (/* We have a user-defined screen + gamma value */) + { + screen_gamma = user_defined_screen_gamma; + } + /* One way that applications can share the same + screen gamma value */ + else if ((gamma_str = getenv("SCREEN_GAMMA")) + != NULL) + { + screen_gamma = atof(gamma_str); + } + /* If we don't have another value */ + else + { + screen_gamma = 2.2; /* A good guess for a + PC monitor in a bright office or a dim room */ + screen_gamma = 2.0; /* A good guess for a + PC monitor in a dark room */ + screen_gamma = 1.7 or 1.0; /* A good + guess for Mac systems */ + } + +The png_set_gamma() function handles gamma transformations of the data. +Pass both the file gamma and the current screen_gamma. If the file does +not have a gamma value, you can pass one anyway if you have an idea what +it is (usually 0.50 is a good guess for GIF images on PCs). Note +that file gammas are inverted from screen gammas. See the discussions +on gamma in the PNG specification for an excellent description of what +gamma is, and why all applications should support it. It is strongly +recommended that PNG viewers support gamma correction. + + if (png_get_gAMA(png_ptr, info_ptr, &gamma)) + png_set_gamma(png_ptr, screen_gamma, gamma); + else + png_set_gamma(png_ptr, screen_gamma, 0.50); + +If you need to reduce an RGB file to a paletted file, or if a paletted +file has more entries then will fit on your screen, png_set_dither() +will do that. Note that this is a simple match dither that merely +finds the closest color available. This should work fairly well with +optimized palettes, and fairly badly with linear color cubes. If you +pass a palette that is larger then maximum_colors, the file will +reduce the number of colors in the palette so it will fit into +maximum_colors. If there is a histogram, it will use it to make +more intelligent choices when reducing the palette. If there is no +histogram, it may not do as good a job. + + if (color_type & PNG_COLOR_MASK_COLOR) + { + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_PLTE)) + { + png_color_16p histogram; + + png_get_hIST(png_ptr, info_ptr, + &histogram); + png_set_dither(png_ptr, palette, num_palette, + max_screen_colors, histogram, 1); + } + else + { + png_color std_color_cube[MAX_SCREEN_COLORS] = + { ... colors ... }; + + png_set_dither(png_ptr, std_color_cube, + MAX_SCREEN_COLORS, MAX_SCREEN_COLORS, + NULL,0); + } + } + +PNG files describe monochrome as black being zero and white being one. +The following code will reverse this (make black be one and white be +zero): + + if (bit_depth == 1 && color_type == PNG_COLOR_GRAY) + png_set_invert_mono(png_ptr); + +PNG files store 16 bit pixels in network byte order (big-endian, +ie. most significant bits first). This code changes the storage to the +other way (little-endian, i.e. least significant bits first, the +way PCs store them): + + if (bit_depth == 16) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +The last thing to handle is interlacing; this is covered in detail below, +but you must call the function here if you want libpng to handle expansion +of the interlaced image. + + number_of_passes = png_set_interlace_handling(png_ptr); + +After setting the transformations, libpng can update your png_info +structure to reflect any transformations you've requested with this +call. This is most useful to update the info structure's rowbytes +field so you can use it to allocate your image memory. This function +will also update your palette with the correct screen_gamma and +background if these have been given with the calls above. + + png_read_update_info(png_ptr, info_ptr); + +After you call png_read_update_info(), you can allocate any +memory you need to hold the image. The row data is simply +raw byte data for all forms of images. As the actual allocation +varies among applications, no example will be given. If you +are allocating one large chunk, you will need to build an +array of pointers to each row, as it will be needed for some +of the functions below. + +After you've allocated memory, you can read the image data. +The simplest way to do this is in one function call. If you are +allocating enough memory to hold the whole image, you can just +call png_read_image() and libpng will read in all the image data +and put it in the memory area supplied. You will need to pass in +an array of pointers to each row. + +This function automatically handles interlacing, so you don't need +to call png_set_interlace_handling() or call this function multiple +times, or any of that other stuff necessary with png_read_rows(). + + png_read_image(png_ptr, row_pointers); + +where row_pointers is: + + png_bytep row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you don't want to read in the whole image at once, you can +use png_read_rows() instead. If there is no interlacing (check +interlace_type == PNG_INTERLACE_NONE), this is simple: + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +where row_pointers is the same as in the png_read_image() call. + +If you are doing this just one row at a time, you can do this with +row_pointers: + + png_bytep row_pointers = row; + png_read_row(png_ptr, &row_pointers, NULL); + +If the file is interlaced (info_ptr->interlace_type != 0), things get +somewhat harder. The only current (PNG Specification version 1.0) +interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7) +is a somewhat complicated 2D interlace scheme, known as Adam7, that +breaks down an image into seven smaller images of varying size, based +on an 8x8 grid. + +libpng can fill out those images or it can give them to you "as is". +If you want them filled out, there are two ways to do that. The one +mentioned in the PNG specification is to expand each pixel to cover +those pixels that have not been read yet (the "rectangle" method). +This results in a blocky image for the first pass, which gradually +smooths out as more pixels are read. The other method is the "sparkle" +method, where pixels are drawn only in their final locations, with the +rest of the image remaining whatever colors they were initialized to +before the start of the read. The first method usually looks better, +but tends to be slower, as there are more pixels to put in the rows. + +If you don't want libpng to handle the interlacing details, just call +png_read_rows() seven times to read in all seven images. Each of the +images is a valid image by itself, or they can all be combined on an +8x8 grid to form a single image (although if you intend to combine them +you would be far better off using the libpng interlace handling). + +The first pass will return an image 1/8 as wide as the entire image +(every 8th column starting in column 0) and 1/8 as high as the original +(every 8th row starting in row 0), the second will be 1/8 as wide +(starting in column 4) and 1/8 as high (also starting in row 0). The +third pass will be 1/4 as wide (every 4th pixel starting in column 0) and +1/8 as high (every 8th row starting in row 4), and the fourth pass will +be 1/4 as wide and 1/4 as high (every 4th column starting in column 2, +and every 4th row starting in row 0). The fifth pass will return an +image 1/2 as wide, and 1/4 as high (starting at column 0 and row 2), +while the sixth pass will be 1/2 as wide and 1/2 as high as the original +(starting in column 1 and row 0). The seventh and final pass will be as +wide as the original, and 1/2 as high, containing all of the odd +numbered scanlines. Phew! + +If you want libpng to expand the images, call this before calling +png_start_read_image() or png_read_update_info(): + + if (interlace_type == PNG_INTERLACE_ADAM7) + number_of_passes + = png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this +is seven, but may change if another interlace type is added. +This function can be called even if the file is not interlaced, +where it will return one pass. + +If you are not going to display the image after each pass, but are +going to wait until the entire image is read in, use the sparkle +effect. This effect is faster and the end result of either method +is exactly the same. If you are planning on displaying the image +after each pass, the "rectangle" effect is generally considered the +better looking one. + +If you only want the "sparkle" effect, just call png_read_rows() as +normal, with the third parameter NULL. Make sure you make pass over +the image number_of_passes times, and you don't change the data in the +rows between calls. You can change the locations of the data, just +not the data. Each pass only writes the pixels appropriate for that +pass, and assumes the data from previous passes is still valid. + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +If you only want the first effect (the rectangles), do the same as +before except pass the row buffer in the third parameter, and leave +the second parameter NULL. + + png_read_rows(png_ptr, NULL, row_pointers, + number_of_rows); + +After you are finished reading the image, you can finish reading +the file. If you are interested in comments or time, which may be +stored either before or after the image data, you should pass the +separate png_info struct if you want to keep the comments from +before and after the image separate. If you are not interested, you +can pass NULL. + + png_read_end(png_ptr, end_info); + +When you are done, you can free all memory allocated by libpng like this: + + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + +For a more compact example of reading a PNG image, see the file example.c. + + +Reading PNG files progressively: + +The progressive reader is slightly different then the non-progressive +reader. Instead of calling png_read_info(), png_read_rows(), and +png_read_end(), you make one call to png_process_data(), which calls +callbacks when it has the info, a row, or the end of the image. You +set up these callbacks with png_set_progressive_read_fn(). You don't +have to worry about the input/output functions of libpng, as you are +giving the library the data directly in png_process_data(). I will +assume that you have read the section on reading PNG files above, +so I will only highlight the differences (although I will show +all of the code). + +png_structp png_ptr; +png_infop info_ptr; + + /* An example code fragment of how you would + initialize the progressive reader in your + application. */ + int + initialize_png_reader() + { + png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (void *)user_error_ptr, + user_error_fn, user_warning_fn); + if (!png_ptr) + return -1; + info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, (png_infopp)NULL, + (png_infopp)NULL); + return -1; + } + + if (setjmp(png_ptr->jmpbuf)) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return -1; + } + + /* This one's new. You can provide functions + to be called when the header info is valid, + when each row is completed, and when the image + is finished. If you aren't using all functions, + you can specify a NULL parameter. You can use + any struct as the user_ptr (cast to a void pointer + for the function call), and retrieve the pointer + from inside the callbacks using the function + + png_get_progressive_ptr(png_ptr); + + which will return a void pointer, which you have + to cast appropriately. + */ + png_set_progressive_read_fn(png_ptr, (void *)user_ptr, + info_callback, row_callback, end_callback); + + return 0; + } + + /* A code fragment that you call as you receive blocks + of data */ + int + process_data(png_bytep buffer, png_uint_32 length) + { + if (setjmp(png_ptr->jmpbuf)) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return -1; + } + + /* This one's new also. Simply give it a chunk + of data from the file stream (in order, of + course). On machines with segmented memory + models machines, don't give it any more than + 64K. The library seems to run fine with sizes + of 4K. Although you can give it much less if + necessary (I assume you can give it chunks of + 1 byte, I haven't tried less then 256 bytes + yet). When this function returns, you may + want to display any rows that were generated + in the row callback if you don't already do + so there. + */ + png_process_data(png_ptr, info_ptr, buffer, length); + return 0; + } + + /* This function is called (as set by + png_set_progressive_fn() above) when enough data + has been supplied so all of the header has been + read. + */ + void + info_callback(png_structp png_ptr, png_infop info) + { + /* Do any setup here, including setting any of + the transformations mentioned in the Reading + PNG files section. For now, you _must_ call + either png_start_read_image() or + png_read_update_info() after all the + transformations are set (even if you don't set + any). You may start getting rows before + png_process_data() returns, so this is your + last chance to prepare for that. + */ + } + + /* This function is called when each row of image + data is complete */ + void + row_callback(png_structp png_ptr, png_bytep new_row, + png_uint_32 row_num, int pass) + { + /* If the image is interlaced, and you turned + on the interlace handler, this function will + be called for every row in every pass. Some + of these rows will not be changed from the + previous pass. When the row is not changed, + the new_row variable will be NULL. The rows + and passes are called in order, so you don't + really need the row_num and pass, but I'm + supplying them because it may make your life + easier. + + For the non-NULL rows of interlaced images, + you must call png_progressive_combine_row() + passing in the row and the old row. You can + call this function for NULL rows (it will just + return) and for non-interlaced images (it just + does the memcpy for you) if it will make the + code easier. Thus, you can just do this for + all cases: + */ + + png_progressive_combine_row(png_ptr, old_row, + new_row); + + /* where old_row is what was displayed for + previous rows. Note that the first pass + (pass == 0, really) will completely cover + the old row, so the rows do not have to be + initialized. After the first pass (and only + for interlaced images), you will have to pass + the current row, and the function will combine + the old row and the new row. + */ + } + + void + end_callback(png_structp png_ptr, png_infop info) + { + /* This function is called after the whole image + has been read, including any chunks after the + image (up to and including the IEND). You + will usually have the same info chunk as you + had in the header, although some data may have + been added to the comments and time fields. + + Most people won't do much here, perhaps setting + a flag that marks the image as finished. + */ + } + +.SH IV. Writing + +Much of this is very similar to reading. However, everything of +importance is repeated here, so you won't have to constantly look +back up in the reading section to understand writing. + +You will want to do the I/O initialization before you get into libpng, +so if it doesn't work, you don't have anything to undo. If you are not +using the standard I/O functions, you will need to replace them with +custom writing functions. See the discussion under Customizing libpng. + + FILE *fp = fopen(file_name, "wb"); + if (!fp) + { + return; + } + +Next, png_struct and png_info need to be allocated and initialized. +As these can be both relatively large, you may not want to store these +on the stack, unless you have stack space to spare. Of course, you +will want to check if they return NULL. If you are also reading, +you won't want to name your read structure and your write structure +both "png_ptr"; you can call them anything you like, such as +"read_ptr" and "write_ptr". Look at pngtest.c, for example. + + png_structp png_ptr = png_create_write_struct + (PNG_LIBPNG_VER_STRING, (void *)user_error_ptr, + user_error_fn, user_warning_fn); + if (!png_ptr) + return; + + png_infop info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_write_struct(&png_ptr, + (png_infopp)NULL); + return; + } + +After you have these structures, you will need to set up the +error handling. When libpng encounters an error, it expects to +longjmp() back to your routine. Therefore, you will need to call +setjmp and pass the jmpbuf field of your png_struct. If you +write the file from different routines, you will need to update +the jmpbuf field every time you enter a new routine that will +call a png_ function. See your documentation of setjmp/longjmp +for your compiler for more information on setjmp/longjmp. See +the discussion on libpng error handling in the Customizing Libpng +section below for more information on the libpng error handling. + + if (setjmp(png_ptr->jmpbuf)) + { + png_destroy_write_struct(&png_ptr, &info_ptr); + fclose(fp); + return; + } + +Now you need to set up the output code. The default for libpng is to +use the C function fwrite(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. Again, if you wish to handle writing data in +another way, see the discussion on libpng I/O handling in the Customizing +Libpng section below. + + png_init_io(png_ptr, fp); + +At this point, you can set up a callback function that will be +called after each row has been written, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void write_row_callback(png_ptr, png_uint_32 row, int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "write_row_callback") + +To inform libpng about your function, use + + png_set_write_status_fn(png_ptr, write_row_callback); + +You now have the option of modifying how the compression library will +run. The following functions are mainly for testing, but may be useful +in some cases, like if you need to write PNG files extremely fast and +are willing to give up some compression, or if you want to get the +maximum possible compression at the expense of slower writing. If you +have no special needs in this area, let the library do what it wants by +not calling this function at all, as it has been tuned to deliver a good +speed/compression ratio. The second parameter to png_set_filter() is +the filter method, for which the only valid value is '0' (as of the +October 1996 PNG specification, version 1.0). The third parameter is a +flag that indicates +which filter type(s) are to be tested for each scanline. See the +Compression Library for details on the specific filter types. + + + /* turn on or off filtering, and/or choose + specific filters */ + png_set_filter(png_ptr, 0, + PNG_FILTER_NONE | PNG_FILTER_SUB | + PNG_FILTER_PAETH); + +The png_set_compression_???() functions interface to the zlib compression +library, and should mostly be ignored unless you really know what you are +doing. The only generally useful call is png_set_compression_level() +which changes how much time zlib spends on trying to compress the image +data. See the Compression Library for details on the compression levels. + + /* set the zlib compression level */ + png_set_compression_level(png_ptr, + Z_BEST_COMPRESSION); + + /* set other zlib parameters */ + png_set_compression_mem_level(png_ptr, 8); + png_set_compression_strategy(png_ptr, + Z_DEFAULT_STRATEGY); + png_set_compression_window_bits(png_ptr, 15); + png_set_compression_method(png_ptr, 8); + +You now need to fill in the png_info structure with all the data you +wish to write before the actual image. Note that the only thing you +are allowed to write after the image is the text chunks and the time +chunk (as of PNG Specification 1.0, anyway). See png_write_end() and +the latest PNG specification for more information on that. If you +wish to write them before the image, fill them in now, and flag that +data as being valid. If you want to wait until after the data, don't +fill them until png_write_end(). For all the fields in png_info and +their data types, see png.h. For explanations of what the fields +contain, see the PNG specification. + +Some of the more important parts of the png_info are: + + png_set_IHDR(png_ptr, info_ptr, width, height, + bit_depth, color_type, interlace_type, + compression_type, filter_type) + width - holds the width of the image + in pixels (up to 2^31). + height - holds the height of the image + in pixels (up to 2^31). + bit_depth - holds the bit depth of one of the + image channels. + (valid values are 1, 2, 4, 8, 16 + and depend also on the + color_type. See also significant + bits (sBIT) below). + color_type - describes which color/alpha + channels are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + interlace_type - PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7 + compression_type - (must be + PNG_COMPRESSION_TYPE_DEFAULT) + filter_type - (must be PNG_FILTER_TYPE_DEFAULT) + + png_set_PLTE(png_ptr, info_ptr, palette, + num_palette); + palette - the palette for the file + (array of png_color) + num_palette - number of entries in the palette + + png_set_gAMA(png_ptr, info_ptr, gamma); + gamma - the gamma the image was created + at (PNG_INFO_gAMA) + + png_set_sRGB(png_ptr, info_ptr, srgb_intent); + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of + the sRGB chunk means that the pixel + data is in the sRGB color space. + This chunk also implies specific + values of gAMA and cHRM. Rendering + intent is the CSS-1 property that + has been defined by the International + Color Consortium + (http://www.color.org). + It can be one of + PNG_SRGB_INTENT_SATURATION, + PNG_SRGB_INTENT_PERCEPTUAL, + PNG_SRGB_INTENT_ABSOLUTE, or + PNG_SRGB_INTENT_RELATIVE. + + + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, + srgb_intent); + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of the + sRGB chunk means that the pixel + data is in the sRGB color space. + This function also causes gAMA and + cHRM chunks with the specific values + that are consistent with sRGB to be + written. + + png_set_sBIT(png_ptr, info_ptr, sig_bit); + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, red, + green, and blue channels, whichever are + appropriate for the given color type + (png_color_16) + + png_set_tRNS(png_ptr, info_ptr, trans, num_trans, + trans_values); + trans - array of transparent entries for + palette (PNG_INFO_tRNS) + trans_values - transparent pixel for non-paletted + images (PNG_INFO_tRNS) + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + png_set_hIST(png_ptr, info_ptr, hist); + (PNG_INFO_hIST) + hist - histogram of palette (array of + png_color_16) + + png_set_tIME(png_ptr, info_ptr, mod_time); + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_set_bKGD(png_ptr, info_ptr, background); + background - background color (PNG_VALID_bKGD) + + png_set_text(png_ptr, info_ptr, text_ptr, num_text); + text_ptr - array of png_text holding image + comments + text_ptr[i]->key - keyword for comment. + text_ptr[i]->text - text comments for current + keyword. + text_ptr[i]->compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE or + PNG_TEXT_COMPRESSION_zTXt + num_text - number of comments in text_ptr + + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, + unit_type); + offset_x - positive offset from the left + edge of the screen + offset_y - positive offset from the top + edge of the screen + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, + unit_type); + res_x - pixels/unit physical resolution + in x direction + res_y - pixels/unit physical resolution + in y direction + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + +In PNG files, the alpha channel in an image is the level of opacity. +If your data is supplied as a level of transparency, you can invert the +alpha channel before you write it, so that 0 is fully transparent and 255 +(in 8-bit or paletted images) or 65535 (in 16-bit images) is fully opaque, +with + + png_set_invert_alpha(png_ptr); + +This must appear here instead of later with the other transformations +because in the case of paletted images the tRNS chunk data has to +be inverted before the tRNS chunk is written. If your image is not a +paletted image, the tRNS data (which in such cases represents a single +color to be rendered as transparent) won't be changed. + +A quick word about text and num_text. text is an array of png_text +structures. num_text is the number of valid structures in the array. +If you want, you can use max_text to hold the size of the array, but +libpng ignores it for writing (it does use it for reading). Each +png_text structure holds a keyword-text value, and a compression type. +The compression types have the same valid numbers as the compression +types of the image data. Currently, the only valid number is zero. +However, you can store text either compressed or uncompressed, unlike +images which always have to be compressed. So if you don't want the +text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE. +Until text gets around 1000 bytes, it is not worth compressing it. +After the text has been written out to the file, the compression type +is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR, +so that it isn't written out again at the end (in case you are calling +png_write_end() with the same struct. + +The keywords that are given in the PNG Specification are: + + Title Short (one line) title or + caption for image + Author Name of image's creator + Description Description of image (possibly long) + Copyright Copyright notice + Creation Time Time of original image creation + (usually RFC 1123 format, see below) + Software Software used to create the image + Disclaimer Legal disclaimer + Warning Warning of nature of content + Source Device used to create the image + Comment Miscellaneous comment; conversion + from other image format + +The keyword-text pairs work like this. Keywords should be short +simple descriptions of what the comment is about. Some typical +keywords are found in the PNG specification, as is some recommendations +on keywords. You can repeat keywords in a file. You can even write +some text before the image and some after. For example, you may want +to put a description of the image before the image, but leave the +disclaimer until after, so viewers working over modem connections +don't have to wait for the disclaimer to go over the modem before +they start seeing the image. Finally, keywords should be full +words, not abbreviations. Keywords and text are in the ISO 8859-1 +(Latin-1) character set (a superset of regular ASCII) and can not +contain NUL characters, and should not contain control or other +unprintable characters. To make the comments widely readable, stick +with basic ASCII, and avoid machine specific character set extensions +like the IBM-PC character set. The keyword must be present, but +you can leave off the text string on non-compressed pairs. +Compressed pairs must have a text string, as only the text string +is compressed anyway, so the compression would be meaningless. + +PNG supports modification time via the png_time structure. Two +conversion routines are proved, png_convert_from_time_t() for +time_t and png_convert_from_struct_tm() for struct tm. The +time_t routine uses gmtime(). You don't have to use either of +these, but if you wish to fill in the png_time structure directly, +you should provide the time in universal time (GMT) if possible +instead of your local time. Note that the year number is the full +year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and +that months start with 1. + +If you want to store the time of the original image creation, you should +use a plain tEXt chunk with the "Creation Time" keyword. This is +necessary because the "creation time" of a PNG image is somewhat vague, +depending on whether you mean the PNG file, the time the image was +created in a non-PNG format, a still photo from which the image was +scanned, or possibly the subject matter itself. In order to facilitate +machine-readable dates, it is recommended that the "Creation Time" +tEXt chunk use RFC 1123 format dates (e.g. 22 May 1997 18:07:10 GMT"), +although this isn't a requirement. Unlike the tIME chunk, the +"Creation Time" tEXt chunk is not expected to be automatically changed +by the software. To facilitate the use of RFC 1123 dates, a function +png_convert_to_rfc1123(png_timep) is provided to convert from PNG +time to an RFC 1123 format string. + +You are now ready to write all the file information up to the actual +image data. You do this with a call to png_write_info(). + + png_write_info(png_ptr, info_ptr); + +After you've written the file information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +PNG files store RGB pixels packed into 3 bytes. This code tells +the library to expect input data with 4 bytes per pixel + + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); + +where the 0 is the value that will be put in the 4th byte, and the +location is either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending +upon whether the filler byte is stored XRGB or RGBX. + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit files. +If the data is supplied at 1 pixel per byte, use this code, which will +correctly pack the pixels into a single byte: + + png_set_packing(png_ptr); + +PNG files reduce possible bit depths to 1, 2, 4, 8, and 16. If your +data is of another bit depth, you can write an sBIT chunk into the +file so that decoders can get the original data if desired. + + /* Set the true bit depth of the image data */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + sig_bit.red = true_bit_depth; + sig_bit.green = true_bit_depth; + sig_bit.blue = true_bit_depth; + } + else + { + sig_bit.gray = true_bit_depth; + } + if (color_type & PNG_COLOR_MASK_ALPHA) + { + sig_bit.alpha = true_bit_depth; + } + + png_set_sBIT(png_ptr, info_ptr, &sig_bit); + +If the data is stored in the row buffer in a bit depth other than +one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG), +this will scale the values to appear to be the correct bit depth as +is required by PNG. + + png_set_shift(png_ptr, &sig_bit); + +PNG files store 16 bit pixels in network byte order (big-endian, +ie. most significant bits first). This code would be used if they are +supplied the other way (little-endian, i.e. least significant bits +first, the way PCs store them): + + if (bit_depth > 8) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +PNG files store 3 color pixels in red, green, blue order. This code +would be used if they are supplied as blue, green, red: + + png_set_bgr(png_ptr); + +PNG files describe monochrome as black being zero and white being +one. This code would be used if the pixels are supplied with this reversed +(black being one and white being zero): + + png_set_invert_mono(png_ptr); + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_write_user_transform_fn(png_ptr, + write_transform_fn); + +You must supply the function + + void write_transform_fn(png_ptr ptr, row_info_ptr + row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +before any of the other transformations have been processed. + +It is possible to have libpng flush any pending output, either manually, +or automatically after a certain number of lines have been written. To +flush the output stream a single time call: + + png_write_flush(png_ptr); + +and to have libpng flush the output stream periodically after a certain +number of scanlines have been written, call: + + png_set_flush(png_ptr, nrows); + +Note that the distance between rows is from the last time png_write_flush() +was called, or the first row of the image if it has never been called. +So if you write 50 lines, and then png_set_flush 25, it will flush the +output on the next scanline, and every 25 lines thereafter, unless +png_write_flush() is called before 25 more lines have been written. +If nrows is too small (less than about 10 lines for a 640 pixel wide +RGB image) the image compression may decrease noticeably (although this +may be acceptable for real-time applications). Infrequent flushing will +only degrade the compression performance by a few percent over images +that do not use flushing. + +That's it for the transformations. Now you can write the image data. +The simplest way to do this is in one function call. If have the +whole image in memory, you can just call png_write_image() and libpng +will write the image. You will need to pass in an array of pointers to +each row. This function automatically handles interlacing, so you don't +need to call png_set_interlace_handling() or call this function multiple +times, or any of that other stuff necessary with png_write_rows(). + + png_write_image(png_ptr, row_pointers); + +where row_pointers is: + + png_bytef *row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you can't want to write the whole image at once, you can +use png_write_rows() instead. If the file is not interlaced, +this is simple: + + png_write_rows(png_ptr, row_pointers, + number_of_rows); + +row_pointers is the same as in the png_write_image() call. + +If you are just writing one row at a time, you can do this with +row_pointers: + + png_bytep row_pointer = row; + + png_write_row(png_ptr, &row_pointer); + +When the file is interlaced, things can get a good deal more +complicated. The only currently (as of February 1998 -- PNG Specification +version 1.0, dated October 1996) defined interlacing scheme for PNG files +is the "Adam7" interlace scheme, that breaks down an +image into seven smaller images of varying size. libpng will build +these images for you, or you can do them yourself. If you want to +build them yourself, see the PNG specification for details of which +pixels to write when. + +If you don't want libpng to handle the interlacing details, just +use png_set_interlace_handling() and call png_write_rows() the +correct number of times to write all seven sub-images. + +If you want libpng to build the sub-images, call this before you start +writing any rows: + + number_of_passes = + png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this +is seven, but may change if another interlace type is added. + +Then write the complete image number_of_passes times. + + png_write_rows(png_ptr, row_pointers, + number_of_rows); + +As some of these rows are not used, and thus return immediately, +you may want to read about interlacing in the PNG specification, +and only update the rows that are actually used. + +After you are finished writing the image, you should finish writing +the file. If you are interested in writing comments or time, you should +pass an appropriately filled png_info pointer. If you are not interested, +you can pass NULL. + + png_write_end(png_ptr, info_ptr); + +When you are done, you can free all memory used by libpng like this: + + png_destroy_write_struct(&png_ptr, &info_ptr); + +You must free any data you allocated for info_ptr, such as comments, +palette, or histogram, before the call to png_destroy_write_struct(); + +For a more compact example of writing a PNG image, see the file example.c. + + +.SH V. Modifying/Customizing libpng: + +There are two issues here. The first is changing how libpng does +standard things like memory allocation, input/output, and error handling. +The second deals with more complicated things like adding new chunks, +adding new transformations, and generally changing how libpng works. + +All of the memory allocation, input/output, and error handling in libpng +goes through callbacks which are user settable. The default routines are +in pngmem.c, pngrio.c, pngwio.c, and pngerror.c respectively. To change +these functions, call the appropriate png_set_???_fn() function. + +Memory allocation is done through the functions png_large_malloc(), +png_malloc(), png_realloc(), png_large_free(), and png_free(). These +currently just call the standard C functions. The large functions must +handle exactly 64K, but they don't have to handle more than that. If +your pointers can't access more then 64K at a time, you will want to set +MAXSEG_64K in zlib.h. Since it is unlikely that the method of handling +memory allocation on a platform will change between applications, these +functions must be modified in the library at compile time. + +Input/Output in libpng is done through png_read() and png_write(), +which currently just call fread() and fwrite(). The FILE * is stored in +png_struct and is initialized via png_init_io(). If you wish to change +the method of I/O, the library supplies callbacks that you can set +through the function png_set_read_fn() and png_set_write_fn() at run +time, instead of calling the png_init_io() function. These functions +also provide a void pointer that can be retrieved via the function +png_get_io_ptr(). For example: + + png_set_read_fn(png_structp png_ptr, + voidp io_ptr, png_rw_ptr read_data_fn) + + png_set_write_fn(png_structp png_ptr, + voidp io_ptr, png_rw_ptr write_data_fn, + png_flush_ptr output_flush_fn); + + voidp io_ptr = png_get_io_ptr(png_ptr); + +The replacement I/O functions should have prototypes as follows: + + void user_read_data(png_structp png_ptr, + png_bytep data, png_uint_32 length); + void user_write_data(png_structp png_ptr, + png_bytep data, png_uint_32 length); + void user_flush_data(png_structp png_ptr); + +Supplying NULL for the read, write, or flush functions sets them back +to using the default C stream functions. It is an error to read from +a write stream, and vice versa. + +Error handling in libpng is done through png_error() and png_warning(). +Errors handled through png_error() are fatal, meaning that png_error() +should never return to its caller. Currently, this is handled via +setjmp() and longjmp(), but you could change this to do things like +exit() if you should wish. On non-fatal errors, png_warning() is called +to print a warning message, and then control returns to the calling code. +By default png_error() and png_warning() print a message on stderr via +fprintf() unless the library is compiled with PNG_NO_STDIO defined. If +you wish to change the behavior of the error functions, you will need to +set up your own message callbacks. These functions are normally supplied +at the time that the png_struct is created. It is also possible to change +these functions after png_create_???_struct() has been called by calling: + + png_set_error_fn(png_structp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warning_fn); + + png_voidp error_ptr = png_get_error_ptr(png_ptr); + +If NULL is supplied for either error_fn or warning_fn, then the libpng +default function will be used, calling fprintf() and/or longjmp() if a +problem is encountered. The replacement error functions should have +parameters as follows: + + void user_error_fn(png_structp png_ptr, + png_const_charp error_msg); + void user_warning_fn(png_structp png_ptr, + png_const_charp warning_msg); + +The motivation behind using setjmp() and longjmp() is the C++ throw and +catch exception handling methods. This makes the code much easier to write, +as there is no need to check every return code of every function call. +However, there are some uncertainties about the status of local variables +after a longjmp, so the user may want to be careful about doing anything after +setjmp returns non-zero besides returning itself. Consult your compiler +documentation for more details. + +If you need to read or write custom chunks, you will need to get deeper +into the libpng code, as a mechanism has not yet been supplied for user +callbacks with custom chunks. First, read the PNG specification, and have +a first level of understanding of how it works. Pay particular attention +to the sections that describe chunk names, and look at how other chunks +were designed, so you can do things similarly. Second, check out the +sections of libpng that read and write chunks. Try to find a chunk that +is similar to yours and copy off of it. More details can be found in the +comments inside the code. A way of handling unknown chunks in a generic +method, potentially via callback functions, would be best. + +If you wish to write your own transformation for the data, look through +the part of the code that does the transformations, and check out some of +the simpler ones to get an idea of how they work. Try to find a similar +transformation to the one you want to add and copy off of it. More details +can be found in the comments inside the code itself. + +Configuring for 16 bit platforms: + +You may need to change the png_large_malloc() and png_large_free() +routines in pngmem.c, as these are required to allocate 64K, although +there is already support for many of the common DOS compilers. Also, +you will want to look into zconf.h to tell zlib (and thus libpng) that +it cannot allocate more then 64K at a time. Even if you can, the memory +won't be accessible. So limit zlib and libpng to 64K by defining MAXSEG_64K. + +Configuring for DOS: + +For DOS users which only have access to the lower 640K, you will +have to limit zlib's memory usage via a png_set_compression_mem_level() +call. See zlib.h or zconf.h in the zlib library for more information. + +Configuring for Medium Model: + +Libpng's support for medium model has been tested on most of the popular +compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets +defined, and FAR gets defined to far in pngconf.h, and you should be +all set. Everything in the library (except for zlib's structure) is +expecting far data. You must use the typedefs with the p or pp on +the end for pointers (or at least look at them and be careful). Make +note that the row's of data are defined as png_bytepp which is a +unsigned char far * far *. + +Configuring for gui/windowing platforms: + +You will need to write new error and warning functions that use the GUI +interface, as described previously, and set them to be the error and +warning functions at the time that png_create_???_struct() is called, +in order to have them available during the structure initialization. +They can be changed later via png_set_error_fn(). On some compilers, +you may also have to change the memory allocators (png_malloc, etc.). + +Configuring for compiler xxx: + +All includes for libpng are in pngconf.h. If you need to add/change/delete +an include, this is the place to do it. The includes that are not +needed outside libpng are protected by the PNG_INTERNAL definition, +which is only defined for those routines inside libpng itself. The +files in libpng proper only include png.h, which includes pngconf.h. + +Configuring zlib: + +There are special functions to configure the compression. Perhaps the +most useful one changes the compression level, which currently uses +input compression values in the range 0 - 9. The library normally +uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests +have shown that for a large majority of images, compression values in +the range 3-6 compress nearly as well as higher levels, and do so much +faster. For online applications it may be desirable to have maximum speed +(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also +specify no compression (Z_NO_COMPRESSION = 0), but this would create +files larger than just storing the raw bitmap. You can specify the +compression level by calling: + + png_set_compression_level(png_ptr, level); + +Another useful one is to reduce the memory level used by the library. +The memory level defaults to 8, but it can be lowered if you are +short on memory (running DOS, for example, where you only have 640K). + + png_set_compression_mem_level(png_ptr, level); + +The other functions are for configuring zlib. They are not recommended +for normal use and may result in writing an invalid PNG file. See +zlib.h for more information on what these mean. + + png_set_compression_strategy(png_ptr, + strategy); + png_set_compression_window_bits(png_ptr, + window_bits); + png_set_compression_method(png_ptr, method); + +Controlling row filtering: + +If you want to control whether libpng uses filtering or not, which +filters are used, and how it goes about picking row filters, you +can call one of these functions. The selection and configuration +of row filters can have a significant impact on the size and +encoding speed and a somewhat lesser impact on the decoding speed +of an image. Filtering is enabled by default for RGB and grayscale +images (with and without alpha), and for 8-bit paletted images, but +not for paletted images with bit depths less than 8 bits/pixel. + +The 'method' parameter sets the main filtering method, which is +currently only '0' in the PNG 1.0 specification. The 'filters' +parameter sets which filter(s), if any, should be used for each +scanline. Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS +to turn filtering on and off, respectively. + +Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB, +PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise +ORed together '|' to specify one or more filters to use. These +filters are described in more detail in the PNG specification. If +you intend to change the filter type during the course of writing +the image, you should start with flags set for all of the filters +you intend to use so that libpng can initialize its internal +structures appropriately for all of the filter types. + + filters = PNG_FILTER_NONE | PNG_FILTER_SUB + | PNG_FILTER_UP; + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, + filters); + +It is also possible to influence how libpng chooses from among the +available filters. This is done in two ways - by telling it how +important it is to keep the same filter for successive rows, and +by telling it the relative computational costs of the filters. + + double weights[3] = {1.5, 1.3, 1.1}, + costs[PNG_FILTER_VALUE_LAST] = + {1.0, 1.3, 1.3, 1.5, 1.7}; + + png_set_filter_selection(png_ptr, + PNG_FILTER_SELECTION_WEIGHTED, 3, + weights, costs); + +The weights are multiplying factors which indicate to libpng that row +should be the same for successive rows unless another row filter is that +many times better than the previous filter. In the above example, if +the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a +"sum of absolute differences" 1.5 x 1.3 times higher than other filters +and still be chosen, while the NONE filter could have a sum 1.1 times +higher than other filters and still be chosen. Unspecified weights are +taken to be 1.0, and the specified weights should probably be declining +like those above in order to emphasize recent filters over older filters. + +The filter costs specify for each filter type a relative decoding cost +to be considered when selecting row filters. This means that filters +with higher costs are less likely to be chosen over filters with lower +costs, unless their "sum of absolute differences" is that much smaller. +The costs do not necessarily reflect the exact computational speeds of +the various filters, since this would unduly influence the final image +size. + +Note that the numbers above were invented purely for this example and +are given only to help explain the function usage. Little testing has +been done to find optimum values for either the costs or the weights. + +Removing unwanted object code: + +There are a bunch of #define's in pngconf.h that control what parts of +libpng are compiled. All the defines end in _SUPPORTED. If you are +never going to use an ability, you can change the #define to #undef +before recompiling libpng and save yourself code and data space. +You can also turn a number of them off en masse with a compiler directive +that defines PNG_READ[or WRITE]_TRANSFORMS_NOT_SUPPORTED, or +PNG_READ[or WRITE]_ANCILLARY_CHUNKS_NOT_SUPPORTED, or all four, +along with directives to turn on any of the capabilities that you do +want. The PNG_READ[or WRITE]_TRANSFORMS_NOT_SUPPORTED directives disable +the extra transformations but still leave the library fully capable of reading +and writing PNG files with all known public chunks [except for sPLT]. +Use of the PNG_READ[or WRITE]_ANCILLARY_CHUNKS_NOT_SUPPORTED directive +produces a library that is incapable of reading or writing ancillary chunks. +If you are not using the progressive reading capability, you can +turn that off with PNG_PROGRESSIVE_READ_NOT_SUPPORTED (don't confuse +this with the INTERLACING capability, which you'll still have). + +All the reading and writing specific code are in separate files, so the +linker should only grab the files it needs. However, if you want to +make sure, or if you are building a stand alone library, all the +reading files start with pngr and all the writing files start with +pngw. The files that don't match either (like png.c, pngtrans.c, etc.) +are used for both reading and writing, and always need to be included. +The progressive reader is in pngpread.c + +If you are creating or distributing a dynamically linked library (a .so +or DLL file), you should not remove or disable any parts of the library, +as this will cause applications linked with different versions of the +library to fail if they call functions not available in your library. +The size of the library itself should not be an issue, because only +those sections which are actually used will be loaded into memory. + + +Changes to Libpng from version 0.88 + +It should be noted that versions of libpng later than 0.96 are not +distributed by the original libpng author, Guy Schalnat, nor by +Andreas Dilger, who had taken over from Guy during 1996 and 1997, and +distributed versions 0.89 through 0.96, but rather by another member +of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are +still alive and well, but they have moved on to other things. + +The old libpng functions png_read_init(), png_write_init(), +png_info_init(), png_read_destroy(), and png_write_destory() have been +moved to PNG_INTERNAL in version 0.95 to discourage their use. The +preferred method of creating and initializing the libpng structures is +via the png_create_read_struct(), png_create_write_struct(), and +png_create_info_struct() because they isolate the size of the structures +from the application, allow version error checking, and also allow the +use of custom error handling routines during the initialization, which +the old functions do not. The functions png_read_destroy() and +png_write_destroy() do not actually free the memory that libpng +allocated for these structs, but just reset the data structures, so they +can be used instead of png_destroy_read_struct() and +png_destroy_write_struct() if you feel there is too much system overhead +allocating and freeing the png_struct for each image read. + +Setting the error callbacks via png_set_message_fn() before +png_read_init() as was suggested in libpng-0.88 is no longer supported +because this caused applications which do not use custom error functions +to fail if the png_ptr was not initialized to zero. It is still possible +to set the error callbacks AFTER png_read_init(), or to change them with +png_set_error_fn(), which is essentially the same function, but with a +new name to force compilation errors with applications that try to use +the old method. + +.SH NOTE + +Note about libpng version numbers: + +Due to various miscommunications, unforeseen code incompatibilities +and occasional factors outside the authors' control, version numbering +on the library has not always been consistent and straightforward. +The following table summarizes matters since version 0.89c, which was +the first widely used release: + + source png.h shared-lib + version string version + ------- ------ ---------- + 0.89c ("1.0 beta 3") 0.89 1.0.89 + 0.90 ("1.0 beta 4") 0.90 0.90 + [should have been 2.0.90] + 0.95 ("1.0 beta 5") 0.95 0.95 + [should have been 2.0.95] + 0.96 ("1.0 beta 6") 0.96 0.96 + [should have been 2.0.96] + 0.97b ("1.00.97 beta 7") 1.00.97 1.0.1 + [should have been 2.0.97] + 0.97c 0.97 2.0.97 + 0.98 0.98 2.0.98 + 0.99 0.99 2.0.99 + 0.99a-m 0.99 2.0.99 + 1.0.1 1.00 2.1.0 + +Henceforth the source version will match the shared-library minor +and patch numbers; the shared-library major version number will be +used for changes in backward compatibility, as it is intended. + +.SH "SEE ALSO" +libpngpf(3), png(5) +.LP +.IR libpng : +.IP +ftp://ftp.uu.net/graphics/png +http://www.cdrom.com/pub/png + +.LP +.IR zlib : +.IP +(generally) at the same location as +.I libpng +or at +.br +ftp://ftp.uu.net/pub/archiving/zip/zlib +.br +http://www.cdrom.com/pub/infozip/zlib + +.LP +.IR PNG specification: RFC 2083 +.IP +(generally) at the same location as +.I libpng +or at +.br +ftp://ds.internic.net/rfc/rfc2083.txt +.br +or (as a W3C Recommendation) at +.br +http://www.w3.org/TR/REC-png.html + +.LP +In the case of any inconsistency between the PNG specification +and this library, the specification takes precedence. + +.SH AUTHORS +This man page: Glenn Randers-Pehrson + + +Contributing Authors: John Bowler, Kevin Bracey, Sam Bushell, Andreas Dilger, +Magnus Holmgren, Tom Lane, Dave Martindale, Glenn Randers-Pehrson, +Greg Roelofs, Guy Eric Schalnat, Paul Schmidt, Tom Tanner, Willem van +Schaik, Tim Wegner. + + +The contributing authors would like to thank all those who helped +with testing, bug fixes, and patience. This wouldn't have been +possible without all of you. + +Thanks to Frank J. T. Wojcik for helping with the documentation. + +Libpng version 1.0.1 (March 9, 1998): +Initially created in 1995 by Guy Eric Schalnat, then of Group 42, Inc. +Currently maintained by Glenn Randers-Pehrson (randeg@alumni.rpi.edu). + +Supported by the PNG development group +.br +(png-implement@dworkin.wustl.edu). + +.SH COPYRIGHT NOTICE: + +The PNG Reference Library (libpng) is supplied "AS IS". The Contributing +Authors and Group 42, Inc. disclaim all warranties, expressed or implied, +including, without limitation, the warranties of merchantability and of +fitness for any purpose. The Contributing Authors and Group 42, Inc. +assume no liability for direct, indirect, incidental, special, exemplary, +or consequential damages, which may result from the use of the PNG +Reference Library, even if advised of the possibility of such damage. + +Permission is hereby granted to use, copy, modify, and distribute this +source code, or portions hereof, for any purpose, without fee, subject +to the following restrictions: + + 1. The origin of this source code must not be + misrepresented. + + 2. Altered versions must be plainly marked as such + and must not be misrepresented as being the + original source. + + 3. This Copyright notice may not be removed or + altered from any source or altered source + distribution. + +The Contributing Authors and Group 42, Inc. specifically permit, without +fee, and encourage the use of this source code as a component to +supporting the PNG file format in commercial products. If you use this +source code in a product, acknowledgment is not required but would be +appreciated. + +.\" end of man page + diff --git a/thirdparty/libpng/libpng.txt b/thirdparty/libpng/libpng.txt new file mode 100644 index 00000000..36fa38f5 --- /dev/null +++ b/thirdparty/libpng/libpng.txt @@ -0,0 +1,1889 @@ +libpng.txt - A description on how to use and modify libpng + + libpng version 1.0.1 March 9, 1998 + Updated and distributed by Glenn Randers-Pehrson + + Copyright (c) 1998, Glenn Randers-Pehrson + For conditions of distribution and use, see copyright + notice in png.h. + + based on: + + libpng 1.0 beta 6 version 0.96 May 28, 1997 + Updated and distributed by Andreas Dilger + Copyright (c) 1996, 1997 Andreas Dilger + + libpng 1.0 beta 2 - version 0.88 January 26, 1996 + For conditions of distribution and use, see copyright + notice in png.h. Copyright (c) 1995, 1996 Guy Eric + Schalnat, Group 42, Inc. + + Updated/rewritten per request in the libpng FAQ + Copyright (c) 1995 Frank J. T. Wojcik + December 18, 1995 && January 20, 1996 + +Introduction + +This file describes how to use and modify the PNG reference library +(known as libpng) for your own use. There are five sections to this +file: introduction, structures, reading, writing, and modification and +configuration notes for various special platforms. In addition to this +file, example.c is a good starting point for using the library, as +it is heavily commented and should include everything most people +will need. We assume that libpng is already installed; see the +INSTALL file for instructions on how to install libpng. + +Libpng was written as a companion to the PNG specification, as a way +of reducing the amount of time and effort it takes to support the PNG +file format in application programs. The PNG specification is available +as RFC 2083 and as a +W3C Recommendation . Some +additional chunks are described in the special-purpose public chunks +documents at . Other information +about PNG can be found at the PNG home page, . + +Most users will not have to modify the library significantly; advanced +users may want to modify it more. All attempts were made to make it as +complete as possible, while keeping the code easy to understand. +Currently, this library only supports C. Support for other languages +is being considered. + +Libpng has been designed to handle multiple sessions at one time, +to be easily modifiable, to be portable to the vast majority of +machines (ANSI, K&R, 16-, 32-, and 64-bit) available, and to be easy +to use. The ultimate goal of libpng is to promote the acceptance of +the PNG file format in whatever way possible. While there is still +work to be done (see the TODO file), libpng should cover the +majority of the needs of its users. + +Libpng uses zlib for its compression and decompression of PNG files. +The zlib compression utility is a general purpose utility that is +useful for more than PNG files, and can be used without libpng. +See the documentation delivered with zlib for more details. +You can usually find the source files for the zlib utility wherever you +find the libpng source files. + +Libpng is thread safe, provided the threads are using different +instances of the structures. Each thread should have its own +png_struct and png_info instances, and thus its own image. +Libpng does not protect itself against two threads using the +same instance of a structure. + + +II. Structures + +There are two main structures that are important to libpng, png_struct +and png_info. The first, png_struct, is an internal structure that +will not, for the most part, be used by a user except as the first +variable passed to every libpng function call. + +The png_info structure is designed to provide information about the +PNG file. At one time, the fields of png_info were intended to be +directly accessible to the user. However, this tended to cause problems +with applications using dynamically loaded libraries, and as a result +a set of interface functions for png_info was developed. The fields +of png_info are still available for older applications, but it is +suggested that applications use the new interfaces if at all possible. + +The png.h header file is an invaluable reference for programming with libpng. +And while I'm on the topic, make sure you include the libpng header file: + +#include + +III. Reading + +Reading PNG files: + +We'll now walk you through the possible functions to call when reading +in a PNG file, briefly explaining the syntax and purpose of each one. +See example.c and png.h for more detail. While Progressive reading +is covered in the next section, you will still need some of the +functions discussed in this section to read a PNG file. + +You will want to do the I/O initialization(*) before you get into libpng, +so if it doesn't work, you don't have much to undo. Of course, you +will also want to insure that you are, in fact, dealing with a PNG +file. Libpng provides a simple check to see if a file is a PNG file. +To use it, pass in the first 1 to 8 bytes of the file, and it will +return true or false (1 or 0) depending on whether the bytes could be +part of a PNG file. Of course, the more bytes you pass in, the +greater the accuracy of the prediction. + +If you are intending to keep the file pointer open for use in libpng, +you must ensure you don't read more than 8 bytes from the beginning +of the file, and you also have to make a call to png_set_sig_bytes_read() +with the number of bytes you read from the beginning. Libpng will +then only check the bytes (if any) that your program didn't read. + +(*): If you are not using the standard I/O functions, you will need +to replace them with custom functions. See the discussion under +Customizing libpng. + + + FILE *fp = fopen(file_name, "rb"); + if (!fp) + { + return; + } + fread(header, 1, number, fp); + is_png = png_check_sig(header, 0, number); + if (!is_png) + { + return; + } + + +Next, png_struct and png_info need to be allocated and initialized. In +order to ensure that the size of these structures is correct even with a +dynamically linked libpng, there are functions to initialize and +allocate the structures. We also pass the library version, optional +pointers to error handling functions, and a pointer to a data struct for +use by the error functions, if necessary (the pointer and functions can +be NULL if the default error handlers are to be used). See the section +on Changes to Libpng below regarding the old initialization functions. + + png_structp png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (void *)user_error_ptr, + user_error_fn, user_warning_fn); + if (!png_ptr) + return; + + png_infop info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, + (png_infopp)NULL, (png_infopp)NULL); + return; + } + + png_infop end_info = png_create_info_struct(png_ptr); + if (!end_info) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return; + } + + +The error handling routines passed to png_create_read_struct() are only +necessary if you are not using the libpng supplied error handling +functions. When libpng encounters an error, it expects to longjmp back +to your routine. Therefore, you will need to call setjmp and pass the +jmpbuf field of your png_struct. If you read the file from different +routines, you will need to update the jmpbuf field every time you enter +a new routine that will call a png_ function. + +See your documentation of setjmp/longjmp for your compiler for more +handling in the Customizing Libpng section below for more information on +the libpng error handling. If an error occurs, and libpng longjmp's +back to your setjmp, you will want to call png_destroy_read_struct() to +free any memory. + + if (setjmp(png_ptr->jmpbuf)) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + fclose(fp); + return; + } + +Now you need to set up the input code. The default for libpng is to +use the C function fread(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. If you wish to handle reading data in another +way, you need not call the png_init_io() function, but you must then +implement the libpng I/O methods discussed in the Customizing Libpng +section below. + + png_init_io(png_ptr, fp); + +If you had previously opened the file and read any of the signature from +the beginning in order to see if this was a PNG file, you need to let +libpng know that there are some bytes missing from the start of the file. + + png_set_sig_bytes(png_ptr, number); + +At this point, you can set up a callback function that will be +called after each row has been read, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void read_row_callback(png_ptr, png_uint_32 row, int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "read_row_callback") + +To inform libpng about your function, use + + png_set_read_status_fn(png_ptr, read_row_callback); + +In PNG files, the alpha channel in an image is the level of opacity. +If you need the alpha channel in an image to be the level of transparency +instead of opacity, you can invert the alpha channel (or the tRNS chunk +data) after it's read, so that 0 is fully opaque and 255 (in 8-bit or +paletted images) or 65535 (in 16-bit images) is fully transparent, with + + png_set_invert_alpha(png_ptr); + +This has to appear here rather than later with the other transformations +because the tRNS chunk data must be modified in the case of paletted images. +If your image is not a paletted image, the tRNS data (which in such cases +represents a single color to be rendered as transparent) won't be changed. + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_read_user_transform_fn(png_ptr, + read_transform_fn); + +You must supply the function + + void read_transform_fn(png_ptr ptr, row_info_ptr + row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +after all of the other transformations have been processed. + +You are now ready to read all the file information up to the actual +image data. You do this with a call to png_read_info(). + + png_read_info(png_ptr, info_ptr); + +Functions are used to get the information from the info_ptr: + + png_get_IHDR(png_ptr, info_ptr, &width, &height, + &bit_depth, &color_type, &interlace_type, + &compression_type, &filter_type); + + width - holds the width of the image + in pixels (up to 2^31). + height - holds the height of the image + in pixels (up to 2^31). + bit_depth - holds the bit depth of one of the + image channels. (valid values are + 1, 2, 4, 8, 16 and depend also on + the color_type. See also + significant bits (sBIT) below). + color_type - describes which color/alpha channels + are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + filter_type - (must be PNG_FILTER_TYPE_BASE + for PNG 1.0) + compression_type - (must be PNG_COMPRESSION_TYPE_BASE + for PNG 1.0) + interlace_type - (PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7) + Any or all of interlace_type, compression_type, of + filter_type can be + NULL if you are not interested in their values. + + channels = png_get_channels(png_ptr, info_ptr); + channels - number of channels of info for the + color type (valid values are 1 (GRAY, + PALETTE), 2 (GRAY_ALPHA), 3 (RGB), + 4 (RGB_ALPHA or RGB + filler byte)) + rowbytes = png_get_rowbytes(png_ptr, info_ptr); + rowbytes - number of bytes needed to hold a row + + signature = png_get_signature(png_ptr, info_ptr); + signature - holds the signature read from the + file (if any). The data is kept in + the same offset it would be if the + whole signature were read (i.e. if an + application had already read in 4 + bytes of signature before starting + libpng, the remaining 4 bytes would + be in signature[4] through signature[7] + (see png_set_sig_bytes())). + + + width = png_get_image_width(png_ptr, + info_ptr); + height = png_get_image_height(png_ptr, + info_ptr); + bit_depth = png_get_bit_depth(png_ptr, + info_ptr); + color_type = png_get_color_type(png_ptr, + info_ptr); + filter_type = png_get_filter_type(png_ptr, + info_ptr); + compression_type = png_get_compression_type(png_ptr, + info_ptr); + interlace_type = png_get_interlace_type(png_ptr, + info_ptr); + + +These are also important, but their validity depends on whether the chunk +has been read. The png_get_valid(png_ptr, info_ptr, PNG_INFO_) and +png_get_(png_ptr, info_ptr, ...) functions return non-zero if the +data has been read, or zero if it is missing. The parameters to the +png_get_ are set directly if they are simple data types, or a pointer +into the info_ptr is returned for any complex types. + + png_get_PLTE(png_ptr, info_ptr, &palette, + &num_palette); + palette - the palette for the file + (array of png_color) + num_palette - number of entries in the palette + + png_get_gAMA(png_ptr, info_ptr, &gamma); + gamma - the gamma the file is written + at (PNG_INFO_gAMA) + + png_get_sRGB(png_ptr, info_ptr, &srgb_intent); + srgb_intent - the rendering intent (PNG_INFO_sRGB) + The presence of the sRGB chunk + means that the pixel data is in the + sRGB color space. This chunk also + implies specific values of gAMA and + cHRM. + + png_get_sBIT(png_ptr, info_ptr, &sig_bit); + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, + red, green, and blue channels, + whichever are appropriate for the + given color type (png_color_16) + + png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, + &trans_values); + trans - array of transparent entries for + palette (PNG_INFO_tRNS) + trans_values - transparent pixel for non-paletted + images (PNG_INFO_tRNS) + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + png_get_hIST(png_ptr, info_ptr, &hist); + (PNG_INFO_hIST) + hist - histogram of palette (array of + png_color_16) + + png_get_tIME(png_ptr, info_ptr, &mod_time); + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_get_bKGD(png_ptr, info_ptr, &background); + background - background color (PNG_VALID_bKGD) + + num_text = png_get_text(png_ptr, info_ptr, &text_ptr); + text_ptr - array of png_text holding image + comments + text_ptr[i]->key - keyword for comment. + text_ptr[i]->text - text comments for current + keyword. + text_ptr[i]->compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE + or PNG_TEXT_COMPRESSION_zTXt + num_text - number of comments + + png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, + &unit_type); + offset_x - positive offset from the left edge + of the screen + offset_y - positive offset from the top edge + of the screen + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_get_pHYs(png_ptr, info_ptr, &res_x, &res_y, + &unit_type); + res_x - pixels/unit physical resolution in + x direction + res_y - pixels/unit physical resolution in + x direction + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + +The data from the pHYs chunk can be retrieved in several convenient +forms: + + res_x = png_get_x_pixels_per_meter(png_ptr, + info_ptr) + res_y = png_get_y_pixels_per_meter(png_ptr, + info_ptr) + res_x_and_y = png_get_pixels_per_meter(png_ptr, + info_ptr) + aspect_ratio = png_get_pixel_aspect_ratio(png_ptr, + info_ptr) + + (Each of these returns 0 [signifying "unknown"] if + the data is not present or if res_x is 0; + res_x_and_y is 0 if res_x != res_y) + +For more information, see the png_info definition in png.h and the +PNG specification for chunk contents. Be careful with trusting +rowbytes, as some of the transformations could increase the space +needed to hold a row (expand, filler, gray_to_rgb, etc.). +See png_read_update_info(), below. + +A quick word about text_ptr and num_text. PNG stores comments in +keyword/text pairs, one pair per chunk, with no limit on the number +of text chunks, and a 2^31 byte limit on their size. While there are +suggested keywords, there is no requirement to restrict the use to these +strings. It is strongly suggested that keywords and text be sensible +to humans (that's the point), so don't use abbreviations. Non-printing +symbols are not allowed. See the PNG specification for more details. +There is also no requirement to have text after the keyword. + +Keywords should be limited to 79 Latin-1 characters without leading or +trailing spaces, but non-consecutive spaces are allowed within the +keyword. It is possible to have the same keyword any number of times. +The text_ptr is an array of png_text structures, each holding pointer +to a keyword and a pointer to a text string. Only the text string may +be null. The keyword/text pairs are put into the array in the order +that they are received. However, some or all of the text chunks may be +after the image, so, to make sure you have read all the text chunks, +don't mess with these until after you read the stuff after the image. +This will be mentioned again below in the discussion that goes with +png_read_end(). + +After you've read the header information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +The colors used for the background and transparency values should be +supplied in the same format/depth as the current image data. They +are stored in the same format/depth as the image data in a bKGD or tRNS +chunk, so this is what libpng expects for this data. The colors are +transformed to keep in sync with the image data when an application +calls the png_read_update_info() routine (see below). + +Data will be decoded into the supplied row buffers packed into bytes +unless the library has been told to transform it into another format. +For example, 4 bit/pixel paletted or grayscale data will be returned +2 pixels/byte with the leftmost pixel in the high-order bits of the +byte, unless png_set_packing() is called. 8-bit RGB data will be stored +in RGBRGBRGB format unless png_set_filler() is called to insert filler +bytes, either before or after each RGB triplet. 16-bit RGB data will +be returned RRGGBBRRGGBB, with the most significant byte of the color +value first, unless png_set_strip_16() is called to transform it to +regular RGBRGB triplets. + +The following code transforms grayscale images of less than 8 to 8 bits, +changes paletted images to RGB, and adds a full alpha channel if there is +transparency information in a tRNS chunk. This is most useful on +grayscale images with bit depths of 2 or 4 or if there is a multiple-image +viewing application that wishes to treat all images in the same way. + + if (color_type == PNG_COLOR_TYPE_PALETTE && + bit_depth <= 8) png_set_expand(png_ptr); + + if (color_type == PNG_COLOR_TYPE_GRAY && + bit_depth < 8) png_set_expand(png_ptr); + + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_tRNS)) png_set_expand(png_ptr); + +PNG can have files with 16 bits per channel. If you only can handle +8 bits per channel, this will strip the pixels down to 8 bit. + + if (bit_depth == 16) + png_set_strip_16(png_ptr); + +The png_set_background() function tells libpng to composite images +with alpha or simple transparency against the supplied background +color. If the PNG file contains a bKGD chunk (PNG_INFO_bKGD valid), +you may use this color, or supply another color more suitable for +the current display (e.g., the background color from a web page). You +need to tell libpng whether the color is in the gamma space of the +display (PNG_BACKGROUND_GAMMA_SCREEN for colors you supply), the file +(PNG_BACKGROUND_GAMMA_FILE for colors from the bKGD chunk), or one +that is neither of these gammas (PNG_BACKGROUND_GAMMA_UNIQUE - I don't +know why anyone would use this, but it's here). + +If, for some reason, you don't need the alpha channel on an image, +and you want to remove it rather than combining it with the background +(but the image author certainly had in mind that you *would* combine +it with the background, so that's what you should probably do): + + if (color_type & PNG_COLOR_MASK_ALPHA) + png_set_strip_alpha(png_ptr); + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit +files. This code expands to 1 pixel per byte without changing the +values of the pixels: + + if (bit_depth < 8) + png_set_packing(png_ptr); + +PNG files have possible bit depths of 1, 2, 4, 8, and 16. All pixels +stored in a PNG image have been "scaled" or "shifted" up to the next +higher possible bit depth (e.g. from 5 bits/sample in the range [0,31] to +8 bits/sample in the range [0, 255]). However, it is also possible to +convert the PNG pixel data back to the original bit depth of the image. +This call reduces the pixels back down to the original bit depth: + + png_color_16p sig_bit; + + if (png_get_sBIT(png_ptr, info_ptr, &sig_bit)) + png_set_shift(png_ptr, sig_bit); + +PNG files store 3-color pixels in red, green, blue order. This code +changes the storage of the pixels to blue, green, red: + + if (color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_bgr(png_ptr); + +PNG files store RGB pixels packed into 3 bytes. This code expands them +into 4 bytes for windowing systems that need them in this format: + + if (bit_depth == 8 && color_type == + PNG_COLOR_TYPE_RGB) png_set_filler(png_ptr, + filler, PNG_FILLER_BEFORE); + +where "filler" is the number to fill with, and the location is +either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending upon whether +you want the filler before the RGB or after. This transformation +does not affect images that already have full alpha channels. + +If you are reading an image with an alpha channel, and you need the +data as ARGB instead of the normal PNG format RGBA: + + if (color_type == PNG_COLOR_TYPE_RGB_ALPHA) + png_set_swap_alpha(png_ptr); + +For some uses, you may want a grayscale image to be represented as +RGB. This code will do that conversion: + + if (color_type == PNG_COLOR_TYPE_GRAY || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + png_set_gray_to_rgb(png_ptr); + +If you have a grayscale and you are using png_set_expand() to change to +a higher bit-depth you must indicate if the supplied background gray +is supplied in the original file bit depth (need_expand = 1) or in the +expanded bit depth (need_expand = 0). Similarly, if you are reading +a paletted image, you must indicate if you have supplied the background +as a palette index that needs to be expanded (need_expand = 1). You can +also specify an RGB triplet that isn't in the palette when setting your +background for a paletted image. + + png_color_16 my_background; + png_color_16p image_background; + + if (png_get_bKGD(png_ptr, info_ptr, + &image_background)) + png_set_background(png_ptr, image_background), + PNG_BACKGROUND_GAMMA_FILE, 1, 1.0); + else + png_set_background(png_ptr, &my_background, + PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0); + +To properly display PNG images on any kind of system, the application needs +to know what the display gamma is. Ideally, the user will know this, and +the application will allow them to set it. One method of allowing the user +to set the display gamma separately for each system is to check for the +DISPLAY_GAMMA and VIEWING_GAMMA environment variables or for a SCREEN_GAMMA +environment variable, which will hopefully be correctly set. + +Note that display_gamma is the gamma of your display, while screen_gamma is +the overall gamma correction required to produce pleasing results, +which depends on the lighting conditions in the surrounding environment. +Screen_gamma is display_gamma/viewing_gamma, where viewing_gamma is +the amount of additional gamma correction needed to compensate for +a (viewing_gamma=1.25) environment. In a dim or brightly lit room, no +compensation other than the display_gamma is needed (viewing_gamma=1.0). + + if (/* We have a user-defined screen + gamma value */) + { + screen_gamma = user_defined_screen_gamma; + } + /* One way that applications can share the same + screen gamma value */ + else if ((gamma_str = getenv("SCREEN_GAMMA")) + != NULL) + { + screen_gamma = atof(gamma_str); + } + /* If we don't have another value */ + else + { + screen_gamma = 2.2; /* A good guess for a + PC monitor in a bright office or a dim room */ + screen_gamma = 2.0; /* A good guess for a + PC monitor in a dark room */ + screen_gamma = 1.7 or 1.0; /* A good + guess for Mac systems */ + } + +The png_set_gamma() function handles gamma transformations of the data. +Pass both the file gamma and the current screen_gamma. If the file does +not have a gamma value, you can pass one anyway if you have an idea what +it is (usually 0.50 is a good guess for GIF images on PCs). Note +that file gammas are inverted from screen gammas. See the discussions +on gamma in the PNG specification for an excellent description of what +gamma is, and why all applications should support it. It is strongly +recommended that PNG viewers support gamma correction. + + if (png_get_gAMA(png_ptr, info_ptr, &gamma)) + png_set_gamma(png_ptr, screen_gamma, gamma); + else + png_set_gamma(png_ptr, screen_gamma, 0.50); + +If you need to reduce an RGB file to a paletted file, or if a paletted +file has more entries then will fit on your screen, png_set_dither() +will do that. Note that this is a simple match dither that merely +finds the closest color available. This should work fairly well with +optimized palettes, and fairly badly with linear color cubes. If you +pass a palette that is larger then maximum_colors, the file will +reduce the number of colors in the palette so it will fit into +maximum_colors. If there is a histogram, it will use it to make +more intelligent choices when reducing the palette. If there is no +histogram, it may not do as good a job. + + if (color_type & PNG_COLOR_MASK_COLOR) + { + if (png_get_valid(png_ptr, info_ptr, + PNG_INFO_PLTE)) + { + png_color_16p histogram; + + png_get_hIST(png_ptr, info_ptr, + &histogram); + png_set_dither(png_ptr, palette, num_palette, + max_screen_colors, histogram, 1); + } + else + { + png_color std_color_cube[MAX_SCREEN_COLORS] = + { ... colors ... }; + + png_set_dither(png_ptr, std_color_cube, + MAX_SCREEN_COLORS, MAX_SCREEN_COLORS, + NULL,0); + } + } + +PNG files describe monochrome as black being zero and white being one. +The following code will reverse this (make black be one and white be +zero): + + if (bit_depth == 1 && color_type == PNG_COLOR_GRAY) + png_set_invert_mono(png_ptr); + +PNG files store 16 bit pixels in network byte order (big-endian, +ie. most significant bits first). This code changes the storage to the +other way (little-endian, i.e. least significant bits first, the +way PCs store them): + + if (bit_depth == 16) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +The last thing to handle is interlacing; this is covered in detail below, +but you must call the function here if you want libpng to handle expansion +of the interlaced image. + + number_of_passes = png_set_interlace_handling(png_ptr); + +After setting the transformations, libpng can update your png_info +structure to reflect any transformations you've requested with this +call. This is most useful to update the info structure's rowbytes +field so you can use it to allocate your image memory. This function +will also update your palette with the correct screen_gamma and +background if these have been given with the calls above. + + png_read_update_info(png_ptr, info_ptr); + +After you call png_read_update_info(), you can allocate any +memory you need to hold the image. The row data is simply +raw byte data for all forms of images. As the actual allocation +varies among applications, no example will be given. If you +are allocating one large chunk, you will need to build an +array of pointers to each row, as it will be needed for some +of the functions below. + +After you've allocated memory, you can read the image data. +The simplest way to do this is in one function call. If you are +allocating enough memory to hold the whole image, you can just +call png_read_image() and libpng will read in all the image data +and put it in the memory area supplied. You will need to pass in +an array of pointers to each row. + +This function automatically handles interlacing, so you don't need +to call png_set_interlace_handling() or call this function multiple +times, or any of that other stuff necessary with png_read_rows(). + + png_read_image(png_ptr, row_pointers); + +where row_pointers is: + + png_bytep row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you don't want to read in the whole image at once, you can +use png_read_rows() instead. If there is no interlacing (check +interlace_type == PNG_INTERLACE_NONE), this is simple: + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +where row_pointers is the same as in the png_read_image() call. + +If you are doing this just one row at a time, you can do this with +row_pointers: + + png_bytep row_pointers = row; + png_read_row(png_ptr, &row_pointers, NULL); + +If the file is interlaced (info_ptr->interlace_type != 0), things get +somewhat harder. The only current (PNG Specification version 1.0) +interlacing type for PNG is (interlace_type == PNG_INTERLACE_ADAM7) +is a somewhat complicated 2D interlace scheme, known as Adam7, that +breaks down an image into seven smaller images of varying size, based +on an 8x8 grid. + +libpng can fill out those images or it can give them to you "as is". +If you want them filled out, there are two ways to do that. The one +mentioned in the PNG specification is to expand each pixel to cover +those pixels that have not been read yet (the "rectangle" method). +This results in a blocky image for the first pass, which gradually +smooths out as more pixels are read. The other method is the "sparkle" +method, where pixels are drawn only in their final locations, with the +rest of the image remaining whatever colors they were initialized to +before the start of the read. The first method usually looks better, +but tends to be slower, as there are more pixels to put in the rows. + +If you don't want libpng to handle the interlacing details, just call +png_read_rows() seven times to read in all seven images. Each of the +images is a valid image by itself, or they can all be combined on an +8x8 grid to form a single image (although if you intend to combine them +you would be far better off using the libpng interlace handling). + +The first pass will return an image 1/8 as wide as the entire image +(every 8th column starting in column 0) and 1/8 as high as the original +(every 8th row starting in row 0), the second will be 1/8 as wide +(starting in column 4) and 1/8 as high (also starting in row 0). The +third pass will be 1/4 as wide (every 4th pixel starting in column 0) and +1/8 as high (every 8th row starting in row 4), and the fourth pass will +be 1/4 as wide and 1/4 as high (every 4th column starting in column 2, +and every 4th row starting in row 0). The fifth pass will return an +image 1/2 as wide, and 1/4 as high (starting at column 0 and row 2), +while the sixth pass will be 1/2 as wide and 1/2 as high as the original +(starting in column 1 and row 0). The seventh and final pass will be as +wide as the original, and 1/2 as high, containing all of the odd +numbered scanlines. Phew! + +If you want libpng to expand the images, call this before calling +png_start_read_image() or png_read_update_info(): + + if (interlace_type == PNG_INTERLACE_ADAM7) + number_of_passes + = png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this +is seven, but may change if another interlace type is added. +This function can be called even if the file is not interlaced, +where it will return one pass. + +If you are not going to display the image after each pass, but are +going to wait until the entire image is read in, use the sparkle +effect. This effect is faster and the end result of either method +is exactly the same. If you are planning on displaying the image +after each pass, the "rectangle" effect is generally considered the +better looking one. + +If you only want the "sparkle" effect, just call png_read_rows() as +normal, with the third parameter NULL. Make sure you make pass over +the image number_of_passes times, and you don't change the data in the +rows between calls. You can change the locations of the data, just +not the data. Each pass only writes the pixels appropriate for that +pass, and assumes the data from previous passes is still valid. + + png_read_rows(png_ptr, row_pointers, NULL, + number_of_rows); + +If you only want the first effect (the rectangles), do the same as +before except pass the row buffer in the third parameter, and leave +the second parameter NULL. + + png_read_rows(png_ptr, NULL, row_pointers, + number_of_rows); + +After you are finished reading the image, you can finish reading +the file. If you are interested in comments or time, which may be +stored either before or after the image data, you should pass the +separate png_info struct if you want to keep the comments from +before and after the image separate. If you are not interested, you +can pass NULL. + + png_read_end(png_ptr, end_info); + +When you are done, you can free all memory allocated by libpng like this: + + png_destroy_read_struct(&png_ptr, &info_ptr, + &end_info); + +For a more compact example of reading a PNG image, see the file example.c. + + +Reading PNG files progressively: + +The progressive reader is slightly different then the non-progressive +reader. Instead of calling png_read_info(), png_read_rows(), and +png_read_end(), you make one call to png_process_data(), which calls +callbacks when it has the info, a row, or the end of the image. You +set up these callbacks with png_set_progressive_read_fn(). You don't +have to worry about the input/output functions of libpng, as you are +giving the library the data directly in png_process_data(). I will +assume that you have read the section on reading PNG files above, +so I will only highlight the differences (although I will show +all of the code). + +png_structp png_ptr; +png_infop info_ptr; + + /* An example code fragment of how you would + initialize the progressive reader in your + application. */ + int + initialize_png_reader() + { + png_ptr = png_create_read_struct + (PNG_LIBPNG_VER_STRING, (void *)user_error_ptr, + user_error_fn, user_warning_fn); + if (!png_ptr) + return -1; + info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_read_struct(&png_ptr, (png_infopp)NULL, + (png_infopp)NULL); + return -1; + } + + if (setjmp(png_ptr->jmpbuf)) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return -1; + } + + /* This one's new. You can provide functions + to be called when the header info is valid, + when each row is completed, and when the image + is finished. If you aren't using all functions, + you can specify a NULL parameter. You can use + any struct as the user_ptr (cast to a void pointer + for the function call), and retrieve the pointer + from inside the callbacks using the function + + png_get_progressive_ptr(png_ptr); + + which will return a void pointer, which you have + to cast appropriately. + */ + png_set_progressive_read_fn(png_ptr, (void *)user_ptr, + info_callback, row_callback, end_callback); + + return 0; + } + + /* A code fragment that you call as you receive blocks + of data */ + int + process_data(png_bytep buffer, png_uint_32 length) + { + if (setjmp(png_ptr->jmpbuf)) + { + png_destroy_read_struct(&png_ptr, &info_ptr, + (png_infopp)NULL); + return -1; + } + + /* This one's new also. Simply give it a chunk + of data from the file stream (in order, of + course). On machines with segmented memory + models machines, don't give it any more than + 64K. The library seems to run fine with sizes + of 4K. Although you can give it much less if + necessary (I assume you can give it chunks of + 1 byte, I haven't tried less then 256 bytes + yet). When this function returns, you may + want to display any rows that were generated + in the row callback if you don't already do + so there. + */ + png_process_data(png_ptr, info_ptr, buffer, length); + return 0; + } + + /* This function is called (as set by + png_set_progressive_fn() above) when enough data + has been supplied so all of the header has been + read. + */ + void + info_callback(png_structp png_ptr, png_infop info) + { + /* Do any setup here, including setting any of + the transformations mentioned in the Reading + PNG files section. For now, you _must_ call + either png_start_read_image() or + png_read_update_info() after all the + transformations are set (even if you don't set + any). You may start getting rows before + png_process_data() returns, so this is your + last chance to prepare for that. + */ + } + + /* This function is called when each row of image + data is complete */ + void + row_callback(png_structp png_ptr, png_bytep new_row, + png_uint_32 row_num, int pass) + { + /* If the image is interlaced, and you turned + on the interlace handler, this function will + be called for every row in every pass. Some + of these rows will not be changed from the + previous pass. When the row is not changed, + the new_row variable will be NULL. The rows + and passes are called in order, so you don't + really need the row_num and pass, but I'm + supplying them because it may make your life + easier. + + For the non-NULL rows of interlaced images, + you must call png_progressive_combine_row() + passing in the row and the old row. You can + call this function for NULL rows (it will just + return) and for non-interlaced images (it just + does the memcpy for you) if it will make the + code easier. Thus, you can just do this for + all cases: + */ + + png_progressive_combine_row(png_ptr, old_row, + new_row); + + /* where old_row is what was displayed for + previous rows. Note that the first pass + (pass == 0, really) will completely cover + the old row, so the rows do not have to be + initialized. After the first pass (and only + for interlaced images), you will have to pass + the current row, and the function will combine + the old row and the new row. + */ + } + + void + end_callback(png_structp png_ptr, png_infop info) + { + /* This function is called after the whole image + has been read, including any chunks after the + image (up to and including the IEND). You + will usually have the same info chunk as you + had in the header, although some data may have + been added to the comments and time fields. + + Most people won't do much here, perhaps setting + a flag that marks the image as finished. + */ + } + + + +IV. Writing + +Much of this is very similar to reading. However, everything of +importance is repeated here, so you won't have to constantly look +back up in the reading section to understand writing. + +You will want to do the I/O initialization before you get into libpng, +so if it doesn't work, you don't have anything to undo. If you are not +using the standard I/O functions, you will need to replace them with +custom writing functions. See the discussion under Customizing libpng. + + FILE *fp = fopen(file_name, "wb"); + if (!fp) + { + return; + } + +Next, png_struct and png_info need to be allocated and initialized. +As these can be both relatively large, you may not want to store these +on the stack, unless you have stack space to spare. Of course, you +will want to check if they return NULL. If you are also reading, +you won't want to name your read structure and your write structure +both "png_ptr"; you can call them anything you like, such as +"read_ptr" and "write_ptr". Look at pngtest.c, for example. + + png_structp png_ptr = png_create_write_struct + (PNG_LIBPNG_VER_STRING, (void *)user_error_ptr, + user_error_fn, user_warning_fn); + if (!png_ptr) + return; + + png_infop info_ptr = png_create_info_struct(png_ptr); + if (!info_ptr) + { + png_destroy_write_struct(&png_ptr, + (png_infopp)NULL); + return; + } + +After you have these structures, you will need to set up the +error handling. When libpng encounters an error, it expects to +longjmp() back to your routine. Therefore, you will need to call +setjmp and pass the jmpbuf field of your png_struct. If you +write the file from different routines, you will need to update +the jmpbuf field every time you enter a new routine that will +call a png_ function. See your documentation of setjmp/longjmp +for your compiler for more information on setjmp/longjmp. See +the discussion on libpng error handling in the Customizing Libpng +section below for more information on the libpng error handling. + + if (setjmp(png_ptr->jmpbuf)) + { + png_destroy_write_struct(&png_ptr, &info_ptr); + fclose(fp); + return; + } + +Now you need to set up the output code. The default for libpng is to +use the C function fwrite(). If you use this, you will need to pass a +valid FILE * in the function png_init_io(). Be sure that the file is +opened in binary mode. Again, if you wish to handle writing data in +another way, see the discussion on libpng I/O handling in the Customizing +Libpng section below. + + png_init_io(png_ptr, fp); + +At this point, you can set up a callback function that will be +called after each row has been written, which you can use to control +a progress meter or the like. It's demonstrated in pngtest.c. +You must supply a function + + void write_row_callback(png_ptr, png_uint_32 row, int pass); + { + /* put your code here */ + } + +(You can give it another name that you like instead of "write_row_callback") + +To inform libpng about your function, use + + png_set_write_status_fn(png_ptr, write_row_callback); + +You now have the option of modifying how the compression library will +run. The following functions are mainly for testing, but may be useful +in some cases, like if you need to write PNG files extremely fast and +are willing to give up some compression, or if you want to get the +maximum possible compression at the expense of slower writing. If you +have no special needs in this area, let the library do what it wants by +not calling this function at all, as it has been tuned to deliver a good +speed/compression ratio. The second parameter to png_set_filter() is +the filter method, for which the only valid value is '0' (as of the +October 1996 PNG specification, version 1.0). The third parameter is a +flag that indicates +which filter type(s) are to be tested for each scanline. See the +Compression Library for details on the specific filter types. + + + /* turn on or off filtering, and/or choose + specific filters */ + png_set_filter(png_ptr, 0, + PNG_FILTER_NONE | PNG_FILTER_SUB | + PNG_FILTER_PAETH); + +The png_set_compression_???() functions interface to the zlib compression +library, and should mostly be ignored unless you really know what you are +doing. The only generally useful call is png_set_compression_level() +which changes how much time zlib spends on trying to compress the image +data. See the Compression Library for details on the compression levels. + + /* set the zlib compression level */ + png_set_compression_level(png_ptr, + Z_BEST_COMPRESSION); + + /* set other zlib parameters */ + png_set_compression_mem_level(png_ptr, 8); + png_set_compression_strategy(png_ptr, + Z_DEFAULT_STRATEGY); + png_set_compression_window_bits(png_ptr, 15); + png_set_compression_method(png_ptr, 8); + +You now need to fill in the png_info structure with all the data you +wish to write before the actual image. Note that the only thing you +are allowed to write after the image is the text chunks and the time +chunk (as of PNG Specification 1.0, anyway). See png_write_end() and +the latest PNG specification for more information on that. If you +wish to write them before the image, fill them in now, and flag that +data as being valid. If you want to wait until after the data, don't +fill them until png_write_end(). For all the fields in png_info and +their data types, see png.h. For explanations of what the fields +contain, see the PNG specification. + +Some of the more important parts of the png_info are: + + png_set_IHDR(png_ptr, info_ptr, width, height, + bit_depth, color_type, interlace_type, + compression_type, filter_type) + width - holds the width of the image + in pixels (up to 2^31). + height - holds the height of the image + in pixels (up to 2^31). + bit_depth - holds the bit depth of one of the + image channels. + (valid values are 1, 2, 4, 8, 16 + and depend also on the + color_type. See also significant + bits (sBIT) below). + color_type - describes which color/alpha + channels are present. + PNG_COLOR_TYPE_GRAY + (bit depths 1, 2, 4, 8, 16) + PNG_COLOR_TYPE_GRAY_ALPHA + (bit depths 8, 16) + PNG_COLOR_TYPE_PALETTE + (bit depths 1, 2, 4, 8) + PNG_COLOR_TYPE_RGB + (bit_depths 8, 16) + PNG_COLOR_TYPE_RGB_ALPHA + (bit_depths 8, 16) + + PNG_COLOR_MASK_PALETTE + PNG_COLOR_MASK_COLOR + PNG_COLOR_MASK_ALPHA + + interlace_type - PNG_INTERLACE_NONE or + PNG_INTERLACE_ADAM7 + compression_type - (must be + PNG_COMPRESSION_TYPE_DEFAULT) + filter_type - (must be PNG_FILTER_TYPE_DEFAULT) + + png_set_PLTE(png_ptr, info_ptr, palette, + num_palette); + palette - the palette for the file + (array of png_color) + num_palette - number of entries in the palette + + png_set_gAMA(png_ptr, info_ptr, gamma); + gamma - the gamma the image was created + at (PNG_INFO_gAMA) + + png_set_sRGB(png_ptr, info_ptr, srgb_intent); + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of + the sRGB chunk means that the pixel + data is in the sRGB color space. + This chunk also implies specific + values of gAMA and cHRM. Rendering + intent is the CSS-1 property that + has been defined by the International + Color Consortium + (http://www.color.org). + It can be one of + PNG_SRGB_INTENT_SATURATION, + PNG_SRGB_INTENT_PERCEPTUAL, + PNG_SRGB_INTENT_ABSOLUTE, or + PNG_SRGB_INTENT_RELATIVE. + + + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, + srgb_intent); + srgb_intent - the rendering intent + (PNG_INFO_sRGB) The presence of the + sRGB chunk means that the pixel + data is in the sRGB color space. + This function also causes gAMA and + cHRM chunks with the specific values + that are consistent with sRGB to be + written. + + png_set_sBIT(png_ptr, info_ptr, sig_bit); + sig_bit - the number of significant bits for + (PNG_INFO_sBIT) each of the gray, red, + green, and blue channels, whichever are + appropriate for the given color type + (png_color_16) + + png_set_tRNS(png_ptr, info_ptr, trans, num_trans, + trans_values); + trans - array of transparent entries for + palette (PNG_INFO_tRNS) + trans_values - transparent pixel for non-paletted + images (PNG_INFO_tRNS) + num_trans - number of transparent entries + (PNG_INFO_tRNS) + + png_set_hIST(png_ptr, info_ptr, hist); + (PNG_INFO_hIST) + hist - histogram of palette (array of + png_color_16) + + png_set_tIME(png_ptr, info_ptr, mod_time); + mod_time - time image was last modified + (PNG_VALID_tIME) + + png_set_bKGD(png_ptr, info_ptr, background); + background - background color (PNG_VALID_bKGD) + + png_set_text(png_ptr, info_ptr, text_ptr, num_text); + text_ptr - array of png_text holding image + comments + text_ptr[i]->key - keyword for comment. + text_ptr[i]->text - text comments for current + keyword. + text_ptr[i]->compression - type of compression used + on "text" PNG_TEXT_COMPRESSION_NONE or + PNG_TEXT_COMPRESSION_zTXt + num_text - number of comments in text_ptr + + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, + unit_type); + offset_x - positive offset from the left + edge of the screen + offset_y - positive offset from the top + edge of the screen + unit_type - PNG_OFFSET_PIXEL, PNG_OFFSET_MICROMETER + + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, + unit_type); + res_x - pixels/unit physical resolution + in x direction + res_y - pixels/unit physical resolution + in y direction + unit_type - PNG_RESOLUTION_UNKNOWN, + PNG_RESOLUTION_METER + +In PNG files, the alpha channel in an image is the level of opacity. +If your data is supplied as a level of transparency, you can invert the +alpha channel before you write it, so that 0 is fully transparent and 255 +(in 8-bit or paletted images) or 65535 (in 16-bit images) is fully opaque, +with + + png_set_invert_alpha(png_ptr); + +This must appear here instead of later with the other transformations +because in the case of paletted images the tRNS chunk data has to +be inverted before the tRNS chunk is written. If your image is not a +paletted image, the tRNS data (which in such cases represents a single +color to be rendered as transparent) won't be changed. + +A quick word about text and num_text. text is an array of png_text +structures. num_text is the number of valid structures in the array. +If you want, you can use max_text to hold the size of the array, but +libpng ignores it for writing (it does use it for reading). Each +png_text structure holds a keyword-text value, and a compression type. +The compression types have the same valid numbers as the compression +types of the image data. Currently, the only valid number is zero. +However, you can store text either compressed or uncompressed, unlike +images which always have to be compressed. So if you don't want the +text compressed, set the compression type to PNG_TEXT_COMPRESSION_NONE. +Until text gets around 1000 bytes, it is not worth compressing it. +After the text has been written out to the file, the compression type +is set to PNG_TEXT_COMPRESSION_NONE_WR or PNG_TEXT_COMPRESSION_zTXt_WR, +so that it isn't written out again at the end (in case you are calling +png_write_end() with the same struct. + +The keywords that are given in the PNG Specification are: + + Title Short (one line) title or + caption for image + Author Name of image's creator + Description Description of image (possibly long) + Copyright Copyright notice + Creation Time Time of original image creation + (usually RFC 1123 format, see below) + Software Software used to create the image + Disclaimer Legal disclaimer + Warning Warning of nature of content + Source Device used to create the image + Comment Miscellaneous comment; conversion + from other image format + +The keyword-text pairs work like this. Keywords should be short +simple descriptions of what the comment is about. Some typical +keywords are found in the PNG specification, as is some recommendations +on keywords. You can repeat keywords in a file. You can even write +some text before the image and some after. For example, you may want +to put a description of the image before the image, but leave the +disclaimer until after, so viewers working over modem connections +don't have to wait for the disclaimer to go over the modem before +they start seeing the image. Finally, keywords should be full +words, not abbreviations. Keywords and text are in the ISO 8859-1 +(Latin-1) character set (a superset of regular ASCII) and can not +contain NUL characters, and should not contain control or other +unprintable characters. To make the comments widely readable, stick +with basic ASCII, and avoid machine specific character set extensions +like the IBM-PC character set. The keyword must be present, but +you can leave off the text string on non-compressed pairs. +Compressed pairs must have a text string, as only the text string +is compressed anyway, so the compression would be meaningless. + +PNG supports modification time via the png_time structure. Two +conversion routines are proved, png_convert_from_time_t() for +time_t and png_convert_from_struct_tm() for struct tm. The +time_t routine uses gmtime(). You don't have to use either of +these, but if you wish to fill in the png_time structure directly, +you should provide the time in universal time (GMT) if possible +instead of your local time. Note that the year number is the full +year (e.g. 1998, rather than 98 - PNG is year 2000 compliant!), and +that months start with 1. + +If you want to store the time of the original image creation, you should +use a plain tEXt chunk with the "Creation Time" keyword. This is +necessary because the "creation time" of a PNG image is somewhat vague, +depending on whether you mean the PNG file, the time the image was +created in a non-PNG format, a still photo from which the image was +scanned, or possibly the subject matter itself. In order to facilitate +machine-readable dates, it is recommended that the "Creation Time" +tEXt chunk use RFC 1123 format dates (e.g. 22 May 1997 18:07:10 GMT"), +although this isn't a requirement. Unlike the tIME chunk, the +"Creation Time" tEXt chunk is not expected to be automatically changed +by the software. To facilitate the use of RFC 1123 dates, a function +png_convert_to_rfc1123(png_timep) is provided to convert from PNG +time to an RFC 1123 format string. + +You are now ready to write all the file information up to the actual +image data. You do this with a call to png_write_info(). + + png_write_info(png_ptr, info_ptr); + +After you've written the file information, you can set up the library +to handle any special transformations of the image data. The various +ways to transform the data will be described in the order that they +should occur. This is important, as some of these change the color +type and/or bit depth of the data, and some others only work on +certain color types and bit depths. Even though each transformation +checks to see if it has data that it can do something with, you should +make sure to only enable a transformation if it will be valid for the +data. For example, don't swap red and blue on grayscale data. + +PNG files store RGB pixels packed into 3 bytes. This code tells +the library to expect input data with 4 bytes per pixel + + png_set_filler(png_ptr, 0, PNG_FILLER_BEFORE); + +where the 0 is the value that will be put in the 4th byte, and the +location is either PNG_FILLER_BEFORE or PNG_FILLER_AFTER, depending +upon whether the filler byte is stored XRGB or RGBX. + +PNG files pack pixels of bit depths 1, 2, and 4 into bytes as small as +they can, resulting in, for example, 8 pixels per byte for 1 bit files. +If the data is supplied at 1 pixel per byte, use this code, which will +correctly pack the pixels into a single byte: + + png_set_packing(png_ptr); + +PNG files reduce possible bit depths to 1, 2, 4, 8, and 16. If your +data is of another bit depth, you can write an sBIT chunk into the +file so that decoders can get the original data if desired. + + /* Set the true bit depth of the image data */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + sig_bit.red = true_bit_depth; + sig_bit.green = true_bit_depth; + sig_bit.blue = true_bit_depth; + } + else + { + sig_bit.gray = true_bit_depth; + } + if (color_type & PNG_COLOR_MASK_ALPHA) + { + sig_bit.alpha = true_bit_depth; + } + + png_set_sBIT(png_ptr, info_ptr, &sig_bit); + +If the data is stored in the row buffer in a bit depth other than +one supported by PNG (e.g. 3 bit data in the range 0-7 for a 4-bit PNG), +this will scale the values to appear to be the correct bit depth as +is required by PNG. + + png_set_shift(png_ptr, &sig_bit); + +PNG files store 16 bit pixels in network byte order (big-endian, +ie. most significant bits first). This code would be used if they are +supplied the other way (little-endian, i.e. least significant bits +first, the way PCs store them): + + if (bit_depth > 8) + png_set_swap(png_ptr); + +If you are using packed-pixel images (1, 2, or 4 bits/pixel), and you +need to change the order the pixels are packed into bytes, you can use: + + if (bit_depth < 8) + png_set_packswap(png_ptr); + +PNG files store 3 color pixels in red, green, blue order. This code +would be used if they are supplied as blue, green, red: + + png_set_bgr(png_ptr); + +PNG files describe monochrome as black being zero and white being +one. This code would be used if the pixels are supplied with this reversed +(black being one and white being zero): + + png_set_invert_mono(png_ptr); + +Finally, you can write your own transformation function if none of +the existing ones meets your needs. This is done by setting a callback +with + + png_set_write_user_transform_fn(png_ptr, + write_transform_fn); + +You must supply the function + + void write_transform_fn(png_ptr ptr, row_info_ptr + row_info, png_bytep data) + +See pngtest.c for a working example. Your function will be called +before any of the other transformations have been processed. + +It is possible to have libpng flush any pending output, either manually, +or automatically after a certain number of lines have been written. To +flush the output stream a single time call: + + png_write_flush(png_ptr); + +and to have libpng flush the output stream periodically after a certain +number of scanlines have been written, call: + + png_set_flush(png_ptr, nrows); + +Note that the distance between rows is from the last time png_write_flush() +was called, or the first row of the image if it has never been called. +So if you write 50 lines, and then png_set_flush 25, it will flush the +output on the next scanline, and every 25 lines thereafter, unless +png_write_flush() is called before 25 more lines have been written. +If nrows is too small (less than about 10 lines for a 640 pixel wide +RGB image) the image compression may decrease noticeably (although this +may be acceptable for real-time applications). Infrequent flushing will +only degrade the compression performance by a few percent over images +that do not use flushing. + +That's it for the transformations. Now you can write the image data. +The simplest way to do this is in one function call. If have the +whole image in memory, you can just call png_write_image() and libpng +will write the image. You will need to pass in an array of pointers to +each row. This function automatically handles interlacing, so you don't +need to call png_set_interlace_handling() or call this function multiple +times, or any of that other stuff necessary with png_write_rows(). + + png_write_image(png_ptr, row_pointers); + +where row_pointers is: + + png_bytef *row_pointers[height]; + +You can point to void or char or whatever you use for pixels. + +If you can't want to write the whole image at once, you can +use png_write_rows() instead. If the file is not interlaced, +this is simple: + + png_write_rows(png_ptr, row_pointers, + number_of_rows); + +row_pointers is the same as in the png_write_image() call. + +If you are just writing one row at a time, you can do this with +row_pointers: + + png_bytep row_pointer = row; + + png_write_row(png_ptr, &row_pointer); + +When the file is interlaced, things can get a good deal more +complicated. The only currently (as of February 1998 -- PNG Specification +version 1.0, dated October 1996) defined interlacing scheme for PNG files +is the "Adam7" interlace scheme, that breaks down an +image into seven smaller images of varying size. libpng will build +these images for you, or you can do them yourself. If you want to +build them yourself, see the PNG specification for details of which +pixels to write when. + +If you don't want libpng to handle the interlacing details, just +use png_set_interlace_handling() and call png_write_rows() the +correct number of times to write all seven sub-images. + +If you want libpng to build the sub-images, call this before you start +writing any rows: + + number_of_passes = + png_set_interlace_handling(png_ptr); + +This will return the number of passes needed. Currently, this +is seven, but may change if another interlace type is added. + +Then write the complete image number_of_passes times. + + png_write_rows(png_ptr, row_pointers, + number_of_rows); + +As some of these rows are not used, and thus return immediately, +you may want to read about interlacing in the PNG specification, +and only update the rows that are actually used. + +After you are finished writing the image, you should finish writing +the file. If you are interested in writing comments or time, you should +pass an appropriately filled png_info pointer. If you are not interested, +you can pass NULL. + + png_write_end(png_ptr, info_ptr); + +When you are done, you can free all memory used by libpng like this: + + png_destroy_write_struct(&png_ptr, &info_ptr); + +You must free any data you allocated for info_ptr, such as comments, +palette, or histogram, before the call to png_destroy_write_struct(); + +For a more compact example of writing a PNG image, see the file example.c. + + +V. Modifying/Customizing libpng: + +There are two issues here. The first is changing how libpng does +standard things like memory allocation, input/output, and error handling. +The second deals with more complicated things like adding new chunks, +adding new transformations, and generally changing how libpng works. + +All of the memory allocation, input/output, and error handling in libpng +goes through callbacks which are user settable. The default routines are +in pngmem.c, pngrio.c, pngwio.c, and pngerror.c respectively. To change +these functions, call the appropriate png_set_???_fn() function. + +Memory allocation is done through the functions png_large_malloc(), +png_malloc(), png_realloc(), png_large_free(), and png_free(). These +currently just call the standard C functions. The large functions must +handle exactly 64K, but they don't have to handle more than that. If +your pointers can't access more then 64K at a time, you will want to set +MAXSEG_64K in zlib.h. Since it is unlikely that the method of handling +memory allocation on a platform will change between applications, these +functions must be modified in the library at compile time. + +Input/Output in libpng is done through png_read() and png_write(), +which currently just call fread() and fwrite(). The FILE * is stored in +png_struct and is initialized via png_init_io(). If you wish to change +the method of I/O, the library supplies callbacks that you can set +through the function png_set_read_fn() and png_set_write_fn() at run +time, instead of calling the png_init_io() function. These functions +also provide a void pointer that can be retrieved via the function +png_get_io_ptr(). For example: + + png_set_read_fn(png_structp png_ptr, + voidp io_ptr, png_rw_ptr read_data_fn) + + png_set_write_fn(png_structp png_ptr, + voidp io_ptr, png_rw_ptr write_data_fn, + png_flush_ptr output_flush_fn); + + voidp io_ptr = png_get_io_ptr(png_ptr); + +The replacement I/O functions should have prototypes as follows: + + void user_read_data(png_structp png_ptr, + png_bytep data, png_uint_32 length); + void user_write_data(png_structp png_ptr, + png_bytep data, png_uint_32 length); + void user_flush_data(png_structp png_ptr); + +Supplying NULL for the read, write, or flush functions sets them back +to using the default C stream functions. It is an error to read from +a write stream, and vice versa. + +Error handling in libpng is done through png_error() and png_warning(). +Errors handled through png_error() are fatal, meaning that png_error() +should never return to its caller. Currently, this is handled via +setjmp() and longjmp(), but you could change this to do things like +exit() if you should wish. On non-fatal errors, png_warning() is called +to print a warning message, and then control returns to the calling code. +By default png_error() and png_warning() print a message on stderr via +fprintf() unless the library is compiled with PNG_NO_STDIO defined. If +you wish to change the behavior of the error functions, you will need to +set up your own message callbacks. These functions are normally supplied +at the time that the png_struct is created. It is also possible to change +these functions after png_create_???_struct() has been called by calling: + + png_set_error_fn(png_structp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, + png_error_ptr warning_fn); + + png_voidp error_ptr = png_get_error_ptr(png_ptr); + +If NULL is supplied for either error_fn or warning_fn, then the libpng +default function will be used, calling fprintf() and/or longjmp() if a +problem is encountered. The replacement error functions should have +parameters as follows: + + void user_error_fn(png_structp png_ptr, + png_const_charp error_msg); + void user_warning_fn(png_structp png_ptr, + png_const_charp warning_msg); + +The motivation behind using setjmp() and longjmp() is the C++ throw and +catch exception handling methods. This makes the code much easier to write, +as there is no need to check every return code of every function call. +However, there are some uncertainties about the status of local variables +after a longjmp, so the user may want to be careful about doing anything after +setjmp returns non-zero besides returning itself. Consult your compiler +documentation for more details. + +If you need to read or write custom chunks, you will need to get deeper +into the libpng code, as a mechanism has not yet been supplied for user +callbacks with custom chunks. First, read the PNG specification, and have +a first level of understanding of how it works. Pay particular attention +to the sections that describe chunk names, and look at how other chunks +were designed, so you can do things similarly. Second, check out the +sections of libpng that read and write chunks. Try to find a chunk that +is similar to yours and copy off of it. More details can be found in the +comments inside the code. A way of handling unknown chunks in a generic +method, potentially via callback functions, would be best. + +If you wish to write your own transformation for the data, look through +the part of the code that does the transformations, and check out some of +the simpler ones to get an idea of how they work. Try to find a similar +transformation to the one you want to add and copy off of it. More details +can be found in the comments inside the code itself. + +Configuring for 16 bit platforms: + +You may need to change the png_large_malloc() and png_large_free() +routines in pngmem.c, as these are required to allocate 64K, although +there is already support for many of the common DOS compilers. Also, +you will want to look into zconf.h to tell zlib (and thus libpng) that +it cannot allocate more then 64K at a time. Even if you can, the memory +won't be accessible. So limit zlib and libpng to 64K by defining MAXSEG_64K. + +Configuring for DOS: + +For DOS users which only have access to the lower 640K, you will +have to limit zlib's memory usage via a png_set_compression_mem_level() +call. See zlib.h or zconf.h in the zlib library for more information. + +Configuring for Medium Model: + +Libpng's support for medium model has been tested on most of the popular +compilers. Make sure MAXSEG_64K gets defined, USE_FAR_KEYWORD gets +defined, and FAR gets defined to far in pngconf.h, and you should be +all set. Everything in the library (except for zlib's structure) is +expecting far data. You must use the typedefs with the p or pp on +the end for pointers (or at least look at them and be careful). Make +note that the row's of data are defined as png_bytepp which is a +unsigned char far * far *. + +Configuring for gui/windowing platforms: + +You will need to write new error and warning functions that use the GUI +interface, as described previously, and set them to be the error and +warning functions at the time that png_create_???_struct() is called, +in order to have them available during the structure initialization. +They can be changed later via png_set_error_fn(). On some compilers, +you may also have to change the memory allocators (png_malloc, etc.). + +Configuring for compiler xxx: + +All includes for libpng are in pngconf.h. If you need to add/change/delete +an include, this is the place to do it. The includes that are not +needed outside libpng are protected by the PNG_INTERNAL definition, +which is only defined for those routines inside libpng itself. The +files in libpng proper only include png.h, which includes pngconf.h. + +Configuring zlib: + +There are special functions to configure the compression. Perhaps the +most useful one changes the compression level, which currently uses +input compression values in the range 0 - 9. The library normally +uses the default compression level (Z_DEFAULT_COMPRESSION = 6). Tests +have shown that for a large majority of images, compression values in +the range 3-6 compress nearly as well as higher levels, and do so much +faster. For online applications it may be desirable to have maximum speed +(Z_BEST_SPEED = 1). With versions of zlib after v0.99, you can also +specify no compression (Z_NO_COMPRESSION = 0), but this would create +files larger than just storing the raw bitmap. You can specify the +compression level by calling: + + png_set_compression_level(png_ptr, level); + +Another useful one is to reduce the memory level used by the library. +The memory level defaults to 8, but it can be lowered if you are +short on memory (running DOS, for example, where you only have 640K). + + png_set_compression_mem_level(png_ptr, level); + +The other functions are for configuring zlib. They are not recommended +for normal use and may result in writing an invalid PNG file. See +zlib.h for more information on what these mean. + + png_set_compression_strategy(png_ptr, + strategy); + png_set_compression_window_bits(png_ptr, + window_bits); + png_set_compression_method(png_ptr, method); + +Controlling row filtering: + +If you want to control whether libpng uses filtering or not, which +filters are used, and how it goes about picking row filters, you +can call one of these functions. The selection and configuration +of row filters can have a significant impact on the size and +encoding speed and a somewhat lesser impact on the decoding speed +of an image. Filtering is enabled by default for RGB and grayscale +images (with and without alpha), and for 8-bit paletted images, but +not for paletted images with bit depths less than 8 bits/pixel. + +The 'method' parameter sets the main filtering method, which is +currently only '0' in the PNG 1.0 specification. The 'filters' +parameter sets which filter(s), if any, should be used for each +scanline. Possible values are PNG_ALL_FILTERS and PNG_NO_FILTERS +to turn filtering on and off, respectively. + +Individual filter types are PNG_FILTER_NONE, PNG_FILTER_SUB, +PNG_FILTER_UP, PNG_FILTER_AVG, PNG_FILTER_PAETH, which can be bitwise +ORed together '|' to specify one or more filters to use. These +filters are described in more detail in the PNG specification. If +you intend to change the filter type during the course of writing +the image, you should start with flags set for all of the filters +you intend to use so that libpng can initialize its internal +structures appropriately for all of the filter types. + + filters = PNG_FILTER_NONE | PNG_FILTER_SUB + | PNG_FILTER_UP; + png_set_filter(png_ptr, PNG_FILTER_TYPE_BASE, + filters); + +It is also possible to influence how libpng chooses from among the +available filters. This is done in two ways - by telling it how +important it is to keep the same filter for successive rows, and +by telling it the relative computational costs of the filters. + + double weights[3] = {1.5, 1.3, 1.1}, + costs[PNG_FILTER_VALUE_LAST] = + {1.0, 1.3, 1.3, 1.5, 1.7}; + + png_set_filter_selection(png_ptr, + PNG_FILTER_SELECTION_WEIGHTED, 3, + weights, costs); + +The weights are multiplying factors which indicate to libpng that row +should be the same for successive rows unless another row filter is that +many times better than the previous filter. In the above example, if +the previous 3 filters were SUB, SUB, NONE, the SUB filter could have a +"sum of absolute differences" 1.5 x 1.3 times higher than other filters +and still be chosen, while the NONE filter could have a sum 1.1 times +higher than other filters and still be chosen. Unspecified weights are +taken to be 1.0, and the specified weights should probably be declining +like those above in order to emphasize recent filters over older filters. + +The filter costs specify for each filter type a relative decoding cost +to be considered when selecting row filters. This means that filters +with higher costs are less likely to be chosen over filters with lower +costs, unless their "sum of absolute differences" is that much smaller. +The costs do not necessarily reflect the exact computational speeds of +the various filters, since this would unduly influence the final image +size. + +Note that the numbers above were invented purely for this example and +are given only to help explain the function usage. Little testing has +been done to find optimum values for either the costs or the weights. + +Removing unwanted object code: + +There are a bunch of #define's in pngconf.h that control what parts of +libpng are compiled. All the defines end in _SUPPORTED. If you are +never going to use an ability, you can change the #define to #undef +before recompiling libpng and save yourself code and data space. +You can also turn a number of them off en masse with a compiler directive +that defines PNG_READ[or WRITE]_TRANSFORMS_NOT_SUPPORTED, or +PNG_READ[or WRITE]_ANCILLARY_CHUNKS_NOT_SUPPORTED, or all four, +along with directives to turn on any of the capabilities that you do +want. The PNG_READ[or WRITE]_TRANSFORMS_NOT_SUPPORTED directives disable +the extra transformations but still leave the library fully capable of reading +and writing PNG files with all known public chunks [except for sPLT]. +Use of the PNG_READ[or WRITE]_ANCILLARY_CHUNKS_NOT_SUPPORTED directive +produces a library that is incapable of reading or writing ancillary chunks. +If you are not using the progressive reading capability, you can +turn that off with PNG_PROGRESSIVE_READ_NOT_SUPPORTED (don't confuse +this with the INTERLACING capability, which you'll still have). + +All the reading and writing specific code are in separate files, so the +linker should only grab the files it needs. However, if you want to +make sure, or if you are building a stand alone library, all the +reading files start with pngr and all the writing files start with +pngw. The files that don't match either (like png.c, pngtrans.c, etc.) +are used for both reading and writing, and always need to be included. +The progressive reader is in pngpread.c + +If you are creating or distributing a dynamically linked library (a .so +or DLL file), you should not remove or disable any parts of the library, +as this will cause applications linked with different versions of the +library to fail if they call functions not available in your library. +The size of the library itself should not be an issue, because only +those sections which are actually used will be loaded into memory. + + +Changes to Libpng from version 0.88 + +It should be noted that versions of libpng later than 0.96 are not +distributed by the original libpng author, Guy Schalnat, nor by +Andreas Dilger, who had taken over from Guy during 1996 and 1997, and +distributed versions 0.89 through 0.96, but rather by another member +of the original PNG Group, Glenn Randers-Pehrson. Guy and Andreas are +still alive and well, but they have moved on to other things. + +The old libpng functions png_read_init(), png_write_init(), +png_info_init(), png_read_destroy(), and png_write_destory() have been +moved to PNG_INTERNAL in version 0.95 to discourage their use. The +preferred method of creating and initializing the libpng structures is +via the png_create_read_struct(), png_create_write_struct(), and +png_create_info_struct() because they isolate the size of the structures +from the application, allow version error checking, and also allow the +use of custom error handling routines during the initialization, which +the old functions do not. The functions png_read_destroy() and +png_write_destroy() do not actually free the memory that libpng +allocated for these structs, but just reset the data structures, so they +can be used instead of png_destroy_read_struct() and +png_destroy_write_struct() if you feel there is too much system overhead +allocating and freeing the png_struct for each image read. + +Setting the error callbacks via png_set_message_fn() before +png_read_init() as was suggested in libpng-0.88 is no longer supported +because this caused applications which do not use custom error functions +to fail if the png_ptr was not initialized to zero. It is still possible +to set the error callbacks AFTER png_read_init(), or to change them with +png_set_error_fn(), which is essentially the same function, but with a +new name to force compilation errors with applications that try to use +the old method. + diff --git a/thirdparty/libpng/libpngpf.3 b/thirdparty/libpng/libpngpf.3 new file mode 100644 index 00000000..00730b90 --- /dev/null +++ b/thirdparty/libpng/libpngpf.3 @@ -0,0 +1,342 @@ +.TH LIBPNGPF 3 "March 9, 1998" +.SH NAME +libpng \- Portable Network Graphics (PNG) Reference Library +(private functions) +.SH SYNOPSIS +#include + +void png_build_gamma_table (png_structp png_ptr); + +void png_build_grayscale_palette (int bit_depth, png_colorp +palette); + +void png_calculate_crc (png_structp png_ptr, png_bytep ptr, +png_size_t length); +void png_check_chunk_name (png_structp png_ptr, png_bytep +chunk_name); + +png_size_t png_check_keyword (png_structp png_ptr, png_charp +key, png_charpp new_key); + +void png_combine_row (png_structp png_ptr, png_bytep row, int +mask); + +void png_correct_palette (png_structp png_ptr, png_colorp +palette, int num_palette); + +int png_crc_error (png_structp png_ptr); + +int png_crc_finish (png_structp png_ptr, png_uint_32 skip); + +void png_crc_read (png_structp png_ptr, png_bytep buf, +png_size_t length); + +png_voidp png_create_struct (int type); + +void png_destroy_struct (png_voidp struct_ptr); + +void png_do_background (png_row_infop row_info, png_bytep row, +png_color_16p trans_values, png_color_16p background, +png_color_16p background_1, png_bytep gamma_table, png_bytep +gamma_from_1, png_bytep gamma_to_1, png_uint_16pp gamma_16, +png_uint_16pp gamma_16_from_1, png_uint_16pp gamma_16_to_1, int +gamma_shift); + +void png_do_bgr (png_row_infop row_info, png_bytep row); + +void png_do_chop (png_row_infop row_info, png_bytep row); + +void png_do_dither (png_row_infop row_info, png_bytep row, +png_bytep palette_lookup, png_bytep dither_lookup); + +void png_do_expand (png_row_infop row_info, png_bytep row, +png_color_16p trans_value); + +void png_do_expand_palette (png_row_infop row_info, png_bytep +row, png_colorp palette, png_bytep trans, int num_trans); + +void png_do_gamma (png_row_infop row_info, png_bytep row, +png_bytep gamma_table, png_uint_16pp gamma_16_table, int +gamma_shift); + +void png_do_gray_to_rgb (png_row_infop row_info, png_bytep +row); + +void png_do_invert (png_row_infop row_info, png_bytep row); + +void png_do_pack (png_row_infop row_info, png_bytep row, +png_uint_32 bit_depth); + +void png_do_packswap (png_row_infop row_info, png_bytep row); + +void png_do_read_filler (png_row_infop row_info, png_bytep row, +png_uint_32 filler, png_uint_32 flags); + +void png_do_read_interlace (png_row_infop row_info, png_bytep +row, int pass, png_uint_32 transformations); + +void png_do_read_invert_alpha (png_row_infop row_info, +png_bytep row); + +void png_do_read_swap_alpha (png_row_infop row_info, png_bytep +row); + +void png_do_read_transformations (png_structp png_ptr); + +void png_do_rgb_to_gray (png_row_infop row_info, png_bytep +row); + +void png_do_shift (png_row_infop row_info, png_bytep row, +png_color_8p bit_depth); + +void png_do_strip_filler (png_row_infop row_info, png_bytep +row, png_uint_32 flags); + +void png_do_swap (png_row_infop row_info, png_bytep row); + +void png_do_unpack (png_row_infop row_info, png_bytep row); + +void png_do_unshift (png_row_infop row_info, png_bytep row, +png_color_8p sig_bits); + +void png_do_write_interlace (png_row_infop row_info, png_bytep +row, int pass); + +void png_do_write_invert_alpha (png_row_infop row_info, +png_bytep row); + +void png_do_write_swap_alpha (png_row_infop row_info, png_bytep +row); + +void png_do_write_transformations (png_structp png_ptr); + +void *png_far_to_near (png_structp png_ptr,png_voidp ptr, +int check); + +void png_flush (png_structp png_ptr); + +png_int_32 png_get_int_32 (png_bytep buf); + +png_uint_16 png_get_uint_16 (png_bytep buf); + +png_uint_32 png_get_uint_32 (png_bytep buf); + +void png_handle_bKGD (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_cHRM (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_gAMA (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_hIST (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_IEND (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_IHDR (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_oFFs (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_pCAL (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_pHYs (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_PLTE (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_sBIT (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_sRGB (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_tEXt (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_tIME (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_tRNS (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_handle_unknown (png_structp png_ptr, png_infop +info_ptr, png_uint_32 length); + +void png_handle_zTXt (png_structp png_ptr, png_infop info_ptr, +png_uint_32 length); + +void png_info_destroy (png_structp png_ptr, png_infop +info_ptr); + +void png_init_read_transformations (png_structp png_ptr); + +void png_process_IDAT_data (png_structp png_ptr, png_bytep +buffer, png_size_t buffer_length); + +void png_process_some_data (png_structp png_ptr, png_infop +info_ptr); + +void png_push_check_crc (png_structp png_ptr); + +void png_push_crc_finish (png_structp png_ptr); + +void png_push_crc_skip (png_structp png_ptr, png_uint_32 +length); + +void png_push_fill_buffer (png_structp png_ptr, png_bytep +buffer, png_size_t length); + +void png_push_handle_tEXt (png_structp png_ptr, png_infop +info_ptr, png_uint_32 length); + +void png_push_handle_unknown (png_structp png_ptr, png_infop +info_ptr, png_uint_32 length); + +void png_push_handle_zTXt (png_structp png_ptr, png_infop +info_ptr, png_uint_32 length); + +void png_push_have_end (png_structp png_ptr, png_infop +info_ptr); + +void png_push_have_info (png_structp png_ptr, png_infop +info_ptr); + +void png_push_have_row (png_structp png_ptr, png_bytep row); + +void png_push_process_row (png_structp png_ptr); + +void png_push_read_chunk (png_structp png_ptr, png_infop +info_ptr); + +void png_push_read_end (png_structp png_ptr, png_infop +info_ptr); + +void png_push_read_IDAT (png_structp png_ptr); + +void png_push_read_sig (png_structp png_ptr, png_infop +info_ptr); + +void png_push_read_tEXt (png_structp png_ptr, png_infop +info_ptr); + +void png_push_read_zTXt (png_structp png_ptr, png_infop +info_ptr); + +void png_push_restore_buffer (png_structp png_ptr, png_bytep +buffer, png_size_t buffer_length); + +void png_push_save_buffer (png_structp png_ptr); + +void png_read_data (png_structp png_ptr, png_bytep data, +png_size_t length); + +void png_read_filter_row (png_structp png_ptr, png_row_infop +row_info, png_bytep row, png_bytep prev_row, int filter); + +void png_read_finish_row (png_structp png_ptr); + +void png_read_init (png_structp png_ptr); + +void png_read_push_finish_row (png_structp png_ptr); + +void png_read_start_row (png_structp png_ptr); + +void png_read_transform_info (png_structp png_ptr, png_infop +info_ptr); + +void png_reset_crc (png_structp png_ptr); + +void png_save_int_32 (png_bytep buf, png_int_32 i); + +void png_save_uint_16 (png_bytep buf, unsigned int i); + +void png_save_uint_32 (png_bytep buf, png_uint_32 i); + +void png_write_bKGD (png_structp png_ptr, png_color_16p values, +int color_type); + +void png_write_cHRM (png_structp png_ptr, double white_x, +double white_y, double red_x, double red_y, double green_x, +double green_y, double blue_x, double blue_y); + +void png_write_data (png_structp png_ptr, png_bytep data, +png_size_t length); +void png_write_filtered_row (png_structp png_ptr, png_bytep +filtered_row); + +void png_write_find_filter (png_structp png_ptr, png_row_infop +row_info); + +void png_write_finish_row (png_structp png_ptr); + +void png_write_gAMA (png_structp png_ptr, double file_gamma); + +void png_write_hIST (png_structp png_ptr, png_uint_16p hist, +int num_hist); + +void png_write_init (png_structp png_ptr); + +void png_write_IDAT (png_structp png_ptr, png_bytep data, +png_size_t length); + +void png_write_IEND (png_structp png_ptr); + +void png_write_IHDR (png_structp png_ptr, png_uint_32 width, +png_uint_32 height, int bit_depth, int color_type, int +compression_type, int filter_type, int interlace_type); + +void png_write_oFFs (png_structp png_ptr, png_uint_32 x_offset, +png_uint_32 y_offset, int unit_type); + +void png_write_pCAL (png_structp png_ptr, png_charp purpose, +png_int_32 X0, png_int_32 X1, int type, int nparams, png_charp +units, png_charpp params); + +void png_write_pHYs (png_structp png_ptr, png_uint_32 +x_pixels_per_unit, png_uint_32 y_pixels_per_unit, int +unit_type); + +void png_write_PLTE (png_structp png_ptr, png_colorp palette, +png_uint_32 num_pal); + +void png_write_sBIT (png_structp png_ptr, png_color_8p sbit, +int color_type); + +void png_write_sig (png_structp png_ptr); + +void png_write_sRGB (png_structp png_ptr, int intent); + +void png_write_start_row (png_structp png_ptr); + +void png_write_tEXt (png_structp png_ptr, png_charp key, +png_charp text, png_size_t text_len); + +void png_write_tIME (png_structp png_ptr, png_timep mod_time); + +void png_write_tRNS (png_structp png_ptr, png_bytep trans, +png_color_16p values, int number, int color_type); + +void png_write_zTXt (png_structp png_ptr, png_charp key, +png_charp text, png_size_t text_len, int compression); + +voidpf png_zalloc (voidpf png_ptr, uInt items, uInt size); + +void png_zfree (voidpf png_ptr, voidpf ptr); + +.SH DESCRIPTION +The functions listed above are used privately by libpng +and are not recommended for use by applications. They +are listed alphabetically here as an aid to libpng maintainers. +See png.h for more information on these functions. + +.SH SEE ALSO +libpng(3), png(5) +.SH AUTHOR +Glenn Randers-Pehrson diff --git a/thirdparty/libpng/makefile b/thirdparty/libpng/makefile new file mode 100644 index 00000000..7cc60599 --- /dev/null +++ b/thirdparty/libpng/makefile @@ -0,0 +1,68 @@ +# makefile for libpng +# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc. +# For conditions of distribution and use, see copyright notice in png.h + +# Where the zlib library and include files are located +#ZLIBLIB=/usr/local/lib +#ZLIBINC=/usr/local/include +ZLIBLIB=../zlib +ZLIBINC=../zlib + +CC=cc +CFLAGS=-I$(ZLIBINC) -O # -g -DPNG_DEBUG=1 +LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm + +#RANLIB=echo +RANLIB=ranlib + +# where make install puts libpng.a and png.h +prefix=/usr/local + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \ + pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \ + pngwtran.o pngmem.o pngerror.o pngpread.o + +all: libpng.a pngtest + +libpng.a: $(OBJS) + ar rc $@ $(OBJS) + $(RANLIB) $@ + +pngtest: pngtest.o libpng.a + $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS) + +test: pngtest + ./pngtest + +install: libpng.a + -@mkdir $(prefix)/include + -@mkdir $(prefix)/lib + cp png.h $(prefix)/include + cp pngconf.h $(prefix)/include + chmod 644 $(prefix)/include/png.h + chmod 644 $(prefix)/include/pngconf.h + cp libpng.a $(prefix)/lib + chmod 644 $(prefix)/lib/libpng.a + +clean: + rm -f *.o libpng.a pngtest pngout.png + +# DO NOT DELETE THIS LINE -- make depend depends on it. + +png.o: png.h pngconf.h +pngerror.o: png.h pngconf.h +pngrio.o: png.h pngconf.h +pngwio.o: png.h pngconf.h +pngmem.o: png.h pngconf.h +pngset.o: png.h pngconf.h +pngget.o: png.h pngconf.h +pngread.o: png.h pngconf.h +pngrtran.o: png.h pngconf.h +pngrutil.o: png.h pngconf.h +pngtest.o: png.h pngconf.h +pngtrans.o: png.h pngconf.h +pngwrite.o: png.h pngconf.h +pngwtran.o: png.h pngconf.h +pngwutil.o: png.h pngconf.h +pngpread.o: png.h pngconf.h + diff --git a/thirdparty/libpng/png.5 b/thirdparty/libpng/png.5 new file mode 100644 index 00000000..0ba9dfff --- /dev/null +++ b/thirdparty/libpng/png.5 @@ -0,0 +1,44 @@ +.TH PNG 5 "March 9, 1998" +.SH NAME +png \- Portable Network Graphics (PNG) format +.SH DESCRIPTION +PNG (Portable Network Graphics) is an extensible file format for the +lossless, portable, well-compressed storage of raster images. PNG provides +a patent-free replacement for GIF and can also replace many +common uses of TIFF. Indexed-color, grayscale, and truecolor images are +supported, plus an optional alpha channel. Sample depths range from +1 to 16 bits. +.br + +PNG is designed to work well in online viewing applications, such as the +World Wide Web, so it is fully streamable with a progressive display +option. PNG is robust, providing both full file integrity checking and +fast, simple detection of common transmission errors. Also, PNG can store +gamma and chromaticity data for improved color matching on heterogeneous +platforms. + +.SH "SEE ALSO" +.IR libpng(3), zlib(3), deflate(5), and zlib(5) +.LP +PNG specification: +RFC 2083 +.IP +.br +ftp://ds.internic.net/rfc/rfc2083.txt +.br +or (as a W3C Recommendation) at +.br +http://www.w3.org/TR/REC-png.html +.SH AUTHORS +This man page: Glenn Randers-Pehrson +.LP +Portable Network Graphics (PNG) Specification Version 1.0 (October 1, 1996): +Thomas Boutell and others (png-list@dworkin.wustl.edu). +.LP + +.SH COPYRIGHT NOTICE +The PNG specification is copyright (c) 1996 Massachussets Institute of +Technology. See the specification for conditions of use and distribution. +.LP +.\" end of man page + diff --git a/thirdparty/libpng/png.c b/thirdparty/libpng/png.c new file mode 100644 index 00000000..52723df0 --- /dev/null +++ b/thirdparty/libpng/png.c @@ -0,0 +1,304 @@ + +/* png.c - location for general purpose libpng functions + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + */ + +#define PNG_INTERNAL +#define PNG_NO_EXTERN +#include "png.h" + +/* Version information for C files. This had better match the version + * string defined in png.h. + */ +char png_libpng_ver[6] = "1.0.1"; + +/* Place to hold the signature string for a PNG file. */ +png_byte FARDATA png_sig[8] = {137, 80, 78, 71, 13, 10, 26, 10}; + +/* Constant strings for known chunk types. If you need to add a chunk, + * add a string holding the name here. If you want to make the code + * portable to EBCDIC machines, use ASCII numbers, not characters. + */ +png_byte FARDATA png_IHDR[5] = { 73, 72, 68, 82, '\0'}; +png_byte FARDATA png_IDAT[5] = { 73, 68, 65, 84, '\0'}; +png_byte FARDATA png_IEND[5] = { 73, 69, 78, 68, '\0'}; +png_byte FARDATA png_PLTE[5] = { 80, 76, 84, 69, '\0'}; +png_byte FARDATA png_bKGD[5] = { 98, 75, 71, 68, '\0'}; +png_byte FARDATA png_cHRM[5] = { 99, 72, 82, 77, '\0'}; +png_byte FARDATA png_gAMA[5] = {103, 65, 77, 65, '\0'}; +png_byte FARDATA png_hIST[5] = {104, 73, 83, 84, '\0'}; +png_byte FARDATA png_oFFs[5] = {111, 70, 70, 115, '\0'}; +png_byte FARDATA png_pCAL[5] = {112, 67, 65, 76, '\0'}; +png_byte FARDATA png_pHYs[5] = {112, 72, 89, 115, '\0'}; +png_byte FARDATA png_sBIT[5] = {115, 66, 73, 84, '\0'}; +png_byte FARDATA png_sRGB[5] = {115, 82, 71, 66, '\0'}; +png_byte FARDATA png_tEXt[5] = {116, 69, 88, 116, '\0'}; +png_byte FARDATA png_tIME[5] = {116, 73, 77, 69, '\0'}; +png_byte FARDATA png_tRNS[5] = {116, 82, 78, 83, '\0'}; +png_byte FARDATA png_zTXt[5] = {122, 84, 88, 116, '\0'}; + +/* arrays to facilitate easy interlacing - use pass (0 - 6) as index */ + +/* start of interlace block */ +int FARDATA png_pass_start[] = {0, 4, 0, 2, 0, 1, 0}; + +/* offset to next interlace block */ +int FARDATA png_pass_inc[] = {8, 8, 4, 4, 2, 2, 1}; + +/* start of interlace block in the y direction */ +int FARDATA png_pass_ystart[] = {0, 0, 4, 0, 2, 0, 1}; + +/* offset to next interlace block in the y direction */ +int FARDATA png_pass_yinc[] = {8, 8, 8, 4, 4, 2, 2}; + +/* Width of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h +int FARDATA png_pass_width[] = {8, 4, 4, 2, 2, 1, 1}; +*/ + +/* Height of interlace block. This is not currently used - if you need + * it, uncomment it here and in png.h +int FARDATA png_pass_height[] = {8, 8, 4, 4, 2, 2, 1}; +*/ + +/* Mask to determine which pixels are valid in a pass */ +int FARDATA png_pass_mask[] = {0x80, 0x08, 0x88, 0x22, 0xaa, 0x55, 0xff}; + +/* Mask to determine which pixels to overwrite while displaying */ +int FARDATA png_pass_dsp_mask[] = {0xff, 0x0f, 0xff, 0x33, 0xff, 0x55, 0xff}; + + +/* Tells libpng that we have already handled the first "num_bytes" bytes + * of the PNG file signature. If the PNG data is embedded into another + * stream we can set num_bytes = 8 so that libpng will not attempt to read + * or write any of the magic bytes before it starts on the IHDR. + */ +void +png_set_sig_bytes(png_structp png_ptr, int num_bytes) +{ + png_debug(1, "in png_set_sig_bytes\n"); + if (num_bytes > 8) + png_error(png_ptr, "Too many bytes for PNG signature."); + + png_ptr->sig_bytes = num_bytes < 0 ? 0 : num_bytes; +} + +/* Checks whether the supplied bytes match the PNG signature. We allow + * checking less than the full 8-byte signature so that those apps that + * already read the first few bytes of a file to determine the file type + * can simply check the remaining bytes for extra assurance. Returns + * an integer less than, equal to, or greater than zero if sig is found, + * respectively, to be less than, to match, or be greater than the correct + * PNG signature (this is the same behaviour as strcmp, memcmp, etc). + */ +int +png_sig_cmp(png_bytep sig, png_size_t start, png_size_t num_to_check) +{ + if (num_to_check > 8) + num_to_check = 8; + else if (num_to_check < 1) + return (0); + + if (start > 7) + return (0); + + if (start + num_to_check > 8) + num_to_check = 8 - start; + + return ((int)(png_memcmp(&sig[start], &png_sig[start], num_to_check))); +} + +/* (Obsolete) function to check signature bytes. It does not allow one + * to check a partial signature. This function will be removed in the + * future - use png_sig_cmp(). + */ +int +png_check_sig(png_bytep sig, int num) +{ + return ((int)!png_sig_cmp(sig, (png_size_t)0, (png_size_t)num)); +} + +/* Function to allocate memory for zlib. */ +voidpf +png_zalloc(voidpf png_ptr, uInt items, uInt size) +{ + png_voidp ptr; + png_uint_32 num_bytes; + + num_bytes = (png_uint_32)items * size; + ptr = (png_voidp)png_malloc((png_structp)png_ptr, num_bytes); + if (num_bytes > (png_uint_32)0x8000) + { + png_memset(ptr, 0, (png_size_t)0x8000L); + png_memset((png_bytep)ptr + (png_size_t)0x8000L, 0, + (png_size_t)(num_bytes - (png_uint_32)0x8000L)); + } + else + { + png_memset(ptr, 0, (png_size_t)num_bytes); + } + return ((voidpf)ptr); +} + +/* function to free memory for zlib */ +void +png_zfree(voidpf png_ptr, voidpf ptr) +{ + png_free((png_structp)png_ptr, (png_voidp)ptr); +} + +/* Reset the CRC variable to 32 bits of 1's. Care must be taken + * in case CRC is > 32 bits to leave the top bits 0. + */ +void +png_reset_crc(png_structp png_ptr) +{ + png_ptr->crc = crc32(0, Z_NULL, 0); +} + +/* Calculate the CRC over a section of data. We can only pass as + * much data to this routine as the largest single buffer size. We + * also check that this data will actually be used before going to the + * trouble of calculating it. + */ +void +png_calculate_crc(png_structp png_ptr, png_bytep ptr, png_size_t length) +{ + int need_crc = 1; + + if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + else /* critical */ + { + if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) + need_crc = 0; + } + + if (need_crc) + png_ptr->crc = crc32(png_ptr->crc, ptr, (uInt)length); +} + +/* Allocate the memory for an info_struct for the application. We don't + * really need the png_ptr, but it could potentially be useful in the + * future. This should be used in favour of malloc(sizeof(png_info)) + * and png_info_init() so that applications that want to use a shared + * libpng don't have to be recompiled if png_info changes size. + */ +png_infop +png_create_info_struct(png_structp png_ptr) +{ + png_infop info_ptr; + + png_debug(1, "in png_create_info_struct\n"); + if(png_ptr == NULL) return (NULL); + if ((info_ptr = (png_infop)png_create_struct(PNG_STRUCT_INFO)) != NULL) + { + png_info_init(info_ptr); + } + + return (info_ptr); +} + +/* This function frees the memory associated with a single info struct. + * Normally, one would use either png_destroy_read_struct() or + * png_destroy_write_struct() to free an info struct, but this may be + * useful for some applications. + */ +void +png_destroy_info_struct(png_structp png_ptr, png_infopp info_ptr_ptr) +{ + png_infop info_ptr = NULL; + + png_debug(1, "in png_destroy_info_struct\n"); + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (info_ptr != NULL) + { + png_info_destroy(png_ptr, info_ptr); + + png_destroy_struct((png_voidp)info_ptr); + *info_ptr_ptr = (png_infop)NULL; + } +} + +/* Initialize the info structure. This is now an internal function (0.89) + * and applications using it are urged to use png_create_info_struct() + * instead. + */ +void +png_info_init(png_infop info_ptr) +{ + png_debug(1, "in png_info_init\n"); + /* set everything to 0 */ + png_memset(info_ptr, 0, sizeof (png_info)); +} + +/* This is an internal routine to free any memory that the info struct is + * pointing to before re-using it or freeing the struct itself. Recall + * that png_free() checks for NULL pointers for us. + */ +void +png_info_destroy(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) + int i; + + png_debug(1, "in png_info_destroy\n"); + if (info_ptr->text != NULL) + { + for (i = 0; i < info_ptr->num_text; i++) + { + png_free(png_ptr, info_ptr->text[i].key); + } + png_free(png_ptr, info_ptr->text); + } +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + png_free(png_ptr, info_ptr->pcal_purpose); + png_free(png_ptr, info_ptr->pcal_units); + if (info_ptr->pcal_params != NULL) + { + for (i = 0; i < (int)info_ptr->pcal_nparams; i++) + { + png_free(png_ptr, info_ptr->pcal_params[i]); + } + png_free(png_ptr, info_ptr->pcal_params); + } +#endif + + png_info_init(info_ptr); +} + +/* This function returns a pointer to the io_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy() or png_read_destroy() are called. + */ +png_voidp +png_get_io_ptr(png_structp png_ptr) +{ + return (png_ptr->io_ptr); +} + +#if !defined(PNG_NO_STDIO) +/* Initialize the default input/output functions for the PNG file. If you + * use your own read or write routines, you can call either png_set_read_fn() + * or png_set_write_fn() instead of png_init_io(). + */ +void +png_init_io(png_structp png_ptr, FILE *fp) +{ + png_debug(1, "in png_init_io\n"); + png_ptr->io_ptr = (png_voidp)fp; +} +#endif diff --git a/thirdparty/libpng/png.h b/thirdparty/libpng/png.h new file mode 100644 index 00000000..5922edd6 --- /dev/null +++ b/thirdparty/libpng/png.h @@ -0,0 +1,2056 @@ + +/* png.h - header file for PNG reference library + * + * libpng 1.0.1 + * For conditions of distribution and use, see the COPYRIGHT NOTICE below. + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998 Glenn Randers-Pehrson + * March 9, 1998 + * + * Note about libpng version numbers: + * + * Due to various miscommunications, unforeseen code incompatibilities + * and occasional factors outside the authors' control, version numbering + * on the library has not always been consistent and straightforward. + * The following table summarizes matters since version 0.89c, which was + * the first widely used release: + * + * source png.h shared-lib + * version string version + * ------- ------ ---------- + * 0.89c ("1.0 beta 3") 0.89 1.0.89 + * 0.90 ("1.0 beta 4") 0.90 0.90 [should have been 2.0.90] + * 0.95 ("1.0 beta 5") 0.95 0.95 [should have been 2.0.95] + * 0.96 ("1.0 beta 6") 0.96 0.96 [should have been 2.0.96] + * 0.97b ("1.00.97 beta 7") 1.00.97 1.0.1 [should have been 2.0.97] + * 0.97c 0.97 2.0.97 + * 0.98 0.98 2.0.98 + * 0.99 0.99 2.0.99 + * 0.99a-m 0.99 2.0.99 + * 1.0.1 1.00 2.1.0 + * + * Henceforth the source version will match the shared-library minor + * and patch numbers; the shared-library major version number will be + * used for changes in backward compatibility, as it is intended. + * + * See libpng.txt for more information. The PNG specification is available + * as RFC 2083 + * and as a W3C Recommendation + * + * Contributing Authors: + * John Bowler + * Kevin Bracey + * Sam Bushell + * Andreas Dilger + * Magnus Holmgren + * Tom Lane + * Dave Martindale + * Glenn Randers-Pehrson + * Greg Roelofs + * Guy Eric Schalnat + * Paul Schmidt + * Tom Tanner + * Willem van Schaik + * Tim Wegner + * + * The contributing authors would like to thank all those who helped + * with testing, bug fixes, and patience. This wouldn't have been + * possible without all of you. + * + * Thanks to Frank J. T. Wojcik for helping with the documentation. + * + * COPYRIGHT NOTICE: + * + * The PNG Reference Library is supplied "AS IS". The Contributing Authors + * and Group 42, Inc. disclaim all warranties, expressed or implied, + * including, without limitation, the warranties of merchantability and of + * fitness for any purpose. The Contributing Authors and Group 42, Inc. + * assume no liability for direct, indirect, incidental, special, exemplary, + * or consequential damages, which may result from the use of the PNG + * Reference Library, even if advised of the possibility of such damage. + * + * Permission is hereby granted to use, copy, modify, and distribute this + * source code, or portions hereof, for any purpose, without fee, subject + * to the following restrictions: + * 1. The origin of this source code must not be misrepresented. + * 2. Altered versions must be plainly marked as such and must not be + * misrepresented as being the original source. + * 3. This Copyright notice may not be removed or altered from any source or + * altered source distribution. + * + * The Contributing Authors and Group 42, Inc. specifically permit, without + * fee, and encourage the use of this source code as a component to + * supporting the PNG file format in commercial products. If you use this + * source code in a product, acknowledgment is not required but would be + * appreciated. + */ + +#ifndef _PNG_H +#define _PNG_H + +#ifdef __cplusplus +extern "C" { +#endif /* __cplusplus */ + +/* This is not the place to learn how to use libpng. The file libpng.txt + * describes how to use libpng, and the file example.c summarizes it + * with some code on which to build. This file is useful for looking + * at the actual function definitions and structure components. + */ + +/* include the compression library's header */ +#include "zlib.h" + +/* include all user configurable info */ +#include "pngconf.h" + +/* This file is arranged in several sections. The first section contains + * structure and type definitions. The second section contains the external + * library functions, while the third has the internal library functions, + * which applications aren't expected to use directly. + */ + +/* Version information for png.h - this should match the version in png.c */ +#define PNG_LIBPNG_VER_STRING "1.0.1" + +/* careful here. At one time, I wanted to use 082, but that would be octal. + * We must not include leading blanks. + * Versions 0.7 through 1.0.0 were in the range 0 to 100 here. From + * version 1.0.1 it's xxxyyyzzzzL, where x=major, y=minor, z-bugfix*/ +#define PNG_LIBPNG_VER 10000001L + +/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */ +#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN) +/* Version information for C files, stored in png.c. This had better match + * the version above. + */ +extern char png_libpng_ver[6]; + +/* Structures to facilitate easy interlacing. See png.c for more details */ +extern int FARDATA png_pass_start[7]; +extern int FARDATA png_pass_inc[7]; +extern int FARDATA png_pass_ystart[7]; +extern int FARDATA png_pass_yinc[7]; +extern int FARDATA png_pass_mask[7]; +extern int FARDATA png_pass_dsp_mask[7]; +/* These aren't currently used. If you need them, see png.c for more details +extern int FARDATA png_pass_width[7]; +extern int FARDATA png_pass_height[7]; +*/ +#endif /* PNG_NO_EXTERN */ + +/* Three color definitions. The order of the red, green, and blue, (and the + * exact size) is not important, although the size of the fields need to + * be png_byte or png_uint_16 (as defined below). + */ +typedef struct png_color_struct +{ + png_byte red; + png_byte green; + png_byte blue; +} png_color; +typedef png_color FAR * png_colorp; +typedef png_color FAR * FAR * png_colorpp; + +typedef struct png_color_16_struct +{ + png_byte index; /* used for palette files */ + png_uint_16 red; /* for use in red green blue files */ + png_uint_16 green; + png_uint_16 blue; + png_uint_16 gray; /* for use in grayscale files */ +} png_color_16; +typedef png_color_16 FAR * png_color_16p; +typedef png_color_16 FAR * FAR * png_color_16pp; + +typedef struct png_color_8_struct +{ + png_byte red; /* for use in red green blue files */ + png_byte green; + png_byte blue; + png_byte gray; /* for use in grayscale files */ + png_byte alpha; /* for alpha channel files */ +} png_color_8; +typedef png_color_8 FAR * png_color_8p; +typedef png_color_8 FAR * FAR * png_color_8pp; + +/* png_text holds the text in a PNG file, and whether they are compressed + in the PNG file or not. The "text" field points to a regular C string. */ +typedef struct png_text_struct +{ + int compression; /* compression value, see PNG_TEXT_COMPRESSION_ */ + png_charp key; /* keyword, 1-79 character description of "text" */ + png_charp text; /* comment, may be an empty string (ie "") */ + png_size_t text_length; /* length of "text" field */ +} png_text; +typedef png_text FAR * png_textp; +typedef png_text FAR * FAR * png_textpp; + +/* Supported compression types for text in PNG files (tEXt, and zTXt). + * The values of the PNG_TEXT_COMPRESSION_ defines should NOT be changed. */ +#define PNG_TEXT_COMPRESSION_NONE_WR -3 +#define PNG_TEXT_COMPRESSION_zTXt_WR -2 +#define PNG_TEXT_COMPRESSION_NONE -1 +#define PNG_TEXT_COMPRESSION_zTXt 0 +#define PNG_TEXT_COMPRESSION_LAST 1 /* Not a valid value */ + +/* png_time is a way to hold the time in an machine independent way. + * Two conversions are provided, both from time_t and struct tm. There + * is no portable way to convert to either of these structures, as far + * as I know. If you know of a portable way, send it to me. As a side + * note - PNG is Year 2000 compliant! + */ +typedef struct png_time_struct +{ + png_uint_16 year; /* full year, as in, 1995 */ + png_byte month; /* month of year, 1 - 12 */ + png_byte day; /* day of month, 1 - 31 */ + png_byte hour; /* hour of day, 0 - 23 */ + png_byte minute; /* minute of hour, 0 - 59 */ + png_byte second; /* second of minute, 0 - 60 (for leap seconds) */ +} png_time; +typedef png_time FAR * png_timep; +typedef png_time FAR * FAR * png_timepp; + +/* png_info is a structure that holds the information in a PNG file so + * that the application can find out the characteristics of the image. + * If you are reading the file, this structure will tell you what is + * in the PNG file. If you are writing the file, fill in the information + * you want to put into the PNG file, then call png_write_info(). + * The names chosen should be very close to the PNG specification, so + * consult that document for information about the meaning of each field. + * + * With libpng < 0.95, it was only possible to directly set and read the + * the values in the png_info_struct, which meant that the contents and + * order of the values had to remain fixed. With libpng 0.95 and later, + * however, * there are now functions which abstract the contents of + * png_info_struct from the application, so this makes it easier to use + * libpng with dynamic libraries, and even makes it possible to use + * libraries that don't have all of the libpng ancillary chunk-handing + * functionality. + * + * In any case, the order of the parameters in png_info_struct should NOT + * be changed for as long as possible to keep compatibility with applications + * that use the old direct-access method with png_info_struct. + */ +typedef struct png_info_struct +{ + /* the following are necessary for every PNG file */ + png_uint_32 width; /* width of image in pixels (from IHDR) */ + png_uint_32 height; /* height of image in pixels (from IHDR) */ + png_uint_32 valid; /* valid chunk data (see PNG_INFO_ below) */ + png_uint_32 rowbytes; /* bytes needed to hold an untransformed row */ + png_colorp palette; /* array of color values (valid & PNG_INFO_PLTE) */ + png_uint_16 num_palette; /* number of color entries in "palette" (PLTE) */ + png_uint_16 num_trans; /* number of transparent palette color (tRNS) */ + png_byte bit_depth; /* 1, 2, 4, 8, or 16 bits/channel (from IHDR) */ + png_byte color_type; /* see PNG_COLOR_TYPE_ below (from IHDR) */ + png_byte compression_type; /* must be PNG_COMPRESSION_TYPE_BASE (IHDR) */ + png_byte filter_type; /* must be PNG_FILTER_TYPE_BASE (from IHDR) */ + png_byte interlace_type; /* One of PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ + + /* The following is informational only on read, and not used on writes. */ + png_byte channels; /* number of data channels per pixel (1, 3, 4)*/ + png_byte pixel_depth; /* number of bits per pixel */ + png_byte spare_byte; /* to align the data, and for future use */ + png_byte signature[8]; /* magic bytes read by libpng from start of file */ + + /* The rest of the data is optional. If you are reading, check the + * valid field to see if the information in these are valid. If you + * are writing, set the valid field to those chunks you want written, + * and initialize the appropriate fields below. + */ + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) || \ + defined(PNG_READ_GAMMA_SUPPORTED) + /* The gAMA chunk describes the gamma characteristics of the system + * on which the image was created, normally in the range [1.0, 2.5]. + * Data is valid if (valid & PNG_INFO_gAMA) is non-zero. + */ + float gamma; /* gamma value of image, if (valid & PNG_INFO_gAMA) */ +#endif /* PNG_READ_gAMA_SUPPORTED || PNG_WRITE_gAMA_SUPPORTED */ + +#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED) + /* GR-P, 0.96a */ + /* Data valid if (valid & PNG_INFO_sRGB) non-zero. */ + png_byte srgb_intent; /* sRGB rendering intent [0, 1, 2, or 3] */ +#endif /* PNG_READ_sRGB_SUPPORTED || PNG_WRITE_sRGB_SUPPORTED */ + +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \ + defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) + /* The tEXt and zTXt chunks contain human-readable textual data in + * uncompressed and compressed forms, respectively. The data in "text" + * is an array of pointers to uncompressed, null-terminated C strings. + * Each chunk has a keyword which describes the textual data contained + * in that chunk. Keywords are not required to be unique, and the text + * string may be empty. Any number of text chunks may be in an image. + */ + int num_text; /* number of comments read/to write */ + int max_text; /* current size of text array */ + png_textp text; /* array of comments read/to write */ +#endif /* PNG_READ_tEXt/zTXt_SUPPORTED || PNG_WRITE_tEXt/zTXt_SUPPORTED */ +#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED) + /* The tIME chunk holds the last time the displayed image data was + * modified. See the png_time struct for the contents of this struct. + */ + png_time mod_time; +#endif /* PNG_READ_tIME_SUPPORTED || PNG_WRITE_tIME_SUPPORTED */ +#if defined(PNG_READ_sBIT_SUPPORTED) || defined(PNG_WRITE_sBIT_SUPPORTED) + /* The sBIT chunk specifies the number of significant high-order bits + * in the pixel data. Values are in the range [1, bit_depth], and are + * only specified for the channels in the pixel data. The contents of + * the low-order bits is not specified. Data is valid if + * (valid & PNG_INFO_sBIT) is non-zero. + */ + png_color_8 sig_bit; /* significant bits in color channels */ +#endif /* PNG_READ_sBIT_SUPPORTED || PNG_WRITE_sBIT_SUPPORTED */ +#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED) + /* The tRNS chunk supplies transparency data for paletted images and + * other image types that don't need a full alpha channel. There are + * "num_trans" transparency values for a paletted image, stored in the + * same order as the palette colors, starting from index 0. Values + * for the data are in the range [0, 255], ranging from fully transparent + * to fully opaque, respectively. For non-paletted images, there is a + * single color specified which should be treated as fully transparent. + * Data is valid if (valid & PNG_INFO_tRNS) is non-zero. + */ + png_bytep trans; /* transparent values for paletted image */ + png_color_16 trans_values; /* transparent color for non-palette image */ +#endif /* PNG_READ_tRNS_SUPPORTED || PNG_WRITE_tRNS_SUPPORTED */ +#if defined(PNG_READ_bKGD_SUPPORTED) || defined(PNG_WRITE_bKGD_SUPPORTED) || \ + defined(PNG_READ_BACKGROUND_SUPPORTED) + /* The bKGD chunk gives the suggested image background color if the + * display program does not have its own background color and the image + * is needs to composited onto a background before display. The colors + * in "background" are normally in the same color space/depth as the + * pixel data. Data is valid if (valid & PNG_INFO_bKGD) is non-zero. + */ + png_color_16 background; +#endif /* PNG_READ_bKGD_SUPPORTED || PNG_WRITE_bKGD_SUPPORTED */ +#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) + /* The oFFs chunk gives the offset in "offset_unit_type" units rightwards + * and downwards from the top-left corner of the display, page, or other + * application-specific co-ordinate space. See the PNG_OFFSET_ defines + * below for the unit types. Valid if (valid & PNG_INFO_oFFs) non-zero. + */ + png_uint_32 x_offset; /* x offset on page */ + png_uint_32 y_offset; /* y offset on page */ + png_byte offset_unit_type; /* offset units type */ +#endif /* PNG_READ_oFFs_SUPPORTED || PNG_WRITE_oFFs_SUPPORTED */ +#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) + /* The pHYs chunk gives the physical pixel density of the image for + * display or printing in "phys_unit_type" units (see PNG_RESOLUTION_ + * defines below). Data is valid if (valid & PNG_INFO_pHYs) is non-zero. + */ + png_uint_32 x_pixels_per_unit; /* horizontal pixel density */ + png_uint_32 y_pixels_per_unit; /* vertical pixel density */ + png_byte phys_unit_type; /* resolution type (see PNG_RESOLUTION_ below) */ +#endif /* PNG_READ_pHYs_SUPPORTED || PNG_WRITE_pHYs_SUPPORTED */ +#if defined(PNG_READ_hIST_SUPPORTED) || defined(PNG_WRITE_hIST_SUPPORTED) + /* The hIST chunk contains the relative frequency or importance of the + * various palette entries, so that a viewer can intelligently select a + * reduced-color palette, if required. Data is an array of "num_palette" + * values in the range [0,65535]. Data valid if (valid & PNG_INFO_hIST) + * is non-zero. + */ + png_uint_16p hist; +#endif /* PNG_READ_hIST_SUPPORTED || PNG_WRITE_hIST_SUPPORTED */ +#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED) + /* The cHRM chunk describes the CIE color characteristics of the monitor + * on which the PNG was created. This data allows the viewer to do gamut + * mapping of the input image to ensure that the viewer sees the same + * colors in the image as the creator. Values are in the range + * [0.0, 0.8]. Data valid if (valid & PNG_INFO_cHRM) non-zero. + */ + float x_white; + float y_white; + float x_red; + float y_red; + float x_green; + float y_green; + float x_blue; + float y_blue; +#endif /* PNG_READ_cHRM_SUPPORTED || PNG_WRITE_cHRM_SUPPORTED */ +#if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) + /* The pCAL chunk describes a transformation between the stored pixel + * values and original physcical data values used to create the image. + * The integer range [0, 2^bit_depth - 1] maps to the floating-point + * range given by [pcal_X0, pcal_X1], and are further transformed by a + * (possibly non-linear) transformation function given by "pcal_type" + * and "pcal_params" into "pcal_units". Please see the PNG_EQUATION_ + * defines below, and the PNG-Group's Scientific Visualization extension + * chunks document png-scivis-19970203 for a complete description of the + * transformations and how they should be implemented, as well as the + * png-extensions document for a description of the ASCII parameter + * strings. Data values are valid if (valid & PNG_INFO_pCAL) non-zero. + */ + png_charp pcal_purpose; /* pCAL chunk description string */ + png_int_32 pcal_X0; /* minimum value */ + png_int_32 pcal_X1; /* maximum value */ + png_charp pcal_units; /* Latin-1 string giving physical units */ + png_charpp pcal_params; /* ASCII strings containing parameter values */ + png_byte pcal_type; /* equation type (see PNG_EQUATION_ below) */ + png_byte pcal_nparams; /* number of parameters given in pcal_params */ +#endif /* PNG_READ_pCAL_SUPPORTED || PNG_WRITE_pCAL_SUPPORTED */ +} png_info; +typedef png_info FAR * png_infop; +typedef png_info FAR * FAR * png_infopp; + +/* These describe the color_type field in png_info. */ +/* color type masks */ +#define PNG_COLOR_MASK_PALETTE 1 +#define PNG_COLOR_MASK_COLOR 2 +#define PNG_COLOR_MASK_ALPHA 4 + +/* color types. Note that not all combinations are legal */ +#define PNG_COLOR_TYPE_GRAY 0 +#define PNG_COLOR_TYPE_PALETTE (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_PALETTE) +#define PNG_COLOR_TYPE_RGB (PNG_COLOR_MASK_COLOR) +#define PNG_COLOR_TYPE_RGB_ALPHA (PNG_COLOR_MASK_COLOR | PNG_COLOR_MASK_ALPHA) +#define PNG_COLOR_TYPE_GRAY_ALPHA (PNG_COLOR_MASK_ALPHA) + +/* This is for compression type. PNG 1.0 only defines the single type. */ +#define PNG_COMPRESSION_TYPE_BASE 0 /* Deflate method 8, 32K window */ +#define PNG_COMPRESSION_TYPE_DEFAULT PNG_COMPRESSION_TYPE_BASE + +/* This is for filter type. PNG 1.0 only defines the single type. */ +#define PNG_FILTER_TYPE_BASE 0 /* Single row per-byte filtering */ +#define PNG_FILTER_TYPE_DEFAULT PNG_FILTER_TYPE_BASE + +/* These are for the interlacing type. These values should NOT be changed. */ +#define PNG_INTERLACE_NONE 0 /* Non-interlaced image */ +#define PNG_INTERLACE_ADAM7 1 /* Adam7 interlacing */ +#define PNG_INTERLACE_LAST 2 /* Not a valid value */ + +/* These are for the oFFs chunk. These values should NOT be changed. */ +#define PNG_OFFSET_PIXEL 0 /* Offset in pixels */ +#define PNG_OFFSET_MICROMETER 1 /* Offset in micrometers (1/10^6 meter) */ +#define PNG_OFFSET_LAST 2 /* Not a valid value */ + +/* These are for the pCAL chunk. These values should NOT be changed. */ +#define PNG_EQUATION_LINEAR 0 /* Linear transformation */ +#define PNG_EQUATION_BASE_E 1 /* Exponential base e transform */ +#define PNG_EQUATION_ARBITRARY 2 /* Arbitrary base exponential transform */ +#define PNG_EQUATION_HYPERBOLIC 3 /* Hyperbolic sine transformation */ +#define PNG_EQUATION_LAST 4 /* Not a valid value */ + +/* These are for the pHYs chunk. These values should NOT be changed. */ +#define PNG_RESOLUTION_UNKNOWN 0 /* pixels/unknown unit (aspect ratio) */ +#define PNG_RESOLUTION_METER 1 /* pixels/meter */ +#define PNG_RESOLUTION_LAST 2 /* Not a valid value */ + +/* These are for the sRGB chunk. These values should NOT be changed. */ +#define PNG_sRGB_INTENT_SATURATION 0 +#define PNG_sRGB_INTENT_PERCEPTUAL 1 +#define PNG_sRGB_INTENT_ABSOLUTE 2 +#define PNG_sRGB_INTENT_RELATIVE 3 +#define PNG_sRGB_INTENT_LAST 4 /* Not a valid value */ + + + +/* These determine if an ancillary chunk's data has been successfully read + * from the PNG header, or if the application has filled in the corresponding + * data in the info_struct to be written into the output file. The values + * of the PNG_INFO_ defines should NOT be changed. + */ +#define PNG_INFO_gAMA 0x0001 +#define PNG_INFO_sBIT 0x0002 +#define PNG_INFO_cHRM 0x0004 +#define PNG_INFO_PLTE 0x0008 +#define PNG_INFO_tRNS 0x0010 +#define PNG_INFO_bKGD 0x0020 +#define PNG_INFO_hIST 0x0040 +#define PNG_INFO_pHYs 0x0080 +#define PNG_INFO_oFFs 0x0100 +#define PNG_INFO_tIME 0x0200 +#define PNG_INFO_pCAL 0x0400 +#define PNG_INFO_sRGB 0x0800 /* GR-P, 0.96a */ + +/* This is used for the transformation routines, as some of them + * change these values for the row. It also should enable using + * the routines for other purposes. + */ +typedef struct png_row_info_struct +{ + png_uint_32 width; /* width of row */ + png_uint_32 rowbytes; /* number of bytes in row */ + png_byte color_type; /* color type of row */ + png_byte bit_depth; /* bit depth of row */ + png_byte channels; /* number of channels (1, 2, 3, or 4) */ + png_byte pixel_depth; /* bits per pixel (depth * channels) */ +} png_row_info; + +typedef png_row_info FAR * png_row_infop; +typedef png_row_info FAR * FAR * png_row_infopp; + +/* These are the function types for the I/O functions, and the functions which + * modify the default I/O functions to user I/O functions. The png_error_ptr + * type should match that of user supplied warning and error functions, while + * the png_rw_ptr type should match that of the user read/write data functions. + */ +typedef struct png_struct_def png_struct; +typedef png_struct FAR * png_structp; + +typedef void (*png_error_ptr) PNGARG((png_structp, png_const_charp)); +typedef void (*png_rw_ptr) PNGARG((png_structp, png_bytep, png_size_t)); +typedef void (*png_flush_ptr) PNGARG((png_structp)); +typedef void (*png_read_status_ptr) PNGARG((png_structp, png_uint_32, int)); +typedef void (*png_write_status_ptr) PNGARG((png_structp, png_uint_32, int)); +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +typedef void (*png_progressive_info_ptr) PNGARG((png_structp, png_infop)); +typedef void (*png_progressive_end_ptr) PNGARG((png_structp, png_infop)); +typedef void (*png_progressive_row_ptr) PNGARG((png_structp, png_bytep, + png_uint_32, int)); +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +typedef void (*png_user_transform_ptr) PNGARG((png_structp, + png_row_infop, png_bytep)); +#endif /* PNG_READ|WRITE_USER_TRANSFORM_SUPPORTED */ + +/* The structure that holds the information to read and write PNG files. + * The only people who need to care about what is inside of this are the + * people who will be modifying the library for their own special needs. + * It should NOT be accessed directly by an application, except to store + * the jmp_buf. + */ + +struct png_struct_def +{ + jmp_buf jmpbuf; /* used in png_error */ + + png_error_ptr error_fn; /* function for printing errors and aborting */ + png_error_ptr warning_fn; /* function for printing warnings */ + png_voidp error_ptr; /* user supplied struct for error functions */ + png_rw_ptr write_data_fn; /* function for writing output data */ + png_rw_ptr read_data_fn; /* function for reading input data */ +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) || \ + defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) + png_user_transform_ptr read_user_transform_fn; /* user read transform */ + png_user_transform_ptr write_user_transform_fn; /* user write transform */ +#endif + png_voidp io_ptr; /* ptr to application struct for I/O functions*/ + + png_uint_32 mode; /* tells us where we are in the PNG file */ + png_uint_32 flags; /* flags indicating various things to libpng */ + png_uint_32 transformations; /* which transformations to perform */ + + z_stream zstream; /* pointer to decompression structure (below) */ + png_bytep zbuf; /* buffer for zlib */ + png_size_t zbuf_size; /* size of zbuf */ + int zlib_level; /* holds zlib compression level */ + int zlib_method; /* holds zlib compression method */ + int zlib_window_bits; /* holds zlib compression window bits */ + int zlib_mem_level; /* holds zlib compression memory level */ + int zlib_strategy; /* holds zlib compression strategy */ + + png_uint_32 width; /* width of image in pixels */ + png_uint_32 height; /* height of image in pixels */ + png_uint_32 num_rows; /* number of rows in current pass */ + png_uint_32 usr_width; /* width of row at start of write */ + png_uint_32 rowbytes; /* size of row in bytes */ + png_uint_32 irowbytes; /* size of current interlaced row in bytes */ + png_uint_32 iwidth; /* width of current interlaced row in pixels */ + png_uint_32 row_number; /* current row in interlace pass */ + png_bytep prev_row; /* buffer to save previous (unfiltered) row */ + png_bytep row_buf; /* buffer to save current (unfiltered) row */ + png_bytep sub_row; /* buffer to save "sub" row when filtering */ + png_bytep up_row; /* buffer to save "up" row when filtering */ + png_bytep avg_row; /* buffer to save "avg" row when filtering */ + png_bytep paeth_row; /* buffer to save "Paeth" row when filtering */ + png_row_info row_info; /* used for transformation routines */ + + png_uint_32 idat_size; /* current IDAT size for read */ + png_uint_32 crc; /* current chunk CRC value */ + png_colorp palette; /* palette from the input file */ + png_uint_16 num_palette; /* number of color entries in palette */ + png_uint_16 num_trans; /* number of transparency values */ + png_byte chunk_name[5]; /* null-terminated name of current chunk */ + png_byte compression; /* file compression type (always 0) */ + png_byte filter; /* file filter type (always 0) */ + png_byte interlaced; /* PNG_INTERLACE_NONE, PNG_INTERLACE_ADAM7 */ + png_byte pass; /* current interlace pass (0 - 6) */ + png_byte do_filter; /* row filter flags (see PNG_FILTER_ below ) */ + png_byte color_type; /* color type of file */ + png_byte bit_depth; /* bit depth of file */ + png_byte usr_bit_depth; /* bit depth of users row */ + png_byte pixel_depth; /* number of bits per pixel */ + png_byte channels; /* number of channels in file */ + png_byte usr_channels; /* channels at start of write */ + png_byte sig_bytes; /* magic bytes read/written from start of file */ + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) + png_byte filler; /* filler byte for 24->32-bit pixel expansion */ +#endif /* PNG_READ_FILLER_SUPPORTED */ +#if defined(PNG_READ_bKGD_SUPPORTED) + png_byte background_gamma_type; + float background_gamma; + png_color_16 background; /* background color in screen gamma space */ +#if defined(PNG_READ_GAMMA_SUPPORTED) + png_color_16 background_1; /* background normalized to gamma 1.0 */ +#endif /* PNG_READ_GAMMA && PNG_READ_bKGD_SUPPORTED */ +#endif /* PNG_READ_bKGD_SUPPORTED */ +#if defined(PNG_WRITE_FLUSH_SUPPORTED) + png_flush_ptr output_flush_fn;/* Function for flushing output */ + png_uint_32 flush_dist; /* how many rows apart to flush, 0 - no flush */ + png_uint_32 flush_rows; /* number of rows written since last flush */ +#endif /* PNG_WRITE_FLUSH_SUPPORTED */ +#if defined(PNG_READ_GAMMA_SUPPORTED) + int gamma_shift; /* number of "insignificant" bits 16-bit gamma */ + float gamma; /* file gamma value */ + float screen_gamma; /* screen gamma value (display_gamma/viewing_gamma */ +#endif /* PNG_READ_GAMMA_SUPPORTED */ +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + png_bytep gamma_table; /* gamma table for 8 bit depth files */ + png_bytep gamma_from_1; /* converts from 1.0 to screen */ + png_bytep gamma_to_1; /* converts from file to 1.0 */ + png_uint_16pp gamma_16_table; /* gamma table for 16 bit depth files */ + png_uint_16pp gamma_16_from_1; /* converts from 1.0 to screen */ + png_uint_16pp gamma_16_to_1; /* converts from file to 1.0 */ +#endif /* PNG_READ_GAMMA_SUPPORTED || PNG_WRITE_GAMMA_SUPPORTED */ +#if defined(PNG_READ_GAMMA_SUPPORTED) || defined (PNG_READ_sBIT_SUPPORTED) + png_color_8 sig_bit; /* significant bits in each available channel */ +#endif /* PNG_READ_GAMMA_SUPPORTED || PNG_READ_sBIT_SUPPORTED */ +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) + png_color_8 shift; /* shift for significant bit tranformation */ +#endif /* PNG_READ_SHIFT_SUPPORTED || PNG_WRITE_SHIFT_SUPPORTED */ +#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_READ_BACKGROUND_SUPPORTED) + png_bytep trans; /* transparency values for paletted files */ + png_color_16 trans_values; /* transparency values for non-paletted files */ +#endif /* PNG_READ_tRNS_SUPPORTED || PNG_READ_BACKGROUND_SUPPORTED */ + png_read_status_ptr read_row_fn; /* called after each row is decoded */ + png_write_status_ptr write_row_fn; /* called after each row is encoded */ +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_progressive_info_ptr info_fn; /* called after header data fully read */ + png_progressive_row_ptr row_fn; /* called after each prog. row is decoded */ + png_progressive_end_ptr end_fn; /* called after image is complete */ + png_bytep save_buffer_ptr; /* current location in save_buffer */ + png_bytep save_buffer; /* buffer for previously read data */ + png_bytep current_buffer_ptr; /* current location in current_buffer */ + png_bytep current_buffer; /* buffer for recently used data */ + png_uint_32 push_length; /* size of current input chunk */ + png_uint_32 skip_length; /* bytes to skip in input data */ + png_size_t save_buffer_size; /* amount of data now in save_buffer */ + png_size_t save_buffer_max; /* total size of save_buffer */ + png_size_t buffer_size; /* total amount of available input data */ + png_size_t current_buffer_size; /* amount of data now in current_buffer */ + int process_mode; /* what push library is currently doing */ + int cur_palette; /* current push library palette index */ +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) + png_size_t current_text_size; /* current size of text input data */ + png_size_t current_text_left; /* how much text left to read in input */ + png_charp current_text; /* current text chunk buffer */ + png_charp current_text_ptr; /* current location in current_text */ +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED && PNG_READ_tEXt/zTXt_SUPPORTED */ +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ +#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) +/* for the Borland special 64K segment handler */ + png_bytepp offset_table_ptr; + png_bytep offset_table; + png_uint_16 offset_table_number; + png_uint_16 offset_table_count; + png_uint_16 offset_table_count_free; +#endif /* __TURBOC__&&!_Windows&&!__FLAT__ */ +#if defined(PNG_READ_DITHER_SUPPORTED) + png_bytep palette_lookup; /* lookup table for dithering */ + png_bytep dither_index; /* index translation for palette files */ +#endif /* PNG_READ_DITHER_SUPPORTED */ +#if defined(PNG_READ_DITHER_SUPPORTED) || defined(PNG_READ_hIST_SUPPORTED) + png_uint_16p hist; /* histogram */ +#endif +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + png_byte heuristic_method; /* heuristic for row filter selection */ + png_byte num_prev_filters; /* number of weights for previous rows */ + png_bytep prev_filters; /* filter type(s) of previous row(s) */ + png_uint_16p filter_weights; /* weight(s) for previous line(s) */ + png_uint_16p inv_filter_weights; /* 1/weight(s) for previous line(s) */ + png_uint_16p filter_costs; /* relative filter calculation cost */ + png_uint_16p inv_filter_costs; /* 1/relative filter calculation cost */ +#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ +#if defined(PNG_TIME_RFC1123_SUPPORTED) + png_charp time_buffer; /* String to hold RFC 1123 time text */ +#endif /* PNG_TIME_RFC1123_SUPPORTED */ +}; + +typedef png_struct FAR * FAR * png_structpp; + +/* Here are the function definitions most commonly used. This is not + * the place to find out how to use libpng. See libpng.txt for the + * full explanation, see example.c for the summary. This just provides + * a simple one line of the use of each function. + */ + +/* Tell lib we have already handled the first magic bytes. + * Handling more than 8 bytes from the beginning of the file is an error. + */ +extern PNG_EXPORT(void,png_set_sig_bytes) PNGARG((png_structp png_ptr, + int num_bytes)); + +/* Check sig[start] through sig[start + num_to_check - 1] to see if it's a + * PNG file. Returns zero if the supplied bytes match the 8-byte PNG + * signature, and non-zero otherwise. Having num_to_check == 0 or + * start > 7 will always fail (ie return non-zero). + */ +extern PNG_EXPORT(int,png_sig_cmp) PNGARG((png_bytep sig, png_size_t start, + png_size_t num_to_check)); + +/* Simple signature checking function. This is the same as calling + * png_check_sig(sig, n) := !png_sig_cmp(sig, 0, n). + */ +extern PNG_EXPORT(int,png_check_sig) PNGARG((png_bytep sig, int num)); + +/* Allocate and initialize png_ptr struct for reading, and any other memory. */ +extern PNG_EXPORT(png_structp,png_create_read_struct) + PNGARG((png_const_charp user_png_ver, voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn)); + +/* Allocate and initialize png_ptr struct for reading, and any other memory */ +extern PNG_EXPORT(png_structp,png_create_write_struct) + PNGARG((png_const_charp user_png_ver, voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn)); + +/* Write a PNG chunk - size, type, (optional) data, CRC. */ +extern PNG_EXPORT(void,png_write_chunk) PNGARG((png_structp png_ptr, + png_bytep chunk_name, png_bytep data, png_size_t length)); + +/* Write the start of a PNG chunk - length and chunk name. */ +extern PNG_EXPORT(void,png_write_chunk_start) PNGARG((png_structp png_ptr, + png_bytep chunk_name, png_uint_32 length)); + +/* Write the data of a PNG chunk started with png_write_chunk_start(). */ +extern PNG_EXPORT(void,png_write_chunk_data) PNGARG((png_structp png_ptr, + png_bytep data, png_size_t length)); + +/* Finish a chunk started with png_write_chunk_start() (includes CRC). */ +extern PNG_EXPORT(void,png_write_chunk_end) PNGARG((png_structp png_ptr)); + +/* Allocate and initialize the info structure */ +extern PNG_EXPORT(png_infop,png_create_info_struct) + PNGARG((png_structp png_ptr)); + +/* Initialize the info structure (old interface - NOT DLL EXPORTED) */ +extern void png_info_init PNGARG((png_infop info_ptr)); + +/* Writes all the PNG information before the image. */ +extern PNG_EXPORT(void,png_write_info) PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +/* read the information before the actual image data. */ +extern PNG_EXPORT(void,png_read_info) PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +#if defined(PNG_TIME_RFC1123_SUPPORTED) +extern PNG_EXPORT(png_charp,png_convert_to_rfc1123) + PNGARG((png_structp png_ptr, png_timep ptime)); +#endif /* PNG_TIME_RFC1123_SUPPORTED */ + +#if defined(PNG_WRITE_tIME_SUPPORTED) +/* convert from a struct tm to png_time */ +extern PNG_EXPORT(void,png_convert_from_struct_tm) PNGARG((png_timep ptime, + struct tm FAR * ttime)); + +/* convert from time_t to png_time. Uses gmtime() */ +extern PNG_EXPORT(void,png_convert_from_time_t) PNGARG((png_timep ptime, + time_t ttime)); +#endif /* PNG_WRITE_tIME_SUPPORTED */ + +#if defined(PNG_READ_EXPAND_SUPPORTED) +/* Expand data to 24 bit RGB, or 8 bit grayscale, with alpha if available. */ +extern PNG_EXPORT(void,png_set_expand) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_EXPAND_SUPPORTED */ + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* Use blue, green, red order for pixels. */ +extern PNG_EXPORT(void,png_set_bgr) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_BGR_SUPPORTED || PNG_WRITE_BGR_SUPPORTED */ + +#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) +/* Expand the grayscale to 24 bit RGB if necessary. */ +extern PNG_EXPORT(void,png_set_gray_to_rgb) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_GRAY_TO_RGB_SUPPORTED */ + +#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) +/* Reduce RGB to grayscale. (Not yet implemented) */ +extern PNG_EXPORT(void,png_set_rgb_to_gray) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_RGB_TO_GRAY_SUPPORTED */ + +extern PNG_EXPORT(void,png_build_grayscale_palette) PNGARG((int bit_depth, + png_colorp palette)); + +#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +extern PNG_EXPORT(void,png_set_strip_alpha) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_STRIP_ALPHA_SUPPORTED */ + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +extern PNG_EXPORT(void,png_set_swap_alpha) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_SWAP_ALPHA_SUPPORTED || PNG_WRITE_SWAP_ALPHA_SUPPORTED */ + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +extern PNG_EXPORT(void,png_set_invert_alpha) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_INVERT_ALPHA_SUPPORTED || PNG_WRITE_INVERT_ALPHA_SUPPORTED */ + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte to 24-bit RGB images. */ +extern PNG_EXPORT(void,png_set_filler) PNGARG((png_structp png_ptr, + png_uint_32 filler, int flags)); + +/* The values of the PNG_FILLER_ defines should NOT be changed */ +#define PNG_FILLER_BEFORE 0 +#define PNG_FILLER_AFTER 1 +#endif /* PNG_READ_FILLER_SUPPORTED || PNG_WRITE_FILLER_SUPPORTED */ + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* Swap bytes in 16 bit depth files. */ +extern PNG_EXPORT(void,png_set_swap) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_SWAP_SUPPORTED || PNG_WRITE_SWAP_SUPPORTED */ + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* Use 1 byte per pixel in 1, 2, or 4 bit depth files. */ +extern PNG_EXPORT(void,png_set_packing) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_PACK_SUPPORTED || PNG_WRITE_PACK_SUPPORTED */ + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* Swap packing order of pixels in bytes. */ +extern PNG_EXPORT(void,png_set_packswap) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_PACKSWAP_SUPPORTED || PNG_WRITE_PACKSWAP_SUPPOR */ + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +/* Converts files to legal bit depths. */ +extern PNG_EXPORT(void,png_set_shift) PNGARG((png_structp png_ptr, + png_color_8p true_bits)); +#endif /* PNG_READ_SHIFT_SUPPORTED || PNG_WRITE_SHIFT_SUPPORTED */ + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +/* Have the code handle the interlacing. Returns the number of passes. */ +extern PNG_EXPORT(int,png_set_interlace_handling) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_INTERLACING_SUPPORTED || PNG_WRITE_INTERLACING_SUPPORTED */ + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +/* Invert monocrome files */ +extern PNG_EXPORT(void,png_set_invert_mono) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_INVERT_SUPPORTED || PNG_WRITE_INVERT_SUPPORTED */ + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) +/* Handle alpha and tRNS by replacing with a background color. */ +extern PNG_EXPORT(void,png_set_background) PNGARG((png_structp png_ptr, + png_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma)); +#define PNG_BACKGROUND_GAMMA_UNKNOWN 0 +#define PNG_BACKGROUND_GAMMA_SCREEN 1 +#define PNG_BACKGROUND_GAMMA_FILE 2 +#define PNG_BACKGROUND_GAMMA_UNIQUE 3 +#endif /* PNG_READ_BACKGROUND_SUPPORTED */ + +#if defined(PNG_READ_16_TO_8_SUPPORTED) +/* strip the second byte of information from a 16 bit depth file. */ +extern PNG_EXPORT(void,png_set_strip_16) PNGARG((png_structp png_ptr)); +#endif /* PNG_READ_16_TO_8_SUPPORTED */ + +#if defined(PNG_READ_DITHER_SUPPORTED) +/* Turn on dithering, and reduce the palette to the number of colors available. */ +extern PNG_EXPORT(void,png_set_dither) PNGARG((png_structp png_ptr, + png_colorp palette, int num_palette, int maximum_colors, + png_uint_16p histogram, int full_dither)); +#endif /* PNG_READ_DITHER_SUPPORTED */ + +#if defined(PNG_READ_GAMMA_SUPPORTED) +/* Handle gamma correction. Screen_gamma=(display_gamma/viewing_gamma) */ +extern PNG_EXPORT(void,png_set_gamma) PNGARG((png_structp png_ptr, + double screen_gamma, double default_file_gamma)); +#endif /* PNG_READ_GAMMA_SUPPORTED */ + +#if defined(PNG_WRITE_FLUSH_SUPPORTED) +/* Set how many lines between output flushes - 0 for no flushing */ +extern PNG_EXPORT(void,png_set_flush) PNGARG((png_structp png_ptr, int nrows)); + +/* Flush the current PNG output buffer */ +extern PNG_EXPORT(void,png_write_flush) PNGARG((png_structp png_ptr)); +#endif /* PNG_WRITE_FLUSH_SUPPORTED */ + +/* optional update palette with requested transformations */ +extern PNG_EXPORT(void,png_start_read_image) PNGARG((png_structp png_ptr)); + +/* optional call to update the users info structure */ +extern PNG_EXPORT(void,png_read_update_info) PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +/* read a one or more rows of image data.*/ +extern PNG_EXPORT(void,png_read_rows) PNGARG((png_structp png_ptr, + png_bytepp row, png_bytepp display_row, png_uint_32 num_rows)); + +/* read a row of data.*/ +extern PNG_EXPORT(void,png_read_row) PNGARG((png_structp png_ptr, + png_bytep row, + png_bytep display_row)); + +/* read the whole image into memory at once. */ +extern PNG_EXPORT(void,png_read_image) PNGARG((png_structp png_ptr, + png_bytepp image)); + +/* write a row of image data */ +extern PNG_EXPORT(void,png_write_row) PNGARG((png_structp png_ptr, + png_bytep row)); + +/* write a few rows of image data */ +extern PNG_EXPORT(void,png_write_rows) PNGARG((png_structp png_ptr, + png_bytepp row, png_uint_32 num_rows)); + +/* write the image data */ +extern PNG_EXPORT(void,png_write_image) PNGARG((png_structp png_ptr, + png_bytepp image)); + +/* writes the end of the PNG file. */ +extern PNG_EXPORT(void,png_write_end) PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +/* read the end of the PNG file. */ +extern PNG_EXPORT(void,png_read_end) PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +/* free any memory associated with the png_info_struct */ +extern PNG_EXPORT(void,png_destroy_info_struct) PNGARG((png_structp png_ptr, + png_infopp info_ptr_ptr)); + +/* free any memory associated with the png_struct and the png_info_structs */ +extern PNG_EXPORT(void,png_destroy_read_struct) PNGARG((png_structpp + png_ptr_ptr, png_infopp info_ptr_ptr, png_infopp end_info_ptr_ptr)); + +/* free all memory used by the read (old method - NOT DLL EXPORTED) */ +extern void png_read_destroy PNGARG((png_structp png_ptr, png_infop info_ptr, + png_infop end_info_ptr)); + +/* free any memory associated with the png_struct and the png_info_structs */ +extern PNG_EXPORT(void,png_destroy_write_struct) + PNGARG((png_structpp png_ptr_ptr, png_infopp info_ptr_ptr)); + +/* free any memory used in info_ptr struct (old method - NOT DLL EXPORTED) */ +extern void png_write_destroy_info PNGARG((png_infop info_ptr)); + +/* free any memory used in png_ptr struct (old method - NOT DLL EXPORTED) */ +extern void png_write_destroy PNGARG((png_structp png_ptr)); + +/* set the libpng method of handling chunk CRC errors */ +extern PNG_EXPORT(void,png_set_crc_action) PNGARG((png_structp png_ptr, + int crit_action, int ancil_action)); + +/* Values for png_set_crc_action() to say how to handle CRC errors in + * ancillary and critical chunks, and whether to use the data contained + * therein. Note that it is impossible to "discard" data in a critical + * chunk. For versions prior to 0.90, the action was always error/quit, + * whereas in version 0.90 and later, the action for CRC errors in ancillary + * chunks is warn/discard. These values should NOT be changed. + * + * value action:critical action:ancillary + */ +#define PNG_CRC_DEFAULT 0 /* error/quit warn/discard data */ +#define PNG_CRC_ERROR_QUIT 1 /* error/quit error/quit */ +#define PNG_CRC_WARN_DISCARD 2 /* (INVALID) warn/discard data */ +#define PNG_CRC_WARN_USE 3 /* warn/use data warn/use data */ +#define PNG_CRC_QUIET_USE 4 /* quiet/use data quiet/use data */ +#define PNG_CRC_NO_CHANGE 5 /* use current value use current value */ + +/* These functions give the user control over the scan-line filtering in + * libpng and the compression methods used by zlib. These functions are + * mainly useful for testing, as the defaults should work with most users. + * Those users who are tight on memory or want faster performance at the + * expense of compression can modify them. See the compression library + * header file (zlib.h) for an explination of the compression functions. + */ + +/* set the filtering method(s) used by libpng. Currently, the only valid + * value for "method" is 0. + */ +extern PNG_EXPORT(void,png_set_filter) PNGARG((png_structp png_ptr, int method, + int filters)); + +/* Flags for png_set_filter() to say which filters to use. The flags + * are chosen so that they don't conflict with real filter types + * below, in case they are supplied instead of the #defined constants. + * These values should NOT be changed. + */ +#define PNG_NO_FILTERS 0x00 +#define PNG_FILTER_NONE 0x08 +#define PNG_FILTER_SUB 0x10 +#define PNG_FILTER_UP 0x20 +#define PNG_FILTER_AVG 0x40 +#define PNG_FILTER_PAETH 0x80 +#define PNG_ALL_FILTERS (PNG_FILTER_NONE | PNG_FILTER_SUB | PNG_FILTER_UP | \ + PNG_FILTER_AVG | PNG_FILTER_PAETH) + +/* Filter values (not flags) - used in pngwrite.c, pngwutil.c for now. + * These defines should NOT be changed. + */ +#define PNG_FILTER_VALUE_NONE 0 +#define PNG_FILTER_VALUE_SUB 1 +#define PNG_FILTER_VALUE_UP 2 +#define PNG_FILTER_VALUE_AVG 3 +#define PNG_FILTER_VALUE_PAETH 4 +#define PNG_FILTER_VALUE_LAST 5 + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* EXPERIMENTAL */ +/* The "heuristic_method" is given by one of the PNG_FILTER_HEURISTIC_ + * defines, either the default (minimum-sum-of-absolute-differences), or + * the experimental method (weighted-minimum-sum-of-absolute-differences). + * + * Weights are factors >= 1.0, indicating how important it is to keep the + * filter type consistent between rows. Larger numbers mean the current + * filter is that many times as likely to be the same as the "num_weights" + * previous filters. This is cumulative for each previous row with a weight. + * There needs to be "num_weights" values in "filter_weights", or it can be + * NULL if the weights aren't being specified. Weights have no influence on + * the selection of the first row filter. Well chosen weights can (in theory) + * improve the compression for a given image. + * + * Costs are factors >= 1.0 indicating the relative decoding costs of a + * filter type. Higher costs indicate more decoding expense, and are + * therefore less likely to be selected over a filter with lower computational + * costs. There needs to be a value in "filter_costs" for each valid filter + * type (given by PNG_FILTER_VALUE_LAST), or it can be NULL if you aren't + * setting the costs. Costs try to improve the speed of decompression without + * unduly increasing the compressed image size. + * + * A negative weight or cost indicates the default value is to be used, and + * values in the range [0.0, 1.0) indicate the value is to remain unchanged. + * The default values for both weights and costs are currently 1.0, but may + * change if good general weighting/cost heuristics can be found. If both + * the weights and costs are set to 1.0, this degenerates the WEIGHTED method + * to the UNWEIGHTED method, but with added encoding time/computation. + */ +extern PNG_EXPORT(void,png_set_filter_heuristics) PNGARG((png_structp png_ptr, + int heuristic_method, int num_weights, png_doublep filter_weights, + png_doublep filter_costs)); +#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ + +/* Heuristic used for row filter selection. These defines should NOT be + * changed. + */ +#define PNG_FILTER_HEURISTIC_DEFAULT 0 /* Currently "UNWEIGHTED" */ +#define PNG_FILTER_HEURISTIC_UNWEIGHTED 1 /* Used by libpng < 0.95 */ +#define PNG_FILTER_HEURISTIC_WEIGHTED 2 /* Experimental feature */ +#define PNG_FILTER_HEURISTIC_LAST 3 /* Not a valid value */ + +/* Set the library compression level. Currently, valid values range from + * 0 - 9, corresponding directly to the zlib compression levels 0 - 9 + * (0 - no compression, 9 - "maximal" compression). Note that tests have + * shown that zlib compression levels 3-6 usually perform as well as level 9 + * for PNG images, and do considerably fewer caclulations. In the future, + * these values may not correspond directly to the zlib compression levels. + */ +extern PNG_EXPORT(void,png_set_compression_level) PNGARG((png_structp png_ptr, + int level)); + +extern PNG_EXPORT(void,png_set_compression_mem_level) + PNGARG((png_structp png_ptr, int mem_level)); + +extern PNG_EXPORT(void,png_set_compression_strategy) + PNGARG((png_structp png_ptr, int strategy)); + +extern PNG_EXPORT(void,png_set_compression_window_bits) + PNGARG((png_structp png_ptr, int window_bits)); + +extern PNG_EXPORT(void,png_set_compression_method) PNGARG((png_structp png_ptr, + int method)); + +/* These next functions are called for input/output, memory, and error + * handling. They are in the file pngrio.c, pngwio.c, and pngerror.c, + * and call standard C I/O routines such as fread(), fwrite(), and + * fprintf(). These functions can be made to use other I/O routines + * at run time for those applications that need to handle I/O in a + * different manner by calling png_set_???_fn(). See libpng.txt for + * more information. + */ + +#if !defined(PNG_NO_STDIO) +/* Initialize the input/output for the PNG file to the default functions. */ +extern PNG_EXPORT(void,png_init_io) PNGARG((png_structp png_ptr, FILE *fp)); +#endif + +/* Replace the (error and abort), and warning functions with user + * supplied functions. If no messages are to be printed you must still + * write and use replacement functions. The replacement error_fn should + * still do a longjmp to the last setjmp location if you are using this + * method of error handling. If error_fn or warning_fn is NULL, the + * default function will be used. + */ +extern PNG_EXPORT(void,png_set_error_fn) PNGARG((png_structp png_ptr, + png_voidp error_ptr, png_error_ptr error_fn, png_error_ptr warning_fn)); + +/* Return the user pointer associated with the error functions */ +extern PNG_EXPORT(png_voidp,png_get_error_ptr) PNGARG((png_structp png_ptr)); + +/* Replace the default data output functions with a user supplied one(s). + * If buffered output is not used, then output_flush_fn can be set to NULL. + * If PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile time + * output_flush_fn will be ignored (and thus can be NULL). + */ +extern PNG_EXPORT(void,png_set_write_fn) PNGARG((png_structp png_ptr, + png_voidp io_ptr, png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn)); + +/* Replace the default data input function with a user supplied one. */ +extern PNG_EXPORT(void,png_set_read_fn) PNGARG((png_structp png_ptr, + png_voidp io_ptr, png_rw_ptr read_data_fn)); + +/* Return the user pointer associated with the I/O functions */ +extern PNG_EXPORT(png_voidp,png_get_io_ptr) PNGARG((png_structp png_ptr)); + +extern PNG_EXPORT(void,png_set_read_status_fn) PNGARG((png_structp png_ptr, + png_read_status_ptr read_row_fn)); + +extern PNG_EXPORT(void,png_set_write_status_fn) PNGARG((png_structp png_ptr, + png_write_status_ptr write_row_fn)); + +#ifdef PNG_READ_USER_TRANSFORM_SUPPORTED +extern PNG_EXPORT(void,png_set_read_user_transform_fn) PNGARG((png_structp + png_ptr, png_user_transform_ptr read_user_transform_fn)); +#endif + +#ifdef PNG_WRITE_USER_TRANSFORM_SUPPORTED +extern PNG_EXPORT(void,png_set_write_user_transform_fn) PNGARG((png_structp + png_ptr, png_user_transform_ptr write_user_transform_fn)); +#endif + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +/* Sets the function callbacks for the push reader, and a pointer to a + * user-defined structure available to the callback functions. + */ +extern PNG_EXPORT(void,png_set_progressive_read_fn) PNGARG((png_structp png_ptr, + png_voidp progressive_ptr, + png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, + png_progressive_end_ptr end_fn)); + +/* returns the user pointer associated with the push read functions */ +extern PNG_EXPORT(png_voidp,png_get_progressive_ptr) + PNGARG((png_structp png_ptr)); + +/* function to be called when data becomes available */ +extern PNG_EXPORT(void,png_process_data) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_bytep buffer, png_size_t buffer_size)); + +/* function which combines rows. Not very much different than the + * png_combine_row() call. Is this even used????? + */ +extern PNG_EXPORT(void,png_progressive_combine_row) PNGARG((png_structp png_ptr, + png_bytep old_row, png_bytep new_row)); +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ + +extern PNG_EXPORT(png_voidp,png_malloc) PNGARG((png_structp png_ptr, + png_uint_32 size)); + +/* frees a pointer allocated by png_malloc() */ +extern PNG_EXPORT(void,png_free) PNGARG((png_structp png_ptr, png_voidp ptr)); + +extern PNG_EXPORT(png_voidp,png_memcpy_check) PNGARG((png_structp png_ptr, + png_voidp s1, png_voidp s2, png_uint_32 size)); + +extern PNG_EXPORT(png_voidp,png_memset_check) PNGARG((png_structp png_ptr, + png_voidp s1, int value, png_uint_32 size)); + +#ifdef PNGTEST_MEMORY_DEBUG +/* debugging versions of png_malloc() and png_free() */ +extern PNG_EXPORT(png_voidp,png_debug_malloc) PNGARG((png_structp png_ptr, + png_uint_32 size)); +extern PNG_EXPORT(void,png_debug_free) PNGARG((png_structp png_ptr, + png_voidp ptr)); +#endif +#if defined(USE_FAR_KEYWORD) /* memory model conversion function */ +extern void *png_far_to_near PNGARG((png_structp png_ptr,png_voidp ptr, + int check)); +#endif /* USE_FAR_KEYWORD */ + +/* Fatal error in PNG image of libpng - can't continue */ +extern PNG_EXPORT(void,png_error) PNGARG((png_structp png_ptr, + png_const_charp error)); + +/* The same, but the chunk name is prepended to the error string. */ +extern PNG_EXPORT(void,png_chunk_error) PNGARG((png_structp png_ptr, + png_const_charp error)); + +/* Non-fatal error in libpng. Can continue, but may have a problem. */ +extern PNG_EXPORT(void,png_warning) PNGARG((png_structp png_ptr, + png_const_charp message)); + +/* Non-fatal error in libpng, chunk name is prepended to message. */ +extern PNG_EXPORT(void,png_chunk_warning) PNGARG((png_structp png_ptr, + png_const_charp message)); + +/* The png_set_ functions are for storing values in the png_info_struct. + * Similarly, the png_get_ calls are used to read values from the + * png_info_struct, either storing the parameters in the passed variables, or + * setting pointers into the png_info_struct where the data is stored. The + * png_get_ functions return a non-zero value if the data was available + * in info_ptr, or return zero and do not change any of the parameters if the + * data was not available. + * + * These functions should be used instead of directly accessing png_info + * to avoid problems with future changes in the size and internal layout of + * png_info_struct. + */ +/* Returns "flag" if chunk data is valid in info_ptr. */ +extern PNG_EXPORT(png_uint_32,png_get_valid) PNGARG((png_structp png_ptr, +png_infop info_ptr, png_uint_32 flag)); + +/* Returns number of bytes needed to hold a transformed row. */ +extern PNG_EXPORT(png_uint_32,png_get_rowbytes) PNGARG((png_structp png_ptr, +png_infop info_ptr)); + +/* Returns number of color channels in image. */ +extern PNG_EXPORT(png_byte,png_get_channels) PNGARG((png_structp png_ptr, +png_infop info_ptr)); + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* Returns image width in pixels. */ +extern PNG_EXPORT(png_uint_32, png_get_image_width) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns image height in pixels. */ +extern PNG_EXPORT(png_uint_32, png_get_image_height) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns image bit_depth. */ +extern PNG_EXPORT(png_byte, png_get_bit_depth) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns image color_type. */ +extern PNG_EXPORT(png_byte, png_get_color_type) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns image filter_type. */ +extern PNG_EXPORT(png_byte, png_get_filter_type) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns image interlace_type. */ +extern PNG_EXPORT(png_byte, png_get_interlace_type) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns image compression_type. */ +extern PNG_EXPORT(png_byte, png_get_compression_type) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns image resolution in pixels per meter, from pHYs chunk data. */ +extern PNG_EXPORT(png_uint_32, png_get_pixels_per_meter) PNGARG((png_structp +png_ptr, png_infop info_ptr)); +extern PNG_EXPORT(png_uint_32, png_get_x_pixels_per_meter) PNGARG((png_structp +png_ptr, png_infop info_ptr)); +extern PNG_EXPORT(png_uint_32, png_get_y_pixels_per_meter) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns pixel aspect ratio, computed from pHYs chunk data. */ +extern PNG_EXPORT(float, png_get_pixel_aspect_ratio) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +/* Returns image x, y offset in pixels or microns, from oFFs chunk data. */ +extern PNG_EXPORT(png_uint_32, png_get_x_offset_pixels) PNGARG((png_structp +png_ptr, png_infop info_ptr)); +extern PNG_EXPORT(png_uint_32, png_get_y_offset_pixels) PNGARG((png_structp +png_ptr, png_infop info_ptr)); +extern PNG_EXPORT(png_uint_32, png_get_x_offset_microns) PNGARG((png_structp +png_ptr, png_infop info_ptr)); +extern PNG_EXPORT(png_uint_32, png_get_y_offset_microns) PNGARG((png_structp +png_ptr, png_infop info_ptr)); + +#endif /* PNG_EASY_ACCESS_SUPPORTED */ + +/* Returns pointer to signature string read from PNG header */ +extern PNG_EXPORT(png_bytep,png_get_signature) PNGARG((png_structp png_ptr, +png_infop info_ptr)); + +#if defined(PNG_READ_bKGD_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_bKGD) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_color_16p *background)); +#endif /* PNG_READ_bKGD_SUPPORTED */ + +#if defined(PNG_READ_bKGD_SUPPORTED) || defined(PNG_WRITE_bKGD_SUPPORTED) +extern PNG_EXPORT(void,png_set_bKGD) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_color_16p background)); +#endif /* PNG_READ_bKGD_SUPPORTED || PNG_WRITE_bKGD_SUPPORTED */ + +#if defined(PNG_READ_cHRM_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_cHRM) PNGARG((png_structp png_ptr, + png_infop info_ptr, double *white_x, double *white_y, double *red_x, + double *red_y, double *green_x, double *green_y, double *blue_x, + double *blue_y)); +#endif /* PNG_READ_cHRM_SUPPORTED */ + +#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED) +extern PNG_EXPORT(void,png_set_cHRM) PNGARG((png_structp png_ptr, + png_infop info_ptr, double white_x, double white_y, double red_x, + double red_y, double green_x, double green_y, double blue_x, double blue_y)); +#endif /* PNG_READ_cHRM_SUPPORTED || PNG_WRITE_cHRM_SUPPORTED */ + +#if defined(PNG_READ_gAMA_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_gAMA) PNGARG((png_structp png_ptr, + png_infop info_ptr, double *file_gamma)); +#endif /* PNG_READ_gAMA_SUPPORTED */ + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) +extern PNG_EXPORT(void,png_set_gAMA) PNGARG((png_structp png_ptr, + png_infop info_ptr, double file_gamma)); +#endif /* PNG_READ_gAMA_SUPPORTED || PNG_WRITE_gAMA_SUPPORTED */ + +#if defined(PNG_READ_hIST_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_hIST) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_16p *hist)); +#endif /* PNG_READ_hIST_SUPPORTED */ + +#if defined(PNG_READ_hIST_SUPPORTED) || defined(PNG_WRITE_hIST_SUPPORTED) +extern PNG_EXPORT(void,png_set_hIST) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_16p hist)); +#endif /* PNG_READ_hIST_SUPPORTED || PNG_WRITE_hIST_SUPPORTED */ + +extern PNG_EXPORT(png_uint_32,png_get_IHDR) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 *width, png_uint_32 *height, + int *bit_depth, int *color_type, int *interlace_type, + int *compression_type, int *filter_type)); + +extern PNG_EXPORT(void,png_set_IHDR) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, int filter_type)); + +#if defined(PNG_READ_oFFs_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_oFFs) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 *offset_x, png_uint_32 *offset_y, + int *unit_type)); +#endif /* PNG_READ_oFFs_SUPPORTED */ + +#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) +extern PNG_EXPORT(void,png_set_oFFs) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 offset_x, png_uint_32 offset_y, + int unit_type)); +#endif /* PNG_READ_oFFs_SUPPORTED || PNG_WRITE_oFFs_SUPPORTED */ + +#if defined(PNG_READ_pCAL_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_pCAL) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_charp *purpose, png_int_32 *X0, png_int_32 *X1, + int *type, int *nparams, png_charp *units, png_charpp *params)); +#endif /* PNG_READ_pCAL_SUPPORTED */ + +#if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) +extern PNG_EXPORT(void,png_set_pCAL) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_charp purpose, png_int_32 X0, png_int_32 X1, + int type, int nparams, png_charp units, png_charpp params)); +#endif /* PNG_READ_pCAL_SUPPORTED || PNG_WRITE_pCAL_SUPPORTED */ + +#if defined(PNG_READ_pHYs_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_pHYs) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type)); +#endif /* PNG_READ_pHYs_SUPPORTED */ + +#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) +extern PNG_EXPORT(void,png_set_pHYs) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 res_x, png_uint_32 res_y, int unit_type)); +#endif /* PNG_READ_pHYs_SUPPORTED || PNG_WRITE_pHYs_SUPPORTED */ + +extern PNG_EXPORT(png_uint_32,png_get_PLTE) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_colorp *palette, int *num_palette)); + +extern PNG_EXPORT(void,png_set_PLTE) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_colorp palette, int num_palette)); + +#if defined(PNG_READ_sBIT_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_sBIT) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_color_8p *sig_bit)); +#endif /* PNG_READ_sBIT_SUPPORTED */ + +#if defined(PNG_READ_sBIT_SUPPORTED) || defined(PNG_WRITE_sBIT_SUPPORTED) +extern PNG_EXPORT(void,png_set_sBIT) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_color_8p sig_bit)); +#endif /* PNG_READ_sBIT_SUPPORTED || PNG_WRITE_sBIT_SUPPORTED */ + +#if defined(PNG_READ_sRGB_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_sRGB) PNGARG((png_structp png_ptr, + png_infop info_ptr, int *intent)); +#endif /* PNG_READ_sRGB_SUPPORTED */ + +#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED) +extern PNG_EXPORT(void,png_set_sRGB) PNGARG((png_structp png_ptr, + png_infop info_ptr, int intent)); +extern PNG_EXPORT(void,png_set_sRGB_gAMA_and_cHRM) PNGARG((png_structp png_ptr, + png_infop info_ptr, int intent)); +#endif /* PNG_READ_sRGB_SUPPORTED || PNG_WRITE_sRGB_SUPPORTED */ + +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) +/* png_get_text also returns the number of text chunks in text_ptr */ +extern PNG_EXPORT(png_uint_32,png_get_text) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_textp *text_ptr, int *num_text)); +#endif /* PNG_READ_tEXt_SUPPORTED || PNG_READ_zTXt_SUPPORTED */ + +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \ + defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) +extern PNG_EXPORT(void,png_set_text) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_textp text_ptr, int num_text)); +#endif /* PNG_READ_tEXt_SUPPORTED || PNG_WRITE_tEXt_SUPPORTED || + PNG_READ_zTXt_SUPPORTED || PNG_WRITE_zTXt_SUPPORTED */ + +#if defined(PNG_READ_tIME_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_tIME) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_timep *mod_time)); +#endif /* PNG_READ_tIME_SUPPORTED */ + +#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED) +extern PNG_EXPORT(void,png_set_tIME) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_timep mod_time)); +#endif /* PNG_READ_tIME_SUPPORTED || PNG_WRITE_tIME_SUPPORTED */ + +#if defined(PNG_READ_tRNS_SUPPORTED) +extern PNG_EXPORT(png_uint_32,png_get_tRNS) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_bytep *trans, int *num_trans, + png_color_16p *trans_values)); +#endif /* PNG_READ_tRNS_SUPPORTED */ + +#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED) +extern PNG_EXPORT(void,png_set_tRNS) PNGARG((png_structp png_ptr, + png_infop info_ptr, png_bytep trans, int num_trans, + png_color_16p trans_values)); +#endif /* PNG_READ_tRNS_SUPPORTED || PNG_WRITE_tRNS_SUPPORTED */ + +/* Define PNG_DEBUG at compile time for debugging information. Higher + * numbers for PNG_DEBUG mean more debugging information. This has + * only been added since version 0.95 so it is not implemented throughout + * libpng yet, but more support will be added as needed. + */ +#if (PNG_DEBUG > 0) +#ifdef PNG_NO_STDIO +#include +#endif +#ifndef PNG_DEBUG_FILE +#define PNG_DEBUG_FILE stderr +#endif /* PNG_DEBUG_FILE */ + +#define png_debug(l,m) if (PNG_DEBUG > l) \ + fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \ + (l==2 ? "\t\t":(l==3 ? "\t\t\t":"")))) +#define png_debug1(l,m,p1) if (PNG_DEBUG > l) \ + fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \ + (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))),p1) +#define png_debug2(l,m,p1,p2) if (PNG_DEBUG > l) \ + fprintf(PNG_DEBUG_FILE,"%s"m,(l==1 ? "\t" : \ + (l==2 ? "\t\t":(l==3 ? "\t\t\t":""))),p1,p2) +#else +#define png_debug(l, m) +#define png_debug1(l, m, p1) +#define png_debug2(l, m, p1, p2) +#endif /* (PNG_DEBUG > 0) */ + +/* These next functions are used internally in the code. They generally + * shouldn't be used unless you are writing code to add or replace some + * functionality in libpng. More information about most functions can + * be found in the files where the functions are located. + */ + +#if defined(PNG_INTERNAL) + +/* Various modes of operation. Note that after an init, mode is set to + * zero automatically when the structure is created. + */ +#define PNG_BEFORE_IHDR 0x00 +#define PNG_HAVE_IHDR 0x01 +#define PNG_HAVE_PLTE 0x02 +#define PNG_HAVE_IDAT 0x04 +#define PNG_AFTER_IDAT 0x08 +#define PNG_HAVE_IEND 0x10 +#define PNG_HAVE_gAMA 0x20 +#define PNG_HAVE_cHRM 0x40 +#define PNG_HAVE_sRGB 0x80 + +/* push model modes */ +#define PNG_READ_SIG_MODE 0 +#define PNG_READ_CHUNK_MODE 1 +#define PNG_READ_IDAT_MODE 2 +#define PNG_SKIP_MODE 3 +#define PNG_READ_tEXt_MODE 4 +#define PNG_READ_zTXt_MODE 5 +#define PNG_READ_DONE_MODE 6 +#define PNG_ERROR_MODE 7 + +/* flags for the transformations the PNG library does on the image data */ +#define PNG_BGR 0x0001 +#define PNG_INTERLACE 0x0002 +#define PNG_PACK 0x0004 +#define PNG_SHIFT 0x0008 +#define PNG_SWAP_BYTES 0x0010 +#define PNG_INVERT_MONO 0x0020 +#define PNG_DITHER 0x0040 +#define PNG_BACKGROUND 0x0080 +#define PNG_BACKGROUND_EXPAND 0x0100 +#define PNG_RGB_TO_GRAY 0x0200 /* Not currently implemented */ +#define PNG_16_TO_8 0x0400 +#define PNG_RGBA 0x0800 +#define PNG_EXPAND 0x1000 +#define PNG_GAMMA 0x2000 +#define PNG_GRAY_TO_RGB 0x4000 +#define PNG_FILLER 0x8000 +#define PNG_PACKSWAP 0x1.0.1L +#define PNG_SWAP_ALPHA 0x20000L +#define PNG_STRIP_ALPHA 0x40000L +#define PNG_INVERT_ALPHA 0x80000L +#define PNG_USER_TRANSFORM 0x1.0.10L + +/* flags for png_create_struct */ +#define PNG_STRUCT_PNG 0x0001 +#define PNG_STRUCT_INFO 0x0002 + +/* Scaling factor for filter heuristic weighting calculations */ +#define PNG_WEIGHT_SHIFT 8 +#define PNG_WEIGHT_FACTOR (1<<(PNG_WEIGHT_SHIFT)) +#define PNG_COST_SHIFT 3 +#define PNG_COST_FACTOR (1<<(PNG_COST_SHIFT)) + +/* flags for the png_ptr->flags rather than declaring a byte for each one */ +#define PNG_FLAG_ZLIB_CUSTOM_STRATEGY 0x0001 +#define PNG_FLAG_ZLIB_CUSTOM_LEVEL 0x0002 +#define PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL 0x0004 +#define PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS 0x0008 +#define PNG_FLAG_ZLIB_CUSTOM_METHOD 0x0010 +#define PNG_FLAG_ZLIB_FINISHED 0x0020 +#define PNG_FLAG_ROW_INIT 0x0040 +#define PNG_FLAG_FILLER_AFTER 0x0080 +#define PNG_FLAG_CRC_ANCILLARY_USE 0x0100 +#define PNG_FLAG_CRC_ANCILLARY_NOWARN 0x0200 +#define PNG_FLAG_CRC_CRITICAL_USE 0x0400 +#define PNG_FLAG_CRC_CRITICAL_IGNORE 0x0800 +#define PNG_FLAG_FREE_PALETTE 0x1000 +#define PNG_FLAG_FREE_TRANS 0x2000 +#define PNG_FLAG_FREE_HIST 0x4000 +#define PNG_FLAG_HAVE_CHUNK_HEADER 0x8000L +#define PNG_FLAG_WROTE_tIME 0x1.0.1L + +#define PNG_FLAG_CRC_ANCILLARY_MASK (PNG_FLAG_CRC_ANCILLARY_USE | \ + PNG_FLAG_CRC_ANCILLARY_NOWARN) + +#define PNG_FLAG_CRC_CRITICAL_MASK (PNG_FLAG_CRC_CRITICAL_USE | \ + PNG_FLAG_CRC_CRITICAL_IGNORE) + +#define PNG_FLAG_CRC_MASK (PNG_FLAG_CRC_ANCILLARY_MASK | \ + PNG_FLAG_CRC_CRITICAL_MASK) + +/* save typing and make code easier to understand */ +#define PNG_COLOR_DIST(c1, c2) (abs((int)((c1).red) - (int)((c2).red)) + \ + abs((int)((c1).green) - (int)((c2).green)) + \ + abs((int)((c1).blue) - (int)((c2).blue))) + +/* variables declared in png.c - only it needs to define PNG_NO_EXTERN */ +#if !defined(PNG_NO_EXTERN) || defined(PNG_ALWAYS_EXTERN) +/* place to hold the signature string for a PNG file. */ +extern png_byte FARDATA png_sig[8]; + +/* Constant strings for known chunk types. If you need to add a chunk, + * add a string holding the name here. See png.c for more details. We + * can't selectively include these, since we still check for chunk in the + * wrong locations with these labels. + */ +extern png_byte FARDATA png_IHDR[5]; +extern png_byte FARDATA png_IDAT[5]; +extern png_byte FARDATA png_IEND[5]; +extern png_byte FARDATA png_PLTE[5]; +extern png_byte FARDATA png_bKGD[5]; +extern png_byte FARDATA png_cHRM[5]; +extern png_byte FARDATA png_gAMA[5]; +extern png_byte FARDATA png_hIST[5]; +extern png_byte FARDATA png_oFFs[5]; +extern png_byte FARDATA png_pCAL[5]; +extern png_byte FARDATA png_pHYs[5]; +extern png_byte FARDATA png_sBIT[5]; +extern png_byte FARDATA png_sRGB[5]; +extern png_byte FARDATA png_tEXt[5]; +extern png_byte FARDATA png_tIME[5]; +extern png_byte FARDATA png_tRNS[5]; +extern png_byte FARDATA png_zTXt[5]; + +#endif /* PNG_NO_EXTERN */ + +/* Inline macros to do direct reads of bytes from the input buffer. These + * require that you are using an architecture that uses PNG byte ordering + * (MSB first) and supports unaligned data storage. I think that PowerPC + * in big-endian mode and 680x0 are the only ones that will support this. + * The x86 line of processors definitely do not. The png_get_int_32() + * routine also assumes we are using two's complement format for negative + * values, which is almost certainly true. + */ +#if defined(PNG_READ_BIG_ENDIAN_SUPPORTED) +#if defined(PNG_READ_pCAL_SUPPORTED) +#define png_get_int_32(buf) ( *((png_int_32p) (buf))) +#endif /* PNG_READ_pCAL_SUPPORTED */ +#define png_get_uint_32(buf) ( *((png_uint_32p) (buf))) +#define png_get_uint_16(buf) ( *((png_uint_16p) (buf))) +#else +#if defined(PNG_READ_pCAL_SUPPORTED) +PNG_EXTERN png_int_32 png_get_int_32 PNGARG((png_bytep buf)); +#endif /* PNG_READ_pCAL_SUPPORTED */ +PNG_EXTERN png_uint_32 png_get_uint_32 PNGARG((png_bytep buf)); +PNG_EXTERN png_uint_16 png_get_uint_16 PNGARG((png_bytep buf)); +#endif /* PNG_BIG_ENDIAN_GET_SUPPORTED */ + +/* Initialize png_ptr struct for reading, and allocate any other memory. + * (old interface - NOT DLL EXPORTED). + */ +extern void png_read_init PNGARG((png_structp png_ptr)); + +/* Initialize png_ptr struct for writing, and allocate any other memory. + * (old interface - NOT DLL EXPORTED). + */ +extern void png_write_init PNGARG((png_structp png_ptr)); + +/* allocate memory for an internal libpng struct */ +PNG_EXTERN png_voidp png_create_struct PNGARG((int type)); + +/* free memory from internal libpng struct */ +PNG_EXTERN void png_destroy_struct PNGARG((png_voidp struct_ptr)); + +/* free any memory that info_ptr points to and reset struct. */ +PNG_EXTERN void png_info_destroy PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +/* Function to allocate memory for zlib. */ +PNG_EXTERN voidpf png_zalloc PNGARG((voidpf png_ptr, uInt items, uInt size)); + +/* function to free memory for zlib */ +PNG_EXTERN void png_zfree PNGARG((voidpf png_ptr, voidpf ptr)); + +/* reset the CRC variable */ +PNG_EXTERN void png_reset_crc PNGARG((png_structp png_ptr)); + +/* Write the "data" buffer to whatever output you are using. */ +PNG_EXTERN void png_write_data PNGARG((png_structp png_ptr, png_bytep data, + png_size_t length)); + +/* Read data from whatever input you are using into the "data" buffer */ +PNG_EXTERN void png_read_data PNGARG((png_structp png_ptr, png_bytep data, + png_size_t length)); + +/* read bytes into buf, and update png_ptr->crc */ +PNG_EXTERN void png_crc_read PNGARG((png_structp png_ptr, png_bytep buf, + png_size_t length)); + +/* read "skip" bytes, read the file crc, and (optionally) verify png_ptr->crc */ +PNG_EXTERN int png_crc_finish PNGARG((png_structp png_ptr, png_uint_32 skip)); + +/* read the CRC from the file and compare it to the libpng calculated CRC */ +PNG_EXTERN int png_crc_error PNGARG((png_structp png_ptr)); + +/* Calculate the CRC over a section of data. Note that we are only + * passing a maximum of 64K on systems that have this as a memory limit, + * since this is the maximum buffer size we can specify. + */ +PNG_EXTERN void png_calculate_crc PNGARG((png_structp png_ptr, png_bytep ptr, + png_size_t length)); + +#if defined(PNG_WRITE_FLUSH_SUPPORTED) +PNG_EXTERN void png_flush PNGARG((png_structp png_ptr)); +#endif + +/* Place a 32-bit number into a buffer in PNG byte order (big-endian). + * The only currently known PNG chunk that uses signed numbers is + * the ancillary extension chunk, pCAL. + */ +PNG_EXTERN void png_save_uint_32 PNGARG((png_bytep buf, png_uint_32 i)); + +#if defined(PNG_WRITE_pCAL_SUPPORTED) +PNG_EXTERN void png_save_int_32 PNGARG((png_bytep buf, png_int_32 i)); +#endif + +/* Place a 16 bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +PNG_EXTERN void png_save_uint_16 PNGARG((png_bytep buf, unsigned int i)); + +/* simple function to write the signature */ +PNG_EXTERN void png_write_sig PNGARG((png_structp png_ptr)); + +/* write various chunks */ + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. + */ +PNG_EXTERN void png_write_IHDR PNGARG((png_structp png_ptr, png_uint_32 width, + png_uint_32 height, + int bit_depth, int color_type, int compression_type, int filter_type, + int interlace_type)); + +PNG_EXTERN void png_write_PLTE PNGARG((png_structp png_ptr, png_colorp palette, + png_uint_32 num_pal)); + +PNG_EXTERN void png_write_IDAT PNGARG((png_structp png_ptr, png_bytep data, + png_size_t length)); + +PNG_EXTERN void png_write_IEND PNGARG((png_structp png_ptr)); + +#if defined(PNG_WRITE_gAMA_SUPPORTED) +PNG_EXTERN void png_write_gAMA PNGARG((png_structp png_ptr, double file_gamma)); +#endif + +#if defined(PNG_WRITE_sBIT_SUPPORTED) +PNG_EXTERN void png_write_sBIT PNGARG((png_structp png_ptr, png_color_8p sbit, + int color_type)); +#endif + +#if defined(PNG_WRITE_cHRM_SUPPORTED) +PNG_EXTERN void png_write_cHRM PNGARG((png_structp png_ptr, + double white_x, double white_y, + double red_x, double red_y, double green_x, double green_y, + double blue_x, double blue_y)); +#endif + +#if defined(PNG_WRITE_sRGB_SUPPORTED) +PNG_EXTERN void png_write_sRGB PNGARG((png_structp png_ptr, + int intent)); +#endif + +#if defined(PNG_WRITE_tRNS_SUPPORTED) +PNG_EXTERN void png_write_tRNS PNGARG((png_structp png_ptr, png_bytep trans, + png_color_16p values, int number, int color_type)); +#endif + +#if defined(PNG_WRITE_bKGD_SUPPORTED) +PNG_EXTERN void png_write_bKGD PNGARG((png_structp png_ptr, + png_color_16p values, int color_type)); +#endif + +#if defined(PNG_WRITE_hIST_SUPPORTED) +PNG_EXTERN void png_write_hIST PNGARG((png_structp png_ptr, png_uint_16p hist, + int num_hist)); +#endif + +#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) +PNG_EXTERN png_size_t png_check_keyword PNGARG((png_structp png_ptr, + png_charp key, png_charpp new_key)); +#endif + +#if defined(PNG_WRITE_tEXt_SUPPORTED) +PNG_EXTERN void png_write_tEXt PNGARG((png_structp png_ptr, png_charp key, + png_charp text, png_size_t text_len)); +#endif + +#if defined(PNG_WRITE_zTXt_SUPPORTED) +PNG_EXTERN void png_write_zTXt PNGARG((png_structp png_ptr, png_charp key, + png_charp text, png_size_t text_len, int compression)); +#endif + +#if defined(PNG_WRITE_oFFs_SUPPORTED) +PNG_EXTERN void png_write_oFFs PNGARG((png_structp png_ptr, + png_uint_32 x_offset, png_uint_32 y_offset, int unit_type)); +#endif + +#if defined(PNG_WRITE_pCAL_SUPPORTED) +PNG_EXTERN void png_write_pCAL PNGARG((png_structp png_ptr, png_charp purpose, + png_int_32 X0, png_int_32 X1, int type, int nparams, + png_charp units, png_charpp params)); +#endif + +#if defined(PNG_WRITE_pHYs_SUPPORTED) +PNG_EXTERN void png_write_pHYs PNGARG((png_structp png_ptr, + png_uint_32 x_pixels_per_unit, png_uint_32 y_pixels_per_unit, + int unit_type)); +#endif + +#if defined(PNG_WRITE_tIME_SUPPORTED) +PNG_EXTERN void png_write_tIME PNGARG((png_structp png_ptr, + png_timep mod_time)); +#endif + +/* Called when finished processing a row of data */ +PNG_EXTERN void png_write_finish_row PNGARG((png_structp png_ptr)); + +/* Internal use only. Called before first row of data */ +PNG_EXTERN void png_write_start_row PNGARG((png_structp png_ptr)); + +#if defined(PNG_READ_GAMMA_SUPPORTED) +PNG_EXTERN void png_build_gamma_table PNGARG((png_structp png_ptr)); +#endif + +/* combine a row of data, dealing with alpha, etc. if requested */ +PNG_EXTERN void png_combine_row PNGARG((png_structp png_ptr, png_bytep row, + int mask)); + +#if defined(PNG_READ_INTERLACING_SUPPORTED) +/* expand an interlaced row */ +PNG_EXTERN void png_do_read_interlace PNGARG((png_row_infop row_info, + png_bytep row, int pass, png_uint_32 transformations)); +#endif + +#if defined(PNG_WRITE_INTERLACING_SUPPORTED) +/* grab pixels out of a row for an interlaced pass */ +PNG_EXTERN void png_do_write_interlace PNGARG((png_row_infop row_info, + png_bytep row, int pass)); +#endif + +/* unfilter a row */ +PNG_EXTERN void png_read_filter_row PNGARG((png_structp png_ptr, + png_row_infop row_info, png_bytep row, png_bytep prev_row, int filter)); + +/* Choose the best filter to use and filter the row data */ +PNG_EXTERN void png_write_find_filter PNGARG((png_structp png_ptr, + png_row_infop row_info)); + +/* Write out the filtered row. */ +PNG_EXTERN void png_write_filtered_row PNGARG((png_structp png_ptr, + png_bytep filtered_row)); +/* finish a row while reading, dealing with interlacing passes, etc. */ +PNG_EXTERN void png_read_finish_row PNGARG((png_structp png_ptr)); + +/* initialize the row buffers, etc. */ +PNG_EXTERN void png_read_start_row PNGARG((png_structp png_ptr)); +/* optional call to update the users info structure */ +PNG_EXTERN void png_read_transform_info PNGARG((png_structp png_ptr, + png_infop info_ptr)); + +/* these are the functions that do the transformations */ +#if defined(PNG_READ_FILLER_SUPPORTED) +PNG_EXTERN void png_do_read_filler PNGARG((png_row_infop row_info, + png_bytep row, png_uint_32 filler, png_uint_32 flags)); +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) +PNG_EXTERN void png_do_read_swap_alpha PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +PNG_EXTERN void png_do_write_swap_alpha PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) +PNG_EXTERN void png_do_read_invert_alpha PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +PNG_EXTERN void png_do_write_invert_alpha PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ + defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +PNG_EXTERN void png_do_strip_filler PNGARG((png_row_infop row_info, + png_bytep row, png_uint_32 flags)); +#endif + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +PNG_EXTERN void png_do_swap PNGARG((png_row_infop row_info, png_bytep row)); +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) || defined(PNG_WRITE_PACKSWAP_SUPPOR) +PNG_EXTERN void png_do_packswap PNGARG((png_row_infop row_info, png_bytep row)); +#endif + +#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) +PNG_EXTERN void png_do_rgb_to_gray PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) +PNG_EXTERN void png_do_gray_to_rgb PNGARG((png_row_infop row_info, + png_bytep row)); +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) +PNG_EXTERN void png_do_unpack PNGARG((png_row_infop row_info, png_bytep row)); +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) +PNG_EXTERN void png_do_unshift PNGARG((png_row_infop row_info, png_bytep row, + png_color_8p sig_bits)); +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +PNG_EXTERN void png_do_invert PNGARG((png_row_infop row_info, png_bytep row)); +#endif + +#if defined(PNG_READ_16_TO_8_SUPPORTED) +PNG_EXTERN void png_do_chop PNGARG((png_row_infop row_info, png_bytep row)); +#endif + +#if defined(PNG_READ_DITHER_SUPPORTED) +PNG_EXTERN void png_do_dither PNGARG((png_row_infop row_info, + png_bytep row, png_bytep palette_lookup, png_bytep dither_lookup)); + +# if defined(PNG_CORRECT_PALETTE_SUPPORTED) +PNG_EXTERN void png_correct_palette PNGARG((png_structp png_ptr, + png_colorp palette, int num_palette)); +# endif +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +PNG_EXTERN void png_do_bgr PNGARG((png_row_infop row_info, png_bytep row)); +#endif + +#if defined(PNG_WRITE_PACK_SUPPORTED) +PNG_EXTERN void png_do_pack PNGARG((png_row_infop row_info, + png_bytep row, png_uint_32 bit_depth)); +#endif + +#if defined(PNG_WRITE_SHIFT_SUPPORTED) +PNG_EXTERN void png_do_shift PNGARG((png_row_infop row_info, png_bytep row, + png_color_8p bit_depth)); +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) +PNG_EXTERN void png_do_background PNGARG((png_row_infop row_info, png_bytep row, + png_color_16p trans_values, png_color_16p background, + png_color_16p background_1, + png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1, + png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1, + png_uint_16pp gamma_16_to_1, int gamma_shift)); +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) +PNG_EXTERN void png_do_gamma PNGARG((png_row_infop row_info, png_bytep row, + png_bytep gamma_table, png_uint_16pp gamma_16_table, + int gamma_shift)); +#endif + +#if defined(PNG_READ_EXPAND_SUPPORTED) +PNG_EXTERN void png_do_expand_palette PNGARG((png_row_infop row_info, + png_bytep row, png_colorp palette, png_bytep trans, int num_trans)); +PNG_EXTERN void png_do_expand PNGARG((png_row_infop row_info, + png_bytep row, png_color_16p trans_value)); +#endif + +/* The following decodes the appropriate chunks, and does error correction, + * then calls the appropriate callback for the chunk if it is valid. + */ + +/* decode the IHDR chunk */ +PNG_EXTERN void png_handle_IHDR PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +PNG_EXTERN void png_handle_PLTE PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +PNG_EXTERN void png_handle_IEND PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); + +#if defined(PNG_READ_gAMA_SUPPORTED) +PNG_EXTERN void png_handle_gAMA PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_sBIT_SUPPORTED) +PNG_EXTERN void png_handle_sBIT PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_cHRM_SUPPORTED) +PNG_EXTERN void png_handle_cHRM PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_sRGB_SUPPORTED) +PNG_EXTERN void png_handle_sRGB PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_tRNS_SUPPORTED) +PNG_EXTERN void png_handle_tRNS PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_bKGD_SUPPORTED) +PNG_EXTERN void png_handle_bKGD PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_hIST_SUPPORTED) +PNG_EXTERN void png_handle_hIST PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_oFFs_SUPPORTED) +PNG_EXTERN void png_handle_oFFs PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_pCAL_SUPPORTED) +PNG_EXTERN void png_handle_pCAL PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_pHYs_SUPPORTED) +PNG_EXTERN void png_handle_pHYs PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_tIME_SUPPORTED) +PNG_EXTERN void png_handle_tIME PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_tEXt_SUPPORTED) +PNG_EXTERN void png_handle_tEXt PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +#if defined(PNG_READ_zTXt_SUPPORTED) +PNG_EXTERN void png_handle_zTXt PNGARG((png_structp png_ptr, png_infop info_ptr, + png_uint_32 length)); +#endif + +PNG_EXTERN void png_handle_unknown PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); + +PNG_EXTERN void png_check_chunk_name PNGARG((png_structp png_ptr, + png_bytep chunk_name)); + +/* handle the transformations for reading and writing */ +PNG_EXTERN void png_do_read_transformations PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_do_write_transformations PNGARG((png_structp png_ptr)); + +PNG_EXTERN void png_init_read_transformations PNGARG((png_structp png_ptr)); + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED +PNG_EXTERN void png_push_read_chunk PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_push_read_sig PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_push_check_crc PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_push_crc_skip PNGARG((png_structp png_ptr, + png_uint_32 length)); +PNG_EXTERN void png_push_crc_finish PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_push_fill_buffer PNGARG((png_structp png_ptr, + png_bytep buffer, png_size_t length)); +PNG_EXTERN void png_push_save_buffer PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_push_restore_buffer PNGARG((png_structp png_ptr, + png_bytep buffer, png_size_t buffer_length)); +PNG_EXTERN void png_push_read_IDAT PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_process_IDAT_data PNGARG((png_structp png_ptr, + png_bytep buffer, png_size_t buffer_length)); +PNG_EXTERN void png_push_process_row PNGARG((png_structp png_ptr)); +PNG_EXTERN void png_push_handle_unknown PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); +PNG_EXTERN void png_push_have_info PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_push_have_end PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_push_have_row PNGARG((png_structp png_ptr, png_bytep row)); +PNG_EXTERN void png_push_read_end PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_process_some_data PNGARG((png_structp png_ptr, + png_infop info_ptr)); +PNG_EXTERN void png_read_push_finish_row PNGARG((png_structp png_ptr)); +#if defined(PNG_READ_tEXt_SUPPORTED) +PNG_EXTERN void png_push_handle_tEXt PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); +PNG_EXTERN void png_push_read_tEXt PNGARG((png_structp png_ptr, + png_infop info_ptr)); +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) +PNG_EXTERN void png_push_handle_zTXt PNGARG((png_structp png_ptr, + png_infop info_ptr, png_uint_32 length)); +PNG_EXTERN void png_push_read_zTXt PNGARG((png_structp png_ptr, + png_infop info_ptr)); +#endif + +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ + +#endif /* PNG_INTERNAL */ + +#ifdef __cplusplus +} +#endif + +/* do not put anything past this line */ +#endif /* _PNG_H */ diff --git a/thirdparty/libpng/pngconf.h b/thirdparty/libpng/pngconf.h new file mode 100644 index 00000000..56d189bf --- /dev/null +++ b/thirdparty/libpng/pngconf.h @@ -0,0 +1,565 @@ + +/* pngconf.h - machine configurable file for libpng + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + */ + +/* Any machine specific code is near the front of this file, so if you + * are configuring libpng for a machine, you may want to read the section + * starting here down to where it starts to typedef png_color, png_text, + * and png_info. + */ + +#ifndef PNGCONF_H +#define PNGCONF_H + +/* This is the size of the compression buffer, and thus the size of + * an IDAT chunk. Make this whatever size you feel is best for your + * machine. One of these will be allocated per png_struct. When this + * is full, it writes the data to the disk, and does some other + * calculations. Making this an extremely small size will slow + * the library down, but you may want to experiment to determine + * where it becomes significant, if you are concerned with memory + * usage. Note that zlib allocates at least 32Kb also. For readers, + * this describes the size of the buffer available to read the data in. + * Unless this gets smaller than the size of a row (compressed), + * it should not make much difference how big this is. + */ + +#ifndef PNG_ZBUF_SIZE +#define PNG_ZBUF_SIZE 8192 +#endif + +/* If you are running on a machine where you cannot allocate more + * than 64K of memory at once, uncomment this. While libpng will not + * normally need that much memory in a chunk (unless you load up a very + * large file), zlib needs to know how big of a chunk it can use, and + * libpng thus makes sure to check any memory allocation to verify it + * will fit into memory. +#define PNG_MAX_MALLOC_64K + */ +#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) +#define PNG_MAX_MALLOC_64K +#endif + +/* This protects us against compilers which run on a windowing system + * and thus don't have or would rather us not use the stdio types: + * stdin, stdout, and stderr. The only one currently used is stderr + * in png_error() and png_warning(). #defining PNG_NO_STDIO will + * prevent these from being compiled and used. + * #define PNG_NO_STDIO + */ + +#ifndef PNG_NO_STDIO +#include +#endif + +/* This macro protects us against machines that don't have function + * prototypes (ie K&R style headers). If your compiler does not handle + * function prototypes, define this macro and use the included ansi2knr. + * I've always been able to use _NO_PROTO as the indicator, but you may + * need to drag the empty declaration out in front of here, or change the + * ifdef to suit your own needs. + */ +#ifndef PNGARG + +#ifdef OF /* zlib prototype munger */ +#define PNGARG(arglist) OF(arglist) +#else + +#ifdef _NO_PROTO +#define PNGARG(arglist) () +#else +#define PNGARG(arglist) arglist +#endif /* _NO_PROTO */ + +#endif /* OF */ + +#endif /* PNGARG */ + +/* Try to determine if we are compiling on a Mac. Note that testing for + * just __MWERKS__ is not good enough, because the Codewarrior is now used + * on non-Mac platforms. + */ +#ifndef MACOS +#if (defined(__MWERKS__) && defined(macintosh)) || defined(applec) || \ + defined(THINK_C) || defined(__SC__) || defined(TARGET_OS_MAC) +#define MACOS +#endif +#endif + +/* enough people need this for various reasons to include it here */ +#if !defined(MACOS) && !defined(RISCOS) +#include +#endif + +/* This is an attempt to force a single setjmp behaviour on Linux. If + * the X config stuff didn't define _BSD_SOURCE we wouldn't need this. + */ +#ifdef __linux__ +#ifdef _BSD_SOURCE +#define _PNG_SAVE_BSD_SOURCE +#undef _BSD_SOURCE +#endif +#ifdef _SETJMP_H +__png.h__ already includes setjmp.h +__dont__ include it again +#endif +#endif /* __linux__ */ + +/* include setjmp.h for error handling */ +#include + +#ifdef __linux__ +#ifdef _PNG_SAVE_BSD_SOURCE +#define _BSD_SOURCE +#undef _PNG_SAVE_BSD_SOURCE +#endif +#endif /* __linux__ */ + +#ifdef BSD +#include +#else +#include +#endif + +/* Other defines for things like memory and the like can go here. */ +#ifdef PNG_INTERNAL +#include + +/* The functions exported by PNG_EXTERN are PNG_INTERNAL functions, which + * aren't usually used outside the library (as far as I know), so it is + * debatable if they should be exported at all. In the future, when it is + * possible to have run-time registry of chunk-handling functions, some of + * these will be made available again. +#define PNG_EXTERN extern + */ +#define PNG_EXTERN + +/* Other defines specific to compilers can go here. Try to keep + * them inside an appropriate ifdef/endif pair for portability. + */ + +#if defined(MACOS) +/* We need to check that hasn't already been included earlier + * as it seems it doesn't agree with , yet we should really use + * if possible. + */ +#if !defined(__MATH_H__) && !defined(__MATH_H) && !defined(__cmath__) +#include +#endif +#else +#include +#endif + +/* Codewarrior on NT has linking problems without this. */ +#if defined(__MWERKS__) && defined(WIN32) +#define PNG_ALWAYS_EXTERN +#endif + +/* For some reason, Borland C++ defines memcmp, etc. in mem.h, not + * stdlib.h like it should (I think). Or perhaps this is a C++ + * "feature"? + */ +#ifdef __TURBOC__ +#include +#include "alloc.h" +#endif + +#ifdef _MSC_VER +#include +#endif + +/* This controls how fine the dithering gets. As this allocates + * a largish chunk of memory (32K), those who are not as concerned + * with dithering quality can decrease some or all of these. + */ +#ifndef PNG_DITHER_RED_BITS +#define PNG_DITHER_RED_BITS 5 +#endif +#ifndef PNG_DITHER_GREEN_BITS +#define PNG_DITHER_GREEN_BITS 5 +#endif +#ifndef PNG_DITHER_BLUE_BITS +#define PNG_DITHER_BLUE_BITS 5 +#endif + +/* This controls how fine the gamma correction becomes when you + * are only interested in 8 bits anyway. Increasing this value + * results in more memory being used, and more pow() functions + * being called to fill in the gamma tables. Don't set this value + * less then 8, and even that may not work (I haven't tested it). + */ + +#ifndef PNG_MAX_GAMMA_8 +#define PNG_MAX_GAMMA_8 11 +#endif + +/* This controls how much a difference in gamma we can tolerate before + * we actually start doing gamma conversion. + */ +#ifndef PNG_GAMMA_THRESHOLD +#define PNG_GAMMA_THRESHOLD 0.05 +#endif + +#endif /* PNG_INTERNAL */ + +/* The following uses const char * instead of char * for error + * and warning message functions, so some compilers won't complain. + * If you do not want to use const, define PNG_NO_CONST here. + */ + +#ifndef PNG_NO_CONST +# define PNG_CONST const +#else +# define PNG_CONST +#endif + +/* The following defines give you the ability to remove code from the + * library that you will not be using. I wish I could figure out how to + * automate this, but I can't do that without making it seriously hard + * on the users. So if you are not using an ability, change the #define + * to and #undef, and that part of the library will not be compiled. If + * your linker can't find a function, you may want to make sure the + * ability is defined here. Some of these depend upon some others being + * defined. I haven't figured out all the interactions here, so you may + * have to experiment awhile to get everything to compile. If you are + * creating or using a shared library, you probably shouldn't touch this, + * as it will affect the size of the structures, and this will cause bad + * things to happen if the library and/or application ever change. + */ + +/* Any transformations you will not be using can be undef'ed here */ + +/* GR-P, 0.96a: Set "*TRANSFORMS_SUPPORTED as default but allow user + to turn it off with "*TRANSFORMS_NOT_SUPPORTED" on the compile line, + then pick and choose which ones to define without having to edit + this file. It is safe to use the *TRANSFORMS_NOT_SUPPORTED if you + only want to have a png-compliant reader/writer but don't need + any of the extra transformations. This saves about 80 kbytes in a + typical installation of the library. + */ + + +#ifndef PNG_READ_TRANSFORMS_NOT_SUPPORTED +#define PNG_READ_TRANSFORMS_SUPPORTED +#endif +#ifndef PNG_WRITE_TRANSFORMS_NOT_SUPPORTED +#define PNG_WRITE_TRANSFORMS_SUPPORTED +#endif + +#ifdef PNG_READ_TRANSFORMS_SUPPORTED +#define PNG_READ_EXPAND_SUPPORTED +#define PNG_READ_SHIFT_SUPPORTED +#define PNG_READ_PACK_SUPPORTED +#define PNG_READ_BGR_SUPPORTED +#define PNG_READ_SWAP_SUPPORTED +#define PNG_READ_PACKSWAP_SUPPORTED +#define PNG_READ_INVERT_SUPPORTED +#define PNG_READ_DITHER_SUPPORTED +#define PNG_READ_BACKGROUND_SUPPORTED +#define PNG_READ_16_TO_8_SUPPORTED +#define PNG_READ_FILLER_SUPPORTED +#define PNG_READ_GAMMA_SUPPORTED +#define PNG_READ_GRAY_TO_RGB_SUPPORTED +#define PNG_READ_SWAP_ALPHA_SUPPORTED +#define PNG_READ_INVERT_ALPHA_SUPPORTED +#define PNG_READ_STRIP_ALPHA_SUPPORTED +#define PNG_READ_USER_TRANSFORM_SUPPORTED +/* the following aren't implemented yet +#define PNG_READ_RGB_TO_GRAY_SUPPORTED + */ +#endif /* PNG_READ_TRANSFORMS_SUPPORTED */ + +#ifndef PNG_PROGRESSIVE_READ_NOT_SUPPORTED /* if you don't do progressive */ +#define PNG_PROGRESSIVE_READ_SUPPORTED /* reading. This is not talking */ +#endif /* about interlacing capability! You'll */ + /* still have interlacing unless you change the following line: */ +#define PNG_READ_INTERLACING_SUPPORTED /* required for PNG-compliant decoders */ +#define PNG_READ_COMPOSITE_NODIV_SUPPORTED /* well tested on Intel and SGI */ + +#ifdef PNG_WRITE_TRANSFORMS_SUPPORTED +#define PNG_WRITE_SHIFT_SUPPORTED +#define PNG_WRITE_PACK_SUPPORTED +#define PNG_WRITE_BGR_SUPPORTED +#define PNG_WRITE_SWAP_SUPPORTED +#define PNG_WRITE_PACKSWAP_SUPPORTED +#define PNG_WRITE_INVERT_SUPPORTED +#define PNG_WRITE_FILLER_SUPPORTED /* This is the same as WRITE_STRIP_ALPHA */ +#define PNG_WRITE_FLUSH_SUPPORTED +#define PNG_WRITE_SWAP_ALPHA_SUPPORTED +#define PNG_WRITE_INVERT_ALPHA_SUPPORTED +#define PNG_WRITE_WEIGHTED_FILTER_SUPPORTED +#define PNG_WRITE_USER_TRANSFORM_SUPPORTED +#endif /* PNG_WRITE_TRANSFORMS_SUPPORTED */ + +#define PNG_WRITE_INTERLACING_SUPPORTED /* not required for PNG-compliant + encoders, but can cause trouble + if left undefined */ + +#if !defined(PNG_NO_STDIO) +#define PNG_TIME_RFC1123_SUPPORTED +#endif + +/* This adds extra functions in pngget.c for accessing data from the + * info pointer (added in version 0.99) + * png_get_image_width() + * png_get_image_height() + * png_get_bit_depth() + * png_get_color_type() + * png_get_compression_type() + * png_get_filter_type() + * png_get_interlace_type() + * png_get_pixel_aspect_ratio() + * png_get_pixels_per_meter() + * png_get_x_offset_pixels() + * png_get_y_offset_pixels() + * png_get_x_offset_microns() + * png_get_y_offset_microns() + */ +#if !defined(PNG_NO_EASY_ACCESS) +#define PNG_EASY_ACCESS_SUPPORTED +#endif + +/* These are currently experimental features, define them if you want */ + +/* very little testing */ +/* +#define PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED +*/ + +/* This is only for PowerPC big-endian and 680x0 systems */ +/* some testing */ +/* +#define PNG_READ_BIG_ENDIAN_SUPPORTED +*/ + +/* These functions are turned off by default, as they will be phased out. */ +/* +#define PNG_USELESS_TESTS_SUPPORTED +#define PNG_CORRECT_PALETTE_SUPPORTED +*/ + +/* Any chunks you are not interested in, you can undef here. The + * ones that allocate memory may be expecially important (hIST, + * tEXt, zTXt, tRNS, pCAL). Others will just save time and make png_info + * a bit smaller. + */ + +#ifndef PNG_READ_ANCILLARY_CHUNKS_NOT_SUPPORTED +#define PNG_READ_ANCILLARY_CHUNKS_SUPPORTED +#endif +#ifndef PNG_WRITE_ANCILLARY_CHUNKS_NOT_SUPPORTED +#define PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED +#endif + +#ifdef PNG_READ_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_READ_bKGD_SUPPORTED +#define PNG_READ_cHRM_SUPPORTED +#define PNG_READ_gAMA_SUPPORTED +#define PNG_READ_hIST_SUPPORTED +#define PNG_READ_oFFs_SUPPORTED +#define PNG_READ_pCAL_SUPPORTED +#define PNG_READ_pHYs_SUPPORTED +#define PNG_READ_sBIT_SUPPORTED +#define PNG_READ_sRGB_SUPPORTED +#define PNG_READ_tEXt_SUPPORTED +#define PNG_READ_tIME_SUPPORTED +#define PNG_READ_tRNS_SUPPORTED +#define PNG_READ_zTXt_SUPPORTED +#define PNG_READ_OPT_PLTE_SUPPORTED /* only affects support of the optional */ + /* PLTE chunk in RGB and RGBA images */ +#endif /* PNG_READ_ANCILLARY_CHUNKS_SUPPORTED */ + +#ifdef PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED +#define PNG_WRITE_bKGD_SUPPORTED +#define PNG_WRITE_cHRM_SUPPORTED +#define PNG_WRITE_gAMA_SUPPORTED +#define PNG_WRITE_hIST_SUPPORTED +#define PNG_WRITE_oFFs_SUPPORTED +#define PNG_WRITE_pCAL_SUPPORTED +#define PNG_WRITE_pHYs_SUPPORTED +#define PNG_WRITE_sBIT_SUPPORTED +#define PNG_WRITE_sRGB_SUPPORTED +#define PNG_WRITE_tEXt_SUPPORTED +#define PNG_WRITE_tIME_SUPPORTED +#define PNG_WRITE_tRNS_SUPPORTED +#define PNG_WRITE_zTXt_SUPPORTED +#endif /* PNG_WRITE_ANCILLARY_CHUNKS_SUPPORTED */ + +/* need the time information for reading tIME chunks */ +#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED) +#include +#endif + +/* Some typedefs to get us started. These should be safe on most of the + * common platforms. The typedefs should be at least as large as the + * numbers suggest (a png_uint_32 must be at least 32 bits long), but they + * don't have to be exactly that size. Some compilers dislike passing + * unsigned shorts as function parameters, so you may be better off using + * unsigned int for png_uint_16. Likewise, for 64-bit systems, you may + * want to have unsigned int for png_uint_32 instead of unsigned long. + */ + +typedef unsigned long png_uint_32; +typedef long png_int_32; +typedef unsigned short png_uint_16; +typedef short png_int_16; +typedef unsigned char png_byte; + +/* This is usually size_t. It is typedef'ed just in case you need it to + change (I'm not sure if you will or not, so I thought I'd be safe) */ +typedef size_t png_size_t; + +/* The following is needed for medium model support. It cannot be in the + * PNG_INTERNAL section. Needs modification for other compilers besides + * MSC. Model independent support declares all arrays and pointers to be + * large using the far keyword. The zlib version used must also support + * model independent data. As of version zlib 1.0.4, the necessary changes + * have been made in zlib. The USE_FAR_KEYWORD define triggers other + * changes that are needed. (Tim Wegner) + */ + +/* Separate compiler dependencies (problem here is that zlib.h always + defines FAR. (SJT) */ +#ifdef __BORLANDC__ +#if defined(__LARGE__) || defined(__HUGE__) || defined(__COMPACT__) +#define LDATA 1 +#else +#define LDATA 0 +#endif + +#if !defined(__WIN32__) && !defined(__FLAT__) +#define PNG_MAX_MALLOC_64K +#if (LDATA != 1) +#ifndef FAR +#define FAR __far +#endif +#define USE_FAR_KEYWORD +#endif /* LDATA != 1 */ + +/* Possibly useful for moving data out of default segment. + * Uncomment it if you want. Could also define FARDATA as + * const if your compiler supports it. (SJT) +# define FARDATA FAR + */ +#endif /* __WIN32__, __FLAT__ */ + +#endif /* __BORLANDC__ */ + + +/* Suggest testing for specific compiler first before testing for + * FAR. The Watcom compiler defines both __MEDIUM__ and M_I86MM, + * making reliance oncertain keywords suspect. (SJT) + */ + +/* MSC Medium model */ +#if defined(FAR) +# if defined(M_I86MM) +# define USE_FAR_KEYWORD +# define FARDATA FAR +# include +# endif +#endif + +/* SJT: default case */ +#ifndef FAR +# define FAR +#endif + +/* At this point FAR is always defined */ +#ifndef FARDATA +#define FARDATA +#endif + +/* Add typedefs for pointers */ +typedef void FAR * png_voidp; +typedef png_byte FAR * png_bytep; +typedef png_uint_32 FAR * png_uint_32p; +typedef png_int_32 FAR * png_int_32p; +typedef png_uint_16 FAR * png_uint_16p; +typedef png_int_16 FAR * png_int_16p; +typedef PNG_CONST char FAR * png_const_charp; +typedef char FAR * png_charp; +typedef double FAR * png_doublep; + +/* Pointers to pointers; i.e. arrays */ +typedef png_byte FAR * FAR * png_bytepp; +typedef png_uint_32 FAR * FAR * png_uint_32pp; +typedef png_int_32 FAR * FAR * png_int_32pp; +typedef png_uint_16 FAR * FAR * png_uint_16pp; +typedef png_int_16 FAR * FAR * png_int_16pp; +typedef PNG_CONST char FAR * FAR * png_const_charpp; +typedef char FAR * FAR * png_charpp; +typedef double FAR * FAR * png_doublepp; + +/* Pointers to pointers to pointers; i.e. pointer to array */ +typedef char FAR * FAR * FAR * png_charppp; + +/* libpng typedefs for types in zlib. If zlib changes + * or another compression library is used, then change these. + * Eliminates need to change all the source files. + */ +typedef charf * png_zcharp; +typedef charf * FAR * png_zcharpp; +typedef z_stream FAR * png_zstreamp; + +/* allow for compilation as dll under MS Windows */ +#ifdef __WIN32DLL__ +#define PNG_EXPORT(type,symbol) __declspec(dllexport) type symbol +#endif + +/* allow for compilation as dll with BORLAND C++ 5.0 */ +#if defined(__BORLANDC__) && defined(_Windows) && defined(__DLL__) +# define PNG_EXPORT(type,symbol) type _export symbol +#endif + +/* allow for compilation as shared lib under BeOS */ +#ifdef __BEOSDLL__ +#define PNG_EXPORT(type,symbol) __declspec(export) type symbol +#endif + +#ifndef PNG_EXPORT +#define PNG_EXPORT(type,symbol) type symbol +#endif + + +/* User may want to use these so not in PNG_INTERNAL. Any library functions + * that are passed far data must be model independent. + */ + +#if defined(USE_FAR_KEYWORD) /* memory model independent fns */ +/* use this to make far-to-near assignments */ +# define CHECK 1 +# define NOCHECK 0 +# define CVT_PTR(ptr) (png_far_to_near(png_ptr,ptr,CHECK)) +# define CVT_PTR_NOCHECK(ptr) (png_far_to_near(png_ptr,ptr,NOCHECK)) +# define png_strlen _fstrlen +# define png_memcmp _fmemcmp /* SJT: added */ +# define png_memcpy _fmemcpy +# define png_memset _fmemset +#else /* use the usual functions */ +# define CVT_PTR(ptr) (ptr) +# define CVT_PTR_NOCHECK(ptr) (ptr) +# define png_strlen strlen +# define png_memcmp memcmp /* SJT: added */ +# define png_memcpy memcpy +# define png_memset memset +#endif +/* End of memory model independent support */ + +/* Just a double check that someone hasn't tried to define something + * contradictory. + */ +#if (PNG_ZBUF_SIZE > 65536) && defined(PNG_MAX_MALLOC_64K) +#undef PNG_ZBUF_SIZE +#define PNG_ZBUF_SIZE 65536 +#endif + +#endif /* PNGCONF_H */ + diff --git a/thirdparty/libpng/pngerror.c b/thirdparty/libpng/pngerror.c new file mode 100644 index 00000000..2942a5b2 --- /dev/null +++ b/thirdparty/libpng/pngerror.c @@ -0,0 +1,174 @@ + +/* pngerror.c - stub functions for i/o and memory allocation + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * This file provides a location for all error handling. Users which + * need special error handling are expected to write replacement functions + * and use png_set_error_fn() to use those functions. See the instructions + * at each function. + */ + +#define PNG_INTERNAL +#include "png.h" + +static void png_default_error PNGARG((png_structp png_ptr, + png_const_charp message)); +static void png_default_warning PNGARG((png_structp png_ptr, + png_const_charp message)); + +/* This function is called whenever there is a fatal error. This function + * should not be changed. If there is a need to handle errors differently, + * you should supply a replacement error function and use png_set_error_fn() + * to replace the error function at run-time. + */ +void +png_error(png_structp png_ptr, png_const_charp message) +{ + if (png_ptr->error_fn != NULL) + (*(png_ptr->error_fn))(png_ptr, message); + + /* if the following returns or doesn't exist, use the default function, + which will not return */ + png_default_error(png_ptr, message); +} + +/* This function is called whenever there is a non-fatal error. This function + * should not be changed. If there is a need to handle warnings differently, + * you should supply a replacement warning function and use + * png_set_error_fn() to replace the warning function at run-time. + */ +void +png_warning(png_structp png_ptr, png_const_charp message) +{ + if (png_ptr->warning_fn != NULL) + (*(png_ptr->warning_fn))(png_ptr, message); + else + png_default_warning(png_ptr, message); +} + +/* These utilities are used internally to build an error message which relates + * to the current chunk. The chunk name comes from png_ptr->chunk_name, + * this is used to prefix the message. The message is limited in length + * to 63 bytes, the name characters are output as hex digits wrapped in [] + * if the character is invalid. + */ +#define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97)) +static PNG_CONST char png_digit[16] = { + '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' +}; + +static void +png_format_buffer(png_structp png_ptr, png_charp buffer, png_const_charp message) +{ + int iout = 0, iin = 0; + + while (iin < 4) { + int c = png_ptr->chunk_name[iin++]; + if (isnonalpha(c)) { + buffer[iout++] = '['; + buffer[iout++] = png_digit[(c & 0xf0) >> 4]; + buffer[iout++] = png_digit[c & 0xf]; + buffer[iout++] = ']'; + } else { + buffer[iout++] = c; + } + } + + if (message == NULL) + buffer[iout] = 0; + else { + buffer[iout++] = ':'; + buffer[iout++] = ' '; + png_memcpy(buffer+iout, message, 64); + buffer[iout+63] = 0; + } +} + +void +png_chunk_error(png_structp png_ptr, png_const_charp message) +{ + char msg[16+64]; + png_format_buffer(png_ptr, msg, message); + png_error(png_ptr, msg); +} + +void +png_chunk_warning(png_structp png_ptr, png_const_charp message) +{ + char msg[16+64]; + png_format_buffer(png_ptr, msg, message); + png_warning(png_ptr, msg); +} + +/* This is the default error handling function. Note that replacements for + * this function MUST NOT RETURN, or the program will likely crash. This + * function is used by default, or if the program supplies NULL for the + * error function pointer in png_set_error_fn(). + */ +static void +png_default_error(png_structp png_ptr, png_const_charp message) +{ +#ifndef PNG_NO_STDIO + fprintf(stderr, "libpng error: %s\n", message); +#endif + +#ifdef USE_FAR_KEYWORD + { + jmp_buf jmpbuf; + png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf)); + longjmp(jmpbuf, 1); + } +#else + longjmp(png_ptr->jmpbuf, 1); +#endif +} + +/* This function is called when there is a warning, but the library thinks + * it can continue anyway. Replacement functions don't have to do anything + * here if you don't want to. In the default configuration, png_ptr is + * not used, but it is passed in case it may be useful. + */ +static void +png_default_warning(png_structp png_ptr, png_const_charp message) +{ + if (png_ptr == NULL) + return; + +#ifndef PNG_NO_STDIO + fprintf(stderr, "libpng warning: %s\n", message); +#endif +} + +/* This function is called when the application wants to use another method + * of handling errors and warnings. Note that the error function MUST NOT + * return to the calling routine or serious problems will occur. The return + * method used in the default routine calls longjmp(png_ptr->jmpbuf, 1) + */ +void +png_set_error_fn(png_structp png_ptr, png_voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warning_fn) +{ + png_ptr->error_ptr = error_ptr; + png_ptr->error_fn = error_fn; + png_ptr->warning_fn = warning_fn; +} + + +/* This function returns a pointer to the error_ptr associated with the user + * functions. The application should free any memory associated with this + * pointer before png_write_destroy and png_read_destroy are called. + */ +png_voidp +png_get_error_ptr(png_structp png_ptr) +{ + return ((png_voidp)png_ptr->error_ptr); +} + + + diff --git a/thirdparty/libpng/pngget.c b/thirdparty/libpng/pngget.c new file mode 100644 index 00000000..29be31f6 --- /dev/null +++ b/thirdparty/libpng/pngget.c @@ -0,0 +1,644 @@ + +/* pngget.c - retrieval of values from info struct + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + */ + +#define PNG_INTERNAL +#include "png.h" + +png_uint_32 +png_get_valid(png_structp png_ptr, png_infop info_ptr, png_uint_32 flag) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->valid & flag); + else + return(0); +} + +png_uint_32 +png_get_rowbytes(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->rowbytes); + else + return(0); +} + +#ifdef PNG_EASY_ACCESS_SUPPORTED +/* easy access to info, added in libpng-0.99 */ +png_uint_32 +png_get_image_width(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + { + return info_ptr->width; + } + return (0); +} + +png_uint_32 +png_get_image_height(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + { + return info_ptr->height; + } + return (0); +} + +png_byte +png_get_bit_depth(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + { + return info_ptr->bit_depth; + } + return (0); +} + +png_byte +png_get_color_type(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + { + return info_ptr->color_type; + } + return (0); +} + +png_byte +png_get_filter_type(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + { + return info_ptr->filter_type; + } + return (0); +} + +png_byte +png_get_interlace_type(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + { + return info_ptr->interlace_type; + } + return (0); +} + +png_byte +png_get_compression_type(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + { + return info_ptr->compression_type; + } + return (0); +} + +png_uint_32 +png_get_x_pixels_per_meter(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function\n", "png_get_x_pixels_per_meter"); + if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER) + return (0); + else return (info_ptr->x_pixels_per_unit); + } + else +#endif + return (0); +} + +png_uint_32 +png_get_y_pixels_per_meter(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function\n", "png_get_y_pixels_per_meter"); + if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER) + return (0); + else return (info_ptr->y_pixels_per_unit); + } + else +#endif + return (0); +} + +png_uint_32 +png_get_pixels_per_meter(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function\n", "png_get_pixels_per_meter"); + if(info_ptr->phys_unit_type != PNG_RESOLUTION_METER || + info_ptr->x_pixels_per_unit != info_ptr->y_pixels_per_unit) + return (0); + else return (info_ptr->x_pixels_per_unit); + } + else +#endif + return (0); +} + +float +png_get_pixel_aspect_ratio(png_structp png_ptr, png_infop info_ptr) + { +#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_pHYs)) + { + png_debug1(1, "in %s retrieval function\n", "png_get_aspect_ratio"); + if (info_ptr->x_pixels_per_unit == 0) + return ((float)0.0); + else + return ((float)info_ptr->y_pixels_per_unit + /(float)info_ptr->x_pixels_per_unit); + } + else +#endif + return ((float)0.0); +} + +png_uint_32 +png_get_x_offset_microns(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns"); + if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER) + return (0); + else return (info_ptr->x_offset); + } + else +#endif + return (0); +} + +png_uint_32 +png_get_y_offset_microns(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns"); + if(info_ptr->offset_unit_type != PNG_OFFSET_MICROMETER) + return (0); + else return (info_ptr->y_offset); + } + else +#endif + return (0); +} + +png_uint_32 +png_get_x_offset_pixels(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_debug1(1, "in %s retrieval function\n", "png_get_x_offset_microns"); + if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL) + return (0); + else return (info_ptr->x_offset); + } + else +#endif + return (0); +} + +png_uint_32 +png_get_y_offset_pixels(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs)) + { + png_debug1(1, "in %s retrieval function\n", "png_get_y_offset_microns"); + if(info_ptr->offset_unit_type != PNG_OFFSET_PIXEL) + return (0); + else return (info_ptr->y_offset); + } + else +#endif + return (0); +} + +#ifdef PNG_INCH_CONVERSIONS +png_uint_32 +png_get_pixels_per_inch(png_structp png_ptr, png_infop info_ptr) +{ + return ((png_uint_32)((float)png_get_pixels_per_meter(png_ptr, info_ptr) + *.03937 +.5) +} + +png_uint_32 +png_get_x_pixels_per_inch(png_structp png_ptr, png_infop info_ptr) +{ + return ((png_uint_32)((float)png_get_x_pixels_per_meter(png_ptr, info_ptr) + *.03937 +.5) +} + +png_uint_32 +png_get_y_pixels_per_inch(png_structp png_ptr, png_infop info_ptr) +{ + return ((png_uint_32)((float)png_get_y_pixels_per_meter(png_ptr, info_ptr) + *.03937 +.5) +} + +float +png_get_x_offset_inches(png_structp png_ptr, png_infop info_ptr) +{ + return ((float)png_get_x_offset_microns(png_ptr, info_ptr) + *.03937/1.0.100. +.5) +} + +float +png_get_y_offset_inches(png_structp png_ptr, png_infop info_ptr) +{ + return ((float)png_get_y_offset_microns(png_ptr, info_ptr) + *.03937/1.0.100. +.5) +} + +#if defined(PNG_READ_pHYs_SUPPORTED) +png_uint_32 +png_get_pHYs_dpi(png_structp png_ptr, png_infop info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) +{ + png_uint_32 retval = 0; + + if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs) + { + png_debug1(1, "in %s retrieval function\n", "pHYs"); + if (res_x != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + if (res_y != NULL) + { + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + if(unit_type == 1) + { + if (res_x != NULL) *res_x = (png_uint_32)(*res_x * 39.37 + .50); + if (res_y != NULL) *res_y = (png_uint_32)(*res_y * 39.37 + .50); + } + } + } + return (retval); +} +#endif + +#endif /* PNG_INCH_CONVERSIONS */ + +/* png_get_channels really belongs in here, too, but it's been around longer */ +#endif /* PNG_EASY_ACCESS_SUPPORTED */ + +png_byte +png_get_channels(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->channels); + else + return (0); +} + +png_bytep +png_get_signature(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr != NULL && info_ptr != NULL) + return(info_ptr->signature); + else + return (NULL); +} + +#if defined(PNG_READ_bKGD_SUPPORTED) +png_uint_32 +png_get_bKGD(png_structp png_ptr, png_infop info_ptr, + png_color_16p *background) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_bKGD) + && background != NULL) + { + png_debug1(1, "in %s retrieval function\n", "bKGD"); + *background = &(info_ptr->background); + return (PNG_INFO_bKGD); + } + return (0); +} +#endif + +#if defined(PNG_READ_cHRM_SUPPORTED) +png_uint_32 +png_get_cHRM(png_structp png_ptr, png_infop info_ptr, + double *white_x, double *white_y, double *red_x, double *red_y, + double *green_x, double *green_y, double *blue_x, double *blue_y) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_cHRM)) + { + png_debug1(1, "in %s retrieval function\n", "cHRM"); + if (white_x != NULL) + *white_x = (double)info_ptr->x_white; + if (white_y != NULL) + *white_y = (double)info_ptr->y_white; + if (red_x != NULL) + *red_x = (double)info_ptr->x_red; + if (red_y != NULL) + *red_y = (double)info_ptr->y_red; + if (green_x != NULL) + *green_x = (double)info_ptr->x_green; + if (green_y != NULL) + *green_y = (double)info_ptr->y_green; + if (blue_x != NULL) + *blue_x = (double)info_ptr->x_blue; + if (blue_y != NULL) + *blue_y = (double)info_ptr->y_blue; + return (PNG_INFO_cHRM); + } + return (0); +} +#endif + +#if defined(PNG_READ_gAMA_SUPPORTED) +png_uint_32 +png_get_gAMA(png_structp png_ptr, png_infop info_ptr, double *file_gamma) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_gAMA) + && file_gamma != NULL) + { + png_debug1(1, "in %s retrieval function\n", "gAMA"); + *file_gamma = (double)info_ptr->gamma; + return (PNG_INFO_gAMA); + } + return (0); +} +#endif + +#if defined(PNG_READ_sRGB_SUPPORTED) +png_uint_32 +png_get_sRGB(png_structp png_ptr, png_infop info_ptr, int *file_srgb_intent) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_sRGB) + && file_srgb_intent != NULL) + { + png_debug1(1, "in %s retrieval function\n", "sRGB"); + *file_srgb_intent = (int)info_ptr->srgb_intent; + return (PNG_INFO_sRGB); + } + return (0); +} +#endif + +#if defined(PNG_READ_hIST_SUPPORTED) +png_uint_32 +png_get_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p *hist) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_hIST) + && hist != NULL) + { + png_debug1(1, "in %s retrieval function\n", "hIST"); + *hist = info_ptr->hist; + return (PNG_INFO_hIST); + } + return (0); +} +#endif + +png_uint_32 +png_get_IHDR(png_structp png_ptr, png_infop info_ptr, + png_uint_32 *width, png_uint_32 *height, int *bit_depth, + int *color_type, int *interlace_type, int *compression_type, + int *filter_type) + +{ + if (png_ptr != NULL && info_ptr != NULL && width != NULL && height != NULL && + bit_depth != NULL && color_type != NULL) + { + int pixel_depth, channels; + png_uint_32 rowbytes_per_pixel; + + png_debug1(1, "in %s retrieval function\n", "IHDR"); + *width = info_ptr->width; + *height = info_ptr->height; + *bit_depth = info_ptr->bit_depth; + *color_type = info_ptr->color_type; + if (compression_type != NULL) + *compression_type = info_ptr->compression_type; + if (filter_type != NULL) + *filter_type = info_ptr->filter_type; + if (interlace_type != NULL) + *interlace_type = info_ptr->interlace_type; + + /* check for potential overflow of rowbytes */ + if (*color_type == PNG_COLOR_TYPE_PALETTE) + channels = 1; + else if (*color_type & PNG_COLOR_MASK_COLOR) + channels = 3; + else + channels = 1; + if (*color_type & PNG_COLOR_MASK_ALPHA) + channels++; + pixel_depth = *bit_depth * channels; + rowbytes_per_pixel = (pixel_depth + 7) >> 3; + if ((*width > (png_uint_32)2147483647L/rowbytes_per_pixel)) + { + png_warning(png_ptr, + "Width too large for libpng to process image data."); + } + return (1); + } + return (0); +} + +#if defined(PNG_READ_oFFs_SUPPORTED) +png_uint_32 +png_get_oFFs(png_structp png_ptr, png_infop info_ptr, + png_uint_32 *offset_x, png_uint_32 *offset_y, int *unit_type) +{ + if (png_ptr != NULL && info_ptr != NULL && (info_ptr->valid & PNG_INFO_oFFs) + && offset_x != NULL && offset_y != NULL && unit_type != NULL) + { + png_debug1(1, "in %s retrieval function\n", "oFFs"); + *offset_x = info_ptr->x_offset; + *offset_y = info_ptr->y_offset; + *unit_type = (int)info_ptr->offset_unit_type; + return (PNG_INFO_oFFs); + } + return (0); +} +#endif + +#if defined(PNG_READ_pCAL_SUPPORTED) +png_uint_32 +png_get_pCAL(png_structp png_ptr, png_infop info_ptr, + png_charp *purpose, png_int_32 *X0, png_int_32 *X1, int *type, int *nparams, + png_charp *units, png_charpp *params) +{ + if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL && + purpose != NULL && X0 != NULL && X1 != NULL && type != NULL && + nparams != NULL && units != NULL && params != NULL) + { + png_debug1(1, "in %s retrieval function\n", "pCAL"); + *purpose = info_ptr->pcal_purpose; + *X0 = info_ptr->pcal_X0; + *X1 = info_ptr->pcal_X1; + *type = (int)info_ptr->pcal_type; + *nparams = (int)info_ptr->pcal_nparams; + *units = info_ptr->pcal_units; + *params = info_ptr->pcal_params; + return (PNG_INFO_pCAL); + } + return (0); +} +#endif + +#if defined(PNG_READ_pHYs_SUPPORTED) +png_uint_32 +png_get_pHYs(png_structp png_ptr, png_infop info_ptr, + png_uint_32 *res_x, png_uint_32 *res_y, int *unit_type) +{ + png_uint_32 retval = 0; + + if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs) + { + png_debug1(1, "in %s retrieval function\n", "pHYs"); + if (res_x != NULL) + { + *res_x = info_ptr->x_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + if (res_y != NULL) + { + *res_y = info_ptr->y_pixels_per_unit; + retval |= PNG_INFO_pHYs; + } + if (unit_type != NULL) + { + *unit_type = (int)info_ptr->phys_unit_type; + retval |= PNG_INFO_pHYs; + } + } + return (retval); +} +#endif + +png_uint_32 +png_get_PLTE(png_structp png_ptr, png_infop info_ptr, png_colorp *palette, + int *num_palette) +{ + if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_PLTE && + palette != NULL) + { + png_debug1(1, "in %s retrieval function\n", "PLTE"); + *palette = info_ptr->palette; + *num_palette = info_ptr->num_palette; + png_debug1(3, "num_palette = %d\n", *num_palette); + return (PNG_INFO_PLTE); + } + return (0); +} + +#if defined(PNG_READ_sBIT_SUPPORTED) +png_uint_32 +png_get_sBIT(png_structp png_ptr, png_infop info_ptr, png_color_8p *sig_bit) +{ + if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT && + sig_bit != NULL) + { + png_debug1(1, "in %s retrieval function\n", "sBIT"); + *sig_bit = &(info_ptr->sig_bit); + return (PNG_INFO_sBIT); + } + return (0); +} +#endif + +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) +png_uint_32 +png_get_text(png_structp png_ptr, png_infop info_ptr, png_textp *text_ptr, + int *num_text) +{ + if (png_ptr != NULL && info_ptr != NULL && info_ptr->num_text > 0) + { + png_debug1(1, "in %s retrieval function\n", + (png_ptr->chunk_name[0] == '\0' ? "text" + : (png_const_charp)png_ptr->chunk_name)); + if (text_ptr != NULL) + *text_ptr = info_ptr->text; + if (num_text != NULL) + *num_text = info_ptr->num_text; + return ((png_uint_32)info_ptr->num_text); + } + return(0); +} +#endif + +#if defined(PNG_READ_tIME_SUPPORTED) +png_uint_32 +png_get_tIME(png_structp png_ptr, png_infop info_ptr, png_timep *mod_time) +{ + if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME && + mod_time != NULL) + { + png_debug1(1, "in %s retrieval function\n", "tIME"); + *mod_time = &(info_ptr->mod_time); + return (PNG_INFO_tIME); + } + return (0); +} +#endif + +#if defined(PNG_READ_tRNS_SUPPORTED) +png_uint_32 +png_get_tRNS(png_structp png_ptr, png_infop info_ptr, + png_bytep *trans, int *num_trans, png_color_16p *trans_values) +{ + png_uint_32 retval = 0; + if (png_ptr != NULL && info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS) + { + png_debug1(1, "in %s retrieval function\n", "tRNS"); + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (trans != NULL) + { + *trans = info_ptr->trans; + retval |= PNG_INFO_tRNS; + } + if (trans_values != NULL) + *trans_values = &(info_ptr->trans_values); + } + else /* if (info_ptr->color_type != PNG_COLOR_TYPE_PALETTE) */ + { + if (trans_values != NULL) + { + *trans_values = &(info_ptr->trans_values); + retval |= PNG_INFO_tRNS; + } + if(trans != NULL) + *trans = NULL; + } + if(num_trans != NULL) + { + *num_trans = info_ptr->num_trans; + retval |= PNG_INFO_tRNS; + } + } + return (retval); +} +#endif + diff --git a/thirdparty/libpng/pngmem.c b/thirdparty/libpng/pngmem.c new file mode 100644 index 00000000..521556f2 --- /dev/null +++ b/thirdparty/libpng/pngmem.c @@ -0,0 +1,360 @@ + +/* pngmem.c - stub functions for memory allocation + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * This file provides a location for all memory allocation. Users which + * need special memory handling are expected to modify the code in this file + * to meet their needs. See the instructions at each function. + */ + +#define PNG_INTERNAL +#include "png.h" + +/* The following "hides" PNG_MALLOC and PNG_FREE thus allowing the pngtest + application to put a wrapper on top of them. */ +#ifdef PNGTEST_MEMORY_DEBUG +#define PNG_MALLOC png_debug_malloc +#define PNG_FREE png_debug_free +#else +#define PNG_MALLOC png_malloc +#define PNG_FREE png_free +#endif + +/* Borland DOS special memory handler */ +#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) +/* if you change this, be sure to change the one in png.h also */ + +/* Allocate memory for a png_struct. The malloc and memset can be replaced + by a single call to calloc() if this is thought to improve performance. */ +png_voidp +png_create_struct(int type) +{ + png_size_t size; + png_voidp struct_ptr; + + if (type == PNG_STRUCT_INFO) + size = sizeof(png_info); + else if (type == PNG_STRUCT_PNG) + size = sizeof(png_struct); + else + return ((png_voidp)NULL); + + if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL) + { + png_memset(struct_ptr, 0, size); + } + + return (struct_ptr); +} + + +/* Free memory allocated by a png_create_struct() call */ +void +png_destroy_struct(png_voidp struct_ptr) +{ + if (struct_ptr != NULL) + { + farfree (struct_ptr); + struct_ptr = NULL; + } +} + +/* Allocate memory. For reasonable files, size should never exceed + * 64K. However, zlib may allocate more then 64K if you don't tell + * it not to. See zconf.h and png.h for more information. zlib does + * need to allocate exactly 64K, so whatever you call here must + * have the ability to do that. + * + * Borland seems to have a problem in DOS mode for exactly 64K. + * It gives you a segment with an offset of 8 (perhaps to store it's + * memory stuff). zlib doesn't like this at all, so we have to + * detect and deal with it. This code should not be needed in + * Windows or OS/2 modes, and only in 16 bit mode. This code has + * been updated by Alexander Lehmann for version 0.89 to waste less + * memory. + * + * Note that we can't use png_size_t for the "size" declaration, + * since on some systems a png_size_t is a 16-bit quantity, and as a + * result, we would be truncating potentially larger memory requests + * (which should cause a fatal error) and introducing major problems. + */ +png_voidp +PNG_MALLOC(png_structp png_ptr, png_uint_32 size) +{ + png_voidp ret; + if (png_ptr == NULL || size == 0) + return ((png_voidp)NULL); + +#ifdef PNG_MAX_MALLOC_64K + if (size > (png_uint_32)65536L) + png_error(png_ptr, "Cannot Allocate > 64K"); +#endif + + if (size == (png_uint_32)65536L) + { + if (png_ptr->offset_table == NULL) + { + /* try to see if we need to do any of this fancy stuff */ + ret = farmalloc(size); + if (ret == NULL || ((png_size_t)ret & 0xffff)) + { + int num_blocks; + png_uint_32 total_size; + png_bytep table; + int i; + png_byte huge * hptr; + + if (ret != NULL) + { + farfree(ret); + ret = NULL; + } + + num_blocks = (int)(1 << (png_ptr->zlib_window_bits - 14)); + if (num_blocks < 1) + num_blocks = 1; + if (png_ptr->zlib_mem_level >= 7) + num_blocks += (int)(1 << (png_ptr->zlib_mem_level - 7)); + else + num_blocks++; + + total_size = ((png_uint_32)65536L) * (png_uint_32)num_blocks+16; + + table = farmalloc(total_size); + + if (table == NULL) + { + png_error(png_ptr, "Out Of Memory."); /* Note "O" and "M" */ + } + + if ((png_size_t)table & 0xfff0) + { + png_error(png_ptr, "Farmalloc didn't return normalized pointer"); + } + + png_ptr->offset_table = table; + png_ptr->offset_table_ptr = farmalloc(num_blocks * + sizeof (png_bytep)); + + if (png_ptr->offset_table_ptr == NULL) + { + png_error(png_ptr, "Out Of memory."); + } + + hptr = (png_byte huge *)table; + if ((png_size_t)hptr & 0xf) + { + hptr = (png_byte huge *)((long)(hptr) & 0xfffffff0L); + hptr += 16L; + } + for (i = 0; i < num_blocks; i++) + { + png_ptr->offset_table_ptr[i] = (png_bytep)hptr; + hptr += (png_uint_32)65536L; + } + + png_ptr->offset_table_number = num_blocks; + png_ptr->offset_table_count = 0; + png_ptr->offset_table_count_free = 0; + } + } + + if (png_ptr->offset_table_count >= png_ptr->offset_table_number) + png_error(png_ptr, "Out of Memory."); + + ret = png_ptr->offset_table_ptr[png_ptr->offset_table_count++]; + } + else + ret = farmalloc(size); + + if (ret == NULL) + { + png_error(png_ptr, "Out of memory."); /* Note "o" and "m" */ + } + + return (ret); +} + +/* free a pointer allocated by PNG_MALLOC(). In the default + configuration, png_ptr is not used, but is passed in case it + is needed. If ptr is NULL, return without taking any action. */ +void +PNG_FREE(png_structp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL || ptr == NULL) + return; + + if (png_ptr->offset_table != NULL) + { + int i; + + for (i = 0; i < png_ptr->offset_table_count; i++) + { + if (ptr == png_ptr->offset_table_ptr[i]) + { + ptr = NULL; + png_ptr->offset_table_count_free++; + break; + } + } + if (png_ptr->offset_table_count_free == png_ptr->offset_table_count) + { + farfree(png_ptr->offset_table); + farfree(png_ptr->offset_table_ptr); + png_ptr->offset_table = NULL; + png_ptr->offset_table_ptr = NULL; + } + } + + if (ptr != NULL) + { + farfree(ptr); + ptr = NULL; + } +} + +#else /* Not the Borland DOS special memory handler */ + +/* Allocate memory for a png_struct or a png_info. The malloc and + memset can be replaced by a single call to calloc() if this is thought + to improve performance noticably.*/ +png_voidp +png_create_struct(int type) +{ + png_size_t size; + png_voidp struct_ptr; + + if (type == PNG_STRUCT_INFO) + size = sizeof(png_info); + else if (type == PNG_STRUCT_PNG) + size = sizeof(png_struct); + else + return ((png_voidp)NULL); + +#if defined(__TURBOC__) && !defined(__FLAT__) + if ((struct_ptr = (png_voidp)farmalloc(size)) != NULL) +#else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + if ((struct_ptr = (png_voidp)halloc(size,1)) != NULL) +# else + if ((struct_ptr = (png_voidp)malloc(size)) != NULL) +# endif +#endif + { + png_memset(struct_ptr, 0, size); + } + + return (struct_ptr); +} + + +/* Free memory allocated by a png_create_struct() call */ +void +png_destroy_struct(png_voidp struct_ptr) +{ + if (struct_ptr != NULL) + { +#if defined(__TURBOC__) && !defined(__FLAT__) + farfree(struct_ptr); +#else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + hfree(struct_ptr); +# else + free(struct_ptr); +# endif +#endif + } +} + + +/* Allocate memory. For reasonable files, size should never exceed + 64K. However, zlib may allocate more then 64K if you don't tell + it not to. See zconf.h and png.h for more information. zlib does + need to allocate exactly 64K, so whatever you call here must + have the ability to do that. */ + +png_voidp +PNG_MALLOC(png_structp png_ptr, png_uint_32 size) +{ + png_voidp ret; + + if (png_ptr == NULL || size == 0) + return ((png_voidp)NULL); + +#ifdef PNG_MAX_MALLOC_64K + if (size > (png_uint_32)65536L) + png_error(png_ptr, "Cannot Allocate > 64K"); +#endif + +#if defined(__TURBOC__) && !defined(__FLAT__) + ret = farmalloc(size); +#else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + ret = halloc(size, 1); +# else + ret = malloc((size_t)size); +# endif +#endif + + if (ret == NULL) + { + png_error(png_ptr, "Out of Memory"); + } + + return (ret); +} + +/* Free a pointer allocated by PNG_MALLOC(). In the default + configuration, png_ptr is not used, but is passed in case it + is needed. If ptr is NULL, return without taking any action. */ +void +PNG_FREE(png_structp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL || ptr == NULL) + return; + +#if defined(__TURBOC__) && !defined(__FLAT__) + farfree(ptr); +#else +# if defined(_MSC_VER) && defined(MAXSEG_64K) + hfree(ptr); +# else + free(ptr); +# endif +#endif +} + +#endif /* Not Borland DOS special memory handler */ + +png_voidp +png_memcpy_check (png_structp png_ptr, png_voidp s1, png_voidp s2, + png_uint_32 length) +{ + png_size_t size; + + size = (png_size_t)length; + if ((png_uint_32)size != length) + png_error(png_ptr,"Overflow in png_memcpy_check."); + + return(png_memcpy (s1, s2, size)); +} + +png_voidp +png_memset_check (png_structp png_ptr, png_voidp s1, int value, + png_uint_32 length) +{ + png_size_t size; + + size = (png_size_t)length; + if ((png_uint_32)size != length) + png_error(png_ptr,"Overflow in png_memset_check."); + + return (png_memset (s1, value, size)); + +} diff --git a/thirdparty/libpng/pngpread.c b/thirdparty/libpng/pngpread.c new file mode 100644 index 00000000..37d4d255 --- /dev/null +++ b/thirdparty/libpng/pngpread.c @@ -0,0 +1,1143 @@ + +/* pngpread.c - read a png file in push mode + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + */ + +#define PNG_INTERNAL +#include "png.h" + +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + +void +png_process_data(png_structp png_ptr, png_infop info_ptr, + png_bytep buffer, png_size_t buffer_size) +{ + png_push_restore_buffer(png_ptr, buffer, buffer_size); + + while (png_ptr->buffer_size) + { + png_process_some_data(png_ptr, info_ptr); + } +} + +/* What we do with the incoming data depends on what we were previously + * doing before we ran out of data... + */ +void +png_process_some_data(png_structp png_ptr, png_infop info_ptr) +{ + switch (png_ptr->process_mode) + { + case PNG_READ_SIG_MODE: + { + png_push_read_sig(png_ptr, info_ptr); + break; + } + case PNG_READ_CHUNK_MODE: + { + png_push_read_chunk(png_ptr, info_ptr); + break; + } + case PNG_READ_IDAT_MODE: + { + png_push_read_IDAT(png_ptr); + break; + } +#if defined(PNG_READ_tEXt_SUPPORTED) + case PNG_READ_tEXt_MODE: + { + png_push_read_tEXt(png_ptr, info_ptr); + break; + } +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) + case PNG_READ_zTXt_MODE: + { + png_push_read_zTXt(png_ptr, info_ptr); + break; + } +#endif + case PNG_SKIP_MODE: + { + png_push_crc_finish(png_ptr); + break; + } + default: + { + png_ptr->buffer_size = 0; + break; + } + } +} + +/* Read any remaining signature bytes from the stream and compare them with + * the correct PNG signature. It is possible that this routine is called + * with bytes already read from the signature, whether because they have been + * checked by the calling application, or from multiple calls to this routine. + */ +void +png_push_read_sig(png_structp png_ptr, png_infop info_ptr) +{ + png_size_t num_checked = png_ptr->sig_bytes, + num_to_check = 8 - num_checked; + + if (png_ptr->buffer_size < num_to_check) + { + num_to_check = png_ptr->buffer_size; + } + + png_push_fill_buffer(png_ptr, &(info_ptr->signature[num_checked]), + num_to_check); + png_ptr->sig_bytes += num_to_check; + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + else + { + if (png_ptr->sig_bytes >= 8) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } + } +} + +void +png_push_read_chunk(png_structp png_ptr, png_infop info_ptr) +{ + /* First we make sure we have enough data for the 4 byte chunk name + * and the 4 byte chunk length before proceeding with decoding the + * chunk data. To fully decode each of these chunks, we also make + * sure we have enough data in the buffer for the 4 byte CRC at the + * end of every chunk (except IDAT, which is handled separately). + */ + if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER)) + { + png_byte chunk_length[4]; + + if (png_ptr->buffer_size < 8) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_32(chunk_length); + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER; + } + + if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_IHDR(png_ptr, info_ptr, png_ptr->push_length); + } + else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_PLTE(png_ptr, info_ptr, png_ptr->push_length); + } + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + /* If we reach an IDAT chunk, this means we have read all of the + * header chunks, and we can start reading the image (or if this + * is called after the image has been read - we have an error). + */ + if (png_ptr->mode & PNG_HAVE_IDAT) + { + if (png_ptr->push_length == 0) + return; + + if (png_ptr->mode & PNG_AFTER_IDAT) + png_error(png_ptr, "Too many IDAT's found"); + } + + png_ptr->idat_size = png_ptr->push_length; + png_ptr->mode |= PNG_HAVE_IDAT; + png_ptr->process_mode = PNG_READ_IDAT_MODE; + png_push_have_info(png_ptr, info_ptr); + png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; + png_ptr->zstream.next_out = png_ptr->row_buf; + return; + } + else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_IEND(png_ptr, info_ptr, png_ptr->push_length); + png_ptr->process_mode = PNG_READ_DONE_MODE; + png_push_have_end(png_ptr, info_ptr); + } +#if defined(PNG_READ_gAMA_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_gAMA(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_sBIT_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sBIT(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_cHRM(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_sRGB_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_sRGB(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_tRNS_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_tRNS(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_bKGD_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_bKGD(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_hIST_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_hIST(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_pHYs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_pHYs(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_oFFs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_oFFs(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_pCAL(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_tIME_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) + { + if (png_ptr->push_length + 4 > png_ptr->buffer_size) + { + png_push_save_buffer(png_ptr); + return; + } + + png_handle_tIME(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_tEXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) + { + png_push_handle_tEXt(png_ptr, info_ptr, png_ptr->push_length); + } +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) + { + png_push_handle_zTXt(png_ptr, info_ptr, png_ptr->push_length); + } +#endif + else + { + png_push_handle_unknown(png_ptr, info_ptr, png_ptr->push_length); + } + + png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; +} + +void +png_push_crc_skip(png_structp png_ptr, png_uint_32 skip) +{ + png_ptr->process_mode = PNG_SKIP_MODE; + png_ptr->skip_length = skip; +} + +void +png_push_crc_finish(png_structp png_ptr) +{ + if (png_ptr->skip_length && png_ptr->save_buffer_size) + { + png_size_t save_size; + + if (png_ptr->skip_length < (png_uint_32)png_ptr->save_buffer_size) + save_size = (png_size_t)png_ptr->skip_length; + else + save_size = png_ptr->save_buffer_size; + + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_ptr->skip_length -= save_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + if (png_ptr->skip_length && png_ptr->current_buffer_size) + { + png_size_t save_size; + + if (png_ptr->skip_length < (png_uint_32)png_ptr->current_buffer_size) + save_size = (png_size_t)png_ptr->skip_length; + else + save_size = png_ptr->current_buffer_size; + + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_ptr->skip_length -= save_size; + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } + if (!png_ptr->skip_length) + { + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_crc_finish(png_ptr, 0); + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + } +} + +void +png_push_fill_buffer(png_structp png_ptr, png_bytep buffer, png_size_t length) +{ + png_bytep ptr; + + ptr = buffer; + if (png_ptr->save_buffer_size) + { + png_size_t save_size; + + if (length < png_ptr->save_buffer_size) + save_size = length; + else + save_size = png_ptr->save_buffer_size; + + png_memcpy(ptr, png_ptr->save_buffer_ptr, save_size); + length -= save_size; + ptr += save_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + if (length && png_ptr->current_buffer_size) + { + png_size_t save_size; + + if (length < png_ptr->current_buffer_size) + save_size = length; + else + save_size = png_ptr->current_buffer_size; + + png_memcpy(ptr, png_ptr->current_buffer_ptr, save_size); + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } +} + +void +png_push_save_buffer(png_structp png_ptr) +{ + if (png_ptr->save_buffer_size) + { + if (png_ptr->save_buffer_ptr != png_ptr->save_buffer) + { + png_size_t i; + png_bytep sp; + png_bytep dp; + + for (i = 0, sp = png_ptr->save_buffer_ptr, dp = png_ptr->save_buffer; + i < png_ptr->save_buffer_size; + i++, sp++, dp++) + { + *dp = *sp; + } + } + } + if (png_ptr->save_buffer_size + png_ptr->current_buffer_size > + png_ptr->save_buffer_max) + { + png_size_t new_max; + png_bytep old_buffer; + + new_max = png_ptr->save_buffer_size + png_ptr->current_buffer_size + 256; + old_buffer = png_ptr->save_buffer; + png_ptr->save_buffer = (png_bytep)png_malloc(png_ptr, + (png_uint_32)new_max); + png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); + png_free(png_ptr, old_buffer); + png_ptr->save_buffer_max = new_max; + } + if (png_ptr->current_buffer_size) + { + png_memcpy(png_ptr->save_buffer + png_ptr->save_buffer_size, + png_ptr->current_buffer_ptr, png_ptr->current_buffer_size); + png_ptr->save_buffer_size += png_ptr->current_buffer_size; + png_ptr->current_buffer_size = 0; + } + png_ptr->save_buffer_ptr = png_ptr->save_buffer; + png_ptr->buffer_size = 0; +} + +void +png_push_restore_buffer(png_structp png_ptr, png_bytep buffer, + png_size_t buffer_length) +{ + png_ptr->current_buffer = buffer; + png_ptr->current_buffer_size = buffer_length; + png_ptr->buffer_size = buffer_length + png_ptr->save_buffer_size; + png_ptr->current_buffer_ptr = png_ptr->current_buffer; +} + +void +png_push_read_IDAT(png_structp png_ptr) +{ + if (!(png_ptr->flags & PNG_FLAG_HAVE_CHUNK_HEADER)) + { + png_byte chunk_length[4]; + + if (png_ptr->buffer_size < 8) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_fill_buffer(png_ptr, chunk_length, 4); + png_ptr->push_length = png_get_uint_32(chunk_length); + + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + png_ptr->flags |= PNG_FLAG_HAVE_CHUNK_HEADER; + + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + png_ptr->process_mode = PNG_READ_CHUNK_MODE; + if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) + png_error(png_ptr, "Not enough compressed data"); + return; + } + + png_ptr->idat_size = png_ptr->push_length; + } + if (png_ptr->idat_size && png_ptr->save_buffer_size) + { + png_size_t save_size; + + if (png_ptr->idat_size < (png_uint_32)png_ptr->save_buffer_size) + { + save_size = (png_size_t)png_ptr->idat_size; + /* check for overflow */ + if((png_uint_32)save_size != png_ptr->idat_size) + png_error(png_ptr, "save_size overflowed in pngpread"); + } + else + save_size = png_ptr->save_buffer_size; + + png_calculate_crc(png_ptr, png_ptr->save_buffer_ptr, save_size); + png_process_IDAT_data(png_ptr, png_ptr->save_buffer_ptr, save_size); + + png_ptr->idat_size -= save_size; + png_ptr->buffer_size -= save_size; + png_ptr->save_buffer_size -= save_size; + png_ptr->save_buffer_ptr += save_size; + } + if (png_ptr->idat_size && png_ptr->current_buffer_size) + { + png_size_t save_size; + + if (png_ptr->idat_size < (png_uint_32)png_ptr->current_buffer_size) + { + save_size = (png_size_t)png_ptr->idat_size; + /* check for overflow */ + if((png_uint_32)save_size != png_ptr->idat_size) + png_error(png_ptr, "save_size overflowed in pngpread"); + } + else + save_size = png_ptr->current_buffer_size; + + png_calculate_crc(png_ptr, png_ptr->current_buffer_ptr, save_size); + png_process_IDAT_data(png_ptr, png_ptr->current_buffer_ptr, save_size); + + png_ptr->idat_size -= save_size; + png_ptr->buffer_size -= save_size; + png_ptr->current_buffer_size -= save_size; + png_ptr->current_buffer_ptr += save_size; + } + if (!png_ptr->idat_size) + { + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_crc_finish(png_ptr, 0); + png_ptr->flags &= ~PNG_FLAG_HAVE_CHUNK_HEADER; + } +} + +void +png_process_IDAT_data(png_structp png_ptr, png_bytep buffer, + png_size_t buffer_length) +{ + int ret; + + if ((png_ptr->flags & PNG_FLAG_ZLIB_FINISHED) && buffer_length) + png_error(png_ptr, "Extra compression data"); + + png_ptr->zstream.next_in = buffer; + png_ptr->zstream.avail_in = (uInt)buffer_length; + for(;;) + { + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + if (ret == Z_STREAM_END) + { + if (png_ptr->zstream.avail_in) + png_error(png_ptr, "Extra compressed data"); + if (!(png_ptr->zstream.avail_out)) + { + png_push_process_row(png_ptr); + } + + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + else if (ret == Z_BUF_ERROR) + break; + else if (ret != Z_OK) + png_error(png_ptr, "Decompression Error"); + if (!(png_ptr->zstream.avail_out)) + { + png_push_process_row(png_ptr); + png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; + png_ptr->zstream.next_out = png_ptr->row_buf; + } + else + break; + } +} + +void +png_push_process_row(png_structp png_ptr) +{ + png_ptr->row_info.color_type = png_ptr->color_type; + png_ptr->row_info.width = png_ptr->iwidth; + png_ptr->row_info.channels = png_ptr->channels; + png_ptr->row_info.bit_depth = png_ptr->bit_depth; + png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; + + png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * + (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); + + png_read_filter_row(png_ptr, &(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->prev_row + 1, + (int)(png_ptr->row_buf[0])); + + png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, + png_ptr->rowbytes + 1); + + if (png_ptr->transformations) + png_do_read_transformations(png_ptr); + +#if defined(PNG_READ_INTERLACING_SUPPORTED) + /* blow up interlaced rows to full size */ + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + { + if (png_ptr->pass < 6) + png_do_read_interlace(&(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); + + switch (png_ptr->pass) + { + case 0: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 0; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + break; + } + case 1: + { + int i; + for (i = 0; i < 8 && png_ptr->pass == 1; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + if (png_ptr->pass == 2) + { + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + break; + } + case 2: + { + int i; + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + for (i = 0; i < 4 && png_ptr->pass == 2; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + break; + } + case 3: + { + int i; + for (i = 0; i < 4 && png_ptr->pass == 3; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + if (png_ptr->pass == 4) + { + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + break; + } + case 4: + { + int i; + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + for (i = 0; i < 2 && png_ptr->pass == 4; i++) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + break; + } + case 5: + { + int i; + for (i = 0; i < 2 && png_ptr->pass == 5; i++) + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } + if (png_ptr->pass == 6) + { + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + break; + } + case 6: + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + if (png_ptr->pass != 6) + break; + png_push_have_row(png_ptr, NULL); + png_read_push_finish_row(png_ptr); + } + } + } + else +#endif + { + png_push_have_row(png_ptr, png_ptr->row_buf + 1); + png_read_push_finish_row(png_ptr); + } +} + +void +png_read_push_finish_row(png_structp png_ptr) +{ + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + + if (png_ptr->interlaced) + { + png_ptr->row_number = 0; + png_memset_check(png_ptr, png_ptr->prev_row, 0, + png_ptr->rowbytes + 1); + do + { + png_ptr->pass++; + if (png_ptr->pass >= 7) + break; + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + png_ptr->irowbytes = ((png_ptr->iwidth * + png_ptr->pixel_depth + 7) >> 3) + 1; + + if (!(png_ptr->transformations & PNG_INTERLACE)) + { + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + if (!(png_ptr->num_rows)) + continue; + } + if (png_ptr->transformations & PNG_INTERLACE) + break; + } while (png_ptr->iwidth == 0); + } +} + +#if defined(PNG_READ_tEXt_SUPPORTED) +void +png_push_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND) + { + png_error(png_ptr, "Out of place tEXt"); + /* to quiet some compiler warnings */ + if(info_ptr == NULL) return; + } + +#ifdef PNG_MAX_MALLOC_64K + png_ptr->skip_length = 0; /* This may not be necessary */ + + if (length > (png_uint_32)65535L) /* Can't hold the entire string in memory */ + { + png_warning(png_ptr, "tEXt chunk too large to fit in memory"); + png_ptr->skip_length = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + png_ptr->current_text = (png_charp)png_malloc(png_ptr, + (png_uint_32)(length+1)); + png_ptr->current_text[length] = '\0'; + png_ptr->current_text_ptr = png_ptr->current_text; + png_ptr->current_text_size = (png_size_t)length; + png_ptr->current_text_left = (png_size_t)length; + png_ptr->process_mode = PNG_READ_tEXt_MODE; +} + +void +png_push_read_tEXt(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->buffer_size && png_ptr->current_text_left) + { + png_size_t text_size; + + if (png_ptr->buffer_size < png_ptr->current_text_left) + text_size = png_ptr->buffer_size; + else + text_size = png_ptr->current_text_left; + png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); + png_ptr->current_text_left -= text_size; + png_ptr->current_text_ptr += text_size; + } + if (!(png_ptr->current_text_left)) + { + png_textp text_ptr; + png_charp text; + png_charp key; + + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_crc_finish(png_ptr); + +#if defined(PNG_MAX_MALLOC_64K) + if (png_ptr->skip_length) + return; +#endif + + key = png_ptr->current_text; + png_ptr->current_text = 0; + + for (text = key; *text; text++) + /* empty loop */ ; + + if (text != key + png_ptr->current_text_size) + text++; + + text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); + text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr->key = key; + text_ptr->text = text; + + png_set_text(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); + } +} +#endif + +#if defined(PNG_READ_zTXt_SUPPORTED) +void +png_push_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + if (png_ptr->mode == PNG_BEFORE_IHDR || png_ptr->mode & PNG_HAVE_IEND) + { + png_error(png_ptr, "Out of place zTXt"); + /* to quiet some compiler warnings */ + if(info_ptr == NULL) return; + } + +#ifdef PNG_MAX_MALLOC_64K + /* We can't handle zTXt chunks > 64K, since we don't have enough space + * to be able to store the uncompressed data. Actually, the threshold + * is probably around 32K, but it isn't as definite as 64K is. + */ + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "zTXt chunk too large to fit in memory"); + png_push_crc_skip(png_ptr, length); + return; + } +#endif + + png_ptr->current_text = (png_charp)png_malloc(png_ptr, + (png_uint_32)(length+1)); + png_ptr->current_text[length] = '\0'; + png_ptr->current_text_ptr = png_ptr->current_text; + png_ptr->current_text_size = (png_size_t)length; + png_ptr->current_text_left = (png_size_t)length; + png_ptr->process_mode = PNG_READ_zTXt_MODE; +} + +void +png_push_read_zTXt(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->buffer_size && png_ptr->current_text_left) + { + png_size_t text_size; + + if (png_ptr->buffer_size < (png_uint_32)png_ptr->current_text_left) + text_size = png_ptr->buffer_size; + else + text_size = png_ptr->current_text_left; + png_crc_read(png_ptr, (png_bytep)png_ptr->current_text_ptr, text_size); + png_ptr->current_text_left -= text_size; + png_ptr->current_text_ptr += text_size; + } + if (!(png_ptr->current_text_left)) + { + png_textp text_ptr; + png_charp text; + png_charp key; + int ret; + png_size_t text_size, key_size; + + if (png_ptr->buffer_size < 4) + { + png_push_save_buffer(png_ptr); + return; + } + + png_push_crc_finish(png_ptr); + + key = png_ptr->current_text; + png_ptr->current_text = 0; + + for (text = key; *text; text++) + /* empty loop */ ; + + /* zTXt can't have zero text */ + if (text == key + png_ptr->current_text_size) + { + png_free(png_ptr, key); + return; + } + + text++; + + if (*text != PNG_TEXT_COMPRESSION_zTXt) /* check compression byte */ + { + png_free(png_ptr, key); + return; + } + + text++; + + png_ptr->zstream.next_in = (png_bytep )text; + png_ptr->zstream.avail_in = (uInt)(png_ptr->current_text_size - + (text - key)); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + key_size = text - key; + text_size = 0; + text = NULL; + ret = Z_STREAM_END; + + while (png_ptr->zstream.avail_in) + { + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + if (ret != Z_OK && ret != Z_STREAM_END) + { + inflateReset(&png_ptr->zstream); + png_ptr->zstream.avail_in = 0; + png_free(png_ptr, key); + png_free(png_ptr, text); + return; + } + if (!(png_ptr->zstream.avail_out) || ret == Z_STREAM_END) + { + if (text == NULL) + { + text = (png_charp)png_malloc(png_ptr, + (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out + + key_size + 1)); + png_memcpy(text + key_size, png_ptr->zbuf, + png_ptr->zbuf_size - png_ptr->zstream.avail_out); + png_memcpy(text, key, key_size); + text_size = key_size + png_ptr->zbuf_size - + png_ptr->zstream.avail_out; + *(text + text_size) = '\0'; + } + else + { + png_charp tmp; + + tmp = text; + text = (png_charp)png_malloc(png_ptr, text_size + + (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out + + 1)); + png_memcpy(text, tmp, text_size); + png_free(png_ptr, tmp); + png_memcpy(text + text_size, png_ptr->zbuf, + png_ptr->zbuf_size - png_ptr->zstream.avail_out); + text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; + *(text + text_size) = '\0'; + } + if (ret != Z_STREAM_END) + { + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + } + else + { + break; + } + + if (ret == Z_STREAM_END) + break; + } + + inflateReset(&png_ptr->zstream); + png_ptr->zstream.avail_in = 0; + + if (ret != Z_STREAM_END) + { + png_free(png_ptr, key); + png_free(png_ptr, text); + return; + } + + png_free(png_ptr, key); + key = text; + text += key_size; + + text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); + text_ptr->compression = PNG_TEXT_COMPRESSION_zTXt; + text_ptr->key = key; + text_ptr->text = text; + + png_set_text(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); + } +} +#endif + +/* This function is called when we haven't found a handler for this + * chunk. In the future we will have code here which can handle + * user-defined callback functions for unknown chunks before they are + * ignored or cause an error. If there isn't a problem with the + * chunk itself (ie a bad chunk name or a critical chunk), the chunk + * is (currently) silently ignored. + */ +void +png_push_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + + if (!(png_ptr->chunk_name[0] & 0x20)) + { + png_chunk_error(png_ptr, "unknown critical chunk"); + /* to quiet some compiler warnings */ + if(info_ptr == NULL) return; + } + + png_push_crc_skip(png_ptr, length); +} + +void +png_push_have_info(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->info_fn != NULL) + (*(png_ptr->info_fn))(png_ptr, info_ptr); +} + +void +png_push_have_end(png_structp png_ptr, png_infop info_ptr) +{ + if (png_ptr->end_fn != NULL) + (*(png_ptr->end_fn))(png_ptr, info_ptr); +} + +void +png_push_have_row(png_structp png_ptr, png_bytep row) +{ + if (png_ptr->row_fn != NULL) + (*(png_ptr->row_fn))(png_ptr, row, png_ptr->row_number, + (int)png_ptr->pass); +} + +void +png_progressive_combine_row (png_structp png_ptr, + png_bytep old_row, png_bytep new_row) +{ + if (new_row != NULL) + png_combine_row(png_ptr, old_row, png_pass_dsp_mask[png_ptr->pass]); +} + +void +png_set_progressive_read_fn(png_structp png_ptr, png_voidp progressive_ptr, + png_progressive_info_ptr info_fn, png_progressive_row_ptr row_fn, + png_progressive_end_ptr end_fn) +{ + png_ptr->info_fn = info_fn; + png_ptr->row_fn = row_fn; + png_ptr->end_fn = end_fn; + + png_set_read_fn(png_ptr, progressive_ptr, png_push_fill_buffer); +} + +png_voidp +png_get_progressive_ptr(png_structp png_ptr) +{ + return png_ptr->io_ptr; +} + +#endif /* PNG_PROGRESSIVE_READ_SUPPORTED */ + diff --git a/thirdparty/libpng/pngread.c b/thirdparty/libpng/pngread.c new file mode 100644 index 00000000..cc490c21 --- /dev/null +++ b/thirdparty/libpng/pngread.c @@ -0,0 +1,789 @@ + +/* pngread.c - read a PNG file + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * This file contains routines that an application calls directly to + * read a PNG file or stream. + */ + +#define PNG_INTERNAL +#include "png.h" + +/* Create a PNG structure for reading, and allocate any memory needed. */ +png_structp +png_create_read_struct(png_const_charp user_png_ver, voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn) +{ + png_structp png_ptr; +#ifdef USE_FAR_KEYWORD + jmp_buf jmpbuf; +#endif + png_debug(1, "in png_create_read_struct\n"); + if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL) + { + return (png_structp)NULL; + } +#ifdef USE_FAR_KEYWORD + if (setjmp(jmpbuf)) +#else + if (setjmp(png_ptr->jmpbuf)) +#endif + { + png_free(png_ptr, png_ptr->zbuf); + png_destroy_struct(png_ptr); + return (png_structp)NULL; + } +#ifdef USE_FAR_KEYWORD + png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf)); +#endif + png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); + + /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so + * we must recompile any applications that use any older library version. + * For versions after libpng 1.0, we will be compatible, so we need + * only check the first digit. + */ + if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || + (user_png_ver[0] == '0' && user_png_ver[2] < '9')) + { + png_error(png_ptr, + "Incompatible libpng version in application and library"); + } + + /* initialize zbuf - compression buffer */ + png_ptr->zbuf_size = PNG_ZBUF_SIZE; + png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, + (png_uint_32)png_ptr->zbuf_size); + png_ptr->zstream.zalloc = png_zalloc; + png_ptr->zstream.zfree = png_zfree; + png_ptr->zstream.opaque = (voidpf)png_ptr; + + switch (inflateInit(&png_ptr->zstream)) + { + case Z_OK: /* Do nothing */ break; + case Z_MEM_ERROR: + case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory error"); break; + case Z_VERSION_ERROR: png_error(png_ptr, "zlib version error"); break; + default: png_error(png_ptr, "Unknown zlib error"); + } + + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + png_set_read_fn(png_ptr, NULL, NULL); + + return (png_ptr); +} + +/* Initialize PNG structure for reading, and allocate any memory needed. + This interface is depreciated in favour of the png_create_read_struct(), + and it will eventually disappear. */ +void +png_read_init(png_structp png_ptr) +{ + jmp_buf tmp_jmp; /* to save current jump buffer */ + + png_debug(1, "in png_read_init\n"); + /* save jump buffer and error functions */ + png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); + + /* reset all variables to 0 */ + png_memset(png_ptr, 0, sizeof (png_struct)); + + /* restore jump buffer */ + png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); + + /* initialize zbuf - compression buffer */ + png_ptr->zbuf_size = PNG_ZBUF_SIZE; + png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, + (png_uint_32)png_ptr->zbuf_size); + png_ptr->zstream.zalloc = png_zalloc; + png_ptr->zstream.zfree = png_zfree; + png_ptr->zstream.opaque = (voidpf)png_ptr; + + switch (inflateInit(&png_ptr->zstream)) + { + case Z_OK: /* Do nothing */ break; + case Z_MEM_ERROR: + case Z_STREAM_ERROR: png_error(png_ptr, "zlib memory"); break; + case Z_VERSION_ERROR: png_error(png_ptr, "zlib version"); break; + default: png_error(png_ptr, "Unknown zlib error"); + } + + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + png_set_read_fn(png_ptr, NULL, NULL); +} + +/* Read the information before the actual image data. This has been + * changed in v0.90 to allow reading a file which already has the magic + * bytes read from the stream. You can tell libpng how many bytes have + * been read from the beginning of the stream (up to the maxumum of 8) + * via png_set_sig_bytes(), and we will only check the remaining bytes + * here. The application can then have access to the signature bytes we + * read if it is determined that this isn't a valid PNG file. + */ +void +png_read_info(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_info\n"); + /* save jump buffer and error functions */ + /* If we haven't checked all of the PNG signature bytes, do so now. */ + if (png_ptr->sig_bytes < 8) + { + png_size_t num_checked = png_ptr->sig_bytes, + num_to_check = 8 - num_checked; + + png_read_data(png_ptr, &(info_ptr->signature[num_checked]), num_to_check); + png_ptr->sig_bytes = 8; + + if (png_sig_cmp(info_ptr->signature, num_checked, num_to_check)) + { + if (num_checked < 4 && + png_sig_cmp(info_ptr->signature, num_checked, num_to_check - 4)) + png_error(png_ptr, "Not a PNG file"); + else + png_error(png_ptr, "PNG file corrupted by ASCII conversion"); + } + } + + for(;;) + { + png_byte chunk_length[4]; + png_uint_32 length; + + png_read_data(png_ptr, chunk_length, 4); + length = png_get_uint_32(chunk_length); + + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + + png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name); + + /* This should be a binary subdivision search or a hash for + * matching the chunk name rather than a linear search. + */ + if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + png_handle_IHDR(png_ptr, info_ptr, length); + else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + png_handle_PLTE(png_ptr, info_ptr, length); + else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + png_handle_IEND(png_ptr, info_ptr, length); + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before IDAT"); + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + png_error(png_ptr, "Missing PLTE before IDAT"); + + png_ptr->idat_size = length; + png_ptr->mode |= PNG_HAVE_IDAT; + break; + } +#if defined(PNG_READ_bKGD_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_gAMA_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_hIST_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) + png_handle_hIST(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_oFFs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_pHYs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sBIT_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sRGB_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tEXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tIME_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) + png_handle_tIME(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tRNS_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif + else + png_handle_unknown(png_ptr, info_ptr, length); + } +} + +/* optional call to update the users info_ptr structure */ +void +png_read_update_info(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_update_info\n"); + /* save jump buffer and error functions */ + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); + png_read_transform_info(png_ptr, info_ptr); +} + +/* Initialize palette, background, etc, after transformations + * are set, but before any reading takes place. This allows + * the user to obtail a gamma corrected palette, for example. + * If the user doesn't call this, we will do it ourselves. + */ +void +png_start_read_image(png_structp png_ptr) +{ + png_debug(1, "in png_start_read_image\n"); + /* save jump buffer and error functions */ + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); +} + +void +png_read_row(png_structp png_ptr, png_bytep row, png_bytep dsp_row) +{ + int ret; + png_debug2(1, "in png_read_row (row %d, pass %d)\n", + png_ptr->row_number, png_ptr->pass); + /* save jump buffer and error functions */ + if (!(png_ptr->flags & PNG_FLAG_ROW_INIT)) + png_read_start_row(png_ptr); + +#if defined(PNG_READ_INTERLACING_SUPPORTED) + /* if interlaced and we do not need a new row, combine row and return */ + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + { + switch (png_ptr->pass) + { + case 0: + if (png_ptr->row_number & 7) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + png_read_finish_row(png_ptr); + return; + } + break; + case 1: + if ((png_ptr->row_number & 7) || png_ptr->width < 5) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + png_read_finish_row(png_ptr); + return; + } + break; + case 2: + if ((png_ptr->row_number & 7) != 4) + { + if (dsp_row != NULL && (png_ptr->row_number & 4)) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + png_read_finish_row(png_ptr); + return; + } + break; + case 3: + if ((png_ptr->row_number & 3) || png_ptr->width < 3) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + png_read_finish_row(png_ptr); + return; + } + break; + case 4: + if ((png_ptr->row_number & 3) != 2) + { + if (dsp_row != NULL && (png_ptr->row_number & 2)) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + png_read_finish_row(png_ptr); + return; + } + break; + case 5: + if ((png_ptr->row_number & 1) || png_ptr->width < 2) + { + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + png_read_finish_row(png_ptr); + return; + } + break; + case 6: + if (!(png_ptr->row_number & 1)) + { + png_read_finish_row(png_ptr); + return; + } + break; + } + } +#endif + + if (!(png_ptr->mode & PNG_HAVE_IDAT)) + png_error(png_ptr, "Invalid attempt to read row data"); + + png_ptr->zstream.next_out = png_ptr->row_buf; + png_ptr->zstream.avail_out = (uInt)png_ptr->irowbytes; + do + { + if (!(png_ptr->zstream.avail_in)) + { + while (!png_ptr->idat_size) + { + png_byte chunk_length[4]; + + png_crc_finish(png_ptr, 0); + + png_read_data(png_ptr, chunk_length, 4); + png_ptr->idat_size = png_get_uint_32(chunk_length); + + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + png_error(png_ptr, "Not enough image data"); + } + png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_in = png_ptr->zbuf; + if (png_ptr->zbuf_size > png_ptr->idat_size) + png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; + png_crc_read(png_ptr, png_ptr->zbuf, + (png_size_t)png_ptr->zstream.avail_in); + png_ptr->idat_size -= png_ptr->zstream.avail_in; + } + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + if (ret == Z_STREAM_END) + { + if (png_ptr->zstream.avail_out || png_ptr->zstream.avail_in || + png_ptr->idat_size) + png_error(png_ptr, "Extra compressed data"); + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + if (ret != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : + "Decompression error"); + + } while (png_ptr->zstream.avail_out); + + png_ptr->row_info.color_type = png_ptr->color_type; + png_ptr->row_info.width = png_ptr->iwidth; + png_ptr->row_info.channels = png_ptr->channels; + png_ptr->row_info.bit_depth = png_ptr->bit_depth; + png_ptr->row_info.pixel_depth = png_ptr->pixel_depth; + { + png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * + (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); + } + + png_read_filter_row(png_ptr, &(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->prev_row + 1, + (int)(png_ptr->row_buf[0])); + + png_memcpy_check(png_ptr, png_ptr->prev_row, png_ptr->row_buf, + png_ptr->rowbytes + 1); + + if (png_ptr->transformations) + png_do_read_transformations(png_ptr); + +#if defined(PNG_READ_INTERLACING_SUPPORTED) + /* blow up interlaced rows to full size */ + if (png_ptr->interlaced && + (png_ptr->transformations & PNG_INTERLACE)) + { + if (png_ptr->pass < 6) + png_do_read_interlace(&(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->pass, png_ptr->transformations); + + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, + png_pass_dsp_mask[png_ptr->pass]); + if (row != NULL) + png_combine_row(png_ptr, row, + png_pass_mask[png_ptr->pass]); + } + else +#endif + { + if (row != NULL) + png_combine_row(png_ptr, row, 0xff); + if (dsp_row != NULL) + png_combine_row(png_ptr, dsp_row, 0xff); + } + png_read_finish_row(png_ptr); + + if (png_ptr->read_row_fn != NULL) + (*(png_ptr->read_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); +} + +/* Read one or more rows of image data. If the image is interlaced, + * and png_set_interlace_handling() has been called, the rows need to + * contain the contents of the rows from the previous pass. If the + * image has alpha or transparency, and png_handle_alpha() has been + * called, the rows contents must be initialized to the contents of the + * screen. + * + * "row" holds the actual image, and pixels are placed in it + * as they arrive. If the image is displayed after each pass, it will + * appear to "sparkle" in. "display_row" can be used to display a + * "chunky" progressive image, with finer detail added as it becomes + * available. If you do not want this "chunky" display, you may pass + * NULL for display_row. If you do not want the sparkle display, and + * you have not called png_handle_alpha(), you may pass NULL for rows. + * If you have called png_handle_alpha(), and the image has either an + * alpha channel or a transparency chunk, you must provide a buffer for + * rows. In this case, you do not have to provide a display_row buffer + * also, but you may. If the image is not interlaced, or if you have + * not called png_set_interlace_handling(), the display_row buffer will + * be ignored, so pass NULL to it. + */ + +void +png_read_rows(png_structp png_ptr, png_bytepp row, + png_bytepp display_row, png_uint_32 num_rows) +{ + png_uint_32 i; + png_bytepp rp; + png_bytepp dp; + + png_debug(1, "in png_read_rows\n"); + /* save jump buffer and error functions */ + rp = row; + dp = display_row; + for (i = 0; i < num_rows; i++) + { + png_bytep rptr; + png_bytep dptr; + + if (rp != NULL) + rptr = *rp; + else + rptr = NULL; + if (dp != NULL) + dptr = *dp; + else + dptr = NULL; + png_read_row(png_ptr, rptr, dptr); + if (row != NULL) + rp++; + if (display_row != NULL) + dp++; + } +} + +/* Read the entire image. If the image has an alpha channel or a tRNS + * chunk, and you have called png_handle_alpha(), you will need to + * initialize the image to the current image that PNG will be overlaying. + * We set the num_rows again here, in case it was incorrectly set in + * png_read_start_row() by a call to png_read_update_info() or + * png_start_read_image() if png_set_interlace_handling() wasn't called + * prior to either of these functions like it should have been. You can + * only call this function once. If you desire to have an image for + * each pass of a interlaced image, use png_read_rows() instead. + */ +void +png_read_image(png_structp png_ptr, png_bytepp image) +{ + png_uint_32 i; + int pass, j; + png_bytepp rp; + + png_debug(1, "in png_read_image\n"); + /* save jump buffer and error functions */ + pass = png_set_interlace_handling(png_ptr); + + png_ptr->num_rows = png_ptr->height; /* Make sure this is set correctly */ + + for (j = 0; j < pass; j++) + { + rp = image; + for (i = 0; i < png_ptr->height; i++) + { + png_read_row(png_ptr, *rp, NULL); + rp++; + } + } +} + +/* Read the end of the PNG file. Will not read past the end of the + * file, will verify the end is accurate, and will read any comments + * or time information at the end of the file, if info is not NULL. + */ +void +png_read_end(png_structp png_ptr, png_infop info_ptr) +{ + png_byte chunk_length[4]; + png_uint_32 length; + + png_debug(1, "in png_read_end\n"); + /* save jump buffer and error functions */ + png_crc_finish(png_ptr, 0); /* Finish off CRC from last IDAT chunk */ + + do + { + png_read_data(png_ptr, chunk_length, 4); + length = png_get_uint_32(chunk_length); + + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + + png_debug1(0, "Reading %s chunk.\n", png_ptr->chunk_name); + + if (!png_memcmp(png_ptr->chunk_name, png_IHDR, 4)) + png_handle_IHDR(png_ptr, info_ptr, length); + else if (!png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + { + /* Zero length IDATs are legal after the last IDAT has been + * read, but not after other chunks have been read. + */ + if (length > 0 || png_ptr->mode & PNG_AFTER_IDAT) + png_error(png_ptr, "Too many IDAT's found"); + else + png_crc_finish(png_ptr, 0); + } + else if (!png_memcmp(png_ptr->chunk_name, png_PLTE, 4)) + png_handle_PLTE(png_ptr, info_ptr, length); + else if (!png_memcmp(png_ptr->chunk_name, png_IEND, 4)) + png_handle_IEND(png_ptr, info_ptr, length); +#if defined(PNG_READ_bKGD_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_bKGD, 4)) + png_handle_bKGD(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_cHRM, 4)) + png_handle_cHRM(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_gAMA_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_gAMA, 4)) + png_handle_gAMA(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_hIST_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_hIST, 4)) + png_handle_hIST(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_oFFs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_oFFs, 4)) + png_handle_oFFs(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pCAL, 4)) + png_handle_pCAL(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_pHYs_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_pHYs, 4)) + png_handle_pHYs(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sBIT_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sBIT, 4)) + png_handle_sBIT(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_sRGB_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_sRGB, 4)) + png_handle_sRGB(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tEXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tEXt, 4)) + png_handle_tEXt(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tIME_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tIME, 4)) + png_handle_tIME(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_tRNS_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_tRNS, 4)) + png_handle_tRNS(png_ptr, info_ptr, length); +#endif +#if defined(PNG_READ_zTXt_SUPPORTED) + else if (!png_memcmp(png_ptr->chunk_name, png_zTXt, 4)) + png_handle_zTXt(png_ptr, info_ptr, length); +#endif + else + png_handle_unknown(png_ptr, info_ptr, length); + } while (!(png_ptr->mode & PNG_HAVE_IEND)); +} + +/* free all memory used by the read */ +void +png_destroy_read_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr, + png_infopp end_info_ptr_ptr) +{ + png_structp png_ptr = NULL; + png_infop info_ptr = NULL, end_info_ptr = NULL; + + png_debug(1, "in png_destroy_read_struct\n"); + /* save jump buffer and error functions */ + if (png_ptr_ptr != NULL) + png_ptr = *png_ptr_ptr; + + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (end_info_ptr_ptr != NULL) + end_info_ptr = *end_info_ptr_ptr; + + png_read_destroy(png_ptr, info_ptr, end_info_ptr); + + if (info_ptr != NULL) + { +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) + png_free(png_ptr, info_ptr->text); +#endif + png_destroy_struct((png_voidp)info_ptr); + *info_ptr_ptr = (png_infop)NULL; + } + + if (end_info_ptr != NULL) + { +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_READ_zTXt_SUPPORTED) + png_free(png_ptr, end_info_ptr->text); +#endif + png_destroy_struct((png_voidp)end_info_ptr); + *end_info_ptr_ptr = (png_infop)NULL; + } + + if (png_ptr != NULL) + { + png_destroy_struct((png_voidp)png_ptr); + *png_ptr_ptr = (png_structp)NULL; + } +} + +/* free all memory used by the read (old method) */ +void +png_read_destroy(png_structp png_ptr, png_infop info_ptr, png_infop end_info_ptr) +{ + jmp_buf tmp_jmp; + png_error_ptr error_fn; + png_error_ptr warning_fn; + png_voidp error_ptr; + + png_debug(1, "in png_read_destroy\n"); + /* save jump buffer and error functions */ + if (info_ptr != NULL) + png_info_destroy(png_ptr, info_ptr); + + if (end_info_ptr != NULL) + png_info_destroy(png_ptr, end_info_ptr); + + png_free(png_ptr, png_ptr->zbuf); + png_free(png_ptr, png_ptr->row_buf); + png_free(png_ptr, png_ptr->prev_row); +#if defined(PNG_READ_DITHER_SUPPORTED) + png_free(png_ptr, png_ptr->palette_lookup); + png_free(png_ptr, png_ptr->dither_index); +#endif +#if defined(PNG_READ_GAMMA_SUPPORTED) + png_free(png_ptr, png_ptr->gamma_table); +#endif +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + png_free(png_ptr, png_ptr->gamma_from_1); + png_free(png_ptr, png_ptr->gamma_to_1); +#endif + if (png_ptr->flags & PNG_FLAG_FREE_PALETTE) + png_zfree(png_ptr, png_ptr->palette); +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_bKGD_SUPPORTED) + if (png_ptr->flags & PNG_FLAG_FREE_TRANS) + png_free(png_ptr, png_ptr->trans); +#endif +#if defined(PNG_READ_hIST_SUPPORTED) + if (png_ptr->flags & PNG_FLAG_FREE_HIST) + png_free(png_ptr, png_ptr->hist); +#endif +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (png_ptr->gamma_16_table != NULL) + { + int i; + for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) + { + png_free(png_ptr, png_ptr->gamma_16_table[i]); + } + } +#endif +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + png_free(png_ptr, png_ptr->gamma_16_table); + if (png_ptr->gamma_16_from_1 != NULL) + { + int i; + for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) + { + png_free(png_ptr, png_ptr->gamma_16_from_1[i]); + } + } + png_free(png_ptr, png_ptr->gamma_16_from_1); + if (png_ptr->gamma_16_to_1 != NULL) + { + int i; + for (i = 0; i < (1 << (8 - png_ptr->gamma_shift)); i++) + { + png_free(png_ptr, png_ptr->gamma_16_to_1[i]); + } + } + png_free(png_ptr, png_ptr->gamma_16_to_1); +#endif + + inflateEnd(&png_ptr->zstream); +#ifdef PNG_PROGRESSIVE_READ_SUPPORTED + png_free(png_ptr, png_ptr->save_buffer); +#endif + + /* Save the important info out of the png_struct, in case it is + * being used again. + */ + png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); + + error_fn = png_ptr->error_fn; + warning_fn = png_ptr->warning_fn; + error_ptr = png_ptr->error_ptr; + + png_memset(png_ptr, 0, sizeof (png_struct)); + + png_ptr->error_fn = error_fn; + png_ptr->warning_fn = warning_fn; + png_ptr->error_ptr = error_ptr; + + png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); +} + +void +png_set_read_status_fn(png_structp png_ptr, png_read_status_ptr read_row_fn) +{ + png_ptr->read_row_fn = read_row_fn; +} diff --git a/thirdparty/libpng/pngrio.c b/thirdparty/libpng/pngrio.c new file mode 100644 index 00000000..f165018a --- /dev/null +++ b/thirdparty/libpng/pngrio.c @@ -0,0 +1,145 @@ + +/* pngrio.c - functions for data input + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * This file provides a location for all input. Users which need + * special handling are expected to write a function which has the same + * arguments as this, and perform a similar function, but possibly has + * a different input method. Note that you shouldn't change this + * function, but rather write a replacement function and then make + * libpng use it at run time with png_set_read_fn(...). + */ + +#define PNG_INTERNAL +#include "png.h" + +/* Read the data from whatever input you are using. The default routine + reads from a file pointer. Note that this routine sometimes gets called + with very small lengths, so you should implement some kind of simple + buffering if you are using unbuffered reads. This should never be asked + to read more then 64K on a 16 bit machine. */ +void +png_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_debug1(4,"reading %d bytes\n", length); + if (png_ptr->read_data_fn != NULL) + (*(png_ptr->read_data_fn))(png_ptr, data, length); + else + png_error(png_ptr, "Call to NULL read function"); +} + +#if !defined(PNG_NO_STDIO) +/* This is the function which does the actual reading of data. If you are + not reading from a standard C stream, you should create a replacement + read_data function and use it at run time with png_set_read_fn(), rather + than changing the library. */ +#ifndef USE_FAR_KEYWORD +static void +png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + + /* fread() returns 0 on error, so it is OK to store this in a png_size_t + * instead of an int, which is what fread() actually returns. + */ + check = (png_size_t)fread(data, (png_size_t)1, length, + (FILE *)png_ptr->io_ptr); + + if (check != length) + { + png_error(png_ptr, "Read Error"); + } +} +#else +/* this is the model-independent version. Since the standard I/O library + can't handle far buffers in the medium and small models, we have to copy + the data. +*/ + +#define NEAR_BUF_SIZE 1024 +#define MIN(a,b) (a <= b ? a : b) + +static void +png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + int check; + png_byte *n_data; + FILE *io_ptr; + + /* Check if data really is near. If so, use usual code. */ + n_data = (png_byte *)CVT_PTR_NOCHECK(data); + io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr); + if ((png_bytep)n_data == data) + { + check = fread(n_data, 1, length, io_ptr); + } + else + { + png_byte buf[NEAR_BUF_SIZE]; + png_size_t read, remaining, err; + check = 0; + remaining = length; + do + { + read = MIN(NEAR_BUF_SIZE, remaining); + err = fread(buf, (png_size_t)1, read, io_ptr); + png_memcpy(data, buf, read); /* copy far buffer to near buffer */ + if(err != read) + break; + else + check += err; + data += read; + remaining -= read; + } + while (remaining != 0); + } + if ((png_uint_32)check != (png_uint_32)length) + { + png_error(png_ptr, "read Error"); + } +} +#endif +#endif + +/* This function allows the application to supply a new input function + for libpng if standard C streams aren't being used. + + This function takes as its arguments: + png_ptr - pointer to a png input data structure + io_ptr - pointer to user supplied structure containing info about + the input functions. May be NULL. + read_data_fn - pointer to a new input function which takes as it's + arguments a pointer to a png_struct, a pointer to + a location where input data can be stored, and a 32-bit + unsigned int which is the number of bytes to be read. + To exit and output any fatal error messages the new write + function should call png_error(png_ptr, "Error msg"). */ +void +png_set_read_fn(png_structp png_ptr, png_voidp io_ptr, + png_rw_ptr read_data_fn) +{ + png_ptr->io_ptr = io_ptr; + +#if !defined(PNG_NO_STDIO) + if (read_data_fn != NULL) + png_ptr->read_data_fn = read_data_fn; + else + png_ptr->read_data_fn = png_default_read_data; +#else + png_ptr->read_data_fn = read_data_fn; +#endif + + /* It is an error to write to a read device */ + png_ptr->write_data_fn = NULL; + +#if defined(PNG_WRITE_FLUSH_SUPPORTED) + png_ptr->output_flush_fn = NULL; +#endif /* PNG_WRITE_FLUSH_SUPPORTED */ +} + diff --git a/thirdparty/libpng/pngrtran.c b/thirdparty/libpng/pngrtran.c new file mode 100644 index 00000000..e1699d5a --- /dev/null +++ b/thirdparty/libpng/pngrtran.c @@ -0,0 +1,3430 @@ + +/* pngrtran.c - transforms the data in a row for PNG readers + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * This file contains functions optionally called by an application + * in order to tell libpng how to handle data when reading a PNG. + * Transformations which are used in both reading and writing are + * in pngtrans.c. + */ + +#define PNG_INTERNAL +#include "png.h" + +#ifdef PNG_READ_COMPOSITE_NODIV_SUPPORTED +/* With these routines, we avoid an integer divide, which will be slower on + * many machines. However, it does take more operations than the corresponding + * divide method, so it may be slower on some RISC systems. There are two + * shifts (by 8 or 16 bits) and an addition, versus a single integer divide. + * + * Note that the rounding factors are NOT supposed to be the same! 128 and + * 32768 are correct for the NODIV code; 127 and 32767 are correct for the + * standard method. + * + * [Optimized code by Greg Roelofs and Mark Adler...blame us for bugs. :-) ] + */ + + /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ +# define png_composite(composite, fg, alpha, bg) \ + { png_uint_16 temp = ((png_uint_16)(fg) * (png_uint_16)(alpha) + \ + (png_uint_16)(bg)*(png_uint_16)(255 - \ + (png_uint_16)(alpha)) + (png_uint_16)128); \ + (composite) = (png_byte)((temp + (temp >> 8)) >> 8); } +# define png_composite_16(composite, fg, alpha, bg) \ + { png_uint_32 temp = ((png_uint_32)(fg) * (png_uint_32)(alpha) + \ + (png_uint_32)(bg)*(png_uint_32)(65535L - \ + (png_uint_32)(alpha)) + (png_uint_32)32768L); \ + (composite) = (png_uint_16)((temp + (temp >> 16)) >> 16); } + +#else /* standard method using integer division */ + + /* fg and bg should be in `gamma 1.0' space; alpha is the opacity */ +# define png_composite(composite, fg, alpha, bg) \ + (composite) = (png_byte)(((png_uint_16)(fg) * (png_uint_16)(alpha) + \ + (png_uint_16)(bg) * (png_uint_16)(255 - (png_uint_16)(alpha)) + \ + (png_uint_16)127) / 255) +# define png_composite_16(composite, fg, alpha, bg) \ + (composite) = (png_uint_16)(((png_uint_32)(fg) * (png_uint_32)(alpha) + \ + (png_uint_32)(bg)*(png_uint_32)(65535L - (png_uint_32)(alpha)) + \ + (png_uint_32)32767) / (png_uint_32)65535L) + +#endif /* ?PNG_READ_COMPOSITE_NODIV_SUPPORTED */ + + +/* Set the action on getting a CRC error for an ancillary or critical chunk. */ +void +png_set_crc_action(png_structp png_ptr, int crit_action, int ancil_action) +{ + png_debug(1, "in png_set_crc_action\n"); + /* Tell libpng how we react to CRC errors in critical chunks */ + switch (crit_action) + { + case PNG_CRC_NO_CHANGE: /* leave setting as is */ + break; + case PNG_CRC_WARN_USE: /* warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE; + break; + case PNG_CRC_QUIET_USE: /* quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + png_ptr->flags |= PNG_FLAG_CRC_CRITICAL_USE | + PNG_FLAG_CRC_CRITICAL_IGNORE; + break; + case PNG_CRC_WARN_DISCARD: /* not a valid action for critical data */ + png_warning(png_ptr, "Can't discard critical data on CRC error."); + case PNG_CRC_ERROR_QUIT: /* error/quit */ + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_CRITICAL_MASK; + break; + } + + switch (ancil_action) + { + case PNG_CRC_NO_CHANGE: /* leave setting as is */ + break; + case PNG_CRC_WARN_USE: /* warn/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE; + break; + case PNG_CRC_QUIET_USE: /* quiet/use data */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_USE | + PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + case PNG_CRC_ERROR_QUIT: /* error/quit */ + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + png_ptr->flags |= PNG_FLAG_CRC_ANCILLARY_NOWARN; + break; + case PNG_CRC_WARN_DISCARD: /* warn/discard data */ + case PNG_CRC_DEFAULT: + default: + png_ptr->flags &= ~PNG_FLAG_CRC_ANCILLARY_MASK; + break; + } +} + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) +/* handle alpha and tRNS via a background color */ +void +png_set_background(png_structp png_ptr, + png_color_16p background_color, int background_gamma_code, + int need_expand, double background_gamma) +{ + png_debug(1, "in png_set_background\n"); + if (background_gamma_code == PNG_BACKGROUND_GAMMA_UNKNOWN) + { + png_warning(png_ptr, "Application must supply a known background gamma"); + return; + } + + png_ptr->transformations |= PNG_BACKGROUND; + png_memcpy(&(png_ptr->background), background_color, + sizeof(png_color_16)); + png_ptr->background_gamma = (float)background_gamma; + png_ptr->background_gamma_type = (png_byte)(background_gamma_code); + png_ptr->transformations |= (need_expand ? PNG_BACKGROUND_EXPAND : 0); +} +#endif + +#if defined(PNG_READ_16_TO_8_SUPPORTED) +/* strip 16 bit depth files to 8 bit depth */ +void +png_set_strip_16(png_structp png_ptr) +{ + png_debug(1, "in png_set_strip_16\n"); + png_ptr->transformations |= PNG_16_TO_8; +} +#endif + +#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +void +png_set_strip_alpha(png_structp png_ptr) +{ + png_debug(1, "in png_set_strip_alpha\n"); + png_ptr->transformations |= PNG_STRIP_ALPHA; +} +#endif + +#if defined(PNG_READ_DITHER_SUPPORTED) +/* Dither file to 8 bit. Supply a palette, the current number + * of elements in the palette, the maximum number of elements + * allowed, and a histogram if possible. If the current number + * of colors is greater then the maximum number, the palette will be + * modified to fit in the maximum number. "full_dither" indicates + * whether we need a dithering cube set up for RGB images, or if we + * simply are reducing the number of colors in a paletted image. + */ + +typedef struct png_dsort_struct +{ + struct png_dsort_struct FAR * next; + png_byte left; + png_byte right; +} png_dsort; +typedef png_dsort FAR * png_dsortp; +typedef png_dsort FAR * FAR * png_dsortpp; + +void +png_set_dither(png_structp png_ptr, png_colorp palette, + int num_palette, int maximum_colors, png_uint_16p histogram, + int full_dither) +{ + png_debug(1, "in png_set_dither\n"); + png_ptr->transformations |= PNG_DITHER; + + if (!full_dither) + { + int i; + + png_ptr->dither_index = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * sizeof (png_byte))); + for (i = 0; i < num_palette; i++) + png_ptr->dither_index[i] = (png_byte)i; + } + + if (num_palette > maximum_colors) + { + if (histogram != NULL) + { + /* This is easy enough, just throw out the least used colors. + Perhaps not the best solution, but good enough. */ + + int i; + png_bytep sort; + + /* initialize an array to sort colors */ + sort = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_palette + * sizeof (png_byte))); + + /* initialize the sort array */ + for (i = 0; i < num_palette; i++) + sort[i] = (png_byte)i; + + /* Find the least used palette entries by starting a + bubble sort, and running it until we have sorted + out enough colors. Note that we don't care about + sorting all the colors, just finding which are + least used. */ + + for (i = num_palette - 1; i >= maximum_colors; i--) + { + int done; /* to stop early if the list is pre-sorted */ + int j; + + done = 1; + for (j = 0; j < i; j++) + { + if (histogram[sort[j]] < histogram[sort[j + 1]]) + { + png_byte t; + + t = sort[j]; + sort[j] = sort[j + 1]; + sort[j + 1] = t; + done = 0; + } + } + if (done) + break; + } + + /* swap the palette around, and set up a table, if necessary */ + if (full_dither) + { + int j; + + /* put all the useful colors within the max, but don't + move the others */ + for (i = 0, j = num_palette; i < maximum_colors; i++) + { + if ((int)sort[i] >= maximum_colors) + { + do + j--; + while ((int)sort[j] >= maximum_colors); + palette[i] = palette[j]; + } + } + } + else + { + int j; + + /* move all the used colors inside the max limit, and + develop a translation table */ + for (i = 0, j = num_palette; i < maximum_colors; i++) + { + /* only move the colors we need to */ + if ((int)sort[i] >= maximum_colors) + { + png_color tmp_color; + + do + j--; + while ((int)sort[j] >= maximum_colors); + + tmp_color = palette[j]; + palette[j] = palette[i]; + palette[i] = tmp_color; + /* indicate where the color went */ + png_ptr->dither_index[j] = (png_byte)i; + png_ptr->dither_index[i] = (png_byte)j; + } + } + + /* find closest color for those colors we are not using */ + for (i = 0; i < num_palette; i++) + { + if ((int)png_ptr->dither_index[i] >= maximum_colors) + { + int min_d, k, min_k, d_index; + + /* find the closest color to one we threw out */ + d_index = png_ptr->dither_index[i]; + min_d = PNG_COLOR_DIST(palette[d_index], palette[0]); + for (k = 1, min_k = 0; k < maximum_colors; k++) + { + int d; + + d = PNG_COLOR_DIST(palette[d_index], palette[k]); + + if (d < min_d) + { + min_d = d; + min_k = k; + } + } + /* point to closest color */ + png_ptr->dither_index[i] = (png_byte)min_k; + } + } + } + png_free(png_ptr, sort); + } + else + { + /* This is much harder to do simply (and quickly). Perhaps + we need to go through a median cut routine, but those + don't always behave themselves with only a few colors + as input. So we will just find the closest two colors, + and throw out one of them (chosen somewhat randomly). + [I don't understand this at all, so if someone wants to + work on improving it, be my guest - AED] + */ + int i; + int max_d; + int num_new_palette; + png_dsortpp hash; + png_bytep index_to_palette; + /* where the original index currently is in the palette */ + png_bytep palette_to_index; + /* which original index points to this palette color */ + + /* initialize palette index arrays */ + index_to_palette = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * sizeof (png_byte))); + palette_to_index = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(num_palette * sizeof (png_byte))); + + /* initialize the sort array */ + for (i = 0; i < num_palette; i++) + { + index_to_palette[i] = (png_byte)i; + palette_to_index[i] = (png_byte)i; + } + + hash = (png_dsortpp)png_malloc(png_ptr, (png_uint_32)(769 * + sizeof (png_dsortp))); + for (i = 0; i < 769; i++) + hash[i] = NULL; +/* png_memset(hash, 0, 769 * sizeof (png_dsortp)); */ + + num_new_palette = num_palette; + + /* initial wild guess at how far apart the farthest pixel + pair we will be eliminating will be. Larger + numbers mean more areas will be allocated, Smaller + numbers run the risk of not saving enough data, and + having to do this all over again. + + I have not done extensive checking on this number. + */ + max_d = 96; + + while (num_new_palette > maximum_colors) + { + for (i = 0; i < num_new_palette - 1; i++) + { + int j; + + for (j = i + 1; j < num_new_palette; j++) + { + int d; + + d = PNG_COLOR_DIST(palette[i], palette[j]); + + if (d <= max_d) + { + png_dsortp t; + + t = (png_dsortp)png_malloc(png_ptr, (png_uint_32)(sizeof + (png_dsort))); + t->next = hash[d]; + t->left = (png_byte)i; + t->right = (png_byte)j; + hash[d] = t; + } + } + } + + for (i = 0; i <= max_d; i++) + { + if (hash[i] != NULL) + { + png_dsortp p; + + for (p = hash[i]; p; p = p->next) + { + if ((int)index_to_palette[p->left] < num_new_palette && + (int)index_to_palette[p->right] < num_new_palette) + { + int j, next_j; + + if (num_new_palette & 1) + { + j = p->left; + next_j = p->right; + } + else + { + j = p->right; + next_j = p->left; + } + + num_new_palette--; + palette[index_to_palette[j]] = palette[num_new_palette]; + if (!full_dither) + { + int k; + + for (k = 0; k < num_palette; k++) + { + if (png_ptr->dither_index[k] == + index_to_palette[j]) + png_ptr->dither_index[k] = + index_to_palette[next_j]; + if ((int)png_ptr->dither_index[k] == + num_new_palette) + png_ptr->dither_index[k] = + index_to_palette[j]; + } + } + + index_to_palette[palette_to_index[num_new_palette]] = + index_to_palette[j]; + palette_to_index[index_to_palette[j]] = + palette_to_index[num_new_palette]; + + index_to_palette[j] = (png_byte)num_new_palette; + palette_to_index[num_new_palette] = (png_byte)j; + } + if (num_new_palette <= maximum_colors) + break; + } + if (num_new_palette <= maximum_colors) + break; + } + } + + for (i = 0; i < 769; i++) + { + if (hash[i] != NULL) + { + png_dsortp p; + + p = hash[i]; + while (p) + { + png_dsortp t; + + t = p->next; + png_free(png_ptr, p); + p = t; + } + } + hash[i] = 0; + } + max_d += 96; + } + png_free(png_ptr, hash); + png_free(png_ptr, palette_to_index); + png_free(png_ptr, index_to_palette); + } + num_palette = maximum_colors; + } + if (png_ptr->palette == NULL) + { + png_ptr->palette = palette; + } + png_ptr->num_palette = (png_uint_16)num_palette; + + if (full_dither) + { + int i; + int total_bits, num_red, num_green, num_blue; + png_size_t num_entries; + png_bytep distance; + + total_bits = PNG_DITHER_RED_BITS + PNG_DITHER_GREEN_BITS + + PNG_DITHER_BLUE_BITS; + + num_red = (1 << PNG_DITHER_RED_BITS); + num_green = (1 << PNG_DITHER_GREEN_BITS); + num_blue = (1 << PNG_DITHER_BLUE_BITS); + num_entries = ((png_size_t)1 << total_bits); + + png_ptr->palette_lookup = (png_bytep )png_malloc(png_ptr, + (png_uint_32)(num_entries * sizeof (png_byte))); + + png_memset(png_ptr->palette_lookup, 0, num_entries * sizeof (png_byte)); + + distance = (png_bytep)png_malloc(png_ptr, (png_uint_32)(num_entries * + sizeof(png_byte))); + + png_memset(distance, 0xff, num_entries * sizeof(png_byte)); + + for (i = 0; i < num_palette; i++) + { + int r, g, b, ir, ig, ib; + + r = (palette[i].red >> (8 - PNG_DITHER_RED_BITS)); + g = (palette[i].green >> (8 - PNG_DITHER_GREEN_BITS)); + b = (palette[i].blue >> (8 - PNG_DITHER_BLUE_BITS)); + + for (ir = 0; ir < num_red; ir++) + { + int dr, index_r; + + dr = abs(ir - r); + index_r = (ir << (PNG_DITHER_BLUE_BITS + PNG_DITHER_GREEN_BITS)); + for (ig = 0; ig < num_green; ig++) + { + int dg, dt, dm, index_g; + + dg = abs(ig - g); + dt = dr + dg; + dm = ((dr > dg) ? dr : dg); + index_g = index_r | (ig << PNG_DITHER_BLUE_BITS); + for (ib = 0; ib < num_blue; ib++) + { + int d_index, db, dmax, d; + + d_index = index_g | ib; + db = abs(ib - b); + dmax = ((dm > db) ? dm : db); + d = dmax + dt + db; + + if (d < (int)distance[d_index]) + { + distance[d_index] = (png_byte)d; + png_ptr->palette_lookup[d_index] = (png_byte)i; + } + } + } + } + } + + png_free(png_ptr, distance); + } +} +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) +/* Transform the image from the file_gamma to the screen_gamma. We + * only do transformations on images where the file_gamma and screen_gamma + * are not close reciprocals, otherwise it slows things down slightly, and + * also needlessly introduces small errors. + */ +void +png_set_gamma(png_structp png_ptr, double scrn_gamma, double file_gamma) +{ + png_debug(1, "in png_set_gamma\n"); + if (fabs(scrn_gamma * file_gamma - 1.0) > PNG_GAMMA_THRESHOLD) + png_ptr->transformations |= PNG_GAMMA; + png_ptr->gamma = (float)file_gamma; + png_ptr->screen_gamma = (float)scrn_gamma; +} +#endif + +#if defined(PNG_READ_EXPAND_SUPPORTED) +/* Expand paletted images to rgb, expand grayscale images of + * less then 8 bit depth to 8 bit depth, and expand tRNS chunks + * to alpha channels. + */ +void +png_set_expand(png_structp png_ptr) +{ + png_debug(1, "in png_set_expand\n"); + png_ptr->transformations |= PNG_EXPAND; +} +#endif + +#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) +void +png_set_gray_to_rgb(png_structp png_ptr) +{ + png_debug(1, "in png_set_gray_to_rgb\n"); + png_ptr->transformations |= PNG_GRAY_TO_RGB; +} +#endif + +#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) +/* Convert a RGB image to a grayscale of the given width. This would + * allow us, for example, to convert a 24 bpp RGB image into an 8 or + * 16 bpp grayscale image. (Not yet implemented.) + */ +void +png_set_rgb_to_gray(png_structp png_ptr, int gray_bits) +{ + png_debug(1, "in png_set_rgb_to_gray\n"); + png_ptr->transformations |= PNG_RGB_TO_GRAY; + /* Need to do something with gray_bits here. */ + png_warning(png_ptr, "RGB to GRAY transformation is not yet implemented."); +} +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) +void +png_set_read_user_transform_fn(png_structp png_ptr, png_user_transform_ptr + read_user_transform_fn) +{ + png_debug(1, "in png_set_read_user_transform_fn\n"); + png_ptr->transformations |= PNG_USER_TRANSFORM; + png_ptr->read_user_transform_fn = read_user_transform_fn; +} +#endif + +/* Initialize everything needed for the read. This includes modifying + * the palette. + */ +void +png_init_read_transformations(png_structp png_ptr) +{ + int color_type; + + png_debug(1, "in png_init_read_transformations\n"); + color_type = png_ptr->color_type; + +#if defined(PNG_READ_EXPAND_SUPPORTED) && defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->transformations & PNG_BACKGROUND_EXPAND) + { + if (color_type == PNG_COLOR_TYPE_GRAY) + { + /* expand background chunk. */ + switch (png_ptr->bit_depth) + { + case 1: + png_ptr->background.gray *= (png_uint_16)0xff; + png_ptr->background.red = png_ptr->background.green = + png_ptr->background.blue = png_ptr->background.gray; + break; + case 2: + png_ptr->background.gray *= (png_uint_16)0x55; + png_ptr->background.red = png_ptr->background.green = + png_ptr->background.blue = png_ptr->background.gray; + break; + case 4: + png_ptr->background.gray *= (png_uint_16)0x11; + png_ptr->background.red = png_ptr->background.green = + png_ptr->background.blue = png_ptr->background.gray; + break; + case 8: + case 16: + png_ptr->background.red = png_ptr->background.green = + png_ptr->background.blue = png_ptr->background.gray; + break; + } + } + else if (color_type == PNG_COLOR_TYPE_PALETTE) + { + png_ptr->background.red = + png_ptr->palette[png_ptr->background.index].red; + png_ptr->background.green = + png_ptr->palette[png_ptr->background.index].green; + png_ptr->background.blue = + png_ptr->palette[png_ptr->background.index].blue; + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) + if (png_ptr->transformations & PNG_INVERT_ALPHA) + { +#if defined(PNG_READ_EXPAND_SUPPORTED) + /* GRR BUG #1: was (png_ptr->transformations & !PNG_EXPAND) */ + if (!(png_ptr->transformations & PNG_EXPAND)) +#endif + { + /* invert the alpha channel (in tRNS) unless the pixels are + going to be expanded, in which case leave it for later */ + int i; + for (i=0; i<(int)png_ptr->num_trans; i++) + png_ptr->trans[i] = 255 - png_ptr->trans[i]; + } + } +#endif + + } + } +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + png_ptr->background_1 = png_ptr->background; +#endif +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (png_ptr->transformations & PNG_GAMMA) + { + png_build_gamma_table(png_ptr); +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->transformations & PNG_BACKGROUND) + { + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + int num_palette, i; + png_color back, back_1; + png_colorp palette; + + palette = png_ptr->palette; + num_palette = png_ptr->num_palette; + + if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) + { + back.red = png_ptr->gamma_table[png_ptr->background.red]; + back.green = png_ptr->gamma_table[png_ptr->background.green]; + back.blue = png_ptr->gamma_table[png_ptr->background.blue]; + + back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; + back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; + back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; + } + else + { + double g, gs; + +/* + GRR BUG #3: inconsistent with handling of full RGBA below + g = 1.0 / png_ptr->background_gamma; + gs = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma); + */ + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + g = (png_ptr->screen_gamma); + gs = 1.0; + break; + case PNG_BACKGROUND_GAMMA_FILE: + g = 1.0 / (png_ptr->gamma); + gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); + break; + case PNG_BACKGROUND_GAMMA_UNIQUE: + g = 1.0 / (png_ptr->background_gamma); + gs = 1.0 / (png_ptr->background_gamma * + png_ptr->screen_gamma); + break; + default: + g = 1.0; /* back_1 */ + gs = 1.0; /* back */ + } + + if ( +/* + GRR BUG #2: This creates self-inconsistent images--fully + transparent and fully opaque look fine, but translucent + pixels are wrong (too bright if XV's code can be trusted). + Commenting it out makes an internally self-consistent + image, but still not consistent with RGBA version of same + thing (again, too bright in XV). + png_ptr->background_gamma_type==PNG_BACKGROUND_GAMMA_SCREEN|| + */ + fabs(gs - 1.0) < PNG_GAMMA_THRESHOLD) + { + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + } + else + { + back.red = (png_byte)(pow( + (double)png_ptr->background.red/255, gs) * 255.0 + .5); + back.green = (png_byte)(pow( + (double)png_ptr->background.green/255, gs) * 255.0 + .5); + back.blue = (png_byte)(pow( + (double)png_ptr->background.blue/255, gs) * 255.0 + .5); + } + + back_1.red = (png_byte)(pow( + (double)png_ptr->background.red/255, g) * 255.0 + .5); + back_1.green = (png_byte)(pow( + (double)png_ptr->background.green/255, g) * 255.0 + .5); + back_1.blue = (png_byte)(pow( + (double)png_ptr->background.blue/255, g) * 255.0 + .5); + } + + for (i = 0; i < num_palette; i++) + { + if (i < (int)png_ptr->num_trans && png_ptr->trans[i] != 0xff) + { + if (png_ptr->trans[i] == 0) + { + palette[i] = back; + } + else /* if (png_ptr->trans[i] != 0xff) */ + { + png_byte v, w; + + v = png_ptr->gamma_to_1[palette[i].red]; + png_composite(w, v, png_ptr->trans[i], back_1.red); + palette[i].red = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[palette[i].green]; + png_composite(w, v, png_ptr->trans[i], back_1.green); + palette[i].green = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[palette[i].blue]; + png_composite(w, v, png_ptr->trans[i], back_1.blue); + palette[i].blue = png_ptr->gamma_from_1[w]; + } + } + else + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + } + } + /* if (png_ptr->background_gamma_type!=PNG_BACKGROUND_GAMMA_UNKNOWN)*/ + else + /* color_type != PNG_COLOR_TYPE_PALETTE */ + { + double g, gs, m; + + m = (double)(((png_uint_32)1 << png_ptr->bit_depth) - 1); + g = 1.0; + gs = 1.0; + + switch (png_ptr->background_gamma_type) + { + case PNG_BACKGROUND_GAMMA_SCREEN: + g = (png_ptr->screen_gamma); + gs = 1.0; + break; + case PNG_BACKGROUND_GAMMA_FILE: + g = 1.0 / (png_ptr->gamma); + gs = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); + break; + case PNG_BACKGROUND_GAMMA_UNIQUE: + g = 1.0 / (png_ptr->background_gamma); + gs = 1.0 / (png_ptr->background_gamma * + png_ptr->screen_gamma); + break; + } + + if (color_type & PNG_COLOR_MASK_COLOR) + { + /* RGB or RGBA */ + png_ptr->background_1.red = (png_uint_16)(pow( + (double)png_ptr->background.red / m, g) * m + .5); + png_ptr->background_1.green = (png_uint_16)(pow( + (double)png_ptr->background.green / m, g) * m + .5); + png_ptr->background_1.blue = (png_uint_16)(pow( + (double)png_ptr->background.blue / m, g) * m + .5); + png_ptr->background.red = (png_uint_16)(pow( + (double)png_ptr->background.red / m, gs) * m + .5); + png_ptr->background.green = (png_uint_16)(pow( + (double)png_ptr->background.green / m, gs) * m + .5); + png_ptr->background.blue = (png_uint_16)(pow( + (double)png_ptr->background.blue / m, gs) * m + .5); + } + else + { + /* GRAY or GRAY ALPHA */ + png_ptr->background_1.gray = (png_uint_16)(pow( + (double)png_ptr->background.gray / m, g) * m + .5); + png_ptr->background.gray = (png_uint_16)(pow( + (double)png_ptr->background.gray / m, gs) * m + .5); + } + } + } + else + /* transformation does not include PNG_BACKGROUND */ +#endif + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + int num_palette, i; + png_colorp palette; + + palette = png_ptr->palette; + num_palette = png_ptr->num_palette; + + for (i = 0; i < num_palette; i++) + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + } + } +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + else +#endif +#endif +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + /* No GAMMA transformation */ + if (png_ptr->transformations & PNG_BACKGROUND && + color_type == PNG_COLOR_TYPE_PALETTE) + { + int i; + png_color back; + png_colorp palette; + + palette = png_ptr->palette; + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + + for (i = 0; i < (int)png_ptr->num_trans; i++) + { + if (png_ptr->trans[i] == 0) + { + palette[i] = back; + } + else if (png_ptr->trans[i] != 0xff) + { + png_composite(palette[i].red, palette[i].red, + png_ptr->trans[i], back.red); + png_composite(palette[i].green, palette[i].green, + png_ptr->trans[i], back.green); + png_composite(palette[i].blue, palette[i].blue, + png_ptr->trans[i], back.blue); + } + } + } +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) + if ((png_ptr->transformations & PNG_SHIFT) && + color_type == PNG_COLOR_TYPE_PALETTE) + { + png_uint_16 i; + int sr, sg, sb; + + sr = 8 - png_ptr->sig_bit.red; + if (sr < 0 || sr > 8) + sr = 0; + sg = 8 - png_ptr->sig_bit.green; + if (sg < 0 || sg > 8) + sg = 0; + sb = 8 - png_ptr->sig_bit.blue; + if (sb < 0 || sb > 8) + sb = 0; + for (i = 0; i < png_ptr->num_palette; i++) + { + png_ptr->palette[i].red >>= sr; + png_ptr->palette[i].green >>= sg; + png_ptr->palette[i].blue >>= sb; + } + } +#endif +} + +/* Modify the info structure to reflect the transformations. The + * info should be updated so a PNG file could be written with it, + * assuming the transformations result in valid PNG data. + */ +void +png_read_transform_info(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_read_transform_info\n"); +#if defined(PNG_READ_EXPAND_SUPPORTED) + if (png_ptr->transformations & PNG_EXPAND) + { + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (png_ptr->num_trans) + info_ptr->color_type = PNG_COLOR_TYPE_RGB_ALPHA; + else + info_ptr->color_type = PNG_COLOR_TYPE_RGB; + info_ptr->bit_depth = 8; + info_ptr->num_trans = 0; + } + else + { + if (png_ptr->num_trans) + info_ptr->color_type |= PNG_COLOR_MASK_ALPHA; + if (info_ptr->bit_depth < 8) + info_ptr->bit_depth = 8; + info_ptr->num_trans = 0; + } + } +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->transformations & PNG_BACKGROUND) + { + info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; + info_ptr->num_trans = 0; + info_ptr->background = png_ptr->background; + } +#endif + +#if defined(PNG_READ_16_TO_8_SUPPORTED) + if ((png_ptr->transformations & PNG_16_TO_8) && info_ptr->bit_depth == 16) + info_ptr->bit_depth = 8; +#endif + +#if defined(PNG_READ_DITHER_SUPPORTED) + if (png_ptr->transformations & PNG_DITHER) + { + if (((info_ptr->color_type == PNG_COLOR_TYPE_RGB) || + (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)) && + png_ptr->palette_lookup && info_ptr->bit_depth == 8) + { + info_ptr->color_type = PNG_COLOR_TYPE_PALETTE; + } + } +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) + if ((png_ptr->transformations & PNG_PACK) && info_ptr->bit_depth < 8) + info_ptr->bit_depth = 8; +#endif + +#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) + if ((png_ptr->transformations & PNG_GRAY_TO_RGB) && + !(info_ptr->color_type & PNG_COLOR_MASK_COLOR)) + info_ptr->color_type |= PNG_COLOR_MASK_COLOR; +#endif + + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + info_ptr->channels = 1; + else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) + info_ptr->channels = 3; + else + info_ptr->channels = 1; + +#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) + if ((png_ptr->transformations & PNG_STRIP_ALPHA) && + info_ptr->color_type & PNG_COLOR_MASK_ALPHA) + { + info_ptr->channels--; + info_ptr->color_type &= ~PNG_COLOR_MASK_ALPHA; + } +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) + if ((png_ptr->transformations & PNG_FILLER) && + info_ptr->color_type & PNG_COLOR_TYPE_RGB && + info_ptr->channels == 3) + { + info_ptr->channels = 4; + } +#endif + + if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) + info_ptr->channels++; + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * + info_ptr->bit_depth); + + info_ptr->rowbytes = ((info_ptr->width * info_ptr->pixel_depth + 7) >> 3); +} + +/* Transform the row. The order of transformations is significant, + * and is very touchy. If you add a transformation, take care to + * decide how it fits in with the other transformations here. + */ +void +png_do_read_transformations(png_structp png_ptr) +{ + png_debug(1, "in png_do_read_transformations\n"); +#if !defined(PNG_USELESS_TESTS_SUPPORTED) + if (png_ptr->row_buf == NULL) + { +#if !defined(PNG_NO_STDIO) + char msg[50]; + + sprintf(msg, "NULL row buffer for row %ld, pass %d", png_ptr->row_number, + png_ptr->pass); + png_error(png_ptr, msg); +#else + png_error(png_ptr, "NULL row buffer"); +#endif + } +#endif + +#if defined(PNG_READ_EXPAND_SUPPORTED) + if (png_ptr->transformations & PNG_EXPAND) + { + if (png_ptr->row_info.color_type == PNG_COLOR_TYPE_PALETTE) + { + png_do_expand_palette(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_ptr->palette, png_ptr->trans, png_ptr->num_trans); + } + else if (png_ptr->transformations & PNG_EXPAND) + { + if (png_ptr->num_trans) + png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, + &(png_ptr->trans_values)); + else + png_do_expand(&(png_ptr->row_info), png_ptr->row_buf + 1, + NULL); + } + } +#endif + +#if defined(PNG_READ_STRIP_ALPHA_SUPPORTED) + if (png_ptr->transformations & PNG_STRIP_ALPHA) + png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, + PNG_FLAG_FILLER_AFTER); +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + if ((png_ptr->transformations & PNG_BACKGROUND) && + ((png_ptr->num_trans != 0 ) || + (png_ptr->color_type & PNG_COLOR_MASK_ALPHA))) + png_do_background(&(png_ptr->row_info), png_ptr->row_buf + 1, + &(png_ptr->trans_values), &(png_ptr->background), + &(png_ptr->background_1), + png_ptr->gamma_table, png_ptr->gamma_from_1, + png_ptr->gamma_to_1, png_ptr->gamma_16_table, + png_ptr->gamma_16_from_1, png_ptr->gamma_16_to_1, + png_ptr->gamma_shift); +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) + if ((png_ptr->transformations & PNG_GAMMA) && + !(png_ptr->transformations & PNG_BACKGROUND) && + (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE)) + png_do_gamma(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_ptr->gamma_table, png_ptr->gamma_16_table, + png_ptr->gamma_shift); +#endif + +#if defined(PNG_READ_RGB_TO_GRAY_SUPPORTED) + if (png_ptr->transformations & PNG_RGB_TO_GRAY) + png_do_rgb_to_gray(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_16_TO_8_SUPPORTED) + if (png_ptr->transformations & PNG_16_TO_8) + png_do_chop(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_DITHER_SUPPORTED) + if (png_ptr->transformations & PNG_DITHER) + { + png_do_dither((png_row_infop)&(png_ptr->row_info), png_ptr->row_buf + 1, + png_ptr->palette_lookup, png_ptr->dither_index); + if(png_ptr->row_info.rowbytes == (png_uint_32)0) + png_error(png_ptr, "png_do_dither returned rowbytes=0"); + } +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) + if (png_ptr->transformations & PNG_INVERT_MONO) + png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) + if (png_ptr->transformations & PNG_SHIFT) + png_do_unshift(&(png_ptr->row_info), png_ptr->row_buf + 1, + &(png_ptr->shift)); +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) + if (png_ptr->transformations & PNG_PACK) + png_do_unpack(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) + if (png_ptr->transformations & PNG_BGR) + png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED) + if (png_ptr->transformations & PNG_PACKSWAP) + png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) + if (png_ptr->transformations & PNG_GRAY_TO_RGB) + png_do_gray_to_rgb(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) + if (png_ptr->transformations & PNG_FILLER) + png_do_read_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, + (png_uint_32)png_ptr->filler, png_ptr->flags); +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) + if (png_ptr->transformations & PNG_INVERT_ALPHA) + png_do_read_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) + if (png_ptr->transformations & PNG_SWAP_ALPHA) + png_do_read_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_SWAP_SUPPORTED) + if (png_ptr->transformations & PNG_SWAP_BYTES) + png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif + +#if defined(PNG_READ_USER_TRANSFORM_SUPPORTED) + if (png_ptr->transformations & PNG_USER_TRANSFORM) + if(png_ptr->read_user_transform_fn != NULL) + (*(png_ptr->read_user_transform_fn)) /* user read transform function */ + (png_ptr, /* png_ptr */ + &(png_ptr->row_info), /* row_info: */ + /* png_uint_32 width; width of row */ + /* png_uint_32 rowbytes; number of bytes in row */ + /* png_byte color_type; color type of pixels */ + /* png_byte bit_depth; bit depth of samples */ + /* png_byte channels; number of channels (1-4) */ + /* png_byte pixel_depth; bits per pixel (depth*channels) */ + png_ptr->row_buf + 1); /* start of pixel data for row */ +#endif + +} + +#if defined(PNG_READ_PACK_SUPPORTED) +/* Unpack pixels of 1, 2, or 4 bits per pixel into 1 byte per pixel, + * without changing the actual values. Thus, if you had a row with + * a bit depth of 1, you would end up with bytes that only contained + * the numbers 0 or 1. If you would rather they contain 0 and 255, use + * png_do_shift() after this. + */ +void +png_do_unpack(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_unpack\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL && row_info->bit_depth < 8) +#else + if (row_info->bit_depth < 8) +#endif + { + png_uint_32 shift, i; + png_bytep sp, dp; + + switch (row_info->bit_depth) + { + case 1: + { + sp = row + (png_size_t)((row_info->width - 1) >> 3); + dp = row + (png_size_t)row_info->width - 1; + shift = 7 - (int)((row_info->width + 7) & 7); + for (i = 0; i < row_info->width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x1); + if (shift == 7) + { + shift = 0; + sp--; + } + else + shift++; + + dp--; + } + break; + } + case 2: + { + + sp = row + (png_size_t)((row_info->width - 1) >> 2); + dp = row + (png_size_t)row_info->width - 1; + shift = (int)((3 - ((row_info->width + 3) & 3)) << 1); + for (i = 0; i < row_info->width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0x3); + if (shift == 6) + { + shift = 0; + sp--; + } + else + shift += 2; + + dp--; + } + break; + } + case 4: + { + sp = row + (png_size_t)((row_info->width - 1) >> 1); + dp = row + (png_size_t)row_info->width - 1; + shift = (int)((1 - ((row_info->width + 1) & 1)) << 2); + for (i = 0; i < row_info->width; i++) + { + *dp = (png_byte)((*sp >> shift) & 0xf); + if (shift == 4) + { + shift = 0; + sp--; + } + else + shift = 4; + + dp--; + } + break; + } + } + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_info->width * row_info->channels; + } +} +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) +/* Reverse the effects of png_do_shift. This routine merely shifts the + * pixels back to their significant bits values. Thus, if you have + * a row of bit depth 8, but only 5 are significant, this will shift + * the values back to 0 through 31. + */ +void +png_do_unshift(png_row_infop row_info, png_bytep row, png_color_8p sig_bits) +{ + png_debug(1, "in png_do_unshift\n"); + if ( +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && sig_bits != NULL && +#endif + row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + int shift[4]; + int channels, c; + png_uint_16 value; + + channels = 0; + if (row_info->color_type & PNG_COLOR_MASK_COLOR) + { + shift[channels++] = row_info->bit_depth - sig_bits->red; + shift[channels++] = row_info->bit_depth - sig_bits->green; + shift[channels++] = row_info->bit_depth - sig_bits->blue; + } + else + { + shift[channels++] = row_info->bit_depth - sig_bits->gray; + } + if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + { + shift[channels++] = row_info->bit_depth - sig_bits->alpha; + } + + value = 0; + + for (c = 0; c < channels; c++) + { + if (shift[c] <= 0) + shift[c] = 0; + else + value = 1; + } + + if (!value) + return; + + switch (row_info->bit_depth) + { + case 2: + { + png_bytep bp; + png_uint_32 i; + + for (bp = row, i = 0; i < row_info->rowbytes; i++, bp++) + { + *bp >>= 1; + *bp &= 0x55; + } + break; + } + case 4: + { + png_bytep bp; + png_byte mask; + png_uint_32 i; + + mask = (png_byte)(((int)0xf0 >> shift[0]) & (int)0xf0) | + (png_byte)((int)0xf >> shift[0]); + for (bp = row, i = 0; i < row_info->rowbytes; i++, bp++) + { + *bp >>= shift[0]; + *bp &= mask; + } + break; + } + case 8: + { + png_bytep bp; + png_uint_32 i; + + for (bp = row, i = 0; i < row_info->width; i++) + { + for (c = 0; c < (int)row_info->channels; c++, bp++) + { + *bp >>= shift[c]; + } + } + break; + } + case 16: + { + png_bytep bp; + png_size_t i; + + for (bp = row, i = 0; i < row_info->width; i++) + { + for (c = 0; c < (int)row_info->channels; c++, bp += 2) + { + value = (png_uint_16)((*bp << 8) + *(bp + 1)); + value >>= shift[c]; + *bp = (png_byte)(value >> 8); + *(bp + 1) = (png_byte)(value & 0xff); + } + } + break; + } + } + } +} +#endif + +#if defined(PNG_READ_16_TO_8_SUPPORTED) +/* chop rows of bit depth 16 down to 8 */ +void +png_do_chop(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_chop\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL && row_info->bit_depth == 16) +#else + if (row_info->bit_depth == 16) +#endif + { + png_bytep sp, dp; + png_uint_32 i; + + sp = row; + dp = row; + for (i = 0; i < row_info->width * row_info->channels; i++, sp += 2, dp++) + { +#if defined(PNG_READ_16_TO_8_ACCURATE_SCALE_SUPPORTED) + /* This does a more accurate scaling of the 16-bit color + * value, rather than a simple low-byte truncation. + * + * What the ideal calculation should be: + *dp = (((((png_uint_32)(*sp) << 8) | + (png_uint_32)(*(sp + 1))) * 255 + 127) / (png_uint_32)65535L; + + + * GRR: no, I think this is what it really should be: + *dp = (((((png_uint_32)(*sp) << 8) | + (png_uint_32)(*(sp + 1))) + 128L) / (png_uint_32)257L; + + * GRR: here's the exact calculation with shifts: + temp = (((png_uint_32)(*sp) << 8) | (png_uint_32)(*(sp + 1))) + 128L; + *dp = (temp - (temp >> 8)) >> 8; + + + * Approximate calculation with shift/add instead of multiply/divide: + *dp = ((((png_uint_32)(*sp) << 8) | + (png_uint_32)((int)(*(sp + 1)) - *sp)) + 128) >> 8; + + * What we actually do to avoid extra shifting and conversion: */ + *dp = *sp + ((((int)(*(sp + 1)) - *sp) > 128) ? 1 : 0); +#else + *dp = *sp; +#endif + } + row_info->bit_depth = 8; + row_info->pixel_depth = (png_byte)(8 * row_info->channels); + row_info->rowbytes = row_info->width * row_info->channels; + } +} +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) +void +png_do_read_swap_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_read_swap_alpha\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL) +#endif + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + /* This converts from RGBA to ARGB */ + if (row_info->bit_depth == 8) + { + png_bytep sp, dp; + png_byte save; + png_uint_32 i; + + for (i = 0, sp = dp = row + row_info->rowbytes; + i < row_info->width; i++) + { + save = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save; + } + } + /* This converts from RRGGBBAA to AARRGGBB */ + else + { + png_bytep sp, dp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0, sp = dp = row + row_info->rowbytes; + i < row_info->width; i++) + { + save[0] = *(--sp); + save[1] = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save[0]; + *(--dp) = save[1]; + } + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + /* This converts from GA to AG */ + if (row_info->bit_depth == 8) + { + png_bytep sp, dp; + png_byte save; + png_uint_32 i; + + for (i = 0, sp = dp = row + row_info->rowbytes; + i < row_info->width; i++) + { + save = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save; + } + } + /* This converts from GGAA to AAGG */ + else + { + png_bytep sp, dp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0, sp = dp = row + row_info->rowbytes; + i < row_info->width; i++) + { + save[0] = *(--sp); + save[1] = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = save[0]; + *(--dp) = save[1]; + } + } + } + } +} +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) +void +png_do_read_invert_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_read_invert_alpha\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL) +#endif + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + /* This inverts the alpha channel in RGBA */ + if (row_info->bit_depth == 8) + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = dp = row + row_info->rowbytes; + i < row_info->width; i++) + { + *(--dp) = 255 - *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + } + /* This inverts the alpha channel in RRGGBBAA */ + else + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = dp = row + row_info->rowbytes; + i < row_info->width; i++) + { + *(--dp) = 255 - *(--sp); + *(--dp) = 255 - *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + /* This inverts the alpha channel in GA */ + if (row_info->bit_depth == 8) + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = dp = row + row_info->rowbytes; + i < row_info->width; i++) + { + *(--dp) = 255 - *(--sp); + *(--dp) = *(--sp); + } + } + /* This inverts the alpha channel in GGAA */ + else + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = dp = row + row_info->rowbytes; + i < row_info->width; i++) + { + *(--dp) = 255 - *(--sp); + *(--dp) = 255 - *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + } + } + } +} +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) +/* Add filler channel if we have RGB color */ +void +png_do_read_filler(png_row_infop row_info, png_bytep row, + png_uint_32 filler, png_uint_32 flags) +{ + png_bytep sp, dp; + png_uint_32 i; + + png_debug(1, "in png_do_read_filler\n"); + if ( +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + row_info->color_type == PNG_COLOR_TYPE_RGB && row_info->bit_depth == 8) + { + /* This changes the data from RGB to RGBX */ + if (flags & PNG_FLAG_FILLER_AFTER) + { + for (i = 1, sp = row + (png_size_t)row_info->width * 3, + dp = row + (png_size_t)row_info->width * 4; + i < row_info->width; + i++) + { + *(--dp) = (png_byte)filler; + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + } + *(--dp) = (png_byte)filler; + row_info->channels = 4; + row_info->pixel_depth = 32; + row_info->rowbytes = row_info->width * 4; + } + /* This changes the data from RGB to XRGB */ + else + { + for (i = 0, sp = row + (png_size_t)row_info->width * 3, + dp = row + (png_size_t)row_info->width * 4; + i < row_info->width; + i++) + { + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = *(--sp); + *(--dp) = (png_byte)filler; + } + row_info->channels = 4; + row_info->pixel_depth = 32; + row_info->rowbytes = row_info->width * 4; + } + } +} +#endif + +#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) +/* expand grayscale files to RGB, with or without alpha */ +void +png_do_gray_to_rgb(png_row_infop row_info, png_bytep row) +{ + png_bytep sp, dp; + png_uint_32 i; + + png_debug(1, "in png_do_gray_to_rgb\n"); + if (row_info->bit_depth >= 8 && +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + !(row_info->color_type & PNG_COLOR_MASK_COLOR)) + { + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + if (row_info->bit_depth == 8) + { + for (i = 0, sp = row + (png_size_t)row_info->width - 1, + dp = row + (png_size_t)row_info->width * 3 - 1; + i < row_info->width; + i++) + { + *(dp--) = *sp; + *(dp--) = *sp; + *(dp--) = *sp; + sp--; + } + } + else + { + for (i = 0, sp = row + (png_size_t)row_info->width * 2 - 1, + dp = row + (png_size_t)row_info->width * 6 - 1; + i < row_info->width; + i++) + { + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + sp--; + sp--; + } + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (row_info->bit_depth == 8) + { + for (i = 0, sp = row + (png_size_t)row_info->width * 2 - 1, + dp = row + (png_size_t)row_info->width * 4 - 1; + i < row_info->width; + i++) + { + *(dp--) = *(sp--); + *(dp--) = *sp; + *(dp--) = *sp; + *(dp--) = *sp; + sp--; + } + } + else + { + for (i = 0, sp = row + (png_size_t)row_info->width * 4 - 1, + dp = row + (png_size_t)row_info->width * 8 - 1; + i < row_info->width; + i++) + { + *(dp--) = *(sp--); + *(dp--) = *(sp--); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + *(dp--) = *sp; + *(dp--) = *(sp - 1); + sp--; + sp--; + } + } + } + row_info->channels += (png_byte)2; + row_info->color_type |= PNG_COLOR_MASK_COLOR; + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = ((row_info->width * + row_info->pixel_depth + 7) >> 3); + } +} +#endif + +/* Build a grayscale palette. Palette is assumed to be 1 << bit_depth + * large of png_color. This lets grayscale images be treated as + * paletted. Most useful for gamma correction and simplification + * of code. + */ +void +png_build_grayscale_palette(int bit_depth, png_colorp palette) +{ + int num_palette; + int color_inc; + int i; + int v; + + png_debug(1, "in png_do_build_grayscale_palette\n"); + if (palette == NULL) + return; + + switch (bit_depth) + { + case 1: + num_palette = 2; + color_inc = 0xff; + break; + case 2: + num_palette = 4; + color_inc = 0x55; + break; + case 4: + num_palette = 16; + color_inc = 0x11; + break; + case 8: + num_palette = 256; + color_inc = 1; + break; + default: + num_palette = 0; + color_inc = 0; + break; + } + + for (i = 0, v = 0; i < num_palette; i++, v += color_inc) + { + palette[i].red = (png_byte)v; + palette[i].green = (png_byte)v; + palette[i].blue = (png_byte)v; + } +} + +/* This function is currently unused. Do we really need it? */ +#if defined(PNG_READ_DITHER_SUPPORTED) && defined(PNG_CORRECT_PALETTE_SUPPORTED) +void +png_correct_palette(png_structp png_ptr, png_colorp palette, + int num_palette) +{ + png_debug(1, "in png_correct_palette\n"); +#if defined(PNG_READ_BACKGROUND_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) + if ((png_ptr->transformations & (PNG_GAMMA)) && + (png_ptr->transformations & (PNG_BACKGROUND))) + { + png_color back, back_1; + + if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_FILE) + { + back.red = png_ptr->gamma_table[png_ptr->background.red]; + back.green = png_ptr->gamma_table[png_ptr->background.green]; + back.blue = png_ptr->gamma_table[png_ptr->background.blue]; + + back_1.red = png_ptr->gamma_to_1[png_ptr->background.red]; + back_1.green = png_ptr->gamma_to_1[png_ptr->background.green]; + back_1.blue = png_ptr->gamma_to_1[png_ptr->background.blue]; + } + else + { + double g; + + g = 1.0 / (png_ptr->background_gamma * png_ptr->screen_gamma); + + if (png_ptr->background_gamma_type == PNG_BACKGROUND_GAMMA_SCREEN || + fabs(g - 1.0) < PNG_GAMMA_THRESHOLD) + { + back.red = png_ptr->background.red; + back.green = png_ptr->background.green; + back.blue = png_ptr->background.blue; + } + else + { + back.red = + (png_byte)(pow((double)png_ptr->background.red/255, g) * + 255.0 + 0.5); + back.green = + (png_byte)(pow((double)png_ptr->background.green/255, g) * + 255.0 + 0.5); + back.blue = + (png_byte)(pow((double)png_ptr->background.blue/255, g) * + 255.0 + 0.5); + } + + g = 1.0 / png_ptr->background_gamma; + + back_1.red = + (png_byte)(pow((double)png_ptr->background.red/255, g) * + 255.0 + 0.5); + back_1.green = + (png_byte)(pow((double)png_ptr->background.green/255, g) * + 255.0 + 0.5); + back_1.blue = + (png_byte)(pow((double)png_ptr->background.blue/255, g) * + 255.0 + 0.5); + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_uint_32 i; + + for (i = 0; i < (png_uint_32)num_palette; i++) + { + if (i < png_ptr->num_trans && png_ptr->trans[i] == 0) + { + palette[i] = back; + } + else if (i < png_ptr->num_trans && png_ptr->trans[i] != 0xff) + { + png_byte v, w; + + v = png_ptr->gamma_to_1[png_ptr->palette[i].red]; + png_composite(w, v, png_ptr->trans[i], back_1.red); + palette[i].red = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[png_ptr->palette[i].green]; + png_composite(w, v, png_ptr->trans[i], back_1.green); + palette[i].green = png_ptr->gamma_from_1[w]; + + v = png_ptr->gamma_to_1[png_ptr->palette[i].blue]; + png_composite(w, v, png_ptr->trans[i], back_1.blue); + palette[i].blue = png_ptr->gamma_from_1[w]; + } + else + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + } + } + else + { + int i; + + for (i = 0; i < num_palette; i++) + { + if (palette[i].red == (png_byte)png_ptr->trans_values.gray) + { + palette[i] = back; + } + else + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + } + } + } + else +#endif +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (png_ptr->transformations & PNG_GAMMA) + { + int i; + + for (i = 0; i < num_palette; i++) + { + palette[i].red = png_ptr->gamma_table[palette[i].red]; + palette[i].green = png_ptr->gamma_table[palette[i].green]; + palette[i].blue = png_ptr->gamma_table[palette[i].blue]; + } + } +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + else +#endif +#endif +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->transformations & PNG_BACKGROUND) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_color back; + + back.red = (png_byte)png_ptr->background.red; + back.green = (png_byte)png_ptr->background.green; + back.blue = (png_byte)png_ptr->background.blue; + + for (i = 0; i < (int)png_ptr->num_trans; i++) + { + if (png_ptr->trans[i] == 0) + { + palette[i].red = back.red; + palette[i].green = back.green; + palette[i].blue = back.blue; + } + else if (png_ptr->trans[i] != 0xff) + { + png_composite(palette[i].red, png_ptr->palette[i].red, + png_ptr->trans[i], back.red); + png_composite(palette[i].green, png_ptr->palette[i].green, + png_ptr->trans[i], back.green); + png_composite(palette[i].blue, png_ptr->palette[i].blue, + png_ptr->trans[i], back.blue); + } + } + } + else /* assume grayscale palette (what else could it be?) */ + { + int i; + + for (i = 0; i < num_palette; i++) + { + if (i == (png_byte)png_ptr->trans_values.gray) + { + palette[i].red = (png_byte)png_ptr->background.red; + palette[i].green = (png_byte)png_ptr->background.green; + palette[i].blue = (png_byte)png_ptr->background.blue; + } + } + } + } +#endif +} +#endif + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) +/* Replace any alpha or transparency with the supplied background color. + * "background" is already in the screen gamma, while "background_1" is + * at a gamma of 1.0. Paletted files have already been taken care of. + */ +void +png_do_background(png_row_infop row_info, png_bytep row, + png_color_16p trans_values, png_color_16p background, + png_color_16p background_1, + png_bytep gamma_table, png_bytep gamma_from_1, png_bytep gamma_to_1, + png_uint_16pp gamma_16, png_uint_16pp gamma_16_from_1, + png_uint_16pp gamma_16_to_1, int gamma_shift) +{ + png_bytep sp, dp; + png_uint_32 i; + int shift; + + png_debug(1, "in png_do_background\n"); + if (background != NULL && +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + (!(row_info->color_type & PNG_COLOR_MASK_ALPHA) || + (row_info->color_type != PNG_COLOR_TYPE_PALETTE && trans_values))) + { + switch (row_info->color_type) + { + case PNG_COLOR_TYPE_GRAY: + { + switch (row_info->bit_depth) + { + case 1: + { + sp = row; + shift = 7; + for (i = 0; i < row_info->width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x1) + == trans_values->gray) + { + *sp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); + *sp |= (png_byte)(background->gray << shift); + } + if (!shift) + { + shift = 7; + sp++; + } + else + shift--; + } + break; + } + case 2: + { + sp = row; + shift = 6; + for (i = 0; i < row_info->width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0x3) + == trans_values->gray) + { + *sp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); + *sp |= (png_byte)(background->gray << shift); + } + if (!shift) + { + shift = 6; + sp++; + } + else + shift -= 2; + } + break; + } + case 4: + { + sp = row; + shift = 4; + for (i = 0; i < row_info->width; i++) + { + if ((png_uint_16)((*sp >> shift) & 0xf) + == trans_values->gray) + { + *sp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); + *sp |= (png_byte)(background->gray << shift); + } + if (!shift) + { + shift = 4; + sp++; + } + else + shift -= 4; + } + break; + } + case 8: + { +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (gamma_table != NULL) + { + for (i = 0, sp = row; i < row_info->width; i++, sp++) + { + if (*sp == trans_values->gray) + { + *sp = (png_byte)background->gray; + } + else + { + *sp = gamma_table[*sp]; + } + } + } + else +#endif + { + for (i = 0, sp = row; i < row_info->width; i++, sp++) + { + if (*sp == trans_values->gray) + { + *sp = (png_byte)background->gray; + } + } + } + break; + } + case 16: + { +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (gamma_16 != NULL) + { + for (i = 0, sp = row; i < row_info->width; i++, sp += 2) + { + png_uint_16 v; + + v = ((png_uint_16)(*sp) << 8) + *(sp + 1); + if (v == trans_values->gray) + { + /* background is already in screen gamma */ + *sp = (png_byte)((background->gray >> 8) & 0xff); + *(sp + 1) = (png_byte)(background->gray & 0xff); + } + else + { + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + } + } + } + else +#endif + { + for (i = 0, sp = row; i < row_info->width; i++, sp += 2) + { + png_uint_16 v; + + v = ((png_uint_16)(*sp) << 8) + *(sp + 1); + if (v == trans_values->gray) + { + *sp = (png_byte)((background->gray >> 8) & 0xff); + *(sp + 1) = (png_byte)(background->gray & 0xff); + } + } + } + break; + } + } + break; + } + case PNG_COLOR_TYPE_RGB: + { + if (row_info->bit_depth == 8) + { +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (gamma_table != NULL) + { + for (i = 0, sp = row; i < row_info->width; i++, sp += 3) + { + if (*sp == trans_values->red && + *(sp + 1) == trans_values->green && + *(sp + 2) == trans_values->blue) + { + *sp = (png_byte)background->red; + *(sp + 1) = (png_byte)background->green; + *(sp + 2) = (png_byte)background->blue; + } + else + { + *sp = gamma_table[*sp]; + *(sp + 1) = gamma_table[*(sp + 1)]; + *(sp + 2) = gamma_table[*(sp + 2)]; + } + } + } + else +#endif + { + for (i = 0, sp = row; i < row_info->width; i++, sp += 3) + { + if (*sp == trans_values->red && + *(sp + 1) == trans_values->green && + *(sp + 2) == trans_values->blue) + { + *sp = (png_byte)background->red; + *(sp + 1) = (png_byte)background->green; + *(sp + 2) = (png_byte)background->blue; + } + } + } + } + else /* if (row_info->bit_depth == 16) */ + { +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (gamma_16 != NULL) + { + for (i = 0, sp = row; i < row_info->width; i++, sp += 6) + { + png_uint_16 r, g, b; + + r = ((png_uint_16)(*sp) << 8) + *(sp + 1); + g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); + b = ((png_uint_16)(*(sp + 4)) << 8) + *(sp + 5); + if (r == trans_values->red && g == trans_values->green && + b == trans_values->blue) + { + /* background is already in screen gamma */ + *sp = (png_byte)((background->red >> 8) & 0xff); + *(sp + 1) = (png_byte)(background->red & 0xff); + *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); + *(sp + 3) = (png_byte)(background->green & 0xff); + *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); + *(sp + 5) = (png_byte)(background->blue & 0xff); + } + else + { + png_uint_16 v; + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + *(sp + 2) = (png_byte)((v >> 8) & 0xff); + *(sp + 3) = (png_byte)(v & 0xff); + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + *(sp + 4) = (png_byte)((v >> 8) & 0xff); + *(sp + 5) = (png_byte)(v & 0xff); + } + } + } + else +#endif + { + for (i = 0, sp = row; i < row_info->width; i++, sp += 6) + { + png_uint_16 r, g, b; + + r = ((png_uint_16)(*sp) << 8) + *(sp + 1); + g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); + b = ((png_uint_16)(*(sp + 4)) << 8) + *(sp + 5); + if (r == trans_values->red && g == trans_values->green && + b == trans_values->blue) + { + *sp = (png_byte)((background->red >> 8) & 0xff); + *(sp + 1) = (png_byte)(background->red & 0xff); + *(sp + 2) = (png_byte)((background->green >> 8) & 0xff); + *(sp + 3) = (png_byte)(background->green & 0xff); + *(sp + 4) = (png_byte)((background->blue >> 8) & 0xff); + *(sp + 5) = (png_byte)(background->blue & 0xff); + } + } + } + } + break; + } + case PNG_COLOR_TYPE_GRAY_ALPHA: + { + if (row_info->bit_depth == 8) + { +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (gamma_to_1 != NULL && gamma_from_1 != NULL && + gamma_table != NULL) + { + for (i = 0, sp = row, dp = row; + i < row_info->width; i++, sp += 2, dp++) + { + png_uint_16 a; + + a = *(sp + 1); + if (a == 0xff) + { + *dp = gamma_table[*sp]; + } + else if (a == 0) + { + /* background is already in screen gamma */ + *dp = (png_byte)background->gray; + } + else + { + png_byte v, w; + + v = gamma_to_1[*sp]; + png_composite(w, v, a, background_1->gray); + *dp = gamma_from_1[w]; + } + } + } + else +#endif + { + for (i = 0, sp = row, dp = row; + i < row_info->width; i++, sp += 2, dp++) + { + png_byte a; + + a = *(sp + 1); + if (a == 0xff) + { + *dp = *sp; + } + else if (a == 0) + { + *dp = (png_byte)background->gray; + } + else + { + png_composite(*dp, *sp, a, background_1->gray); + } + } + } + } + else /* if (png_ptr->bit_depth == 16) */ + { +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (gamma_16 != NULL && gamma_16_from_1 != NULL && + gamma_16_to_1 != NULL) + { + for (i = 0, sp = row, dp = row; + i < row_info->width; i++, sp += 4, dp += 2) + { + png_uint_16 a; + + a = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); + if (a == (png_uint_16)0xffff) + { + png_uint_16 v; + + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *dp = (png_byte)((v >> 8) & 0xff); + *(dp + 1) = (png_byte)(v & 0xff); + } + else if (a == 0) + { + /* background is already in screen gamma */ + *dp = (png_byte)((background->gray >> 8) & 0xff); + *(dp + 1) = (png_byte)(background->gray & 0xff); + } + else + { + png_uint_16 g, v, w; + + g = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + png_composite_16(v, g, a, background_1->gray); + w = gamma_16_from_1[(v&0xff) >> gamma_shift][v >> 8]; + *dp = (png_byte)((w >> 8) & 0xff); + *(dp + 1) = (png_byte)(w & 0xff); + } + } + } + else +#endif + { + for (i = 0, sp = row, dp = row; + i < row_info->width; i++, sp += 4, dp += 2) + { + png_uint_16 a; + + a = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); + if (a == (png_uint_16)0xffff) + { + png_memcpy(dp, sp, 2); + } + else if (a == 0) + { + *dp = (png_byte)((background->gray >> 8) & 0xff); + *(dp + 1) = (png_byte)(background->gray & 0xff); + } + else + { + png_uint_16 g, v; + + g = ((png_uint_16)(*sp) << 8) + *(sp + 1); + png_composite_16(v, g, a, background_1->gray); + *dp = (png_byte)((v >> 8) & 0xff); + *(dp + 1) = (png_byte)(v & 0xff); + } + } + } + } + break; + } + case PNG_COLOR_TYPE_RGB_ALPHA: + { + if (row_info->bit_depth == 8) + { +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (gamma_to_1 != NULL && gamma_from_1 != NULL && + gamma_table != NULL) + { + for (i = 0, sp = row, dp = row; + i < row_info->width; i++, sp += 4, dp += 3) + { + png_byte a; + + a = *(sp + 3); + if (a == 0xff) + { + *dp = gamma_table[*sp]; + *(dp + 1) = gamma_table[*(sp + 1)]; + *(dp + 2) = gamma_table[*(sp + 2)]; + } + else if (a == 0) + { + /* background is already in screen gamma */ + *dp = (png_byte)background->red; + *(dp + 1) = (png_byte)background->green; + *(dp + 2) = (png_byte)background->blue; + } + else + { + png_byte v, w; + + v = gamma_to_1[*sp]; + png_composite(w, v, a, background_1->red); + *dp = gamma_from_1[w]; + v = gamma_to_1[*(sp + 1)]; + png_composite(w, v, a, background_1->green); + *(dp + 1) = gamma_from_1[w]; + v = gamma_to_1[*(sp + 2)]; + png_composite(w, v, a, background_1->blue); + *(dp + 2) = gamma_from_1[w]; + } + } + } + else +#endif + { + for (i = 0, sp = row, dp = row; + i < row_info->width; i++, sp += 4, dp += 3) + { + png_byte a; + + a = *(sp + 3); + if (a == 0xff) + { + *dp = *sp; + *(dp + 1) = *(sp + 1); + *(dp + 2) = *(sp + 2); + } + else if (a == 0) + { + *dp = (png_byte)background->red; + *(dp + 1) = (png_byte)background->green; + *(dp + 2) = (png_byte)background->blue; + } + else + { + png_composite(*dp, *sp, a, background->red); + png_composite(*(dp + 1), *(sp + 1), a, + background->green); + png_composite(*(dp + 2), *(sp + 2), a, + background->blue); + } + } + } + } + else /* if (row_info->bit_depth == 16) */ + { +#if defined(PNG_READ_GAMMA_SUPPORTED) + if (gamma_16 != NULL && gamma_16_from_1 != NULL && + gamma_16_to_1 != NULL) + { + for (i = 0, sp = row, dp = row; + i < row_info->width; i++, sp += 8, dp += 6) + { + png_uint_16 a; + + a = (png_uint_16)(((png_uint_16)(*(sp + 6)) << 8) + + (png_uint_16)(*(sp + 7))); + if (a == (png_uint_16)0xffff) + { + png_uint_16 v; + + v = gamma_16[*(sp + 1) >> gamma_shift][*sp]; + *dp = (png_byte)((v >> 8) & 0xff); + *(dp + 1) = (png_byte)(v & 0xff); + v = gamma_16[*(sp + 3) >> gamma_shift][*(sp + 2)]; + *(dp + 2) = (png_byte)((v >> 8) & 0xff); + *(dp + 3) = (png_byte)(v & 0xff); + v = gamma_16[*(sp + 5) >> gamma_shift][*(sp + 4)]; + *(dp + 4) = (png_byte)((v >> 8) & 0xff); + *(dp + 5) = (png_byte)(v & 0xff); + } + else if (a == 0) + { + /* background is already in screen gamma */ + *dp = (png_byte)((background->red >> 8) & 0xff); + *(dp + 1) = (png_byte)(background->red & 0xff); + *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); + *(dp + 3) = (png_byte)(background->green & 0xff); + *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); + *(dp + 5) = (png_byte)(background->blue & 0xff); + } + else + { + png_uint_16 v, w, x; + + v = gamma_16_to_1[*(sp + 1) >> gamma_shift][*sp]; + png_composite_16(w, v, a, background->red); + x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; + *dp = (png_byte)((x >> 8) & 0xff); + *(dp + 1) = (png_byte)(x & 0xff); + v = gamma_16_to_1[*(sp + 3) >> gamma_shift][*(sp + 2)]; + png_composite_16(w, v, a, background->green); + x = gamma_16_from_1[((w&0xff) >> gamma_shift)][w >> 8]; + *(dp + 2) = (png_byte)((x >> 8) & 0xff); + *(dp + 3) = (png_byte)(x & 0xff); + v = gamma_16_to_1[*(sp + 5) >> gamma_shift][*(sp + 4)]; + png_composite_16(w, v, a, background->blue); + x = gamma_16_from_1[(w & 0xff) >> gamma_shift][w >> 8]; + *(dp + 4) = (png_byte)((x >> 8) & 0xff); + *(dp + 5) = (png_byte)(x & 0xff); + } + } + } + else +#endif + { + for (i = 0, sp = row, dp = row; + i < row_info->width; i++, sp += 8, dp += 6) + { + png_uint_16 a; + + a = (png_uint_16)(((png_uint_16)(*(sp + 6)) << 8) + + (png_uint_16)(*(sp + 7))); + if (a == (png_uint_16)0xffff) + { + png_memcpy(dp, sp, 6); + } + else if (a == 0) + { + *dp = (png_byte)((background->red >> 8) & 0xff); + *(dp + 1) = (png_byte)(background->red & 0xff); + *(dp + 2) = (png_byte)((background->green >> 8) & 0xff); + *(dp + 3) = (png_byte)(background->green & 0xff); + *(dp + 4) = (png_byte)((background->blue >> 8) & 0xff); + *(dp + 5) = (png_byte)(background->blue & 0xff); + } + else + { + png_uint_16 r, g, b, v; + + r = ((png_uint_16)(*sp) << 8) + *(sp + 1); + g = ((png_uint_16)(*(sp + 2)) << 8) + *(sp + 3); + b = ((png_uint_16)(*(sp + 4)) << 8) + *(sp + 5); + + png_composite_16(v, r, a, background->red); + *dp = (png_byte)((v >> 8) & 0xff); + *(dp + 1) = (png_byte)(v & 0xff); + png_composite_16(v, g, a, background->green); + *(dp + 2) = (png_byte)((v >> 8) & 0xff); + *(dp + 3) = (png_byte)(v & 0xff); + png_composite_16(v, b, a, background->blue); + *(dp + 4) = (png_byte)((v >> 8) & 0xff); + *(dp + 5) = (png_byte)(v & 0xff); + } + } + } + } + break; + } + } + + if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + { + row_info->color_type &= ~PNG_COLOR_MASK_ALPHA; + row_info->channels--; + row_info->pixel_depth = (png_byte)(row_info->channels * + row_info->bit_depth); + row_info->rowbytes = ((row_info->width * + row_info->pixel_depth + 7) >> 3); + } + } +} +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) +/* Gamma correct the image, avoiding the alpha channel. Make sure + * you do this after you deal with the trasparency issue on grayscale + * or rgb images. If your bit depth is 8, use gamma_table, if it + * is 16, use gamma_16_table and gamma_shift. Build these with + * build_gamma_table(). + */ +void +png_do_gamma(png_row_infop row_info, png_bytep row, + png_bytep gamma_table, png_uint_16pp gamma_16_table, + int gamma_shift) +{ + png_bytep sp; + png_uint_32 i; + + png_debug(1, "in png_do_gamma\n"); + if ( +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + ((row_info->bit_depth <= 8 && gamma_table != NULL) || + (row_info->bit_depth == 16 && gamma_16_table != NULL))) + { + switch (row_info->color_type) + { + case PNG_COLOR_TYPE_RGB: + { + if (row_info->bit_depth == 8) + { + for (i = 0, sp = row; i < row_info->width; i++) + { + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + } + } + else /* if (row_info->bit_depth == 16) */ + { + for (i = 0, sp = row; i < row_info->width; i++) + { + png_uint_16 v; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + } + } + break; + } + case PNG_COLOR_TYPE_RGB_ALPHA: + { + if (row_info->bit_depth == 8) + { + for (i = 0, sp = row; + i < row_info->width; i++) + { + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + *sp = gamma_table[*sp]; + sp++; + sp++; + } + } + else /* if (row_info->bit_depth == 16) */ + { + for (i = 0, sp = row; + i < row_info->width; i++) + { + png_uint_16 v; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 4; + } + } + break; + } + case PNG_COLOR_TYPE_GRAY_ALPHA: + { + if (row_info->bit_depth == 8) + { + for (i = 0, sp = row; + i < row_info->width; i++) + { + *sp = gamma_table[*sp]; + sp += 2; + } + } + else /* if (row_info->bit_depth == 16) */ + { + for (i = 0, sp = row; + i < row_info->width; i++) + { + png_uint_16 v; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 4; + } + } + break; + } + case PNG_COLOR_TYPE_GRAY: + { + if (row_info->bit_depth == 2) + { + for (i = 0, sp = row; i < row_info->width; i += 4) + { + int a = *sp & 0xc0; + int b = *sp & 0x30; + int c = *sp & 0x0c; + int d = *sp & 0x03; + + *sp = ((((int)gamma_table[a|(a>>2)|(a>>4)|(a>>6)]) ) & 0xc0)| + ((((int)gamma_table[(b<<2)|b|(b>>2)|(b>>4)])>>2) & 0x30)| + ((((int)gamma_table[(c<<4)|(c<<2)|c|(c>>2)])>>4) & 0x0c)| + ((((int)gamma_table[(d<<6)|(d<<4)|(d<<2)|d])>>6) ); + sp++; + } + } + if (row_info->bit_depth == 4) + { + for (i = 0, sp = row; i < row_info->width; i += 2) + { + int msb = *sp & 0xf0; + int lsb = *sp & 0x0f; + + *sp = (((int)gamma_table[msb | (msb >> 4)]) & 0xf0) | + (((int)gamma_table[(lsb << 4) | lsb]) >> 4); + sp++; + } + } + else if (row_info->bit_depth == 8) + { + for (i = 0, sp = row; i < row_info->width; i++) + { + *sp = gamma_table[*sp]; + sp++; + } + } + else if (row_info->bit_depth == 16) + { + for (i = 0, sp = row; i < row_info->width; i++) + { + png_uint_16 v; + + v = gamma_16_table[*(sp + 1) >> gamma_shift][*sp]; + *sp = (png_byte)((v >> 8) & 0xff); + *(sp + 1) = (png_byte)(v & 0xff); + sp += 2; + } + } + break; + } + } + } +} +#endif + +#if defined(PNG_READ_EXPAND_SUPPORTED) +/* Expands a palette row to an rgb or rgba row depending + * upon whether you supply trans and num_trans. + */ +void +png_do_expand_palette(png_row_infop row_info, png_bytep row, + png_colorp palette, png_bytep trans, int num_trans) +{ + int shift, value; + png_bytep sp, dp; + png_uint_32 i; + + png_debug(1, "in png_do_expand_palette\n"); + if ( +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + row_info->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (row_info->bit_depth < 8) + { + switch (row_info->bit_depth) + { + case 1: + { + sp = row + (png_size_t)((row_info->width - 1) >> 3); + dp = row + (png_size_t)row_info->width - 1; + shift = 7 - (int)((row_info->width + 7) & 7); + for (i = 0; i < row_info->width; i++) + { + if ((*sp >> shift) & 0x1) + *dp = 1; + else + *dp = 0; + if (shift == 7) + { + shift = 0; + sp--; + } + else + shift++; + + dp--; + } + break; + } + case 2: + { + sp = row + (png_size_t)((row_info->width - 1) >> 2); + dp = row + (png_size_t)row_info->width - 1; + shift = (int)((3 - ((row_info->width + 3) & 3)) << 1); + for (i = 0; i < row_info->width; i++) + { + value = (*sp >> shift) & 0x3; + *dp = (png_byte)value; + if (shift == 6) + { + shift = 0; + sp--; + } + else + shift += 2; + + dp--; + } + break; + } + case 4: + { + sp = row + (png_size_t)((row_info->width - 1) >> 1); + dp = row + (png_size_t)row_info->width - 1; + shift = (int)((row_info->width & 1) << 2); + for (i = 0; i < row_info->width; i++) + { + value = (*sp >> shift) & 0xf; + *dp = (png_byte)value; + if (shift == 4) + { + shift = 0; + sp--; + } + else + shift += 4; + + dp--; + } + break; + } + } + row_info->bit_depth = 8; + row_info->pixel_depth = 8; + row_info->rowbytes = row_info->width; + } + switch (row_info->bit_depth) + { + case 8: + { + if (trans != NULL) + { + sp = row + (png_size_t)row_info->width - 1; + dp = row + (png_size_t)(row_info->width << 2) - 1; + + for (i = 0; i < row_info->width; i++) + { + if ((int)(*sp) >= num_trans) + *dp-- = 0xff; + else + *dp-- = trans[*sp]; + *dp-- = palette[*sp].blue; + *dp-- = palette[*sp].green; + *dp-- = palette[*sp].red; + sp--; + } + row_info->bit_depth = 8; + row_info->pixel_depth = 32; + row_info->rowbytes = row_info->width * 4; + row_info->color_type = 6; + row_info->channels = 4; + } + else + { + sp = row + (png_size_t)row_info->width - 1; + dp = row + (png_size_t)(row_info->width * 3) - 1; + + for (i = 0; i < row_info->width; i++) + { + *dp-- = palette[*sp].blue; + *dp-- = palette[*sp].green; + *dp-- = palette[*sp].red; + sp--; + } + row_info->bit_depth = 8; + row_info->pixel_depth = 24; + row_info->rowbytes = row_info->width * 3; + row_info->color_type = 2; + row_info->channels = 3; + } + break; + } + } + } +} + +/* If the bit depth < 8, it is expanded to 8. Also, if the + * transparency value is supplied, an alpha channel is built. + */ +void +png_do_expand(png_row_infop row_info, png_bytep row, + png_color_16p trans_value) +{ + int shift, value; + png_bytep sp, dp; + png_uint_32 i; + + png_debug(1, "in png_do_expand\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL) +#endif + { + if (row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + png_uint_16 gray = trans_value ? trans_value->gray : 0; + + if (row_info->bit_depth < 8) + { + switch (row_info->bit_depth) + { + case 1: + { + gray *= 0xff; + sp = row + (png_size_t)((row_info->width - 1) >> 3); + dp = row + (png_size_t)row_info->width - 1; + shift = 7 - (int)((row_info->width + 7) & 7); + for (i = 0; i < row_info->width; i++) + { + if ((*sp >> shift) & 0x1) + *dp = 0xff; + else + *dp = 0; + if (shift == 7) + { + shift = 0; + sp--; + } + else + shift++; + + dp--; + } + break; + } + case 2: + { + gray *= 0x55; + sp = row + (png_size_t)((row_info->width - 1) >> 2); + dp = row + (png_size_t)row_info->width - 1; + shift = (int)((3 - ((row_info->width + 3) & 3)) << 1); + for (i = 0; i < row_info->width; i++) + { + value = (*sp >> shift) & 0x3; + *dp = (png_byte)(value | (value << 2) | (value << 4) | + (value << 6)); + if (shift == 6) + { + shift = 0; + sp--; + } + else + shift += 2; + + dp--; + } + break; + } + case 4: + { + gray *= 0x11; + sp = row + (png_size_t)((row_info->width - 1) >> 1); + dp = row + (png_size_t)row_info->width - 1; + shift = (int)((1 - ((row_info->width + 1) & 1)) << 2); + for (i = 0; i < row_info->width; i++) + { + value = (*sp >> shift) & 0xf; + *dp = (png_byte)(value | (value << 4)); + if (shift == 4) + { + shift = 0; + sp--; + } + else + shift = 4; + + dp--; + } + break; + } + } + row_info->bit_depth = 8; + row_info->pixel_depth = 8; + row_info->rowbytes = row_info->width; + } + + if (trans_value != NULL) + { + if (row_info->bit_depth == 8) + { + sp = row + (png_size_t)row_info->width - 1; + dp = row + (png_size_t)(row_info->width << 1) - 1; + for (i = 0; i < row_info->width; i++) + { + if (*sp == gray) + *dp-- = 0; + else + *dp-- = 0xff; + *dp-- = *sp--; + } + } + else if (row_info->bit_depth == 16) + { + sp = row + row_info->rowbytes - 1; + dp = row + (row_info->rowbytes << 1) - 1; + for (i = 0; i < row_info->width; i++) + { + if (((png_uint_16)*(sp) | + ((png_uint_16)*(sp - 1) << 8)) == gray) + { + *dp-- = 0; + *dp-- = 0; + } + else + { + *dp-- = 0xff; + *dp-- = 0xff; + } + *dp-- = *sp--; + *dp-- = *sp--; + } + } + row_info->color_type = PNG_COLOR_TYPE_GRAY_ALPHA; + row_info->channels = 2; + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 1); + row_info->rowbytes = + ((row_info->width * row_info->pixel_depth) >> 3); + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_RGB && trans_value) + { + if (row_info->bit_depth == 8) + { + sp = row + (png_size_t)row_info->rowbytes - 1; + dp = row + (png_size_t)(row_info->width << 2) - 1; + for (i = 0; i < row_info->width; i++) + { + if (*(sp - 2) == trans_value->red && + *(sp - 1) == trans_value->green && + *(sp - 0) == trans_value->blue) + *dp-- = 0; + else + *dp-- = 0xff; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + } + } + else if (row_info->bit_depth == 16) + { + sp = row + row_info->rowbytes - 1; + dp = row + (png_size_t)(row_info->width << 3) - 1; + for (i = 0; i < row_info->width; i++) + { + if ((((png_uint_16)*(sp - 4) | + ((png_uint_16)*(sp - 5) << 8)) == trans_value->red) && + (((png_uint_16)*(sp - 2) | + ((png_uint_16)*(sp - 3) << 8)) == trans_value->green) && + (((png_uint_16)*(sp - 0) | + ((png_uint_16)*(sp - 1) << 8)) == trans_value->blue)) + { + *dp-- = 0; + *dp-- = 0; + } + else + { + *dp-- = 0xff; + *dp-- = 0xff; + } + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + *dp-- = *sp--; + } + } + row_info->color_type = PNG_COLOR_TYPE_RGB_ALPHA; + row_info->channels = 4; + row_info->pixel_depth = (png_byte)(row_info->bit_depth << 2); + row_info->rowbytes = + ((row_info->width * row_info->pixel_depth) >> 3); + } + } +} +#endif + +#if defined(PNG_READ_DITHER_SUPPORTED) +void +png_do_dither(png_row_infop row_info, png_bytep row, + png_bytep palette_lookup, png_bytep dither_lookup) +{ + png_bytep sp, dp; + png_uint_32 i; + + png_debug(1, "in png_do_dither\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL) +#endif + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB && + palette_lookup && row_info->bit_depth == 8) + { + int r, g, b, p; + sp = row; + dp = row; + for (i = 0; i < row_info->width; i++) + { + r = *sp++; + g = *sp++; + b = *sp++; + + /* this looks real messy, but the compiler will reduce + it down to a reasonable formula. For example, with + 5 bits per color, we get: + p = (((r >> 3) & 0x1f) << 10) | + (((g >> 3) & 0x1f) << 5) | + ((b >> 3) & 0x1f); + */ + p = (((r >> (8 - PNG_DITHER_RED_BITS)) & + ((1 << PNG_DITHER_RED_BITS) - 1)) << + (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | + (((g >> (8 - PNG_DITHER_GREEN_BITS)) & + ((1 << PNG_DITHER_GREEN_BITS) - 1)) << + (PNG_DITHER_BLUE_BITS)) | + ((b >> (8 - PNG_DITHER_BLUE_BITS)) & + ((1 << PNG_DITHER_BLUE_BITS) - 1)); + + *dp++ = palette_lookup[p]; + } + row_info->color_type = PNG_COLOR_TYPE_PALETTE; + row_info->channels = 1; + row_info->pixel_depth = row_info->bit_depth; + row_info->rowbytes = + ((row_info->width * row_info->pixel_depth + 7) >> 3); + } + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA && + palette_lookup != NULL && row_info->bit_depth == 8) + { + int r, g, b, p; + sp = row; + dp = row; + for (i = 0; i < row_info->width; i++) + { + r = *sp++; + g = *sp++; + b = *sp++; + sp++; + + p = (((r >> (8 - PNG_DITHER_RED_BITS)) & + ((1 << PNG_DITHER_RED_BITS) - 1)) << + (PNG_DITHER_GREEN_BITS + PNG_DITHER_BLUE_BITS)) | + (((g >> (8 - PNG_DITHER_GREEN_BITS)) & + ((1 << PNG_DITHER_GREEN_BITS) - 1)) << + (PNG_DITHER_BLUE_BITS)) | + ((b >> (8 - PNG_DITHER_BLUE_BITS)) & + ((1 << PNG_DITHER_BLUE_BITS) - 1)); + + *dp++ = palette_lookup[p]; + } + row_info->color_type = PNG_COLOR_TYPE_PALETTE; + row_info->channels = 1; + row_info->pixel_depth = row_info->bit_depth; + row_info->rowbytes = + ((row_info->width * row_info->pixel_depth + 7) >> 3); + } + else if (row_info->color_type == PNG_COLOR_TYPE_PALETTE && + dither_lookup && row_info->bit_depth == 8) + { + sp = row; + for (i = 0; i < row_info->width; i++, sp++) + { + *sp = dither_lookup[*sp]; + } + } + } +} +#endif + +#if defined(PNG_READ_GAMMA_SUPPORTED) +static int png_gamma_shift[] = + {0x10, 0x21, 0x42, 0x84, 0x110, 0x248, 0x550, 0xff0}; + +/* We build the 8- or 16-bit gamma tables here. Note that for 16-bit + * tables, we don't make a full table if we are reducing to 8-bit in + * the future. Note also how the gamma_16 tables are segmented so that + * we don't need to allocate > 64K chunks for a full 16-bit table. + */ +void +png_build_gamma_table(png_structp png_ptr) +{ + png_debug(1, "in png_build_gamma_table\n"); + if (png_ptr->bit_depth <= 8) + { + int i; + double g; + + g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); + + png_ptr->gamma_table = (png_bytep)png_malloc(png_ptr, + (png_uint_32)256); + + for (i = 0; i < 256; i++) + { + png_ptr->gamma_table[i] = (png_byte)(pow((double)i / 255.0, + g) * 255.0 + .5); + } + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->transformations & PNG_BACKGROUND) + { + g = 1.0 / (png_ptr->gamma); + + png_ptr->gamma_to_1 = (png_bytep)png_malloc(png_ptr, + (png_uint_32)256); + + for (i = 0; i < 256; i++) + { + png_ptr->gamma_to_1[i] = (png_byte)(pow((double)i / 255.0, + g) * 255.0 + .5); + } + + g = 1.0 / (png_ptr->screen_gamma); + + png_ptr->gamma_from_1 = (png_bytep)png_malloc(png_ptr, + (png_uint_32)256); + + for (i = 0; i < 256; i++) + { + png_ptr->gamma_from_1[i] = (png_byte)(pow((double)i / 255.0, + g) * 255.0 + .5); + } + } +#endif /* PNG_BACKGROUND_SUPPORTED */ + } + else + { + double g; + int i, j, shift, num; + int sig_bit; + png_uint_32 ig; + + if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) + { + sig_bit = (int)png_ptr->sig_bit.red; + if ((int)png_ptr->sig_bit.green > sig_bit) + sig_bit = png_ptr->sig_bit.green; + if ((int)png_ptr->sig_bit.blue > sig_bit) + sig_bit = png_ptr->sig_bit.blue; + } + else + { + sig_bit = (int)png_ptr->sig_bit.gray; + } + + if (sig_bit > 0) + shift = 16 - sig_bit; + else + shift = 0; + + if (png_ptr->transformations & PNG_16_TO_8) + { + if (shift < (16 - PNG_MAX_GAMMA_8)) + shift = (16 - PNG_MAX_GAMMA_8); + } + + if (shift > 8) + shift = 8; + if (shift < 0) + shift = 0; + + png_ptr->gamma_shift = (png_byte)shift; + + num = (1 << (8 - shift)); + + g = 1.0 / (png_ptr->gamma * png_ptr->screen_gamma); + + png_ptr->gamma_16_table = (png_uint_16pp)png_malloc(png_ptr, + (png_uint_32)(num * sizeof (png_uint_16p))); + + if ((png_ptr->transformations & PNG_16_TO_8) && + !(png_ptr->transformations & PNG_BACKGROUND)) + { + double fin, fout; + png_uint_32 last, max; + + for (i = 0; i < num; i++) + { + png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(256 * sizeof (png_uint_16))); + } + + g = 1.0 / g; + last = 0; + for (i = 0; i < 256; i++) + { + fout = ((double)i + 0.5) / 256.0; + fin = pow(fout, g); + max = (png_uint_32)(fin * (double)((png_uint_32)num << 8)); + while (last <= max) + { + png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] + [(int)(last >> (8 - shift))] = (png_uint_16)( + (png_uint_16)i | ((png_uint_16)i << 8)); + last++; + } + } + while (last < ((png_uint_32)num << 8)) + { + png_ptr->gamma_16_table[(int)(last & (0xff >> shift))] + [(int)(last >> (8 - shift))] = (png_uint_16)65535L; + last++; + } + } + else + { + for (i = 0; i < num; i++) + { + png_ptr->gamma_16_table[i] = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(256 * sizeof (png_uint_16))); + + ig = (((png_uint_32)i * (png_uint_32)png_gamma_shift[shift]) >> 4); + for (j = 0; j < 256; j++) + { + png_ptr->gamma_16_table[i][j] = + (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / + 65535.0, g) * 65535.0 + .5); + } + } + } + +#if defined(PNG_READ_BACKGROUND_SUPPORTED) + if (png_ptr->transformations & PNG_BACKGROUND) + { + g = 1.0 / (png_ptr->gamma); + + png_ptr->gamma_16_to_1 = (png_uint_16pp)png_malloc(png_ptr, + (png_uint_32)(num * sizeof (png_uint_16p ))); + + for (i = 0; i < num; i++) + { + png_ptr->gamma_16_to_1[i] = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(256 * sizeof (png_uint_16))); + + ig = (((png_uint_32)i * + (png_uint_32)png_gamma_shift[shift]) >> 4); + for (j = 0; j < 256; j++) + { + png_ptr->gamma_16_to_1[i][j] = + (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / + 65535.0, g) * 65535.0 + .5); + } + } + g = 1.0 / (png_ptr->screen_gamma); + + png_ptr->gamma_16_from_1 = (png_uint_16pp)png_malloc(png_ptr, + (png_uint_32)(num * sizeof (png_uint_16p))); + + for (i = 0; i < num; i++) + { + png_ptr->gamma_16_from_1[i] = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(256 * sizeof (png_uint_16))); + + ig = (((png_uint_32)i * + (png_uint_32)png_gamma_shift[shift]) >> 4); + for (j = 0; j < 256; j++) + { + png_ptr->gamma_16_from_1[i][j] = + (png_uint_16)(pow((double)(ig + ((png_uint_32)j << 8)) / + 65535.0, g) * 65535.0 + .5); + } + } + } +#endif /* PNG_BACKGROUND_SUPPORTED */ + } +} +#endif + diff --git a/thirdparty/libpng/pngrutil.c b/thirdparty/libpng/pngrutil.c new file mode 100644 index 00000000..94664de8 --- /dev/null +++ b/thirdparty/libpng/pngrutil.c @@ -0,0 +1,2245 @@ + +/* pngrutil.c - utilities to read a PNG file + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * This file contains routines which are only called from within + * libpng itself during the course of reading an image. + */ + +#define PNG_INTERNAL +#include "png.h" + +#ifndef PNG_READ_BIG_ENDIAN_SUPPORTED +/* Grab an unsigned 32-bit integer from a buffer in big endian format. */ +png_uint_32 +png_get_uint_32(png_bytep buf) +{ + png_uint_32 i; + + i = ((png_uint_32)(*buf) << 24) + + ((png_uint_32)(*(buf + 1)) << 16) + + ((png_uint_32)(*(buf + 2)) << 8) + + (png_uint_32)(*(buf + 3)); + + return (i); +} + +#if defined(PNG_READ_pCAL_SUPPORTED) +/* Grab a signed 32-bit integer from a buffer in big endian format. The + * data is stored in the PNG file in two's complement format, and it is + * assumed that the machine format for signed integers is the same. */ +png_int_32 +png_get_int_32(png_bytep buf) +{ + png_int_32 i; + + i = ((png_int_32)(*buf) << 24) + + ((png_int_32)(*(buf + 1)) << 16) + + ((png_int_32)(*(buf + 2)) << 8) + + (png_int_32)(*(buf + 3)); + + return (i); +} +#endif /* PNG_READ_pCAL_SUPPORTED */ + +/* Grab an unsigned 16-bit integer from a buffer in big endian format. */ +png_uint_16 +png_get_uint_16(png_bytep buf) +{ + png_uint_16 i; + + i = (png_uint_16)(((png_uint_16)(*buf) << 8) + + (png_uint_16)(*(buf + 1))); + + return (i); +} +#endif /* PNG_READ_BIG_ENDIAN_SUPPORTED */ + +/* Read data, and (optionally) run it through the CRC. */ +void +png_crc_read(png_structp png_ptr, png_bytep buf, png_size_t length) +{ + png_read_data(png_ptr, buf, length); + png_calculate_crc(png_ptr, buf, length); +} + +/* Optionally skip data and then check the CRC. Depending on whether we + are reading a ancillary or critical chunk, and how the program has set + things up, we may calculate the CRC on the data and print a message. + Returns '1' if there was a CRC error, '0' otherwise. */ +int +png_crc_finish(png_structp png_ptr, png_uint_32 skip) +{ + png_uint_32 i; + + for (i = skip; i > (png_uint_32)png_ptr->zbuf_size; i -= png_ptr->zbuf_size) + { + png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + } + if (i) + { + png_crc_read(png_ptr, png_ptr->zbuf, (png_size_t)i); + } + + if (png_crc_error(png_ptr)) + { + if ((png_ptr->chunk_name[0] & 0x20 && /* Ancillary */ + !(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) || + (!(png_ptr->chunk_name[0] & 0x20) && /* Critical */ + png_ptr->flags & PNG_FLAG_CRC_CRITICAL_USE)) + { + png_chunk_warning(png_ptr, "CRC error"); + } + else + { + png_chunk_error(png_ptr, "CRC error"); + } + return (1); + } + + return (0); +} + +/* Compare the CRC stored in the PNG file with that calculated by libpng from + the data it has read thus far. */ +int +png_crc_error(png_structp png_ptr) +{ + png_byte crc_bytes[4]; + png_uint_32 crc; + int need_crc = 1; + + if (png_ptr->chunk_name[0] & 0x20) /* ancillary */ + { + if ((png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_MASK) == + (PNG_FLAG_CRC_ANCILLARY_USE | PNG_FLAG_CRC_ANCILLARY_NOWARN)) + need_crc = 0; + } + else /* critical */ + { + if (png_ptr->flags & PNG_FLAG_CRC_CRITICAL_IGNORE) + need_crc = 0; + } + + png_read_data(png_ptr, crc_bytes, 4); + + if (need_crc) + { + crc = png_get_uint_32(crc_bytes); + return ((int)(crc != png_ptr->crc)); + } + else + return (0); +} + + +/* read and check the IDHR chunk */ +void +png_handle_IHDR(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[13]; + png_uint_32 width, height; + int bit_depth, color_type, compression_type, filter_type; + int interlace_type; + + png_debug(1, "in png_handle_IHDR\n"); + + if (png_ptr->mode != PNG_BEFORE_IHDR) + png_error(png_ptr, "Out of place IHDR"); + + /* check the length */ + if (length != 13) + png_error(png_ptr, "Invalid IHDR chunk"); + + png_ptr->mode |= PNG_HAVE_IHDR; + + png_crc_read(png_ptr, buf, 13); + png_crc_finish(png_ptr, 0); + + width = png_get_uint_32(buf); + height = png_get_uint_32(buf + 4); + bit_depth = buf[8]; + color_type = buf[9]; + compression_type = buf[10]; + filter_type = buf[11]; + interlace_type = buf[12]; + + /* check for width and height valid values */ + if (width == 0 || width > (png_uint_32)2147483647L || height == 0 || + height > (png_uint_32)2147483647L) + png_error(png_ptr, "Invalid image size in IHDR"); + + /* check other values */ + if (bit_depth != 1 && bit_depth != 2 && bit_depth != 4 && + bit_depth != 8 && bit_depth != 16) + png_error(png_ptr, "Invalid bit depth in IHDR"); + + if (color_type < 0 || color_type == 1 || + color_type == 5 || color_type > 6) + png_error(png_ptr, "Invalid color type in IHDR"); + + if ((color_type == PNG_COLOR_TYPE_PALETTE && bit_depth) > 8 || + ((color_type == PNG_COLOR_TYPE_RGB || + color_type == PNG_COLOR_TYPE_GRAY_ALPHA || + color_type == PNG_COLOR_TYPE_RGB_ALPHA) && bit_depth < 8)) + png_error(png_ptr, "Invalid color type/bit depth combination in IHDR"); + + if (interlace_type >= PNG_INTERLACE_LAST) + png_error(png_ptr, "Unknown interlace method in IHDR"); + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + png_error(png_ptr, "Unknown compression method in IHDR"); + + if (filter_type != PNG_FILTER_TYPE_BASE) + png_error(png_ptr, "Unknown filter method in IHDR"); + + /* set internal variables */ + png_ptr->width = width; + png_ptr->height = height; + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->interlaced = (png_byte)interlace_type; + png_ptr->color_type = (png_byte)color_type; + + /* find number of channels */ + switch (png_ptr->color_type) + { + case PNG_COLOR_TYPE_GRAY: + case PNG_COLOR_TYPE_PALETTE: + png_ptr->channels = 1; + break; + case PNG_COLOR_TYPE_RGB: + png_ptr->channels = 3; + break; + case PNG_COLOR_TYPE_GRAY_ALPHA: + png_ptr->channels = 2; + break; + case PNG_COLOR_TYPE_RGB_ALPHA: + png_ptr->channels = 4; + break; + } + + /* set up other useful info */ + png_ptr->pixel_depth = (png_byte)(png_ptr->bit_depth * + png_ptr->channels); + png_ptr->rowbytes = ((png_ptr->width * + (png_uint_32)png_ptr->pixel_depth + 7) >> 3); + png_debug1(3,"bit_depth = %d\n", png_ptr->bit_depth); + png_debug1(3,"channels = %d\n", png_ptr->channels); + png_debug1(3,"rowbytes = %d\n", png_ptr->rowbytes); + png_set_IHDR(png_ptr, info_ptr, width, height, bit_depth, + color_type, interlace_type, compression_type, filter_type); +} + +/* read and check the palette */ +void +png_handle_PLTE(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_colorp palette; + int num, i; + + png_debug(1, "in png_handle_PLTE\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before PLTE"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid PLTE after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + png_error(png_ptr, "Duplicate PLTE chunk"); + + png_ptr->mode |= PNG_HAVE_PLTE; + +#if defined (PNG_READ_tRNS_SUPPORTED) + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS) + { + if (png_ptr->num_trans > png_ptr->num_palette) + { + png_warning(png_ptr, "Truncating incorrect tRNS chunk length"); + png_ptr->num_trans = png_ptr->num_palette; + } + } + } +#endif + +#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + png_crc_finish(png_ptr, length); + return; + } +#endif + + if (length % 3) + { + if (png_ptr->color_type != PNG_COLOR_TYPE_PALETTE) + { + png_warning(png_ptr, "Invalid palette chunk"); + png_crc_finish(png_ptr, length); + return; + } + else + { + png_error(png_ptr, "Invalid palette chunk"); + } + } + + num = (int)length / 3; + palette = (png_colorp)png_zalloc(png_ptr, (uInt)num, sizeof (png_color)); + png_ptr->flags |= PNG_FLAG_FREE_PALETTE; + for (i = 0; i < num; i++) + { + png_byte buf[3]; + + png_crc_read(png_ptr, buf, 3); + /* don't depend upon png_color being any order */ + palette[i].red = buf[0]; + palette[i].green = buf[1]; + palette[i].blue = buf[2]; + } + + /* If we actually NEED the PLTE chunk (ie for a paletted image), we do + whatever the normal CRC configuration tells us. However, if we + have an RGB image, the PLTE can be considered ancillary, so + we will act as though it is. */ +#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) +#endif + { + png_crc_finish(png_ptr, 0); + } +#if !defined(PNG_READ_OPT_PLTE_SUPPORTED) + else if (png_crc_error(png_ptr)) /* Only if we have a CRC error */ + { + /* If we don't want to use the data from an ancillary chunk, + we have two options: an error abort, or a warning and we + ignore the data in this chunk (which should be OK, since + it's considered ancillary for a RGB or RGBA image). */ + if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_USE)) + { + if (png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN) + { + png_chunk_error(png_ptr, "CRC error"); + } + else + { + png_chunk_warning(png_ptr, "CRC error"); + png_ptr->flags &= ~PNG_FLAG_FREE_PALETTE; + png_zfree(png_ptr, palette); + return; + } + } + /* Otherwise, we (optionally) emit a warning and use the chunk. */ + else if (!(png_ptr->flags & PNG_FLAG_CRC_ANCILLARY_NOWARN)) + { + png_chunk_warning(png_ptr, "CRC error"); + } + } +#endif + png_ptr->palette = palette; + png_ptr->num_palette = (png_uint_16)num; + png_set_PLTE(png_ptr, info_ptr, palette, num); +} + +void +png_handle_IEND(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_debug(1, "in png_handle_IEND\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR) || !(png_ptr->mode & PNG_HAVE_IDAT)) + { + png_error(png_ptr, "No image in file"); + + /* to quiet compiler warnings about unused info_ptr */ + if (info_ptr == NULL) + return; + } + + png_ptr->mode |= PNG_AFTER_IDAT | PNG_HAVE_IEND; + + if (length != 0) + { + png_warning(png_ptr, "Incorrect IEND chunk length"); + } + png_crc_finish(png_ptr, length); +} + +#if defined(PNG_READ_gAMA_SUPPORTED) +void +png_handle_gAMA(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_uint_32 igamma; + float file_gamma; + png_byte buf[4]; + + png_debug(1, "in png_handle_gAMA\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before gAMA"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid gAMA after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place gAMA chunk"); + + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_gAMA +#if defined(PNG_READ_sRGB_SUPPORTED) + && !(info_ptr->valid & PNG_INFO_sRGB) +#endif + ) + { + png_warning(png_ptr, "Duplicate gAMA chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 4) + { + png_warning(png_ptr, "Incorrect gAMA chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 4); + if (png_crc_finish(png_ptr, 0)) + return; + + igamma = png_get_uint_32(buf); + /* check for zero gamma */ + if (igamma == 0) + return; + +#if defined(PNG_READ_sRGB_SUPPORTED) + if (info_ptr->valid & PNG_INFO_sRGB) + if(igamma != (png_uint_32)45000L) + { + png_warning(png_ptr, + "Ignoring incorrect gAMA value when sRGB is also present"); +#ifndef PNG_NO_STDIO + fprintf(stderr, "igamma = %lu\n", igamma); +#endif + return; + } +#endif /* PNG_READ_sRGB_SUPPORTED */ + + file_gamma = (float)igamma / (float)1.0.10.0; +#ifdef PNG_READ_GAMMA_SUPPORTED + png_ptr->gamma = file_gamma; +#endif + png_set_gAMA(png_ptr, info_ptr, file_gamma); +} +#endif + +#if defined(PNG_READ_sBIT_SUPPORTED) +void +png_handle_sBIT(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_size_t truelen; + png_byte buf[4]; + + png_debug(1, "in png_handle_sBIT\n"); + + buf[0] = buf[1] = buf[2] = buf[3] = 0; + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sBIT"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sBIT after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + { + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place sBIT chunk"); + } + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sBIT) + { + png_warning(png_ptr, "Duplicate sBIT chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + truelen = 3; + else + truelen = (png_size_t)png_ptr->channels; + + if (length != truelen) + { + png_warning(png_ptr, "Incorrect sBIT chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, truelen); + if (png_crc_finish(png_ptr, 0)) + return; + + if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) + { + png_ptr->sig_bit.red = buf[0]; + png_ptr->sig_bit.green = buf[1]; + png_ptr->sig_bit.blue = buf[2]; + png_ptr->sig_bit.alpha = buf[3]; + } + else + { + png_ptr->sig_bit.gray = buf[0]; + png_ptr->sig_bit.alpha = buf[1]; + } + png_set_sBIT(png_ptr, info_ptr, &(png_ptr->sig_bit)); +} +#endif + +#if defined(PNG_READ_cHRM_SUPPORTED) +void +png_handle_cHRM(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[4]; + png_uint_32 val; + float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; + + png_debug(1, "in png_handle_cHRM\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sBIT"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid cHRM after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Missing PLTE before cHRM"); + + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_cHRM +#if defined(PNG_READ_sRGB_SUPPORTED) + && !(info_ptr->valid & PNG_INFO_sRGB) +#endif + ) + { + png_warning(png_ptr, "Duplicate cHRM chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 32) + { + png_warning(png_ptr, "Incorrect cHRM chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 4); + val = png_get_uint_32(buf); + white_x = (float)val / (float)1.0.10.0; + + png_crc_read(png_ptr, buf, 4); + val = png_get_uint_32(buf); + white_y = (float)val / (float)1.0.10.0; + + if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 || + white_x + white_y > 1.0) + { + png_warning(png_ptr, "Invalid cHRM white point"); + png_crc_finish(png_ptr, 24); + return; + } + + png_crc_read(png_ptr, buf, 4); + val = png_get_uint_32(buf); + red_x = (float)val / (float)1.0.10.0; + + png_crc_read(png_ptr, buf, 4); + val = png_get_uint_32(buf); + red_y = (float)val / (float)1.0.10.0; + + if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 || + red_x + red_y > 1.0) + { + png_warning(png_ptr, "Invalid cHRM red point"); + png_crc_finish(png_ptr, 16); + return; + } + + png_crc_read(png_ptr, buf, 4); + val = png_get_uint_32(buf); + green_x = (float)val / (float)1.0.10.0; + + png_crc_read(png_ptr, buf, 4); + val = png_get_uint_32(buf); + green_y = (float)val / (float)1.0.10.0; + + if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 || + green_x + green_y > 1.0) + { + png_warning(png_ptr, "Invalid cHRM green point"); + png_crc_finish(png_ptr, 8); + return; + } + + png_crc_read(png_ptr, buf, 4); + val = png_get_uint_32(buf); + blue_x = (float)val / (float)1.0.10.0; + + png_crc_read(png_ptr, buf, 4); + val = png_get_uint_32(buf); + blue_y = (float)val / (float)1.0.10.0; + + if (blue_x < (float)0 || blue_x > (float)0.8 || blue_y < (float)0 || + blue_y > (float)0.8 || blue_x + blue_y > (float)1.0) + { + png_warning(png_ptr, "Invalid cHRM blue point"); + png_crc_finish(png_ptr, 0); + return; + } + + if (png_crc_finish(png_ptr, 0)) + return; + +#if defined(PNG_READ_sRGB_SUPPORTED) + if (info_ptr->valid & PNG_INFO_sRGB) + { + if (fabs(white_x - (float).3127) > (float).001 || + fabs(white_y - (float).3290) > (float).001 || + fabs( red_x - (float).6400) > (float).001 || + fabs( red_y - (float).3300) > (float).001 || + fabs(green_x - (float).3000) > (float).001 || + fabs(green_y - (float).6000) > (float).001 || + fabs( blue_x - (float).1500) > (float).001 || + fabs( blue_y - (float).0600) > (float).001) + { + + png_warning(png_ptr, + "Ignoring incorrect cHRM value when sRGB is also present"); +#ifndef PNG_NO_STDIO + fprintf(stderr,"wx=%f, wy=%f, rx=%f, ry=%f\n", + white_x, white_y, red_x, red_y); + fprintf(stderr,"gx=%f, gy=%f, bx=%f, by=%f\n", + green_x, green_y, blue_x, blue_y); +#endif + } + return; + } +#endif /* PNG_READ_sRGB_SUPPORTED */ + + png_set_cHRM(png_ptr, info_ptr, + white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); +} +#endif + +#if defined(PNG_READ_sRGB_SUPPORTED) +void +png_handle_sRGB(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + int intent; + png_byte buf[1]; + + png_debug(1, "in png_handle_sRGB\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before sRGB"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid sRGB after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->mode & PNG_HAVE_PLTE) + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Out of place sRGB chunk"); + + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_sRGB) + { + png_warning(png_ptr, "Duplicate sRGB chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 1) + { + png_warning(png_ptr, "Incorrect sRGB chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 1); + if (png_crc_finish(png_ptr, 0)) + return; + + intent = buf[0]; + /* check for bad intent */ + if (intent >= PNG_sRGB_INTENT_LAST) + { + png_warning(png_ptr, "Unknown sRGB intent"); + return; + } + +#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_READ_GAMMA_SUPPORTED) + if ((info_ptr->valid & PNG_INFO_gAMA)) + if((png_uint_32)(png_ptr->gamma*(float)1.0.10.+.5) != (png_uint_32)45000L) + { + png_warning(png_ptr, + "Ignoring incorrect gAMA value when sRGB is also present"); +#ifndef PNG_NO_STDIO + fprintf(stderr,"gamma=%f\n",png_ptr->gamma); +#endif + } +#endif /* PNG_READ_gAMA_SUPPORTED */ + +#ifdef PNG_READ_cHRM_SUPPORTED + if (info_ptr->valid & PNG_INFO_cHRM) + if (fabs(info_ptr->x_white - (float).3127) > (float).001 || + fabs(info_ptr->y_white - (float).3290) > (float).001 || + fabs( info_ptr->x_red - (float).6400) > (float).001 || + fabs( info_ptr->y_red - (float).3300) > (float).001 || + fabs(info_ptr->x_green - (float).3000) > (float).001 || + fabs(info_ptr->y_green - (float).6000) > (float).001 || + fabs( info_ptr->x_blue - (float).1500) > (float).001 || + fabs( info_ptr->y_blue - (float).0600) > (float).001) + { + png_warning(png_ptr, + "Ignoring incorrect cHRM value when sRGB is also present"); + } +#endif /* PNG_READ_cHRM_SUPPORTED */ + + png_set_sRGB_gAMA_and_cHRM(png_ptr, info_ptr, intent); +} +#endif /* PNG_READ_sRGB_SUPPORTED */ + +#if defined(PNG_READ_tRNS_SUPPORTED) +void +png_handle_tRNS(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_debug(1, "in png_handle_tRNS\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before tRNS"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid tRNS after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tRNS) + { + png_warning(png_ptr, "Duplicate tRNS chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (!(png_ptr->mode & PNG_HAVE_PLTE)) + { + /* Should be an error, but we can cope with it */ + png_warning(png_ptr, "Missing PLTE before tRNS"); + } + else if (length > png_ptr->num_palette) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_ptr->trans = (png_bytep)png_malloc(png_ptr, length); + png_ptr->flags |= PNG_FLAG_FREE_TRANS; + png_crc_read(png_ptr, png_ptr->trans, (png_size_t)length); + png_ptr->num_trans = (png_uint_16)length; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + png_byte buf[6]; + + if (length != 6) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, (png_size_t)length); + png_ptr->num_trans = 1; + png_ptr->trans_values.red = png_get_uint_16(buf); + png_ptr->trans_values.green = png_get_uint_16(buf + 2); + png_ptr->trans_values.blue = png_get_uint_16(buf + 4); + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + png_byte buf[6]; + + if (length != 2) + { + png_warning(png_ptr, "Incorrect tRNS chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 2); + png_ptr->num_trans = 1; + png_ptr->trans_values.gray = png_get_uint_16(buf); + } + else + { + png_warning(png_ptr, "tRNS chunk not allowed with alpha channel"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_crc_finish(png_ptr, 0)) + return; + + png_set_tRNS(png_ptr, info_ptr, png_ptr->trans, png_ptr->num_trans, + &(png_ptr->trans_values)); +} +#endif + +#if defined(PNG_READ_bKGD_SUPPORTED) +void +png_handle_bKGD(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_size_t truelen; + png_byte buf[6]; + + png_debug(1, "in png_handle_bKGD\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before bKGD"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid bKGD after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE && + !(png_ptr->mode & PNG_HAVE_PLTE)) + { + png_warning(png_ptr, "Missing PLTE before bKGD"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_bKGD) + { + png_warning(png_ptr, "Duplicate bKGD chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + truelen = 1; + else if (png_ptr->color_type & PNG_COLOR_MASK_COLOR) + truelen = 6; + else + truelen = 2; + + if (length != truelen) + { + png_warning(png_ptr, "Incorrect bKGD chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, truelen); + if (png_crc_finish(png_ptr, 0)) + return; + + /* We convert the index value into RGB components so that we can allow + * arbitrary RGB values for background when we have transparency, and + * so it is easy to determine the RGB values of the background color + * from the info_ptr struct. */ + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_ptr->background.index = buf[0]; + png_ptr->background.red = (png_uint_16)png_ptr->palette[buf[0]].red; + png_ptr->background.green = (png_uint_16)png_ptr->palette[buf[0]].green; + png_ptr->background.blue = (png_uint_16)png_ptr->palette[buf[0]].blue; + } + else if (!(png_ptr->color_type & PNG_COLOR_MASK_COLOR)) /* GRAY */ + { + png_ptr->background.red = + png_ptr->background.green = + png_ptr->background.blue = + png_ptr->background.gray = png_get_uint_16(buf); + } + else + { + png_ptr->background.red = png_get_uint_16(buf); + png_ptr->background.green = png_get_uint_16(buf + 2); + png_ptr->background.blue = png_get_uint_16(buf + 4); + } + + png_set_bKGD(png_ptr, info_ptr, &(png_ptr->background)); +} +#endif + +#if defined(PNG_READ_hIST_SUPPORTED) +void +png_handle_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + int num, i; + + png_debug(1, "in png_handle_hIST\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before hIST"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid hIST after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (!(png_ptr->mode & PNG_HAVE_PLTE)) + { + png_warning(png_ptr, "Missing PLTE before hIST"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_hIST) + { + png_warning(png_ptr, "Duplicate hIST chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != (png_uint_32)(2 * png_ptr->num_palette)) + { + png_warning(png_ptr, "Incorrect hIST chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + num = (int)length / 2; + png_ptr->hist = (png_uint_16p)png_malloc(png_ptr, + (png_uint_32)(num * sizeof (png_uint_16))); + png_ptr->flags |= PNG_FLAG_FREE_HIST; + for (i = 0; i < num; i++) + { + png_byte buf[2]; + + png_crc_read(png_ptr, buf, 2); + png_ptr->hist[i] = png_get_uint_16(buf); + } + + if (png_crc_finish(png_ptr, 0)) + return; + + png_set_hIST(png_ptr, info_ptr, png_ptr->hist); +} +#endif + +#if defined(PNG_READ_pHYs_SUPPORTED) +void +png_handle_pHYs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_uint_32 res_x, res_y; + int unit_type; + + png_debug(1, "in png_handle_pHYs\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before pHYS"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid pHYS after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pHYs) + { + png_warning(png_ptr, "Duplicate pHYS chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 9) + { + png_warning(png_ptr, "Incorrect pHYs chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 9); + if (png_crc_finish(png_ptr, 0)) + return; + + res_x = png_get_uint_32(buf); + res_y = png_get_uint_32(buf + 4); + unit_type = buf[8]; + png_set_pHYs(png_ptr, info_ptr, res_x, res_y, unit_type); +} +#endif + +#if defined(PNG_READ_oFFs_SUPPORTED) +void +png_handle_oFFs(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[9]; + png_uint_32 offset_x, offset_y; + int unit_type; + + png_debug(1, "in png_handle_oFFs\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before oFFs"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid oFFs after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_oFFs) + { + png_warning(png_ptr, "Duplicate oFFs chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (length != 9) + { + png_warning(png_ptr, "Incorrect oFFs chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 9); + if (png_crc_finish(png_ptr, 0)) + return; + + offset_x = png_get_uint_32(buf); + offset_y = png_get_uint_32(buf + 4); + unit_type = buf[8]; + png_set_oFFs(png_ptr, info_ptr, offset_x, offset_y, unit_type); +} +#endif + +#if defined(PNG_READ_pCAL_SUPPORTED) +/* read the pCAL chunk (png-scivis-19970203) */ +void +png_handle_pCAL(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_charp purpose; + png_int_32 X0, X1; + png_byte type, nparams; + png_charp buf, units, endptr; + png_charpp params; + png_size_t slength; + int i; + + png_debug(1, "in png_handle_pCAL\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before pCAL"); + else if (png_ptr->mode & PNG_HAVE_IDAT) + { + png_warning(png_ptr, "Invalid pCAL after IDAT"); + png_crc_finish(png_ptr, length); + return; + } + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_pCAL) + { + png_warning(png_ptr, "Duplicate pCAL chunk"); + png_crc_finish(png_ptr, length); + return; + } + + png_debug1(2, "Allocating and reading pCAL chunk data (%d bytes)\n", + length + 1); + purpose = (png_charp)png_malloc(png_ptr, length + 1); + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)purpose, slength); + + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, purpose); + return; + } + + purpose[slength] = 0x00; /* null terminate the last string */ + + png_debug(3, "Finding end of pCAL purpose string\n"); + for (buf = purpose; *buf != '\0'; buf++) + /* empty loop */; + + endptr = purpose + slength; + + /* We need to have at least 12 bytes after the purpose string + in order to get the parameter information. */ + if (endptr <= buf + 12) + { + png_warning(png_ptr, "Invalid pCAL data"); + png_free(png_ptr, purpose); + return; + } + + png_debug(3, "Reading pCAL X0, X1, type, nparams, and units\n"); + X0 = png_get_int_32((png_bytep)buf+1); + X1 = png_get_int_32((png_bytep)buf+5); + type = buf[9]; + nparams = buf[10]; + units = buf + 11; + + png_debug(3, "Checking pCAL equation type and number of parameters\n"); + /* Check that we have the right number of parameters for known + equation types. */ + if ((type == PNG_EQUATION_LINEAR && nparams != 2) || + (type == PNG_EQUATION_BASE_E && nparams != 3) || + (type == PNG_EQUATION_ARBITRARY && nparams != 3) || + (type == PNG_EQUATION_HYPERBOLIC && nparams != 4)) + { + png_warning(png_ptr, "Invalid pCAL parameters for equation type"); + png_free(png_ptr, purpose); + return; + } + else if (type >= PNG_EQUATION_LAST) + { + png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); + } + + /* Empty loop to move past the units string. */ + for (buf = units; *buf != 0x00; buf++); + + png_debug(3, "Allocating pCAL parameters array\n"); + params = (png_charpp)png_malloc(png_ptr, (png_uint_32)(nparams + *sizeof(png_charp))) ; + + /* Get pointers to the start of each parameter string. */ + for (i = 0; i < (int)nparams; i++) + { + buf++; /* Skip the null string terminator from previous parameter. */ + + png_debug1(3, "Reading pCAL parameter %d\n", i); + /* Empty loop to move past each paramter string */ + for (params[i] = buf; *buf != 0x00 && buf <= endptr; buf++); + + /* Make sure we haven't run out of data yet */ + if (buf > endptr) + { + png_warning(png_ptr, "Invalid pCAL data"); + png_free(png_ptr, purpose); + png_free(png_ptr, params); + return; + } + } + + png_set_pCAL(png_ptr, info_ptr, purpose, X0, X1, type, nparams, + units, params); + + png_free(png_ptr, purpose); + png_free(png_ptr, params); +} +#endif + +#if defined(PNG_READ_tIME_SUPPORTED) +void +png_handle_tIME(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_byte buf[7]; + png_time mod_time; + + png_debug(1, "in png_handle_tIME\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Out of place tIME chunk"); + else if (info_ptr != NULL && info_ptr->valid & PNG_INFO_tIME) + { + png_warning(png_ptr, "Duplicate tIME chunk"); + png_crc_finish(png_ptr, length); + return; + } + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + + if (length != 7) + { + png_warning(png_ptr, "Incorrect tIME chunk length"); + png_crc_finish(png_ptr, length); + return; + } + + png_crc_read(png_ptr, buf, 7); + if (png_crc_finish(png_ptr, 0)) + return; + + mod_time.second = buf[6]; + mod_time.minute = buf[5]; + mod_time.hour = buf[4]; + mod_time.day = buf[3]; + mod_time.month = buf[2]; + mod_time.year = png_get_uint_16(buf); + + png_set_tIME(png_ptr, info_ptr, &mod_time); +} +#endif + +#if defined(PNG_READ_tEXt_SUPPORTED) +/* Note: this does not properly handle chunks that are > 64K under DOS */ +void +png_handle_tEXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_textp text_ptr; + png_charp key; + png_charp text; + png_uint_32 skip = 0; + png_size_t slength; + + png_debug(1, "in png_handle_tEXt\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before tEXt"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr, "tEXt chunk too large to fit in memory"); + skip = length - (png_uint_32)65535L; + length = (png_uint_32)65535L; + } +#endif + + key = (png_charp)png_malloc(png_ptr, length + 1); + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)key, slength); + + if (png_crc_finish(png_ptr, skip)) + { + png_free(png_ptr, key); + return; + } + + key[slength] = 0x00; + + for (text = key; *text; text++) + /* empty loop to find end of key */ ; + + if (text != key + slength) + text++; + + text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); + text_ptr->compression = PNG_TEXT_COMPRESSION_NONE; + text_ptr->key = key; + text_ptr->text = text; + + png_set_text(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); +} +#endif + +#if defined(PNG_READ_zTXt_SUPPORTED) +/* note: this does not correctly handle chunks that are > 64K under DOS */ +void +png_handle_zTXt(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + static char msg[] = "Error decoding zTXt chunk"; + png_textp text_ptr; + png_charp key; + png_charp text; + int comp_type = PNG_TEXT_COMPRESSION_NONE; + png_size_t slength; + + png_debug(1, "in png_handle_zTXt\n"); + + if (!(png_ptr->mode & PNG_HAVE_IHDR)) + png_error(png_ptr, "Missing IHDR before zTXt"); + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + +#ifdef PNG_MAX_MALLOC_64K + /* We will no doubt have problems with chunks even half this size, but + there is no hard and fast rule to tell us where to stop. */ + if (length > (png_uint_32)65535L) + { + png_warning(png_ptr,"zTXt chunk too large to fit in memory"); + png_crc_finish(png_ptr, length); + return; + } +#endif + + key = (png_charp)png_malloc(png_ptr, length + 1); + slength = (png_size_t)length; + png_crc_read(png_ptr, (png_bytep)key, slength); + if (png_crc_finish(png_ptr, 0)) + { + png_free(png_ptr, key); + return; + } + + key[slength] = 0x00; + + for (text = key; *text; text++) + /* empty loop */ ; + + /* zTXt must have some text after the keyword */ + if (text == key + slength) + { + png_warning(png_ptr, "Zero length zTXt chunk"); + } + else if ((comp_type = *(++text)) == PNG_TEXT_COMPRESSION_zTXt) + { + png_size_t text_size, key_size; + text++; + + png_ptr->zstream.next_in = (png_bytep)text; + png_ptr->zstream.avail_in = (uInt)(length - (text - key)); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + key_size = (png_size_t)(text - key); + text_size = 0; + text = NULL; + + while (png_ptr->zstream.avail_in) + { + int ret; + + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + if (ret != Z_OK && ret != Z_STREAM_END) + { + if (png_ptr->zstream.msg != NULL) + png_warning(png_ptr, png_ptr->zstream.msg); + else + png_warning(png_ptr, msg); + inflateReset(&png_ptr->zstream); + png_ptr->zstream.avail_in = 0; + + if (text == NULL) + { + text_size = key_size + sizeof(msg) + 1; + text = (png_charp)png_malloc(png_ptr, (png_uint_32)text_size); + png_memcpy(text, key, key_size); + } + + text[text_size - 1] = 0x00; + + /* Copy what we can of the error message into the text chunk */ + text_size = (png_size_t)(slength - (text - key) - 1); + text_size = sizeof(msg) > text_size ? text_size : sizeof(msg); + png_memcpy(text + key_size, msg, text_size + 1); + break; + } + if (!png_ptr->zstream.avail_out || ret == Z_STREAM_END) + { + if (text == NULL) + { + text = (png_charp)png_malloc(png_ptr, + (png_uint_32)(png_ptr->zbuf_size - png_ptr->zstream.avail_out + + key_size + 1)); + png_memcpy(text + key_size, png_ptr->zbuf, + png_ptr->zbuf_size - png_ptr->zstream.avail_out); + png_memcpy(text, key, key_size); + text_size = key_size + png_ptr->zbuf_size - + png_ptr->zstream.avail_out; + *(text + text_size) = 0x00; + } + else + { + png_charp tmp; + + tmp = text; + text = (png_charp)png_malloc(png_ptr, (png_uint_32)(text_size + + png_ptr->zbuf_size - png_ptr->zstream.avail_out + 1)); + png_memcpy(text, tmp, text_size); + png_free(png_ptr, tmp); + png_memcpy(text + text_size, png_ptr->zbuf, + (png_ptr->zbuf_size - png_ptr->zstream.avail_out)); + text_size += png_ptr->zbuf_size - png_ptr->zstream.avail_out; + *(text + text_size) = 0x00; + } + if (ret != Z_STREAM_END) + { + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + else + { + break; + } + } + } + + inflateReset(&png_ptr->zstream); + png_ptr->zstream.avail_in = 0; + + png_free(png_ptr, key); + key = text; + text += key_size; + } + else /* if (comp_type >= PNG_TEXT_COMPRESSION_LAST) */ + { + png_size_t text_size; +#if !defined(PNG_NO_STDIO) + char umsg[50]; + + sprintf(umsg, "Unknown zTXt compression type %d", comp_type); + png_warning(png_ptr, umsg); +#else + png_warning(png_ptr, "Unknown zTXt compression type"); +#endif + + /* Copy what we can of the error message into the text chunk */ + text_size = (png_size_t)(slength - (text - key) - 1); + text_size = sizeof(msg) > text_size ? text_size : sizeof(msg); + png_memcpy(text, msg, text_size + 1); + } + + text_ptr = (png_textp)png_malloc(png_ptr, (png_uint_32)sizeof(png_text)); + text_ptr->compression = comp_type; + text_ptr->key = key; + text_ptr->text = text; + + png_set_text(png_ptr, info_ptr, text_ptr, 1); + + png_free(png_ptr, text_ptr); +} +#endif + +/* This function is called when we haven't found a handler for a + chunk. If there isn't a problem with the chunk itself (ie bad + chunk name, CRC, or a critical chunk), the chunk is silently ignored. */ +void +png_handle_unknown(png_structp png_ptr, png_infop info_ptr, png_uint_32 length) +{ + png_debug(1, "in png_handle_unknown\n"); + + /* In the future we can have code here that calls user-supplied + * callback functions for unknown chunks before they are ignored or + * cause an error. + */ + png_check_chunk_name(png_ptr, png_ptr->chunk_name); + + if (!(png_ptr->chunk_name[0] & 0x20)) + { + png_chunk_error(png_ptr, "unknown critical chunk"); + + /* to quiet compiler warnings about unused info_ptr */ + if (info_ptr == NULL) + return; + } + + if (png_ptr->mode & PNG_HAVE_IDAT) + png_ptr->mode |= PNG_AFTER_IDAT; + + png_crc_finish(png_ptr, length); + +} + +/* This function is called to verify that a chunk name is valid. + This function can't have the "critical chunk check" incorporated + into it, since in the future we will need to be able to call user + functions to handle unknown critical chunks after we check that + the chunk name itself is valid. */ + +#define isnonalpha(c) ((c) < 41 || (c) > 122 || ((c) > 90 && (c) < 97)) + +void +png_check_chunk_name(png_structp png_ptr, png_bytep chunk_name) +{ + png_debug(1, "in png_check_chunk_name\n"); + if (isnonalpha(chunk_name[0]) || isnonalpha(chunk_name[1]) || + isnonalpha(chunk_name[2]) || isnonalpha(chunk_name[3])) + { + png_chunk_error(png_ptr, "invalid chunk type"); + } +} + +/* Combines the row recently read in with the previous row. + This routine takes care of alpha and transparency if requested. + This routine also handles the two methods of progressive display + of interlaced images, depending on the mask value. + The mask value describes which pixels are to be combined with + the row. The pattern always repeats every 8 pixels, so just 8 + bits are needed. A one indicates the pixels is to be combined, + a zero indicates the pixel is to be skipped. This is in addition + to any alpha or transparency value associated with the pixel. If + you want all pixels to be combined, pass 0xff (255) in mask. */ +void +png_combine_row(png_structp png_ptr, png_bytep row, + int mask) +{ + png_debug(1,"in png_combine_row\n"); + if (mask == 0xff) + { + png_memcpy(row, png_ptr->row_buf + 1, + (png_size_t)((png_ptr->width * + png_ptr->row_info.pixel_depth + 7) >> 3)); + } + else + { + switch (png_ptr->row_info.pixel_depth) + { + case 1: + { + png_bytep sp; + png_bytep dp; + int s_inc, s_start, s_end; + int m; + int shift; + png_uint_32 i; + + sp = png_ptr->row_buf + 1; + dp = row; + m = 0x80; +#if defined(PNG_READ_PACKSWAP_SUPPORTED) + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 7; + s_inc = 1; + } + else +#endif + { + s_start = 7; + s_end = 0; + s_inc = -1; + } + + shift = s_start; + + for (i = 0; i < png_ptr->width; i++) + { + if (m & mask) + { + int value; + + value = (*sp >> shift) & 0x1; + *dp &= (png_byte)((0x7f7f >> (7 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + else + shift += s_inc; + + if (m == 1) + m = 0x80; + else + m >>= 1; + } + break; + } + case 2: + { + png_bytep sp; + png_bytep dp; + int s_start, s_end, s_inc; + int m; + int shift; + png_uint_32 i; + int value; + + sp = png_ptr->row_buf + 1; + dp = row; + m = 0x80; +#if defined(PNG_READ_PACKSWAP_SUPPORTED) + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 6; + s_inc = 2; + } + else +#endif + { + s_start = 6; + s_end = 0; + s_inc = -2; + } + + shift = s_start; + + for (i = 0; i < png_ptr->width; i++) + { + if (m & mask) + { + value = (*sp >> shift) & 0x3; + *dp &= (png_byte)((0x3f3f >> (6 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + else + shift += s_inc; + if (m == 1) + m = 0x80; + else + m >>= 1; + } + break; + } + case 4: + { + png_bytep sp; + png_bytep dp; + int s_start, s_end, s_inc; + int m; + int shift; + png_uint_32 i; + int value; + + sp = png_ptr->row_buf + 1; + dp = row; + m = 0x80; +#if defined(PNG_READ_PACKSWAP_SUPPORTED) + if (png_ptr->transformations & PNG_PACKSWAP) + { + s_start = 0; + s_end = 4; + s_inc = 4; + } + else +#endif + { + s_start = 4; + s_end = 0; + s_inc = -4; + } + shift = s_start; + + for (i = 0; i < png_ptr->width; i++) + { + if (m & mask) + { + value = (*sp >> shift) & 0xf; + *dp &= (png_byte)((0xf0f >> (4 - shift)) & 0xff); + *dp |= (png_byte)(value << shift); + } + + if (shift == s_end) + { + shift = s_start; + sp++; + dp++; + } + else + shift += s_inc; + if (m == 1) + m = 0x80; + else + m >>= 1; + } + break; + } + default: + { + png_bytep sp; + png_bytep dp; + png_size_t pixel_bytes; + png_uint_32 i; + png_byte m; + + pixel_bytes = (png_ptr->row_info.pixel_depth >> 3); + + sp = png_ptr->row_buf + 1; + dp = row; + m = 0x80; + for (i = 0; i < png_ptr->width; i++) + { + if (m & mask) + { + png_memcpy(dp, sp, pixel_bytes); + } + + sp += pixel_bytes; + dp += pixel_bytes; + + if (m == 1) + m = 0x80; + else + m >>= 1; + } + break; + } + } + } +} + +#if defined(PNG_READ_INTERLACING_SUPPORTED) +void +png_do_read_interlace(png_row_infop row_info, png_bytep row, int pass, + png_uint_32 transformations) +{ + png_debug(1,"in png_do_read_interlace\n"); + if (row != NULL && row_info != NULL) + { + png_uint_32 final_width; + + final_width = row_info->width * png_pass_inc[pass]; + + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp, dp; + int sshift, dshift; + int s_start, s_end, s_inc; + png_byte v; + png_uint_32 i; + int j; + + sp = row + (png_size_t)((row_info->width - 1) >> 3); + dp = row + (png_size_t)((final_width - 1) >> 3); +#if defined(PNG_READ_PACKSWAP_SUPPORTED) + if (transformations & PNG_PACKSWAP) + { + sshift = (int)((row_info->width + 7) & 7); + dshift = (int)((final_width + 7) & 7); + s_start = 7; + s_end = 0; + s_inc = -1; + } + else +#endif + { + sshift = 7 - (int)((row_info->width + 7) & 7); + dshift = 7 - (int)((final_width + 7) & 7); + s_start = 0; + s_end = 7; + s_inc = 1; + } + + for (i = row_info->width; i; i--) + { + v = (png_byte)((*sp >> sshift) & 0x1); + for (j = 0; j < png_pass_inc[pass]; j++) + { + *dp &= (png_byte)((0x7f7f >> (7 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + else + dshift += s_inc; + } + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + else + sshift += s_inc; + } + break; + } + case 2: + { + png_bytep sp, dp; + int sshift, dshift; + int s_start, s_end, s_inc; + png_uint_32 i; + + sp = row + (png_uint_32)((row_info->width - 1) >> 2); + dp = row + (png_uint_32)((final_width - 1) >> 2); +#if defined(PNG_READ_PACKSWAP_SUPPORTED) + if (transformations & PNG_PACKSWAP) + { + sshift = (int)(((row_info->width + 3) & 3) << 1); + dshift = (int)(((final_width + 3) & 3) << 1); + s_start = 6; + s_end = 0; + s_inc = -2; + } + else +#endif + { + sshift = (int)((3 - ((row_info->width + 3) & 3)) << 1); + dshift = (int)((3 - ((final_width + 3) & 3)) << 1); + s_start = 0; + s_end = 6; + s_inc = 2; + } + + for (i = row_info->width; i; i--) + { + png_byte v; + int j; + + v = (png_byte)((*sp >> sshift) & 0x3); + for (j = 0; j < png_pass_inc[pass]; j++) + { + *dp &= (png_byte)((0x3f3f >> (6 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + else + dshift += s_inc; + } + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + else + sshift += s_inc; + } + break; + } + case 4: + { + png_bytep sp, dp; + int sshift, dshift; + int s_start, s_end, s_inc; + png_uint_32 i; + + sp = row + (png_size_t)((row_info->width - 1) >> 1); + dp = row + (png_size_t)((final_width - 1) >> 1); +#if defined(PNG_READ_PACKSWAP_SUPPORTED) + if (transformations & PNG_PACKSWAP) + { + sshift = (int)(((row_info->width + 1) & 1) << 2); + dshift = (int)(((final_width + 1) & 1) << 2); + s_start = 4; + s_end = 0; + s_inc = -4; + } + else +#endif + { + sshift = (int)((1 - ((row_info->width + 1) & 1)) << 2); + dshift = (int)((1 - ((final_width + 1) & 1)) << 2); + s_start = 0; + s_end = 4; + s_inc = 4; + } + + for (i = row_info->width; i; i--) + { + png_byte v; + int j; + + v = (png_byte)((*sp >> sshift) & 0xf); + for (j = 0; j < png_pass_inc[pass]; j++) + { + *dp &= (png_byte)((0xf0f >> (4 - dshift)) & 0xff); + *dp |= (png_byte)(v << dshift); + if (dshift == s_end) + { + dshift = s_start; + dp--; + } + else + dshift += s_inc; + } + if (sshift == s_end) + { + sshift = s_start; + sp--; + } + else + sshift += s_inc; + } + break; + } + default: + { + png_bytep sp, dp; + png_uint_32 i; + png_size_t pixel_bytes; + + pixel_bytes = (row_info->pixel_depth >> 3); + + sp = row + (png_size_t)(row_info->width - 1) * pixel_bytes; + dp = row + (png_size_t)(final_width - 1) * pixel_bytes; + for (i = row_info->width; i; i--) + { + png_byte v[8]; + int j; + + png_memcpy(v, sp, pixel_bytes); + for (j = 0; j < png_pass_inc[pass]; j++) + { + png_memcpy(dp, v, pixel_bytes); + dp -= pixel_bytes; + } + sp -= pixel_bytes; + } + break; + } + } + row_info->width = final_width; + row_info->rowbytes = ((final_width * + (png_uint_32)row_info->pixel_depth + 7) >> 3); + } +} +#endif + +void +png_read_filter_row(png_structp png_ptr, png_row_infop row_info, png_bytep row, + png_bytep prev_row, int filter) +{ + png_debug(1, "in png_read_filter_row\n"); + png_debug2(2,"row = %d, filter = %d\n", png_ptr->row_number, filter); + + + switch (filter) + { + case PNG_FILTER_VALUE_NONE: + break; + case PNG_FILTER_VALUE_SUB: + { + png_uint_32 i; + int bpp; + png_bytep rp; + png_bytep lp; + + bpp = (row_info->pixel_depth + 7) / 8; + for (i = (png_uint_32)bpp, rp = row + bpp, lp = row; + i < row_info->rowbytes; i++, rp++, lp++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*lp)) & 0xff); + } + break; + } + case PNG_FILTER_VALUE_UP: + { + png_uint_32 i; + png_bytep rp; + png_bytep pp; + + for (i = 0, rp = row, pp = prev_row; + i < row_info->rowbytes; i++, rp++, pp++) + { + *rp = (png_byte)(((int)(*rp) + (int)(*pp)) & 0xff); + } + break; + } + case PNG_FILTER_VALUE_AVG: + { + png_uint_32 i; + int bpp; + png_bytep rp; + png_bytep pp; + png_bytep lp; + + bpp = (row_info->pixel_depth + 7) / 8; + for (i = 0, rp = row, pp = prev_row; + i < (png_uint_32)bpp; i++, rp++, pp++) + { + *rp = (png_byte)(((int)(*rp) + + ((int)(*pp) / 2)) & 0xff); + } + for (lp = row; i < row_info->rowbytes; i++, rp++, lp++, pp++) + { + *rp = (png_byte)(((int)(*rp) + + (int)(*pp + *lp) / 2) & 0xff); + } + break; + } + case PNG_FILTER_VALUE_PAETH: + { + int bpp; + png_uint_32 i; + png_bytep rp; + png_bytep pp; + png_bytep lp; + png_bytep cp; + + bpp = (row_info->pixel_depth + 7) / 8; + for (i = 0, rp = row, pp = prev_row, + lp = row - bpp, cp = prev_row - bpp; + i < row_info->rowbytes; i++, rp++, pp++, lp++, cp++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp; + if (i >= (png_uint_32)bpp) + { + c = *cp; + a = *lp; + } + else + { + a = c = 0; + } + p = a + b - c; + pa = abs(p - a); + pb = abs(p - b); + pc = abs(p - c); + + if (pa <= pb && pa <= pc) + p = a; + else if (pb <= pc) + p = b; + else + p = c; + + *rp = (png_byte)(((int)(*rp) + p) & 0xff); + } + break; + } + default: + png_error(png_ptr, "Bad adaptive filter type"); + break; + } +} + +void +png_read_finish_row(png_structp png_ptr) +{ + png_debug(1, "in png_read_finish_row\n"); + png_ptr->row_number++; + if (png_ptr->row_number < png_ptr->num_rows) + return; + + if (png_ptr->interlaced) + { + png_ptr->row_number = 0; + png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + do + { + png_ptr->pass++; + if (png_ptr->pass >= 7) + break; + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + png_ptr->irowbytes = ((png_ptr->iwidth * + (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; + + if (!(png_ptr->transformations & PNG_INTERLACE)) + { + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + if (!(png_ptr->num_rows)) + continue; + } + if (png_ptr->transformations & PNG_INTERLACE) + break; + } while (png_ptr->iwidth == 0); + + if (png_ptr->pass < 7) + return; + } + + if (!(png_ptr->flags & PNG_FLAG_ZLIB_FINISHED)) + { + char extra; + int ret; + + png_ptr->zstream.next_out = (Byte *)&extra; + png_ptr->zstream.avail_out = (uInt)1; + for(;;) + { + if (!(png_ptr->zstream.avail_in)) + { + while (!png_ptr->idat_size) + { + png_byte chunk_length[4]; + + png_crc_finish(png_ptr, 0); + + png_read_data(png_ptr, chunk_length, 4); + png_ptr->idat_size = png_get_uint_32(chunk_length); + + png_reset_crc(png_ptr); + png_crc_read(png_ptr, png_ptr->chunk_name, 4); + if (png_memcmp(png_ptr->chunk_name, png_IDAT, 4)) + png_error(png_ptr, "Not enough image data"); + + } + png_ptr->zstream.avail_in = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_in = png_ptr->zbuf; + if (png_ptr->zbuf_size > png_ptr->idat_size) + png_ptr->zstream.avail_in = (uInt)png_ptr->idat_size; + png_crc_read(png_ptr, png_ptr->zbuf, png_ptr->zstream.avail_in); + png_ptr->idat_size -= png_ptr->zstream.avail_in; + } + ret = inflate(&png_ptr->zstream, Z_PARTIAL_FLUSH); + if (ret == Z_STREAM_END) + { + if (!(png_ptr->zstream.avail_out) || png_ptr->zstream.avail_in || + png_ptr->idat_size) + png_error(png_ptr, "Extra compressed data"); + png_ptr->mode |= PNG_AFTER_IDAT; + png_ptr->flags |= PNG_FLAG_ZLIB_FINISHED; + break; + } + if (ret != Z_OK) + png_error(png_ptr, png_ptr->zstream.msg ? png_ptr->zstream.msg : + "Decompression Error"); + + if (!(png_ptr->zstream.avail_out)) + png_error(png_ptr, "Extra compressed data"); + + } + png_ptr->zstream.avail_out = 0; + } + + if (png_ptr->idat_size || png_ptr->zstream.avail_in) + png_error(png_ptr, "Extra compression data"); + + inflateReset(&png_ptr->zstream); + + png_ptr->mode |= PNG_AFTER_IDAT; +} + +void +png_read_start_row(png_structp png_ptr) +{ + int max_pixel_depth; + png_uint_32 rowbytes; + + png_debug(1, "in png_read_start_row\n"); + png_ptr->zstream.avail_in = 0; + png_init_read_transformations(png_ptr); + if (png_ptr->interlaced) + { + if (!(png_ptr->transformations & PNG_INTERLACE)) + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + else + png_ptr->num_rows = png_ptr->height; + + png_ptr->iwidth = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + + rowbytes = ((png_ptr->iwidth * + (png_uint_32)png_ptr->pixel_depth + 7) >> 3) +1; + png_ptr->irowbytes = (png_size_t)rowbytes; + if((png_uint_32)png_ptr->irowbytes != rowbytes) + png_error(png_ptr, "Rowbytes overflow in png_read_start_row"); + } + else + { + png_ptr->num_rows = png_ptr->height; + png_ptr->iwidth = png_ptr->width; + png_ptr->irowbytes = png_ptr->rowbytes + 1; + } + max_pixel_depth = png_ptr->pixel_depth; + +#if defined(PNG_READ_PACK_SUPPORTED) + if ((png_ptr->transformations & PNG_PACK) && png_ptr->bit_depth < 8) + max_pixel_depth = 8; +#endif + +#if defined(PNG_READ_EXPAND_SUPPORTED) + if (png_ptr->transformations & PNG_EXPAND) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + if (png_ptr->num_trans) + max_pixel_depth = 32; + else + max_pixel_depth = 24; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_GRAY) + { + if (max_pixel_depth < 8) + max_pixel_depth = 8; + if (png_ptr->num_trans) + max_pixel_depth *= 2; + } + else if (png_ptr->color_type == PNG_COLOR_TYPE_RGB) + { + if (png_ptr->num_trans) + { + max_pixel_depth *= 4; + max_pixel_depth /= 3; + } + } + } +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) + if (png_ptr->transformations & (PNG_FILLER)) + { + if (max_pixel_depth < 32) + max_pixel_depth = 32; + } +#endif + +#if defined(PNG_READ_GRAY_TO_RGB_SUPPORTED) + if (png_ptr->transformations & PNG_GRAY_TO_RGB) + { + if ((png_ptr->num_trans && (png_ptr->transformations & PNG_EXPAND)) || + png_ptr->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + if (max_pixel_depth <= 16) + max_pixel_depth = 32; + else if (max_pixel_depth <= 32) + max_pixel_depth = 64; + } + else + { + if (max_pixel_depth <= 8) + max_pixel_depth = 24; + else if (max_pixel_depth <= 16) + max_pixel_depth = 48; + } + } +#endif + + /* align the width on the next larger 8 pixels. Mainly used + for interlacing */ + rowbytes = ((png_ptr->width + 7) & ~((png_uint_32)7)); + /* calculate the maximum bytes needed, adding a byte and a pixel + for safety sake */ + rowbytes = ((rowbytes * (png_uint_32)max_pixel_depth + 7) >> 3) + + 1 + ((max_pixel_depth + 7) >> 3); +#ifdef PNG_MAX_MALLOC_64K + if (rowbytes > (png_uint_32)65536L) + png_error(png_ptr, "This image requires a row greater than 64KB"); +#endif + png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, rowbytes); + +#ifdef PNG_MAX_MALLOC_64K + if ((png_uint_32)png_ptr->rowbytes + 1 > (png_uint_32)65536L) + png_error(png_ptr, "This image requires a row greater than 64KB"); +#endif + png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)( + png_ptr->rowbytes + 1)); + + png_memset_check(png_ptr, png_ptr->prev_row, 0, png_ptr->rowbytes + 1); + + png_debug1(3, "width = %d,\n", png_ptr->width); + png_debug1(3, "height = %d,\n", png_ptr->height); + png_debug1(3, "iwidth = %d,\n", png_ptr->iwidth); + png_debug1(3, "num_rows = %d\n", png_ptr->num_rows); + png_debug1(3, "rowbytes = %d,\n", png_ptr->rowbytes); + png_debug1(3, "irowbytes = %d,\n", png_ptr->irowbytes); + + png_ptr->flags |= PNG_FLAG_ROW_INIT; +} diff --git a/thirdparty/libpng/pngset.c b/thirdparty/libpng/pngset.c new file mode 100644 index 00000000..d58f2fed --- /dev/null +++ b/thirdparty/libpng/pngset.c @@ -0,0 +1,380 @@ + +/* pngset.c - storage of image information into info struct + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * The functions here are used during reads to store data from the file + * into the info struct, and during writes to store application data + * into the info struct for writing into the file. This abstracts the + * info struct and allows us to change the structure in the future. + */ + +#define PNG_INTERNAL +#include "png.h" + +#if defined(PNG_READ_bKGD_SUPPORTED) || defined(PNG_WRITE_bKGD_SUPPORTED) +void +png_set_bKGD(png_structp png_ptr, png_infop info_ptr, png_color_16p background) +{ + png_debug1(1, "in %s storage function\n", "bKGD"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_memcpy(&(info_ptr->background), background, sizeof(png_color_16)); + info_ptr->valid |= PNG_INFO_bKGD; +} +#endif + +#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED) +void +png_set_cHRM(png_structp png_ptr, png_infop info_ptr, + double white_x, double white_y, double red_x, double red_y, + double green_x, double green_y, double blue_x, double blue_y) +{ + png_debug1(1, "in %s storage function\n", "cHRM"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_white = (float)white_x; + info_ptr->y_white = (float)white_y; + info_ptr->x_red = (float)red_x; + info_ptr->y_red = (float)red_y; + info_ptr->x_green = (float)green_x; + info_ptr->y_green = (float)green_y; + info_ptr->x_blue = (float)blue_x; + info_ptr->y_blue = (float)blue_y; + info_ptr->valid |= PNG_INFO_cHRM; +} +#endif + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) +void +png_set_gAMA(png_structp png_ptr, png_infop info_ptr, double file_gamma) +{ + png_debug1(1, "in %s storage function\n", "gAMA"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->gamma = (float)file_gamma; + info_ptr->valid |= PNG_INFO_gAMA; +} +#endif + +#if defined(PNG_READ_hIST_SUPPORTED) || defined(PNG_WRITE_hIST_SUPPORTED) +void +png_set_hIST(png_structp png_ptr, png_infop info_ptr, png_uint_16p hist) +{ + png_debug1(1, "in %s storage function\n", "hIST"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->hist = hist; + info_ptr->valid |= PNG_INFO_hIST; +} +#endif + +void +png_set_IHDR(png_structp png_ptr, png_infop info_ptr, + png_uint_32 width, png_uint_32 height, int bit_depth, + int color_type, int interlace_type, int compression_type, + int filter_type) +{ + int rowbytes_per_pixel; + png_debug1(1, "in %s storage function\n", "IHDR"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->width = width; + info_ptr->height = height; + info_ptr->bit_depth = (png_byte)bit_depth; + info_ptr->color_type =(png_byte) color_type; + info_ptr->compression_type = (png_byte)compression_type; + info_ptr->filter_type = (png_byte)filter_type; + info_ptr->interlace_type = (png_byte)interlace_type; + if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + info_ptr->channels = 1; + else if (info_ptr->color_type & PNG_COLOR_MASK_COLOR) + info_ptr->channels = 3; + else + info_ptr->channels = 1; + if (info_ptr->color_type & PNG_COLOR_MASK_ALPHA) + info_ptr->channels++; + info_ptr->pixel_depth = (png_byte)(info_ptr->channels * info_ptr->bit_depth); + + /* check for overflow */ + rowbytes_per_pixel = (info_ptr->pixel_depth + 7) >> 3; + info_ptr->rowbytes = info_ptr->width * rowbytes_per_pixel; + if (( width > (png_uint_32)2147483647L/rowbytes_per_pixel)) + { + png_warning(png_ptr, + "Width too large to process image data; rowbytes will overflow."); + info_ptr->rowbytes = (png_size_t)0; + } +} + +#if defined(PNG_READ_oFFs_SUPPORTED) || defined(PNG_WRITE_oFFs_SUPPORTED) +void +png_set_oFFs(png_structp png_ptr, png_infop info_ptr, + png_uint_32 offset_x, png_uint_32 offset_y, int unit_type) +{ + png_debug1(1, "in %s storage function\n", "oFFs"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_offset = offset_x; + info_ptr->y_offset = offset_y; + info_ptr->offset_unit_type = (png_byte)unit_type; + info_ptr->valid |= PNG_INFO_oFFs; +} +#endif + +#if defined(PNG_READ_pCAL_SUPPORTED) || defined(PNG_WRITE_pCAL_SUPPORTED) +void +png_set_pCAL(png_structp png_ptr, png_infop info_ptr, + png_charp purpose, png_int_32 X0, png_int_32 X1, int type, int nparams, + png_charp units, png_charpp params) +{ + png_uint_32 length; + int i; + + png_debug1(1, "in %s storage function\n", "pCAL"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + length = png_strlen(purpose) + 1; + png_debug1(3, "allocating purpose for info (%d bytes)\n", length); + info_ptr->pcal_purpose = (png_charp)png_malloc(png_ptr, length); + png_memcpy(info_ptr->pcal_purpose, purpose, (png_size_t)length); + + png_debug(3, "storing X0, X1, type, and nparams in info\n"); + info_ptr->pcal_X0 = X0; + info_ptr->pcal_X1 = X1; + info_ptr->pcal_type = (png_byte)type; + info_ptr->pcal_nparams = (png_byte)nparams; + + length = png_strlen(units) + 1; + png_debug1(3, "allocating units for info (%d bytes)\n", length); + info_ptr->pcal_units = (png_charp)png_malloc(png_ptr, length); + png_memcpy(info_ptr->pcal_units, units, (png_size_t)length); + + info_ptr->pcal_params = (png_charpp)png_malloc(png_ptr, + (png_uint_32)((nparams + 1) * sizeof(png_charp))); + info_ptr->pcal_params[nparams] = NULL; + + for (i = 0; i < nparams; i++) + { + length = png_strlen(params[i]) + 1; + png_debug2(3, "allocating parameter %d for info (%d bytes)\n", i, length); + info_ptr->pcal_params[i] = (png_charp)png_malloc(png_ptr, length); + png_memcpy(info_ptr->pcal_params[i], params[i], (png_size_t)length); + } + + info_ptr->valid |= PNG_INFO_pCAL; +} +#endif + +#if defined(PNG_READ_pHYs_SUPPORTED) || defined(PNG_WRITE_pHYs_SUPPORTED) +void +png_set_pHYs(png_structp png_ptr, png_infop info_ptr, + png_uint_32 res_x, png_uint_32 res_y, int unit_type) +{ + png_debug1(1, "in %s storage function\n", "pHYs"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->x_pixels_per_unit = res_x; + info_ptr->y_pixels_per_unit = res_y; + info_ptr->phys_unit_type = (png_byte)unit_type; + info_ptr->valid |= PNG_INFO_pHYs; +} +#endif + +void +png_set_PLTE(png_structp png_ptr, png_infop info_ptr, + png_colorp palette, int num_palette) +{ + png_debug1(1, "in %s storage function\n", "PLTE"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->palette = palette; + info_ptr->num_palette = (png_uint_16)num_palette; + info_ptr->valid |= PNG_INFO_PLTE; +} + +#if defined(PNG_READ_sBIT_SUPPORTED) || defined(PNG_WRITE_sBIT_SUPPORTED) +void +png_set_sBIT(png_structp png_ptr, png_infop info_ptr, + png_color_8p sig_bit) +{ + png_debug1(1, "in %s storage function\n", "sBIT"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_memcpy(&(info_ptr->sig_bit), sig_bit, sizeof (png_color_8)); + info_ptr->valid |= PNG_INFO_sBIT; +} +#endif + +#if defined(PNG_READ_sRGB_SUPPORTED) || defined(PNG_WRITE_sRGB_SUPPORTED) +void +png_set_sRGB(png_structp png_ptr, png_infop info_ptr, int intent) +{ + png_debug1(1, "in %s storage function\n", "sRGB"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + info_ptr->srgb_intent = (png_byte)intent; + info_ptr->valid |= PNG_INFO_sRGB; +} +void +png_set_sRGB_gAMA_and_cHRM(png_structp png_ptr, png_infop info_ptr, + int intent) +{ +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) + float file_gamma; +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED) + float white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; +#endif + png_debug1(1, "in %s storage function\n", "sRGB_gAMA_and_cHRM"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_set_sRGB(png_ptr, info_ptr, intent); + +#if defined(PNG_READ_gAMA_SUPPORTED) || defined(PNG_WRITE_gAMA_SUPPORTED) + file_gamma = (float).45; + png_set_gAMA(png_ptr, info_ptr, file_gamma); +#endif + +#if defined(PNG_READ_cHRM_SUPPORTED) || defined(PNG_WRITE_cHRM_SUPPORTED) + white_x = (float).3127; + white_y = (float).3290; + red_x = (float).64; + red_y = (float).33; + green_x = (float).30; + green_y = (float).60; + blue_x = (float).15; + blue_y = (float).06; + + png_set_cHRM(png_ptr, info_ptr, + white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y); + +#endif +} +#endif + +#if defined(PNG_READ_tEXt_SUPPORTED) || defined(PNG_WRITE_tEXt_SUPPORTED) || \ + defined(PNG_READ_zTXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) +void +png_set_text(png_structp png_ptr, png_infop info_ptr, png_textp text_ptr, + int num_text) +{ + int i; + + png_debug1(1, "in %s storage function\n", (png_ptr->chunk_name[0] == '\0' ? + "text" : (png_const_charp)png_ptr->chunk_name)); + + if (png_ptr == NULL || info_ptr == NULL || num_text == 0) + return; + + /* Make sure we have enough space in the "text" array in info_struct + * to hold all of the incoming text_ptr objects. + */ + if (info_ptr->num_text + num_text > info_ptr->max_text) + { + if (info_ptr->text != NULL) + { + png_textp old_text; + int old_max; + + old_max = info_ptr->max_text; + info_ptr->max_text = info_ptr->num_text + num_text + 8; + old_text = info_ptr->text; + info_ptr->text = (png_textp)png_malloc(png_ptr, + (png_uint_32)(info_ptr->max_text * sizeof (png_text))); + png_memcpy(info_ptr->text, old_text, (png_size_t)(old_max * + sizeof(png_text))); + png_free(png_ptr, old_text); + } + else + { + info_ptr->max_text = num_text + 8; + info_ptr->num_text = 0; + info_ptr->text = (png_textp)png_malloc(png_ptr, + (png_uint_32)(info_ptr->max_text * sizeof (png_text))); + } + png_debug1(3, "allocated %d entries for info_ptr->text\n", + info_ptr->max_text); + } + + for (i = 0; i < num_text; i++) + { + png_textp textp = &(info_ptr->text[info_ptr->num_text]); + + if (text_ptr[i].text == NULL) + text_ptr[i].text = (png_charp)""; + + if (text_ptr[i].text[0] == '\0') + { + textp->text_length = 0; + textp->compression = PNG_TEXT_COMPRESSION_NONE; + } + else + { + textp->text_length = png_strlen(text_ptr[i].text); + textp->compression = text_ptr[i].compression; + } + textp->text = text_ptr[i].text; + textp->key = text_ptr[i].key; + info_ptr->num_text++; + png_debug1(3, "transferred text chunk %d\n", info_ptr->num_text); + } +} +#endif + +#if defined(PNG_READ_tIME_SUPPORTED) || defined(PNG_WRITE_tIME_SUPPORTED) +void +png_set_tIME(png_structp png_ptr, png_infop info_ptr, png_timep mod_time) +{ + png_debug1(1, "in %s storage function\n", "tIME"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + png_memcpy(&(info_ptr->mod_time), mod_time, sizeof (png_time)); + info_ptr->valid |= PNG_INFO_tIME; +} +#endif + +#if defined(PNG_READ_tRNS_SUPPORTED) || defined(PNG_WRITE_tRNS_SUPPORTED) +void +png_set_tRNS(png_structp png_ptr, png_infop info_ptr, + png_bytep trans, int num_trans, png_color_16p trans_values) +{ + png_debug1(1, "in %s storage function\n", "tRNS"); + if (png_ptr == NULL || info_ptr == NULL) + return; + + if (trans != NULL) + { + info_ptr->trans = trans; + } + + if (trans_values != NULL) + { + png_memcpy(&(info_ptr->trans_values), trans_values, + sizeof(png_color_16)); + if (num_trans == 0) + num_trans = 1; + } + info_ptr->num_trans = (png_uint_16)num_trans; + info_ptr->valid |= PNG_INFO_tRNS; +} +#endif + diff --git a/thirdparty/libpng/pngtest.c b/thirdparty/libpng/pngtest.c new file mode 100644 index 00000000..76df2daa --- /dev/null +++ b/thirdparty/libpng/pngtest.c @@ -0,0 +1,1036 @@ + +/* pngtest.c - a simple test program to test libpng + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * This program reads in a PNG image, writes it out again, and then + * compares the two files. If the files are identical, this shows that + * the basic chunk handling, filtering, and (de)compression code is working + * properly. It does not currently test all of the transforms, although + * it probably should. + * + * The program will fail in certain legitimate cases: + * 1) when the compression level or filter selection method is changed. + * 2) when the chunk size is smaller than 8K. + * 3) unknown ancillary chunks exist in the input file. + * 4) others not listed here... + * In these cases, it is best to check with another tool such as "pngcheck" + * to see what the differences between the two images are. + * + * If a filename is given on the command-line, then this file is used + * for the input, rather than the default "pngtest.png". This allows + * testing a wide variety of files easily. + */ + +#include +#include + +/* Makes pngtest verbose so we can find problems (needs to be before png.h) */ +#ifndef PNG_DEBUG +#define PNG_DEBUG 0 +#endif + +#include "png.h" + +int test_one_file PNGARG((PNG_CONST char *inname, PNG_CONST char *outname)); + +#ifdef __TURBOC__ +#include +#endif + +/* defined so I can write to a file on gui/windowing platforms */ +/* #define STDERR stderr */ +#define STDERR stdout /* for DOS */ + +/* example of using row callbacks to make a simple progress meter */ +static int status_pass=1; +static int status_dots_requested=0; +static int status_dots=1; + +void +read_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass) +{ + if(png_ptr == NULL || row_number > 0x3fffffffL) return; + if(status_pass != pass) + { + fprintf(stdout,"\n Pass %d: ",pass); + status_pass = pass; + status_dots = 30; + } + status_dots--; + if(status_dots == 0) + { + fprintf(stdout, "\n "); + status_dots=30; + } + fprintf(stdout, "r"); +} + +void +write_row_callback(png_structp png_ptr, png_uint_32 row_number, int pass) +{ + if(png_ptr == NULL || row_number > 0x3fffffffL || pass > 7) return; + fprintf(stdout, "w"); +} + + +#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +/* example of using user transform callback (we don't transform anything, + but merely count the black pixels) */ + +static png_uint_32 black_pixels; + +void +count_black_pixels(png_structp png_ptr, png_row_infop row_info, png_bytep data) +{ + png_bytep dp = data; + if(png_ptr == NULL)return; + + /* contents of row_info: + * png_uint_32 width width of row + * png_uint_32 rowbytes number of bytes in row + * png_byte color_type color type of pixels + * png_byte bit_depth bit depth of samples + * png_byte channels number of channels (1-4) + * png_byte pixel_depth bits per pixel (depth*channels) + */ + + /* counts the number of black pixels (or zero pixels if color_type is 3 */ + + if(row_info->color_type == 0 || row_info->color_type == 3) + { + int pos=0; + png_uint_32 n; + for (n=0; nwidth; n++) + { + if(row_info->bit_depth == 1) + if(((*dp << pos++ )& 0x80) == 0) black_pixels++; + if(pos == 8) + { + pos=0; + dp++; + } + if(row_info->bit_depth == 2) + if(((*dp << (pos+=2))& 0xc0) == 0) black_pixels++; + if(pos == 8) + { + pos=0; + dp++; + } + if(row_info->bit_depth == 4) + if(((*dp << (pos+=4))& 0xf0) == 0) black_pixels++; + if(pos == 8) + { + pos=0; + dp++; + } + if(row_info->bit_depth == 8) + if(*dp++ == 0) black_pixels++; + if(row_info->bit_depth == 16) + { + if((*dp | *(dp+1)) == 0) black_pixels++; + dp+=2; + } + } + } + else /* other color types */ + { + png_uint_32 n; + int channel; + int color_channels = row_info->channels; + if(row_info->color_type > 3)color_channels--; + + for (n=0; nwidth; n++) + { + for (channel = 0; channel < color_channels; channel++) + { + if(row_info->bit_depth == 8) + if(*dp++ == 0) black_pixels++; + if(row_info->bit_depth == 16) + { + if((*dp | *(dp+1)) == 0) black_pixels++; + dp+=2; + } + } + if(row_info->color_type > 3) + { + dp++; + if(row_info->bit_depth == 16)dp++; + } + } + } +} +#endif /* PNG_WRITE_USER_TRANSFORM_SUPPORTED */ + +static int verbose = 0; +static int wrote_question = 0; + +#if defined(PNG_NO_STDIO) +/* START of code to validate stdio-free compilation */ +/* These copies of the default read/write functions come from pngrio.c and */ +/* pngwio.c. They allow "don't include stdio" testing of the library. */ +/* This is the function which does the actual reading of data. If you are + not reading from a standard C stream, you should create a replacement + read_data function and use it at run time with png_set_read_fn(), rather + than changing the library. */ +#ifndef USE_FAR_KEYWORD +static void +png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_size_t check; + + /* fread() returns 0 on error, so it is OK to store this in a png_size_t + * instead of an int, which is what fread() actually returns. + */ + check = (png_size_t)fread(data, (png_size_t)1, length, + (FILE *)png_ptr->io_ptr); + + if (check != length) + { + png_error(png_ptr, "Read Error"); + } +} +#else +/* this is the model-independent version. Since the standard I/O library + can't handle far buffers in the medium and small models, we have to copy + the data. +*/ + +#define NEAR_BUF_SIZE 1024 +#define MIN(a,b) (a <= b ? a : b) + +static void +png_default_read_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + int check; + png_byte *n_data; + FILE *io_ptr; + + /* Check if data really is near. If so, use usual code. */ + n_data = (png_byte *)CVT_PTR_NOCHECK(data); + io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr); + if ((png_bytep)n_data == data) + { + check = fread(n_data, 1, length, io_ptr); + } + else + { + png_byte buf[NEAR_BUF_SIZE]; + png_size_t read, remaining, err; + check = 0; + remaining = length; + do + { + read = MIN(NEAR_BUF_SIZE, remaining); + err = fread(buf, (png_size_t)1, read, io_ptr); + png_memcpy(data, buf, read); /* copy far buffer to near buffer */ + if(err != read) + break; + else + check += err; + data += read; + remaining -= read; + } + while (remaining != 0); + } + if (check != length) + { + png_error(png_ptr, "read Error"); + } +} +#endif /* USE_FAR_KEYWORD */ + +#if defined(PNG_WRITE_FLUSH_SUPPORTED) +static void +png_default_flush(png_structp png_ptr) +{ + FILE *io_ptr; + io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr)); + if (io_ptr != NULL) + fflush(io_ptr); +} +#endif + +/* This is the function which does the actual writing of data. If you are + not writing to a standard C stream, you should create a replacement + write_data function and use it at run time with png_set_write_fn(), rather + than changing the library. */ +#ifndef USE_FAR_KEYWORD +static void +png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_uint_32 check; + + check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr)); + if (check != length) + { + png_error(png_ptr, "Write Error"); + } +} +#else +/* this is the model-independent version. Since the standard I/O library + can't handle far buffers in the medium and small models, we have to copy + the data. +*/ + +#define NEAR_BUF_SIZE 1024 +#define MIN(a,b) (a <= b ? a : b) + +static void +png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_uint_32 check; + png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */ + FILE *io_ptr; + + /* Check if data really is near. If so, use usual code. */ + near_data = (png_byte *)CVT_PTR_NOCHECK(data); + io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr); + if ((png_bytep)near_data == data) + { + check = fwrite(near_data, 1, length, io_ptr); + } + else + { + png_byte buf[NEAR_BUF_SIZE]; + png_size_t written, remaining, err; + check = 0; + remaining = length; + do + { + written = MIN(NEAR_BUF_SIZE, remaining); + png_memcpy(buf, data, written); /* copy far buffer to near buffer */ + err = fwrite(buf, 1, written, io_ptr); + if (err != written) + break; + else + check += err; + data += written; + remaining -= written; + } + while (remaining != 0); + } + if (check != length) + { + png_error(png_ptr, "Write Error"); + } +} + +#endif /* USE_FAR_KEYWORD */ + +/* This function is called when there is a warning, but the library thinks + * it can continue anyway. Replacement functions don't have to do anything + * here if you don't want to. In the default configuration, png_ptr is + * not used, but it is passed in case it may be useful. + */ +static void +png_default_warning(png_structp png_ptr, png_const_charp message) +{ + PNG_CONST char *name = "UNKNOWN (ERROR!)"; + if (png_ptr != NULL && png_ptr->error_ptr != NULL) + name = png_ptr->error_ptr; + fprintf(STDERR, "%s: libpng warning: %s\n", name, message); +} + +/* This is the default error handling function. Note that replacements for + * this function MUST NOT RETURN, or the program will likely crash. This + * function is used by default, or if the program supplies NULL for the + * error function pointer in png_set_error_fn(). + */ +static void +png_default_error(png_structp png_ptr, png_const_charp message) +{ + png_default_warning(png_ptr, message); + /* We can return because png_error calls the default handler which is + * actually ok in this case. */ +} +#endif /* PNG_NO_STDIO */ +/* END of code to validate stdio-free compilation */ + +/* START of code to validate memory allocation and deallocation */ +#ifdef PNGTEST_MEMORY_DEBUG +/* Borland DOS special memory handler */ +#if defined(__TURBOC__) && !defined(_Windows) && !defined(__FLAT__) +ERROR - memory debugging is not supported on this platform +#else + +/* Allocate memory. For reasonable files, size should never exceed + 64K. However, zlib may allocate more then 64K if you don't tell + it not to. See zconf.h and png.h for more information. zlib does + need to allocate exactly 64K, so whatever you call here must + have the ability to do that. + + This piece of code can be compiled to validate max 64K allocations + by setting MAXSEG_64K in zlib zconf.h *or* PNG_MAX_MALLOC_64K. */ +typedef struct memory_information { + png_uint_32 size; + png_voidp pointer; + struct memory_information FAR *next; +} memory_information; +typedef memory_information FAR *memory_infop; + +static memory_infop pinformation = NULL; +static int current_allocation = 0; +static int maximum_allocation = 0; + +extern PNG_EXPORT(png_voidp,png_debug_malloc) PNGARG((png_structp png_ptr, + png_uint_32 size)); +extern PNG_EXPORT(void,png_debug_free) PNGARG((png_structp png_ptr, + png_voidp ptr)); + +png_voidp +png_malloc(png_structp png_ptr, png_uint_32 size) { + if (png_ptr == NULL) { + fprintf(STDERR, "NULL pointer to memory allocator\n"); + return (NULL); + } + if (size == 0) + return (png_voidp)(NULL); + + /* This calls the library allocator twice, once to get the requested + buffer and once to get a new free list entry. */ + { + memory_infop pinfo = png_debug_malloc(png_ptr, sizeof *pinfo); + pinfo->size = size; + current_allocation += size; + if (current_allocation > maximum_allocation) + maximum_allocation = current_allocation; + pinfo->pointer = png_debug_malloc(png_ptr, size); + pinfo->next = pinformation; + pinformation = pinfo; + /* Make sure the caller isn't assuming zeroed memory. */ + png_memset(pinfo->pointer, 0xdd, pinfo->size); + return (png_voidp)(pinfo->pointer); + } +} + +/* Free a pointer. It is removed from the list at the same time. */ +void +png_free(png_structp png_ptr, png_voidp ptr) +{ + if (png_ptr == NULL) + fprintf(STDERR, "NULL pointer to memory allocator\n"); + if (ptr == 0) { +#if 0 /* This happens all the time. */ + fprintf(STDERR, "WARNING: freeing NULL pointer\n"); +#endif + return; + } + + /* Unlink the element from the list. */ + { + memory_infop FAR *ppinfo = &pinformation; + for (;;) { + memory_infop pinfo = *ppinfo; + if (pinfo->pointer == ptr) { + *ppinfo = pinfo->next; + current_allocation -= pinfo->size; + if (current_allocation < 0) + fprintf(STDERR, "Duplicate free of memory\n"); + /* We must free the list element too, but first kill + the memory which is to be freed. */ + memset(ptr, 0x55, pinfo->size); + png_debug_free(png_ptr, pinfo); + break; + } + if (pinfo->next == NULL) { + fprintf(STDERR, "Pointer %x not found\n", ptr); + break; + } + ppinfo = &pinfo->next; + } + } + + /* Finally free the data. */ + png_debug_free(png_ptr, ptr); +} +#endif /* Not Borland DOS special memory handler */ +#endif +/* END of code to test memory allocation/deallocation */ + +/* Test one file */ +int +test_one_file(PNG_CONST char *inname, PNG_CONST char *outname) +{ + static FILE *fpin, *fpout; /* "static" prevents setjmp corruption */ + png_structp read_ptr, write_ptr; + png_infop read_info_ptr, write_info_ptr, end_info_ptr; + png_bytep row_buf; + png_uint_32 y; + png_uint_32 width, height; + int num_pass, pass; + int bit_depth, color_type; +#ifdef USE_FAR_KEYWORD + jmp_buf jmpbuf; +#endif + + char inbuf[256], outbuf[256]; + + row_buf = (png_bytep)NULL; + + if ((fpin = fopen(inname, "rb")) == NULL) + { + fprintf(STDERR, "Could not find input file %s\n", inname); + return (1); + } + + if ((fpout = fopen(outname, "wb")) == NULL) + { + fprintf(STDERR, "Could not open output file %s\n", outname); + fclose(fpin); + return (1); + } + + png_debug(0, "Allocating read and write structures\n"); + read_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, + (png_error_ptr)NULL, (png_error_ptr)NULL); +#if defined(PNG_NO_STDIO) + png_set_error_fn(read_ptr, (png_voidp)inname, png_default_error, + png_default_warning); +#endif + write_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, (png_voidp)NULL, + (png_error_ptr)NULL, (png_error_ptr)NULL); +#if defined(PNG_NO_STDIO) + png_set_error_fn(write_ptr, (png_voidp)inname, png_default_error, + png_default_warning); +#endif + png_debug(0, "Allocating read_info, write_info and end_info structures\n"); + read_info_ptr = png_create_info_struct(read_ptr); + write_info_ptr = png_create_info_struct(write_ptr); + end_info_ptr = png_create_info_struct(read_ptr); + + png_debug(0, "Setting jmpbuf for read struct\n"); +#ifdef USE_FAR_KEYWORD + if (setjmp(jmpbuf)) +#else + if (setjmp(read_ptr->jmpbuf)) +#endif + { + fprintf(STDERR, "%s -> %s: libpng read error\n", inname, outname); + png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); + png_destroy_write_struct(&write_ptr, &write_info_ptr); + fclose(fpin); + fclose(fpout); + return (1); + } + + png_debug(0, "Setting jmpbuf for write struct\n"); +#ifdef USE_FAR_KEYWORD + png_memcpy(read_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf)); + if (setjmp(jmpbuf)) +#else + if (setjmp(write_ptr->jmpbuf)) +#endif + { + fprintf(STDERR, "%s -> %s: libpng write error\n", inname, outname); + png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); + png_destroy_write_struct(&write_ptr, &write_info_ptr); + fclose(fpin); + fclose(fpout); + return (1); + } + +#ifdef USE_FAR_KEYWORD + png_memcpy(write_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf)); +#endif + png_debug(0, "Initializing input and output streams\n"); +#if !defined(PNG_NO_STDIO) + png_init_io(read_ptr, fpin); + png_init_io(write_ptr, fpout); +#else + png_set_read_fn(read_ptr, (png_voidp)fpin, png_default_read_data); + png_set_write_fn(write_ptr, (png_voidp)fpout, png_default_write_data, +#if defined(PNG_WRITE_FLUSH_SUPPORTED) + png_default_flush); +#else + NULL); +#endif +#endif + if(status_dots_requested == 1) + { + png_set_write_status_fn(write_ptr, write_row_callback); + png_set_read_status_fn(read_ptr, read_row_callback); + } + else + { + png_set_write_status_fn(write_ptr, NULL); + png_set_read_status_fn(read_ptr, NULL); + } + +# if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) + black_pixels=0; + png_set_write_user_transform_fn(write_ptr, count_black_pixels); +# endif + + png_debug(0, "Reading info struct\n"); + png_read_info(read_ptr, read_info_ptr); + + png_debug(0, "Transferring info struct\n"); + { + int interlace_type, compression_type, filter_type; + + if (png_get_IHDR(read_ptr, read_info_ptr, &width, &height, &bit_depth, + &color_type, &interlace_type, &compression_type, &filter_type)) + { + png_set_IHDR(write_ptr, write_info_ptr, width, height, bit_depth, +#if defined(PNG_WRITE_INTERLACING_SUPPORTED) + color_type, interlace_type, compression_type, filter_type); +#else + color_type, PNG_INTERLACE_NONE, compression_type, filter_type); +#endif + } + } +#if defined(PNG_READ_bKGD_SUPPORTED) && defined(PNG_WRITE_bKGD_SUPPORTED) + { + png_color_16p background; + + if (png_get_bKGD(read_ptr, read_info_ptr, &background)) + { + png_set_bKGD(write_ptr, write_info_ptr, background); + } + } +#endif +#if defined(PNG_READ_cHRM_SUPPORTED) && defined(PNG_WRITE_cHRM_SUPPORTED) + { + double white_x, white_y, red_x, red_y, green_x, green_y, blue_x, blue_y; + + if (png_get_cHRM(read_ptr, read_info_ptr, &white_x, &white_y, &red_x, + &red_y, &green_x, &green_y, &blue_x, &blue_y)) + { + png_set_cHRM(write_ptr, write_info_ptr, white_x, white_y, red_x, + red_y, green_x, green_y, blue_x, blue_y); + } + } +#endif +#if defined(PNG_READ_gAMA_SUPPORTED) && defined(PNG_WRITE_gAMA_SUPPORTED) + { + double gamma; + + if (png_get_gAMA(read_ptr, read_info_ptr, &gamma)) + { + png_set_gAMA(write_ptr, write_info_ptr, gamma); + } + } +#endif +#if defined(PNG_READ_sRGB_SUPPORTED) && defined(PNG_WRITE_sRGB_SUPPORTED) + { + int intent; + + if (png_get_sRGB(read_ptr, read_info_ptr, &intent)) + { + png_set_sRGB(write_ptr, write_info_ptr, intent); + } + } +#endif +#if defined(PNG_READ_hIST_SUPPORTED) && defined(PNG_WRITE_hIST_SUPPORTED) + { + png_uint_16p hist; + + if (png_get_hIST(read_ptr, read_info_ptr, &hist)) + { + png_set_hIST(write_ptr, write_info_ptr, hist); + } + } +#endif +#if defined(PNG_READ_oFFs_SUPPORTED) && defined(PNG_WRITE_oFFs_SUPPORTED) + { + png_uint_32 offset_x, offset_y; + int unit_type; + + if (png_get_oFFs(read_ptr, read_info_ptr,&offset_x,&offset_y,&unit_type)) + { + png_set_oFFs(write_ptr, write_info_ptr, offset_x, offset_y, unit_type); + } + } +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) && defined(PNG_WRITE_pCAL_SUPPORTED) + { + png_charp purpose, units; + png_charpp params; + png_int_32 X0, X1; + int type, nparams; + + if (png_get_pCAL(read_ptr, read_info_ptr, &purpose, &X0, &X1, &type, + &nparams, &units, ¶ms)) + { + png_set_pCAL(write_ptr, write_info_ptr, purpose, X0, X1, type, + nparams, units, params); + } + } +#endif +#if defined(PNG_READ_pHYs_SUPPORTED) && defined(PNG_WRITE_pHYs_SUPPORTED) + { + png_uint_32 res_x, res_y; + int unit_type; + + if (png_get_pHYs(read_ptr, read_info_ptr, &res_x, &res_y, &unit_type)) + { + png_set_pHYs(write_ptr, write_info_ptr, res_x, res_y, unit_type); + } + } +#endif + { + png_colorp palette; + int num_palette; + + if (png_get_PLTE(read_ptr, read_info_ptr, &palette, &num_palette)) + { + png_set_PLTE(write_ptr, write_info_ptr, palette, num_palette); + } + } +#if defined(PNG_READ_sBIT_SUPPORTED) && defined(PNG_WRITE_sBIT_SUPPORTED) + { + png_color_8p sig_bit; + + if (png_get_sBIT(read_ptr, read_info_ptr, &sig_bit)) + { + png_set_sBIT(write_ptr, write_info_ptr, sig_bit); + } + } +#endif +#if (defined(PNG_READ_tEXt_SUPPORTED) && defined(PNG_WRITE_tEXt_SUPPORTED)) || \ + (defined(PNG_READ_zTXt_SUPPORTED) && defined(PNG_WRITE_zTXt_SUPPORTED)) + { + png_textp text_ptr; + int num_text; + + if (png_get_text(read_ptr, read_info_ptr, &text_ptr, &num_text) > 0) + { + png_debug1(0, "Handling %d tEXt/zTXt chunks\n", num_text); + png_set_text(write_ptr, write_info_ptr, text_ptr, num_text); + } + } +#endif +#if defined(PNG_READ_tIME_SUPPORTED) && defined(PNG_WRITE_tIME_SUPPORTED) + { + png_timep mod_time; + + if (png_get_tIME(read_ptr, read_info_ptr, &mod_time)) + { + png_set_tIME(write_ptr, write_info_ptr, mod_time); + } + } +#endif +#if defined(PNG_READ_tRNS_SUPPORTED) && defined(PNG_WRITE_tRNS_SUPPORTED) + { + png_bytep trans; + int num_trans; + png_color_16p trans_values; + + if (png_get_tRNS(read_ptr, read_info_ptr, &trans, &num_trans, + &trans_values)) + { + png_set_tRNS(write_ptr, write_info_ptr, trans, num_trans, + trans_values); + } + } +#endif + + png_debug(0, "\nWriting info struct\n"); + png_write_info(write_ptr, write_info_ptr); + + png_debug(0, "\nAllocating row buffer \n"); + row_buf = (png_bytep)png_malloc(read_ptr, + png_get_rowbytes(read_ptr, read_info_ptr)); + if (row_buf == NULL) + { + fprintf(STDERR, "No memory to allocate row buffer\n"); + png_destroy_read_struct(&read_ptr, &read_info_ptr, (png_infopp)NULL); + png_destroy_write_struct(&write_ptr, &write_info_ptr); + fclose(fpin); + fclose(fpout); + return (1); + } + png_debug(0, "Writing row data\n"); + + num_pass = png_set_interlace_handling(read_ptr); + png_set_interlace_handling(write_ptr); + + for (pass = 0; pass < num_pass; pass++) + { + png_debug1(0, "Writing row data for pass %d\n",pass); + for (y = 0; y < height; y++) + { + png_read_rows(read_ptr, (png_bytepp)&row_buf, (png_bytepp)NULL, 1); + png_write_rows(write_ptr, (png_bytepp)&row_buf, 1); + } + } + + png_debug(0, "Reading and writing end_info data\n"); + png_read_end(read_ptr, end_info_ptr); + png_write_end(write_ptr, end_info_ptr); + +#ifdef PNG_EASY_ACCESS_SUPPORTED + if(verbose) + { + png_uint_32 iwidth, iheight; + iwidth = png_get_image_width(write_ptr, write_info_ptr); + iheight = png_get_image_height(write_ptr, write_info_ptr); + fprintf(STDERR, "Image width = %lu, height = %lu\n", + iwidth, iheight); + } +#endif + + png_debug(0, "Destroying data structs\n"); + png_free(read_ptr, row_buf); + png_destroy_read_struct(&read_ptr, &read_info_ptr, &end_info_ptr); + png_destroy_write_struct(&write_ptr, &write_info_ptr); + + fclose(fpin); + fclose(fpout); + + png_debug(0, "Opening files for comparison\n"); + if ((fpin = fopen(inname, "rb")) == NULL) + { + fprintf(STDERR, "Could not find file %s\n", inname); + return (1); + } + + if ((fpout = fopen(outname, "rb")) == NULL) + { + fprintf(STDERR, "Could not find file %s\n", outname); + fclose(fpin); + return (1); + } + + for(;;) + { + png_size_t num_in, num_out; + + num_in = fread(inbuf, 1, 1, fpin); + num_out = fread(outbuf, 1, 1, fpout); + + if (num_in != num_out) + { + fprintf(STDERR, "Files %s and %s are of a different size\n", + inname, outname); + if(wrote_question == 0) + { + fprintf(STDERR, + " Was %s written with the same chunk size (8k),",inname); + fprintf(STDERR, + " filtering\n heuristic (libpng default), compression"); + fprintf(STDERR, + " level (zlib default)\n and zlib version (%s)?\n\n", + ZLIB_VERSION); + wrote_question=1; + } + fclose(fpin); + fclose(fpout); + return (0); + } + + if (!num_in) + break; + + if (png_memcmp(inbuf, outbuf, num_in)) + { + fprintf(STDERR, "Files %s and %s are different\n", inname, outname); + if(wrote_question == 0) + { + fprintf(STDERR, + " Was %s written with the same chunk size (8k),",inname); + fprintf(STDERR, + " filtering\n heuristic (libpng default), compression"); + fprintf(STDERR, + " level (zlib default)\n and zlib version (%s)?\n\n", + ZLIB_VERSION); + wrote_question=1; + } + fclose(fpin); + fclose(fpout); + return (0); + } + } + + fclose(fpin); + fclose(fpout); + + return (0); +} + +/* input and output filenames */ +#ifdef RISCOS +PNG_CONST char *inname = "pngtest/png"; +PNG_CONST char *outname = "pngout/png"; +#else +static PNG_CONST char *inname = "pngtest.png"; +static PNG_CONST char *outname = "pngout.png"; +#endif + +int +main(int argc, char *argv[]) +{ + int multiple = 0; + int ierror = 0; + + fprintf(STDERR, "Testing libpng version %s\n", PNG_LIBPNG_VER_STRING); + fprintf(STDERR, " with zlib version %s\n", ZLIB_VERSION); + + /* Do some consistency checking on the memory allocation settings, I'm + not sure this matters, but it is nice to know, the first of these + tests should be impossible because of the way the macros are set + in pngconf.h */ +#if defined(MAXSEG_64K) && !defined(PNG_MAX_MALLOC_64K) + fprintf(STDERR, " NOTE: Zlib compiled for max 64k, libpng not\n"); +#endif + /* I think the following can happen. */ +#if !defined(MAXSEG_64K) && defined(PNG_MAX_MALLOC_64K) + fprintf(STDERR, " NOTE: libpng compiled for max 64k, zlib not\n"); +#endif + + if (strcmp(png_libpng_ver, PNG_LIBPNG_VER_STRING)) + { + fprintf(STDERR, + "Warning: versions are different between png.h and png.c\n"); + fprintf(STDERR, " png.h version: %s\n", PNG_LIBPNG_VER_STRING); + fprintf(STDERR, " png.c version: %s\n\n", png_libpng_ver); + ++ierror; + } + + if (argc > 1) + { + if (strcmp(argv[1], "-m") == 0) + { + multiple = 1; + status_dots_requested = 0; + } + else if (strcmp(argv[1], "-mv") == 0 || + strcmp(argv[1], "-vm") == 0 ) + { + multiple = 1; + verbose = 1; + status_dots_requested = 1; + } + else if (strcmp(argv[1], "-v") == 0) + { + verbose = 1; + status_dots_requested = 1; + inname = argv[2]; + } + else + { + inname = argv[1]; + status_dots_requested = 0; + } + } + + if (!multiple && argc == 3+verbose) + outname = argv[2+verbose]; + + if ((!multiple && argc > 3+verbose) || (multiple && argc < 2)) + { + fprintf(STDERR, + "usage: %s [infile.png] [outfile.png]\n\t%s -m {infile.png}\n", + argv[0], argv[0]); + fprintf(STDERR, + " reads/writes one PNG file (without -m) or multiple files (-m)\n"); + fprintf(STDERR, + " with -m %s is used as a temporary file\n", outname); + exit(1); + } + + if (multiple) + { + int i; +#ifdef PNGTEST_MEMORY_DEBUG + int allocation_now = current_allocation; +#endif + for (i=2; isize, pinfo->pointer); + pinfo = pinfo->next; + } + } +#endif + } +#ifdef PNGTEST_MEMORY_DEBUG + fprintf(STDERR, "Maximum memory allocation: %d bytes\n", + maximum_allocation); +#endif + } + else + { + int i; + for (i=0; i<3; ++i) { + int kerror; +#ifdef PNGTEST_MEMORY_DEBUG + int allocation_now = current_allocation; +#endif + if (i == 1) status_dots_requested = 1; + else if(verbose == 0)status_dots_requested = 0; + if (i == 0 || verbose == 1 || ierror != 0) + fprintf(STDERR, "Testing %s:",inname); + kerror = test_one_file(inname, outname); + if(kerror == 0) + { + if(verbose == 1 || i == 2) +#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) + fprintf(STDERR, " PASS (%lu black pixels)\n",black_pixels); +#else + fprintf(STDERR, " PASS\n"); +#endif + } + else + { + if(verbose == 0 && i != 2) + fprintf(STDERR, "Testing %s:",inname); + fprintf(STDERR, " FAIL\n"); + ierror += kerror; + } +#ifdef PNGTEST_MEMORY_DEBUG + if (allocation_now != current_allocation) + fprintf(STDERR, "MEMORY ERROR: %d bytes lost\n", + current_allocation-allocation_now); + if (current_allocation != 0) { + memory_infop pinfo = pinformation; + + fprintf(STDERR, "MEMORY ERROR: %d bytes still allocated\n", + current_allocation); + while (pinfo != NULL) { + fprintf(STDERR, " %d bytes at %x\n", pinfo->size, pinfo->pointer); + pinfo = pinfo->next; + } + } +#endif + } +#ifdef PNGTEST_MEMORY_DEBUG + fprintf(STDERR, "Maximum memory allocation: %d bytes\n", + maximum_allocation); +#endif + } + + if (ierror == 0) + fprintf(STDERR, "libpng passes test\n"); + else + fprintf(STDERR, "libpng FAILS test\n"); + return (int)(ierror != 0); +} diff --git a/thirdparty/libpng/pngtest.png b/thirdparty/libpng/pngtest.png new file mode 100644 index 00000000..f3a6df44 Binary files /dev/null and b/thirdparty/libpng/pngtest.png differ diff --git a/thirdparty/libpng/pngtrans.c b/thirdparty/libpng/pngtrans.c new file mode 100644 index 00000000..771366b7 --- /dev/null +++ b/thirdparty/libpng/pngtrans.c @@ -0,0 +1,577 @@ + +/* pngtrans.c - transforms the data in a row (used by both readers and writers) + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + */ + +#define PNG_INTERNAL +#include "png.h" + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* turn on bgr to rgb mapping */ +void +png_set_bgr(png_structp png_ptr) +{ + png_debug(1, "in png_set_bgr\n"); + png_ptr->transformations |= PNG_BGR; +} +#endif + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* turn on 16 bit byte swapping */ +void +png_set_swap(png_structp png_ptr) +{ + png_debug(1, "in png_set_swap\n"); + if (png_ptr->bit_depth == 16) + png_ptr->transformations |= PNG_SWAP_BYTES; +} +#endif + +#if defined(PNG_READ_PACK_SUPPORTED) || defined(PNG_WRITE_PACK_SUPPORTED) +/* turn on pixel packing */ +void +png_set_packing(png_structp png_ptr) +{ + png_debug(1, "in png_set_packing\n"); + if (png_ptr->bit_depth < 8) + { + png_ptr->transformations |= PNG_PACK; + png_ptr->usr_bit_depth = 8; + } +} +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) +/* turn on packed pixel swapping */ +void +png_set_packswap(png_structp png_ptr) +{ + png_debug(1, "in png_set_packswap\n"); + if (png_ptr->bit_depth < 8) + png_ptr->transformations |= PNG_PACKSWAP; +} +#endif + +#if defined(PNG_READ_SHIFT_SUPPORTED) || defined(PNG_WRITE_SHIFT_SUPPORTED) +void +png_set_shift(png_structp png_ptr, png_color_8p true_bits) +{ + png_debug(1, "in png_set_shift\n"); + png_ptr->transformations |= PNG_SHIFT; + png_ptr->shift = *true_bits; +} +#endif + +#if defined(PNG_READ_INTERLACING_SUPPORTED) || \ + defined(PNG_WRITE_INTERLACING_SUPPORTED) +int +png_set_interlace_handling(png_structp png_ptr) +{ + png_debug(1, "in png_set_interlace handling\n"); + if (png_ptr->interlaced) + { + png_ptr->transformations |= PNG_INTERLACE; + return (7); + } + + return (1); +} +#endif + +#if defined(PNG_READ_FILLER_SUPPORTED) || defined(PNG_WRITE_FILLER_SUPPORTED) +/* Add a filler byte on read, or remove a filler or alpha byte on write. + * The filler type has changed in v0.95 to allow future 2-byte fillers + * for 48-bit input data, as well as avoiding problems with some compilers + * which don't like bytes as parameters. + */ +void +png_set_filler(png_structp png_ptr, png_uint_32 filler, int filler_loc) +{ + png_debug(1, "in png_set_filler\n"); + png_ptr->transformations |= PNG_FILLER; + png_ptr->filler = (png_byte)filler; + if (filler_loc == PNG_FILLER_AFTER) + png_ptr->flags |= PNG_FLAG_FILLER_AFTER; + else + png_ptr->flags &= ~PNG_FLAG_FILLER_AFTER; + + /* This should probably go in the "do_filler" routine */ + if (png_ptr->color_type == PNG_COLOR_TYPE_RGB && png_ptr->bit_depth == 8) + { + png_ptr->usr_channels = 4; + } +} +#endif + +#if defined(PNG_READ_SWAP_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +void +png_set_swap_alpha(png_structp png_ptr) +{ + png_debug(1, "in png_set_swap_alpha\n"); + png_ptr->transformations |= PNG_SWAP_ALPHA; +} +#endif + +#if defined(PNG_READ_INVERT_ALPHA_SUPPORTED) || \ + defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +void +png_set_invert_alpha(png_structp png_ptr) +{ + png_debug(1, "in png_set_invert_alpha\n"); + png_ptr->transformations |= PNG_INVERT_ALPHA; +} +#endif + +#if defined(PNG_READ_INVERT_SUPPORTED) || defined(PNG_WRITE_INVERT_SUPPORTED) +void +png_set_invert_mono(png_structp png_ptr) +{ + png_debug(1, "in png_set_invert_mono\n"); + png_ptr->transformations |= PNG_INVERT_MONO; +} + +/* invert monocrome grayscale data */ +void +png_do_invert(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_invert\n"); + if (row_info->bit_depth == 1 && +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + row_info->color_type == PNG_COLOR_TYPE_GRAY) + { + png_bytep rp; + png_uint_32 i; + + for (i = 0, rp = row; i < row_info->rowbytes; i++, rp++) + { + *rp = (png_byte)(~(*rp)); + } + } +} +#endif + +#if defined(PNG_READ_SWAP_SUPPORTED) || defined(PNG_WRITE_SWAP_SUPPORTED) +/* swaps byte order on 16 bit depth images */ +void +png_do_swap(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_swap\n"); + if ( +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + row_info->bit_depth == 16) + { + png_bytep rp; + png_byte t; + png_uint_32 i; + + for (i = 0, rp = row; + i < row_info->width * row_info->channels; + i++, rp += 2) + { + t = *rp; + *rp = *(rp + 1); + *(rp + 1) = t; + } + } +} +#endif + +#if defined(PNG_READ_PACKSWAP_SUPPORTED)||defined(PNG_WRITE_PACKSWAP_SUPPORTED) +static png_byte onebppswaptable[256] = { + 0x00, 0x80, 0x40, 0xC0, 0x20, 0xA0, 0x60, 0xE0, + 0x10, 0x90, 0x50, 0xD0, 0x30, 0xB0, 0x70, 0xF0, + 0x08, 0x88, 0x48, 0xC8, 0x28, 0xA8, 0x68, 0xE8, + 0x18, 0x98, 0x58, 0xD8, 0x38, 0xB8, 0x78, 0xF8, + 0x04, 0x84, 0x44, 0xC4, 0x24, 0xA4, 0x64, 0xE4, + 0x14, 0x94, 0x54, 0xD4, 0x34, 0xB4, 0x74, 0xF4, + 0x0C, 0x8C, 0x4C, 0xCC, 0x2C, 0xAC, 0x6C, 0xEC, + 0x1C, 0x9C, 0x5C, 0xDC, 0x3C, 0xBC, 0x7C, 0xFC, + 0x02, 0x82, 0x42, 0xC2, 0x22, 0xA2, 0x62, 0xE2, + 0x12, 0x92, 0x52, 0xD2, 0x32, 0xB2, 0x72, 0xF2, + 0x0A, 0x8A, 0x4A, 0xCA, 0x2A, 0xAA, 0x6A, 0xEA, + 0x1A, 0x9A, 0x5A, 0xDA, 0x3A, 0xBA, 0x7A, 0xFA, + 0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, + 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6, + 0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, + 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE, + 0x01, 0x81, 0x41, 0xC1, 0x21, 0xA1, 0x61, 0xE1, + 0x11, 0x91, 0x51, 0xD1, 0x31, 0xB1, 0x71, 0xF1, + 0x09, 0x89, 0x49, 0xC9, 0x29, 0xA9, 0x69, 0xE9, + 0x19, 0x99, 0x59, 0xD9, 0x39, 0xB9, 0x79, 0xF9, + 0x05, 0x85, 0x45, 0xC5, 0x25, 0xA5, 0x65, 0xE5, + 0x15, 0x95, 0x55, 0xD5, 0x35, 0xB5, 0x75, 0xF5, + 0x0D, 0x8D, 0x4D, 0xCD, 0x2D, 0xAD, 0x6D, 0xED, + 0x1D, 0x9D, 0x5D, 0xDD, 0x3D, 0xBD, 0x7D, 0xFD, + 0x03, 0x83, 0x43, 0xC3, 0x23, 0xA3, 0x63, 0xE3, + 0x13, 0x93, 0x53, 0xD3, 0x33, 0xB3, 0x73, 0xF3, + 0x0B, 0x8B, 0x4B, 0xCB, 0x2B, 0xAB, 0x6B, 0xEB, + 0x1B, 0x9B, 0x5B, 0xDB, 0x3B, 0xBB, 0x7B, 0xFB, + 0x07, 0x87, 0x47, 0xC7, 0x27, 0xA7, 0x67, 0xE7, + 0x17, 0x97, 0x57, 0xD7, 0x37, 0xB7, 0x77, 0xF7, + 0x0F, 0x8F, 0x4F, 0xCF, 0x2F, 0xAF, 0x6F, 0xEF, + 0x1F, 0x9F, 0x5F, 0xDF, 0x3F, 0xBF, 0x7F, 0xFF +}; + +static png_byte twobppswaptable[256] = { + 0x00, 0x40, 0x80, 0xC0, 0x10, 0x50, 0x90, 0xD0, + 0x20, 0x60, 0xA0, 0xE0, 0x30, 0x70, 0xB0, 0xF0, + 0x04, 0x44, 0x84, 0xC4, 0x14, 0x54, 0x94, 0xD4, + 0x24, 0x64, 0xA4, 0xE4, 0x34, 0x74, 0xB4, 0xF4, + 0x08, 0x48, 0x88, 0xC8, 0x18, 0x58, 0x98, 0xD8, + 0x28, 0x68, 0xA8, 0xE8, 0x38, 0x78, 0xB8, 0xF8, + 0x0C, 0x4C, 0x8C, 0xCC, 0x1C, 0x5C, 0x9C, 0xDC, + 0x2C, 0x6C, 0xAC, 0xEC, 0x3C, 0x7C, 0xBC, 0xFC, + 0x01, 0x41, 0x81, 0xC1, 0x11, 0x51, 0x91, 0xD1, + 0x21, 0x61, 0xA1, 0xE1, 0x31, 0x71, 0xB1, 0xF1, + 0x05, 0x45, 0x85, 0xC5, 0x15, 0x55, 0x95, 0xD5, + 0x25, 0x65, 0xA5, 0xE5, 0x35, 0x75, 0xB5, 0xF5, + 0x09, 0x49, 0x89, 0xC9, 0x19, 0x59, 0x99, 0xD9, + 0x29, 0x69, 0xA9, 0xE9, 0x39, 0x79, 0xB9, 0xF9, + 0x0D, 0x4D, 0x8D, 0xCD, 0x1D, 0x5D, 0x9D, 0xDD, + 0x2D, 0x6D, 0xAD, 0xED, 0x3D, 0x7D, 0xBD, 0xFD, + 0x02, 0x42, 0x82, 0xC2, 0x12, 0x52, 0x92, 0xD2, + 0x22, 0x62, 0xA2, 0xE2, 0x32, 0x72, 0xB2, 0xF2, + 0x06, 0x46, 0x86, 0xC6, 0x16, 0x56, 0x96, 0xD6, + 0x26, 0x66, 0xA6, 0xE6, 0x36, 0x76, 0xB6, 0xF6, + 0x0A, 0x4A, 0x8A, 0xCA, 0x1A, 0x5A, 0x9A, 0xDA, + 0x2A, 0x6A, 0xAA, 0xEA, 0x3A, 0x7A, 0xBA, 0xFA, + 0x0E, 0x4E, 0x8E, 0xCE, 0x1E, 0x5E, 0x9E, 0xDE, + 0x2E, 0x6E, 0xAE, 0xEE, 0x3E, 0x7E, 0xBE, 0xFE, + 0x03, 0x43, 0x83, 0xC3, 0x13, 0x53, 0x93, 0xD3, + 0x23, 0x63, 0xA3, 0xE3, 0x33, 0x73, 0xB3, 0xF3, + 0x07, 0x47, 0x87, 0xC7, 0x17, 0x57, 0x97, 0xD7, + 0x27, 0x67, 0xA7, 0xE7, 0x37, 0x77, 0xB7, 0xF7, + 0x0B, 0x4B, 0x8B, 0xCB, 0x1B, 0x5B, 0x9B, 0xDB, + 0x2B, 0x6B, 0xAB, 0xEB, 0x3B, 0x7B, 0xBB, 0xFB, + 0x0F, 0x4F, 0x8F, 0xCF, 0x1F, 0x5F, 0x9F, 0xDF, + 0x2F, 0x6F, 0xAF, 0xEF, 0x3F, 0x7F, 0xBF, 0xFF +}; + +static png_byte fourbppswaptable[256] = { + 0x00, 0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, + 0x80, 0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, + 0x01, 0x11, 0x21, 0x31, 0x41, 0x51, 0x61, 0x71, + 0x81, 0x91, 0xA1, 0xB1, 0xC1, 0xD1, 0xE1, 0xF1, + 0x02, 0x12, 0x22, 0x32, 0x42, 0x52, 0x62, 0x72, + 0x82, 0x92, 0xA2, 0xB2, 0xC2, 0xD2, 0xE2, 0xF2, + 0x03, 0x13, 0x23, 0x33, 0x43, 0x53, 0x63, 0x73, + 0x83, 0x93, 0xA3, 0xB3, 0xC3, 0xD3, 0xE3, 0xF3, + 0x04, 0x14, 0x24, 0x34, 0x44, 0x54, 0x64, 0x74, + 0x84, 0x94, 0xA4, 0xB4, 0xC4, 0xD4, 0xE4, 0xF4, + 0x05, 0x15, 0x25, 0x35, 0x45, 0x55, 0x65, 0x75, + 0x85, 0x95, 0xA5, 0xB5, 0xC5, 0xD5, 0xE5, 0xF5, + 0x06, 0x16, 0x26, 0x36, 0x46, 0x56, 0x66, 0x76, + 0x86, 0x96, 0xA6, 0xB6, 0xC6, 0xD6, 0xE6, 0xF6, + 0x07, 0x17, 0x27, 0x37, 0x47, 0x57, 0x67, 0x77, + 0x87, 0x97, 0xA7, 0xB7, 0xC7, 0xD7, 0xE7, 0xF7, + 0x08, 0x18, 0x28, 0x38, 0x48, 0x58, 0x68, 0x78, + 0x88, 0x98, 0xA8, 0xB8, 0xC8, 0xD8, 0xE8, 0xF8, + 0x09, 0x19, 0x29, 0x39, 0x49, 0x59, 0x69, 0x79, + 0x89, 0x99, 0xA9, 0xB9, 0xC9, 0xD9, 0xE9, 0xF9, + 0x0A, 0x1A, 0x2A, 0x3A, 0x4A, 0x5A, 0x6A, 0x7A, + 0x8A, 0x9A, 0xAA, 0xBA, 0xCA, 0xDA, 0xEA, 0xFA, + 0x0B, 0x1B, 0x2B, 0x3B, 0x4B, 0x5B, 0x6B, 0x7B, + 0x8B, 0x9B, 0xAB, 0xBB, 0xCB, 0xDB, 0xEB, 0xFB, + 0x0C, 0x1C, 0x2C, 0x3C, 0x4C, 0x5C, 0x6C, 0x7C, + 0x8C, 0x9C, 0xAC, 0xBC, 0xCC, 0xDC, 0xEC, 0xFC, + 0x0D, 0x1D, 0x2D, 0x3D, 0x4D, 0x5D, 0x6D, 0x7D, + 0x8D, 0x9D, 0xAD, 0xBD, 0xCD, 0xDD, 0xED, 0xFD, + 0x0E, 0x1E, 0x2E, 0x3E, 0x4E, 0x5E, 0x6E, 0x7E, + 0x8E, 0x9E, 0xAE, 0xBE, 0xCE, 0xDE, 0xEE, 0xFE, + 0x0F, 0x1F, 0x2F, 0x3F, 0x4F, 0x5F, 0x6F, 0x7F, + 0x8F, 0x9F, 0xAF, 0xBF, 0xCF, 0xDF, 0xEF, 0xFF +}; + +/* swaps pixel packing order within bytes */ +void +png_do_packswap(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_packswap\n"); + if ( +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + row_info->bit_depth < 8) + { + png_bytep rp, end, table; + + end = row + row_info->rowbytes; + + if (row_info->bit_depth == 1) + table = onebppswaptable; + else if (row_info->bit_depth == 2) + table = twobppswaptable; + else if (row_info->bit_depth == 4) + table = fourbppswaptable; + else + return; + + for (rp = row; rp < end; rp++) + *rp = table[*rp]; + } +} +#endif /* PNG_READ_PACKSWAP_SUPPORTED or PNG_WRITE_PACKSWAP_SUPPORTED */ + +#if defined(PNG_WRITE_FILLER_SUPPORTED) || \ + defined(PNG_READ_STRIP_ALPHA_SUPPORTED) +/* remove filler or alpha byte(s) */ +void +png_do_strip_filler(png_row_infop row_info, png_bytep row, png_uint_32 flags) +{ + png_debug(1, "in png_do_strip_filler\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL) +#endif + { +/* + if (row_info->color_type == PNG_COLOR_TYPE_RGB || + row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) +*/ + if (row_info->channels == 4) + { + if (row_info->bit_depth == 8) + { + /* This converts from RGBX or RGBA to RGB */ + if (flags & PNG_FLAG_FILLER_AFTER) + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 1, sp = row + 4, dp = row + 3; i < row_info->width; i++) + { + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + sp++; + } + } + /* This converts from XRGB or ARGB to RGB */ + else + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = row, dp = row; i < row_info->width; i++) + { + sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + } + } + row_info->pixel_depth = 24; + row_info->rowbytes = row_info->width * 3; + } + else /* if (row_info->bit_depth == 16) */ + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + png_bytep sp, dp; + png_uint_32 i; + + /* This converts from RRGGBBXX or RRGGBBAA to RRGGBB */ + for (i = 1, sp = row + 8, dp = row + 6; i < row_info->width; i++) + { + /* This could be (although memcpy is probably slower): + png_memcpy(dp, sp, 6); + sp += 8; + dp += 6; + */ + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + sp += 2; + } + } + else + { + png_bytep sp, dp; + png_uint_32 i; + + /* This converts from XXRRGGBB or AARRGGBB to RRGGBB */ + for (i = 0, sp = row + 2, dp = row; i < row_info->width; i++) + { + /* This could be (although memcpy is probably slower): + png_memcpy(dp, sp, 6); + sp += 8; + dp += 6; + */ + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + *dp++ = *sp++; + } + } + row_info->pixel_depth = 48; + row_info->rowbytes = row_info->width * 6; + } + row_info->channels = 3; + } +/* + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY || + row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) +*/ + else if (row_info->channels == 2) + { + if (row_info->bit_depth == 8) + { + /* This converts from GX or GA to G */ + if (flags & PNG_FLAG_FILLER_AFTER) + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 1, sp = row + 2, dp = row + 1; i < row_info->width; i++) + { + *dp++ = *sp++; + sp++; + } + } + /* This converts from XG or AG to G */ + else + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = row, dp = row; i < row_info->width; i++) + { + sp++; + *dp++ = *sp++; + } + } + row_info->pixel_depth = 8; + row_info->rowbytes = row_info->width; + } + else /* if (row_info->bit_depth == 16) */ + { + if (flags & PNG_FLAG_FILLER_AFTER) + { + png_bytep sp, dp; + png_uint_32 i; + + /* This converts from GGXX or GGAA to GG */ + for (i = 1, sp = row + 4, dp = row + 2; i < row_info->width; i++) + { + *dp++ = *sp++; + *dp++ = *sp++; + sp += 2; + } + } + else + { + png_bytep sp, dp; + png_uint_32 i; + + /* This converts from XXGG or AAGG to GG */ + for (i = 0, sp = row, dp = row; i < row_info->width; i++) + { + sp += 2; + *dp++ = *sp++; + *dp++ = *sp++; + } + } + row_info->pixel_depth = 16; + row_info->rowbytes = row_info->width * 2; + } + row_info->channels = 1; + } + } +} +#endif + +#if defined(PNG_READ_BGR_SUPPORTED) || defined(PNG_WRITE_BGR_SUPPORTED) +/* swaps red and blue bytes within a pixel */ +void +png_do_bgr(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_bgr\n"); + if ( +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + (row_info->color_type & PNG_COLOR_MASK_COLOR)) + { + if (row_info->bit_depth == 8) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + png_bytep rp; + png_byte save; + png_uint_32 i; + + for (i = 0, rp = row; i < row_info->width; i++, rp += 3) + { + save = *rp; + *rp = *(rp + 2); + *(rp + 2) = save; + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + png_bytep rp; + png_byte save; + png_uint_32 i; + + for (i = 0, rp = row; i < row_info->width; i++, rp += 4) + { + save = *rp; + *rp = *(rp + 2); + *(rp + 2) = save; + } + } + } + else if (row_info->bit_depth == 16) + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB) + { + png_bytep rp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0, rp = row; i < row_info->width; i++, rp += 6) + { + save[0] = *rp; + save[1] = *(rp + 1); + *rp = *(rp + 4); + *(rp + 1) = *(rp + 5); + *(rp + 4) = save[0]; + *(rp + 5) = save[1]; + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + png_bytep rp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0, rp = row; i < row_info->width; i++, rp += 8) + { + save[0] = *rp; + save[1] = *(rp + 1); + *rp = *(rp + 4); + *(rp + 1) = *(rp + 5); + *(rp + 4) = save[0]; + *(rp + 5) = save[1]; + } + } + } + } +} +#endif /* PNG_READ_BGR_SUPPORTED or PNG_WRITE_BGR_SUPPORTED */ + diff --git a/thirdparty/libpng/pngwio.c b/thirdparty/libpng/pngwio.c new file mode 100644 index 00000000..fa5ade87 --- /dev/null +++ b/thirdparty/libpng/pngwio.c @@ -0,0 +1,207 @@ + +/* pngwio.c - functions for data output + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + * + * This file provides a location for all output. Users which need + * special handling are expected to write functions which have the same + * arguments as these, and perform similar functions, but possibly use + * different output methods. Note that you shouldn't change these + * functions, but rather write replacement functions and then change + * them at run time with png_set_write_fn(...). + */ + +#define PNG_INTERNAL +#include "png.h" + +/* Write the data to whatever output you are using. The default routine + writes to a file pointer. Note that this routine sometimes gets called + with very small lengths, so you should implement some kind of simple + buffering if you are using unbuffered writes. This should never be asked + to write more then 64K on a 16 bit machine. */ + +void +png_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + if (png_ptr->write_data_fn != NULL ) + (*(png_ptr->write_data_fn))(png_ptr, data, length); + else + png_error(png_ptr, "Call to NULL write function"); +} + +#if !defined(PNG_NO_STDIO) +/* This is the function which does the actual writing of data. If you are + not writing to a standard C stream, you should create a replacement + write_data function and use it at run time with png_set_write_fn(), rather + than changing the library. */ +#ifndef USE_FAR_KEYWORD +static void +png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_uint_32 check; + + check = fwrite(data, 1, length, (FILE *)(png_ptr->io_ptr)); + if (check != length) + { + png_error(png_ptr, "Write Error"); + } +} +#else +/* this is the model-independent version. Since the standard I/O library + can't handle far buffers in the medium and small models, we have to copy + the data. +*/ + +#define NEAR_BUF_SIZE 1024 +#define MIN(a,b) (a <= b ? a : b) + +static void +png_default_write_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_uint_32 check; + png_byte *near_data; /* Needs to be "png_byte *" instead of "png_bytep" */ + FILE *io_ptr; + + /* Check if data really is near. If so, use usual code. */ + near_data = (png_byte *)CVT_PTR_NOCHECK(data); + io_ptr = (FILE *)CVT_PTR(png_ptr->io_ptr); + if ((png_bytep)near_data == data) + { + check = fwrite(near_data, 1, length, io_ptr); + } + else + { + png_byte buf[NEAR_BUF_SIZE]; + png_size_t written, remaining, err; + check = 0; + remaining = length; + do + { + written = MIN(NEAR_BUF_SIZE, remaining); + png_memcpy(buf, data, written); /* copy far buffer to near buffer */ + err = fwrite(buf, 1, written, io_ptr); + if (err != written) + break; + else + check += err; + data += written; + remaining -= written; + } + while (remaining != 0); + } + if (check != length) + { + png_error(png_ptr, "Write Error"); + } +} + +#endif +#endif + +/* This function is called to output any data pending writing (normally + to disk). After png_flush is called, there should be no data pending + writing in any buffers. */ +#if defined(PNG_WRITE_FLUSH_SUPPORTED) +void +png_flush(png_structp png_ptr) +{ + if (png_ptr->output_flush_fn != NULL) + (*(png_ptr->output_flush_fn))(png_ptr); +} + +#if !defined(PNG_NO_STDIO) +static void +png_default_flush(png_structp png_ptr) +{ + FILE *io_ptr; + io_ptr = (FILE *)CVT_PTR((png_ptr->io_ptr)); + if (io_ptr != NULL) + fflush(io_ptr); +} +#endif +#endif + +/* This function allows the application to supply new output functions for + libpng if standard C streams aren't being used. + + This function takes as its arguments: + png_ptr - pointer to a png output data structure + io_ptr - pointer to user supplied structure containing info about + the output functions. May be NULL. + write_data_fn - pointer to a new output function which takes as its + arguments a pointer to a png_struct, a pointer to + data to be written, and a 32-bit unsigned int which is + the number of bytes to be written. The new write + function should call png_error(png_ptr, "Error msg") + to exit and output any fatal error messages. + flush_data_fn - pointer to a new flush function which takes as its + arguments a pointer to a png_struct. After a call to + the flush function, there should be no data in any buffers + or pending transmission. If the output method doesn't do + any buffering of ouput, a function prototype must still be + supplied although it doesn't have to do anything. If + PNG_WRITE_FLUSH_SUPPORTED is not defined at libpng compile + time, output_flush_fn will be ignored, although it must be + supplied for compatibility. */ +void +png_set_write_fn(png_structp png_ptr, png_voidp io_ptr, + png_rw_ptr write_data_fn, png_flush_ptr output_flush_fn) +{ + png_ptr->io_ptr = io_ptr; + +#if !defined(PNG_NO_STDIO) + if (write_data_fn != NULL) + png_ptr->write_data_fn = write_data_fn; + else + png_ptr->write_data_fn = png_default_write_data; +#else + png_ptr->write_data_fn = write_data_fn; +#endif + +#if defined(PNG_WRITE_FLUSH_SUPPORTED) +#if !defined(PNG_NO_STDIO) + if (output_flush_fn != NULL) + png_ptr->output_flush_fn = output_flush_fn; + else + png_ptr->output_flush_fn = png_default_flush; +#else + png_ptr->output_flush_fn = output_flush_fn; +#endif +#endif /* PNG_WRITE_FLUSH_SUPPORTED */ + + /* It is an error to read while writing a png file */ + png_ptr->read_data_fn = NULL; +} + +#if defined(USE_FAR_KEYWORD) +#if defined(_MSC_VER) +void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check) +{ + void *near_ptr; + void FAR *far_ptr; + FP_OFF(near_ptr) = FP_OFF(ptr); + far_ptr = (void FAR *)near_ptr; + if(check != 0) + if(FP_SEG(ptr) != FP_SEG(far_ptr)) + png_error(png_ptr,"segment lost in conversion"); + return(near_ptr); +} +# else +void *png_far_to_near(png_structp png_ptr,png_voidp ptr, int check) +{ + void *near_ptr; + void FAR *far_ptr; + near_ptr = (void FAR *)ptr; + far_ptr = (void FAR *)near_ptr; + if(check != 0) + if(far_ptr != ptr) + png_error(png_ptr,"segment lost in conversion"); + return(near_ptr); +} +# endif +# endif diff --git a/thirdparty/libpng/pngwrite.c b/thirdparty/libpng/pngwrite.c new file mode 100644 index 00000000..9d3fdc3a --- /dev/null +++ b/thirdparty/libpng/pngwrite.c @@ -0,0 +1,970 @@ + +/* pngwrite.c - general routines to write a PNG file + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + */ + +/* get internal access to png.h */ +#define PNG_INTERNAL +#include "png.h" + +/* Writes all the PNG information. This is the suggested way to use the + * library. If you have a new chunk to add, make a function to write it, + * and put it in the correct location here. If you want the chunk written + * after the image data, put it in png_write_end(). I strongly encurage + * you to supply a PNG_INFO_ flag, and check info_ptr->valid before writing + * the chunk, as that will keep the code from breaking if you want to just + * write a plain PNG file. If you have long comments, I suggest writing + * them in png_write_end(), and compressing them. + */ +void +png_write_info(png_structp png_ptr, png_infop info_ptr) +{ +#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) + int i; +#endif + + png_debug(1, "in png_write_info\n"); + png_write_sig(png_ptr); /* write PNG signature */ + /* write IHDR information. */ + png_write_IHDR(png_ptr, info_ptr->width, info_ptr->height, + info_ptr->bit_depth, info_ptr->color_type, info_ptr->compression_type, + info_ptr->filter_type, +#if defined(PNG_WRITE_INTERLACING_SUPPORTED) + info_ptr->interlace_type); +#else + 0); +#endif + /* the rest of these check to see if the valid field has the appropriate + flag set, and if it does, writes the chunk. */ +#if defined(PNG_WRITE_gAMA_SUPPORTED) + if (info_ptr->valid & PNG_INFO_gAMA) + png_write_gAMA(png_ptr, info_ptr->gamma); +#endif +#if defined(PNG_WRITE_sRGB_SUPPORTED) + if (info_ptr->valid & PNG_INFO_sRGB) + png_write_sRGB(png_ptr, (int)info_ptr->srgb_intent); +#endif +#if defined(PNG_WRITE_sBIT_SUPPORTED) + if (info_ptr->valid & PNG_INFO_sBIT) + png_write_sBIT(png_ptr, &(info_ptr->sig_bit), info_ptr->color_type); +#endif +#if defined(PNG_WRITE_cHRM_SUPPORTED) + if (info_ptr->valid & PNG_INFO_cHRM) + png_write_cHRM(png_ptr, + info_ptr->x_white, info_ptr->y_white, + info_ptr->x_red, info_ptr->y_red, + info_ptr->x_green, info_ptr->y_green, + info_ptr->x_blue, info_ptr->y_blue); +#endif + if (info_ptr->valid & PNG_INFO_PLTE) + png_write_PLTE(png_ptr, info_ptr->palette, + (png_uint_32)info_ptr->num_palette); + else if (info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + png_error(png_ptr, "Valid palette required for paletted images\n"); + +#if defined(PNG_WRITE_tRNS_SUPPORTED) + if (info_ptr->valid & PNG_INFO_tRNS) + { +#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) + /* invert the alpha channel (in tRNS) */ + if (png_ptr->transformations & PNG_INVERT_ALPHA && + info_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + int j; + for (j=0; j<(int)info_ptr->num_trans; j++) + info_ptr->trans[j] = 255 - info_ptr->trans[j]; + } +#endif + png_write_tRNS(png_ptr, info_ptr->trans, &(info_ptr->trans_values), + info_ptr->num_trans, info_ptr->color_type); + } +#endif +#if defined(PNG_WRITE_bKGD_SUPPORTED) + if (info_ptr->valid & PNG_INFO_bKGD) + png_write_bKGD(png_ptr, &(info_ptr->background), info_ptr->color_type); +#endif +#if defined(PNG_WRITE_hIST_SUPPORTED) + if (info_ptr->valid & PNG_INFO_hIST) + png_write_hIST(png_ptr, info_ptr->hist, info_ptr->num_palette); +#endif +#if defined(PNG_WRITE_oFFs_SUPPORTED) + if (info_ptr->valid & PNG_INFO_oFFs) + png_write_oFFs(png_ptr, info_ptr->x_offset, info_ptr->y_offset, + info_ptr->offset_unit_type); +#endif +#if defined(PNG_WRITE_pCAL_SUPPORTED) + if (info_ptr->valid & PNG_INFO_pCAL) + png_write_pCAL(png_ptr, info_ptr->pcal_purpose, info_ptr->pcal_X0, + info_ptr->pcal_X1, info_ptr->pcal_type, info_ptr->pcal_nparams, + info_ptr->pcal_units, info_ptr->pcal_params); +#endif +#if defined(PNG_WRITE_pHYs_SUPPORTED) + if (info_ptr->valid & PNG_INFO_pHYs) + png_write_pHYs(png_ptr, info_ptr->x_pixels_per_unit, + info_ptr->y_pixels_per_unit, info_ptr->phys_unit_type); +#endif +#if defined(PNG_WRITE_tIME_SUPPORTED) + if (info_ptr->valid & PNG_INFO_tIME) + { + png_write_tIME(png_ptr, &(info_ptr->mod_time)); + png_ptr->flags |= PNG_FLAG_WROTE_tIME; + } +#endif +#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) + /* Check to see if we need to write text chunks */ + for (i = 0; i < info_ptr->num_text; i++) + { + png_debug2(2, "Writing header text chunk %d, type %d\n", i, + info_ptr->text[i].compression); + /* If we want a compressed text chunk */ + if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt) + { +#if defined(PNG_WRITE_zTXt_SUPPORTED) + /* write compressed chunk */ + png_write_zTXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, info_ptr->text[i].text_length, + info_ptr->text[i].compression); +#else + png_warning(png_ptr, "Unable to write compressed text\n"); +#endif + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; + } + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + { +#if defined(PNG_WRITE_tEXt_SUPPORTED) + /* write uncompressed chunk */ + png_write_tEXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, info_ptr->text[i].text_length); +#else + png_warning(png_ptr, "Unable to write uncompressed text\n"); +#endif + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + } + } +#endif +} + +/* Writes the end of the PNG file. If you don't want to write comments or + * time information, you can pass NULL for info. If you already wrote these + * in png_write_info(), do not write them again here. If you have long + * comments, I suggest writing them here, and compressing them. + */ +void +png_write_end(png_structp png_ptr, png_infop info_ptr) +{ + png_debug(1, "in png_write_end\n"); + if (!(png_ptr->mode & PNG_HAVE_IDAT)) + png_error(png_ptr, "No IDATs written into file"); + + /* see if user wants us to write information chunks */ + if (info_ptr != NULL) + { +#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) + int i; /* local index variable */ +#endif +#if defined(PNG_WRITE_tIME_SUPPORTED) + /* check to see if user has supplied a time chunk */ + if (info_ptr->valid & PNG_INFO_tIME && + !(png_ptr->flags & PNG_FLAG_WROTE_tIME)) + png_write_tIME(png_ptr, &(info_ptr->mod_time)); +#endif +#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) + /* loop through comment chunks */ + for (i = 0; i < info_ptr->num_text; i++) + { + png_debug2(2, "Writing trailer text chunk %d, type %d\n", i, + info_ptr->text[i].compression); + if (info_ptr->text[i].compression >= PNG_TEXT_COMPRESSION_zTXt) + { +#if defined(PNG_WRITE_zTXt_SUPPORTED) + /* write compressed chunk */ + png_write_zTXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, info_ptr->text[i].text_length, + info_ptr->text[i].compression); +#else + png_warning(png_ptr, "Unable to write compressed text\n"); +#endif + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_zTXt_WR; + } + else if (info_ptr->text[i].compression == PNG_TEXT_COMPRESSION_NONE) + { +#if defined(PNG_WRITE_tEXt_SUPPORTED) + /* write uncompressed chunk */ + png_write_tEXt(png_ptr, info_ptr->text[i].key, + info_ptr->text[i].text, info_ptr->text[i].text_length); +#else + png_warning(png_ptr, "Unable to write uncompressed text\n"); +#endif + + /* Mark this chunk as written */ + info_ptr->text[i].compression = PNG_TEXT_COMPRESSION_NONE_WR; + } + } +#endif + } + + png_ptr->mode |= PNG_AFTER_IDAT; + + /* write end of PNG file */ + png_write_IEND(png_ptr); +} + +#if defined(PNG_TIME_RFC1123_SUPPORTED) +/* Convert the supplied time into an RFC 1123 string suitable for use in + * a "Creation Time" or other text-based time string. + */ +png_charp +png_convert_to_rfc1123(png_structp png_ptr, png_timep ptime) +{ + static PNG_CONST char short_months[12][4] = + {"Jan", "Feb", "Mar", "Apr", "May", "Jun", + "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}; + + if (png_ptr->time_buffer == NULL) + { + png_ptr->time_buffer = (png_charp)png_malloc(png_ptr, (png_uint_32)(29* + sizeof(char))); + } + +#ifdef USE_FAR_KEYWORD + { + char near_time_buf[29]; + sprintf(near_time_buf, "%d %s %d %02d:%02d:%02d +0000", + ptime->day % 31, short_months[ptime->month], + ptime->year, ptime->hour % 24, ptime->minute % 60, + ptime->second % 61); + png_memcpy(png_ptr->time_buffer, near_time_buf, + 29*sizeof(char)); + } +#else + sprintf(png_ptr->time_buffer, "%d %s %d %02d:%02d:%02d +0000", + ptime->day % 31, short_months[ptime->month], + ptime->year, ptime->hour % 24, ptime->minute % 60, + ptime->second % 61); +#endif + return ((png_charp)png_ptr->time_buffer); +} +#endif /* PNG_TIME_RFC1123_SUPPORTED */ + +#if defined(PNG_WRITE_tIME_SUPPORTED) +void +png_convert_from_struct_tm(png_timep ptime, struct tm FAR * ttime) +{ + png_debug(1, "in png_convert_from_struct_tm\n"); + ptime->year = (png_uint_16)(1900 + ttime->tm_year); + ptime->month = (png_byte)(ttime->tm_mon + 1); + ptime->day = (png_byte)ttime->tm_mday; + ptime->hour = (png_byte)ttime->tm_hour; + ptime->minute = (png_byte)ttime->tm_min; + ptime->second = (png_byte)ttime->tm_sec; +} + +void +png_convert_from_time_t(png_timep ptime, time_t ttime) +{ + struct tm *tbuf; + + png_debug(1, "in png_convert_from_time_t\n"); + tbuf = gmtime(&ttime); + png_convert_from_struct_tm(ptime, tbuf); +} +#endif + +/* Initialize png_ptr structure, and allocate any memory needed */ +png_structp +png_create_write_struct(png_const_charp user_png_ver, voidp error_ptr, + png_error_ptr error_fn, png_error_ptr warn_fn) +{ + png_structp png_ptr; +#ifdef USE_FAR_KEYWORD + jmp_buf jmpbuf; +#endif + png_debug(1, "in png_create_write_struct\n"); + if ((png_ptr = (png_structp)png_create_struct(PNG_STRUCT_PNG)) == NULL) + { + return ((png_structp)NULL); + } +#ifdef USE_FAR_KEYWORD + if (setjmp(jmpbuf)) +#else + if (setjmp(png_ptr->jmpbuf)) +#endif + { + png_free(png_ptr, png_ptr->zbuf); + png_destroy_struct(png_ptr); + return ((png_structp)NULL); + } +#ifdef USE_FAR_KEYWORD + png_memcpy(png_ptr->jmpbuf,jmpbuf,sizeof(jmp_buf)); +#endif + png_set_error_fn(png_ptr, error_ptr, error_fn, warn_fn); + + /* Libpng 0.90 and later are binary incompatible with libpng 0.89, so + * we must recompile any applications that use any older library version. + * For versions after libpng 1.0, we will be compatible, so we need + * only check the first digit. + */ + if (user_png_ver == NULL || user_png_ver[0] != png_libpng_ver[0] || + (png_libpng_ver[0] == '0' && user_png_ver[2] < '9')) + { + png_error(png_ptr, + "Incompatible libpng version in application and library"); + } + + /* initialize zbuf - compression buffer */ + png_ptr->zbuf_size = PNG_ZBUF_SIZE; + png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, + (png_uint_32)png_ptr->zbuf_size); + + png_set_write_fn(png_ptr, NULL, NULL, NULL); + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT, + 1, NULL, NULL); +#endif + + return ((png_structp)png_ptr); +} + + +/* Initialize png_ptr structure, and allocate any memory needed */ +void +png_write_init(png_structp png_ptr) +{ + jmp_buf tmp_jmp; /* to save current jump buffer */ + + png_debug(1, "in png_write_init\n"); + /* save jump buffer and error functions */ + png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); + + /* reset all variables to 0 */ + png_memset(png_ptr, 0, sizeof (png_struct)); + + /* restore jump buffer */ + png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); + + /* initialize zbuf - compression buffer */ + png_ptr->zbuf_size = PNG_ZBUF_SIZE; + png_ptr->zbuf = (png_bytep)png_malloc(png_ptr, + (png_uint_32)png_ptr->zbuf_size); + png_set_write_fn(png_ptr, NULL, NULL, NULL); + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + png_set_filter_heuristics(png_ptr, PNG_FILTER_HEURISTIC_DEFAULT, + 1, NULL, NULL); +#endif +} + +/* Write a few rows of image data. If the image is interlaced, + * either you will have to write the 7 sub images, or, if you + * have called png_set_interlace_handling(), you will have to + * "write" the image seven times. + */ +void +png_write_rows(png_structp png_ptr, png_bytepp row, + png_uint_32 num_rows) +{ + png_uint_32 i; /* row counter */ + png_bytepp rp; /* row pointer */ + + png_debug(1, "in png_write_rows\n"); + /* loop through the rows */ + for (i = 0, rp = row; i < num_rows; i++, rp++) + { + png_write_row(png_ptr, *rp); + } +} + +/* Write the image. You only need to call this function once, even + * if you are writing an interlaced image. + */ +void +png_write_image(png_structp png_ptr, png_bytepp image) +{ + png_uint_32 i; /* row index */ + int pass, num_pass; /* pass variables */ + png_bytepp rp; /* points to current row */ + + png_debug(1, "in png_write_image\n"); +#if defined(PNG_WRITE_INTERLACING_SUPPORTED) + /* intialize interlace handling. If image is not interlaced, + this will set pass to 1 */ + num_pass = png_set_interlace_handling(png_ptr); +#else + num_pass = 1; +#endif + /* loop through passes */ + for (pass = 0; pass < num_pass; pass++) + { + /* loop through image */ + for (i = 0, rp = image; i < png_ptr->height; i++, rp++) + { + png_write_row(png_ptr, *rp); + } + } +} + +/* called by user to write a row of image data */ +void +png_write_row(png_structp png_ptr, png_bytep row) +{ + png_debug2(1, "in png_write_row (row %ld, pass %d)\n", + png_ptr->row_number, png_ptr->pass); + /* initialize transformations and other stuff if first time */ + if (png_ptr->row_number == 0 && png_ptr->pass == 0) + { + png_write_start_row(png_ptr); + } + +#if defined(PNG_WRITE_INTERLACING_SUPPORTED) + /* if interlaced and not interested in row, return */ + if (png_ptr->interlaced && (png_ptr->transformations & PNG_INTERLACE)) + { + switch (png_ptr->pass) + { + case 0: + if (png_ptr->row_number & 7) + { + png_write_finish_row(png_ptr); + return; + } + break; + case 1: + if ((png_ptr->row_number & 7) || png_ptr->width < 5) + { + png_write_finish_row(png_ptr); + return; + } + break; + case 2: + if ((png_ptr->row_number & 7) != 4) + { + png_write_finish_row(png_ptr); + return; + } + break; + case 3: + if ((png_ptr->row_number & 3) || png_ptr->width < 3) + { + png_write_finish_row(png_ptr); + return; + } + break; + case 4: + if ((png_ptr->row_number & 3) != 2) + { + png_write_finish_row(png_ptr); + return; + } + break; + case 5: + if ((png_ptr->row_number & 1) || png_ptr->width < 2) + { + png_write_finish_row(png_ptr); + return; + } + break; + case 6: + if (!(png_ptr->row_number & 1)) + { + png_write_finish_row(png_ptr); + return; + } + break; + } + } +#endif + + /* set up row info for transformations */ + png_ptr->row_info.color_type = png_ptr->color_type; + png_ptr->row_info.width = png_ptr->usr_width; + png_ptr->row_info.channels = png_ptr->usr_channels; + png_ptr->row_info.bit_depth = png_ptr->usr_bit_depth; + png_ptr->row_info.pixel_depth = (png_byte)(png_ptr->row_info.bit_depth * + png_ptr->row_info.channels); + + png_ptr->row_info.rowbytes = ((png_ptr->row_info.width * + (png_uint_32)png_ptr->row_info.pixel_depth + 7) >> 3); + + png_debug1(3, "row_info->color_type = %d\n", png_ptr->row_info.color_type); + png_debug1(3, "row_info->width = %d\n", png_ptr->row_info.width); + png_debug1(3, "row_info->channels = %d\n", png_ptr->row_info.channels); + png_debug1(3, "row_info->bit_depth = %d\n", png_ptr->row_info.bit_depth); + png_debug1(3, "row_info->pixel_depth = %d\n", png_ptr->row_info.pixel_depth); + png_debug1(3, "row_info->rowbytes = %d\n", png_ptr->row_info.rowbytes); + + /* Copy user's row into buffer, leaving room for filter byte. */ + png_memcpy_check(png_ptr, png_ptr->row_buf + 1, row, + png_ptr->row_info.rowbytes); + +#if defined(PNG_WRITE_INTERLACING_SUPPORTED) + /* handle interlacing */ + if (png_ptr->interlaced && png_ptr->pass < 6 && + (png_ptr->transformations & PNG_INTERLACE)) + { + png_do_write_interlace(&(png_ptr->row_info), + png_ptr->row_buf + 1, png_ptr->pass); + /* this should always get caught above, but still ... */ + if (!(png_ptr->row_info.width)) + { + png_write_finish_row(png_ptr); + return; + } + } +#endif + + /* handle other transformations */ + if (png_ptr->transformations) + png_do_write_transformations(png_ptr); + + /* Find a filter if necessary, filter the row and write it out. */ + png_write_find_filter(png_ptr, &(png_ptr->row_info)); + + if (png_ptr->write_row_fn != NULL) + (*(png_ptr->write_row_fn))(png_ptr, png_ptr->row_number, png_ptr->pass); +} + +#if defined(PNG_WRITE_FLUSH_SUPPORTED) +/* Set the automatic flush interval or 0 to turn flushing off */ +void +png_set_flush(png_structp png_ptr, int nrows) +{ + png_debug(1, "in png_set_flush\n"); + png_ptr->flush_dist = (nrows < 0 ? 0 : nrows); +} + +/* flush the current output buffers now */ +void +png_write_flush(png_structp png_ptr) +{ + int wrote_IDAT; + + png_debug(1, "in png_write_flush\n"); + /* We have already written out all of the data */ + if (png_ptr->row_number >= png_ptr->num_rows) + return; + + do + { + int ret; + + /* compress the data */ + ret = deflate(&png_ptr->zstream, Z_SYNC_FLUSH); + wrote_IDAT = 0; + + /* check for compression errors */ + if (ret != Z_OK) + { + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + else + png_error(png_ptr, "zlib error"); + } + + if (!(png_ptr->zstream.avail_out)) + { + /* write the IDAT and reset the zlib output buffer */ + png_write_IDAT(png_ptr, png_ptr->zbuf, + png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + wrote_IDAT = 1; + } + } while(wrote_IDAT == 1); + + /* If there is any data left to be output, write it into a new IDAT */ + if (png_ptr->zbuf_size != png_ptr->zstream.avail_out) + { + /* write the IDAT and reset the zlib output buffer */ + png_write_IDAT(png_ptr, png_ptr->zbuf, + png_ptr->zbuf_size - png_ptr->zstream.avail_out); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + png_ptr->flush_rows = 0; + png_flush(png_ptr); +} +#endif /* PNG_WRITE_FLUSH_SUPPORTED */ + +/* free all memory used by the write */ +void +png_destroy_write_struct(png_structpp png_ptr_ptr, png_infopp info_ptr_ptr) +{ + png_structp png_ptr = NULL; + png_infop info_ptr = NULL; + + png_debug(1, "in png_destroy_write_struct\n"); + if (png_ptr_ptr != NULL) + png_ptr = *png_ptr_ptr; + + if (info_ptr_ptr != NULL) + info_ptr = *info_ptr_ptr; + + if (info_ptr != NULL) + { +#ifdef PNG_WRITE_tEXt_SUPPORTED + png_free(png_ptr, info_ptr->text); +#endif +#if defined(PNG_READ_pCAL_SUPPORTED) + png_free(png_ptr, info_ptr->pcal_purpose); + png_free(png_ptr, info_ptr->pcal_units); + if (info_ptr->pcal_params != NULL) + { + int i; + for (i = 0; i < (int)info_ptr->pcal_nparams; i++) + { + png_free(png_ptr, info_ptr->pcal_params[i]); + } + png_free(png_ptr, info_ptr->pcal_params); + } +#endif + png_destroy_struct((png_voidp)info_ptr); + *info_ptr_ptr = (png_infop)NULL; + } + + if (png_ptr != NULL) + { + png_write_destroy(png_ptr); + png_destroy_struct((png_voidp)png_ptr); + *png_ptr_ptr = (png_structp)NULL; + } +} + + +/* Free any memory used in png_ptr struct (old method) */ +void +png_write_destroy(png_structp png_ptr) +{ + jmp_buf tmp_jmp; /* save jump buffer */ + png_error_ptr error_fn; + png_error_ptr warning_fn; + png_voidp error_ptr; + + png_debug(1, "in png_write_destroy\n"); + /* free any memory zlib uses */ + deflateEnd(&png_ptr->zstream); + + /* free our memory. png_free checks NULL for us. */ + png_free(png_ptr, png_ptr->zbuf); + png_free(png_ptr, png_ptr->row_buf); + png_free(png_ptr, png_ptr->prev_row); + png_free(png_ptr, png_ptr->sub_row); + png_free(png_ptr, png_ptr->up_row); + png_free(png_ptr, png_ptr->avg_row); + png_free(png_ptr, png_ptr->paeth_row); +#if defined(PNG_TIME_RFC1123_SUPPORTED) + png_free(png_ptr, png_ptr->time_buffer); +#endif /* PNG_TIME_RFC1123_SUPPORTED */ +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + png_free(png_ptr, png_ptr->prev_filters); + png_free(png_ptr, png_ptr->filter_weights); + png_free(png_ptr, png_ptr->inv_filter_weights); + png_free(png_ptr, png_ptr->filter_costs); + png_free(png_ptr, png_ptr->inv_filter_costs); +#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ + + /* reset structure */ + png_memcpy(tmp_jmp, png_ptr->jmpbuf, sizeof (jmp_buf)); + + error_fn = png_ptr->error_fn; + warning_fn = png_ptr->warning_fn; + error_ptr = png_ptr->error_ptr; + + png_memset(png_ptr, 0, sizeof (png_struct)); + + png_ptr->error_fn = error_fn; + png_ptr->warning_fn = warning_fn; + png_ptr->error_ptr = error_ptr; + + png_memcpy(png_ptr->jmpbuf, tmp_jmp, sizeof (jmp_buf)); +} + +/* Allow the application to select one or more row filters to use. */ +void +png_set_filter(png_structp png_ptr, int method, int filters) +{ + png_debug(1, "in png_set_filter\n"); + /* We allow 'method' only for future expansion of the base filter method. */ + if (method == PNG_FILTER_TYPE_BASE) + { + switch (filters & (PNG_ALL_FILTERS | 0x07)) + { + case 5: + case 6: + case 7: png_warning(png_ptr, "Unknown row filter for method 0"); + case PNG_FILTER_VALUE_NONE: png_ptr->do_filter=PNG_FILTER_NONE; break; + case PNG_FILTER_VALUE_SUB: png_ptr->do_filter=PNG_FILTER_SUB; break; + case PNG_FILTER_VALUE_UP: png_ptr->do_filter=PNG_FILTER_UP; break; + case PNG_FILTER_VALUE_AVG: png_ptr->do_filter=PNG_FILTER_AVG; break; + case PNG_FILTER_VALUE_PAETH: png_ptr->do_filter=PNG_FILTER_PAETH;break; + default: png_ptr->do_filter = (png_byte)filters; break; + } + + /* If we have allocated the row_buf, this means we have already started + * with the image and we should have allocated all of the filter buffers + * that have been selected. If prev_row isn't already allocated, then + * it is too late to start using the filters that need it, since we + * will be missing the data in the previous row. If an application + * wants to start and stop using particular filters during compression, + * it should start out with all of the filters, and then add and + * remove them after the start of compression. + */ + if (png_ptr->row_buf != NULL) + { + if (png_ptr->do_filter & PNG_FILTER_SUB && png_ptr->sub_row == NULL) + { + png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; + } + + if (png_ptr->do_filter & PNG_FILTER_UP && png_ptr->up_row == NULL) + { + if (png_ptr->prev_row == NULL) + { + png_warning(png_ptr, "Can't add Up filter after starting"); + png_ptr->do_filter &= ~PNG_FILTER_UP; + } + else + { + png_ptr->up_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; + } + } + + if (png_ptr->do_filter & PNG_FILTER_AVG && png_ptr->avg_row == NULL) + { + if (png_ptr->prev_row == NULL) + { + png_warning(png_ptr, "Can't add Average filter after starting"); + png_ptr->do_filter &= ~PNG_FILTER_AVG; + } + else + { + png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; + } + } + + if (png_ptr->do_filter & PNG_FILTER_PAETH && + png_ptr->paeth_row == NULL) + { + if (png_ptr->prev_row == NULL) + { + png_warning(png_ptr, "Can't add Paeth filter after starting"); + png_ptr->do_filter &= ~PNG_FILTER_PAETH; + } + else + { + png_ptr->paeth_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; + } + } + + if (png_ptr->do_filter == PNG_NO_FILTERS) + png_ptr->do_filter = PNG_FILTER_NONE; + } + } + else + png_error(png_ptr, "Unknown custom filter method"); +} + +/* This allows us to influence the way in which libpng chooses the "best" + * filter for the current scanline. While the "minimum-sum-of-absolute- + * differences metric is relatively fast and effective, there is some + * question as to whether it can be improved upon by trying to keep the + * filtered data going to zlib more consistent, hopefully resulting in + * better compression. + */ +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) /* GRR 970116 */ +void +png_set_filter_heuristics(png_structp png_ptr, int heuristic_method, + int num_weights, png_doublep filter_weights, + png_doublep filter_costs) +{ +#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) + int i; +#endif + + png_debug(1, "in png_set_filter_heuristics\n"); + if (heuristic_method >= PNG_FILTER_HEURISTIC_LAST) + { + png_warning(png_ptr, "Unknown filter heuristic method"); + return; + } + + if (heuristic_method == PNG_FILTER_HEURISTIC_DEFAULT) + { + heuristic_method = PNG_FILTER_HEURISTIC_UNWEIGHTED; + } + + if (num_weights < 0 || filter_weights == NULL || + heuristic_method == PNG_FILTER_HEURISTIC_UNWEIGHTED) + { + num_weights = 0; + } + + png_ptr->num_prev_filters = num_weights; + png_ptr->heuristic_method = heuristic_method; + + if (num_weights > 0) + { + if (png_ptr->prev_filters == NULL) + { + png_ptr->prev_filters = (png_bytep)png_malloc(png_ptr, + (png_uint_32)(sizeof(png_byte) * num_weights)); + + /* To make sure that the weighting starts out fairly */ + for (i = 0; i < num_weights; i++) + { + png_ptr->prev_filters[i] = 255; + } + } + + if (png_ptr->filter_weights == NULL) + { + png_ptr->filter_weights = (png_uint_16p) png_malloc(png_ptr, + (png_uint_32)(sizeof(png_uint_16) * num_weights)); + + png_ptr->inv_filter_weights = (png_uint_16p) png_malloc(png_ptr, + (png_uint_32)(sizeof(png_uint_16) * num_weights)); + + for (i = 0; i < num_weights; i++) + { + png_ptr->inv_filter_weights[i] = + png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR; + } + } + + for (i = 0; i < num_weights; i++) + { + if (filter_weights[i] < 0.0) + { + png_ptr->inv_filter_weights[i] = + png_ptr->filter_weights[i] = PNG_WEIGHT_FACTOR; + } + else + { + png_ptr->inv_filter_weights[i] = + (png_uint_16)((double)PNG_WEIGHT_FACTOR*filter_weights[i]+0.5); + png_ptr->filter_weights[i] = + (png_uint_16)((double)PNG_WEIGHT_FACTOR/filter_weights[i]+0.5); + } + } + } + + /* If, in the future, there are other filter methods, this would + * need to be based on png_ptr->filter. + */ + if (png_ptr->filter_costs == NULL) + { + png_ptr->filter_costs = (png_uint_16p) png_malloc(png_ptr, + (png_uint_32)(sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST)); + + png_ptr->inv_filter_costs = (png_uint_16p) png_malloc(png_ptr, + (png_uint_32)(sizeof(png_uint_16) * PNG_FILTER_VALUE_LAST)); + + for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) + { + png_ptr->inv_filter_costs[i] = + png_ptr->filter_costs[i] = PNG_COST_FACTOR; + } + } + + /* Here is where we set the relative costs of the different filters. We + * should take the desired compression level into account when setting + * the costs, so that Paeth, for instance, has a high relative cost at low + * compression levels, while it has a lower relative cost at higher + * compression settings. The filter types are in order of increasing + * relative cost, so it would be possible to do this with an algorithm. + */ + for (i = 0; i < PNG_FILTER_VALUE_LAST; i++) + { + if (filter_costs == NULL || filter_costs[i] < 0.0) + { + png_ptr->inv_filter_costs[i] = + png_ptr->filter_costs[i] = PNG_COST_FACTOR; + } + else if (filter_costs[i] >= 1.0) + { + png_ptr->inv_filter_costs[i] = + (png_uint_16)((double)PNG_COST_FACTOR / filter_costs[i] + 0.5); + png_ptr->filter_costs[i] = + (png_uint_16)((double)PNG_COST_FACTOR * filter_costs[i] + 0.5); + } + } +} +#endif /* PNG_WRITE_WEIGHTED_FILTER_SUPPORTED */ + +void +png_set_compression_level(png_structp png_ptr, int level) +{ + png_debug(1, "in png_set_compression_level\n"); + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_LEVEL; + png_ptr->zlib_level = level; +} + +void +png_set_compression_mem_level(png_structp png_ptr, int mem_level) +{ + png_debug(1, "in png_set_compression_mem_level\n"); + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL; + png_ptr->zlib_mem_level = mem_level; +} + +void +png_set_compression_strategy(png_structp png_ptr, int strategy) +{ + png_debug(1, "in png_set_compression_strategy\n"); + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_STRATEGY; + png_ptr->zlib_strategy = strategy; +} + +void +png_set_compression_window_bits(png_structp png_ptr, int window_bits) +{ + if (window_bits > 15) + png_warning(png_ptr, "Only compression windows <= 32k supported by PNG"); + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS; + png_ptr->zlib_window_bits = window_bits; +} + +void +png_set_compression_method(png_structp png_ptr, int method) +{ + png_debug(1, "in png_set_compression_method\n"); + if (method != 8) + png_warning(png_ptr, "Only compression method 8 is supported by PNG"); + png_ptr->flags |= PNG_FLAG_ZLIB_CUSTOM_METHOD; + png_ptr->zlib_method = method; +} + +void +png_set_write_status_fn(png_structp png_ptr, png_write_status_ptr write_row_fn) +{ + png_ptr->write_row_fn = write_row_fn; +} + +#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) +void +png_set_write_user_transform_fn(png_structp png_ptr, png_user_transform_ptr + write_user_transform_fn) +{ + png_debug(1, "in png_set_write_user_transform_fn\n"); + png_ptr->transformations |= PNG_USER_TRANSFORM; + png_ptr->write_user_transform_fn = write_user_transform_fn; +} +#endif + diff --git a/thirdparty/libpng/pngwtran.c b/thirdparty/libpng/pngwtran.c new file mode 100644 index 00000000..2db759e3 --- /dev/null +++ b/thirdparty/libpng/pngwtran.c @@ -0,0 +1,495 @@ + +/* pngwtran.c - transforms the data in a row for PNG writers + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + */ + +#define PNG_INTERNAL +#include "png.h" + +/* Transform the data according to the users wishes. The order of + * transformations is significant. + */ +void +png_do_write_transformations(png_structp png_ptr) +{ + png_debug(1, "in png_do_write_transformations\n"); + +#if defined(PNG_WRITE_USER_TRANSFORM_SUPPORTED) + if (png_ptr->transformations & PNG_USER_TRANSFORM) + if(png_ptr->write_user_transform_fn != NULL) + (*(png_ptr->write_user_transform_fn)) /* user write transform function */ + (png_ptr, /* png_ptr */ + &(png_ptr->row_info), /* row_info: */ + /* png_uint_32 width; width of row */ + /* png_uint_32 rowbytes; number of bytes in row */ + /* png_byte color_type; color type of pixels */ + /* png_byte bit_depth; bit depth of samples */ + /* png_byte channels; number of channels (1-4) */ + /* png_byte pixel_depth; bits per pixel (depth*channels) */ + png_ptr->row_buf + 1); /* start of pixel data for row */ +#endif +#if defined(PNG_WRITE_FILLER_SUPPORTED) + if (png_ptr->transformations & PNG_FILLER) + png_do_strip_filler(&(png_ptr->row_info), png_ptr->row_buf + 1, + png_ptr->flags); +#endif +#if defined(PNG_WRITE_PACKSWAP_SUPPORTED) + if (png_ptr->transformations & PNG_PACKSWAP) + png_do_packswap(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif +#if defined(PNG_WRITE_PACK_SUPPORTED) + if (png_ptr->transformations & PNG_PACK) + png_do_pack(&(png_ptr->row_info), png_ptr->row_buf + 1, + (png_uint_32)png_ptr->bit_depth); +#endif +#if defined(PNG_WRITE_SHIFT_SUPPORTED) + if (png_ptr->transformations & PNG_SHIFT) + png_do_shift(&(png_ptr->row_info), png_ptr->row_buf + 1, + &(png_ptr->shift)); +#endif +#if defined(PNG_WRITE_SWAP_SUPPORTED) + if (png_ptr->transformations & PNG_SWAP_BYTES) + png_do_swap(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif +#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) + if (png_ptr->transformations & PNG_INVERT_ALPHA) + png_do_write_invert_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif +#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) + if (png_ptr->transformations & PNG_SWAP_ALPHA) + png_do_write_swap_alpha(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif +#if defined(PNG_WRITE_BGR_SUPPORTED) + if (png_ptr->transformations & PNG_BGR) + png_do_bgr(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif +#if defined(PNG_WRITE_INVERT_SUPPORTED) + if (png_ptr->transformations & PNG_INVERT_MONO) + png_do_invert(&(png_ptr->row_info), png_ptr->row_buf + 1); +#endif +} + +#if defined(PNG_WRITE_PACK_SUPPORTED) +/* Pack pixels into bytes. Pass the true bit depth in bit_depth. The + * row_info bit depth should be 8 (one pixel per byte). The channels + * should be 1 (this only happens on grayscale and paletted images). + */ +void +png_do_pack(png_row_infop row_info, png_bytep row, png_uint_32 bit_depth) +{ + png_debug(1, "in png_do_pack\n"); + if (row_info->bit_depth == 8 && +#if defined(PNG_USELESS_TESTS_SUPPORTED) + row != NULL && row_info != NULL && +#endif + row_info->channels == 1) + { + switch ((int)bit_depth) + { + case 1: + { + png_bytep sp, dp; + int mask, v; + png_uint_32 i; + + sp = row; + dp = row; + mask = 0x80; + v = 0; + for (i = 0; i < row_info->width; i++) + { + if (*sp != 0) + v |= mask; + sp++; + if (mask > 1) + mask >>= 1; + else + { + mask = 0x80; + *dp = (png_byte)v; + dp++; + v = 0; + } + } + if (mask != 0x80) + *dp = (png_byte)v; + break; + } + case 2: + { + png_bytep sp, dp; + int shift, v; + png_uint_32 i; + + sp = row; + dp = row; + shift = 6; + v = 0; + for (i = 0; i < row_info->width; i++) + { + png_byte value; + + value = (png_byte)(*sp & 0x3); + v |= (value << shift); + if (shift == 0) + { + shift = 6; + *dp = (png_byte)v; + dp++; + v = 0; + } + else + shift -= 2; + sp++; + } + if (shift != 6) + *dp = (png_byte)v; + break; + } + case 4: + { + png_bytep sp, dp; + int shift, v; + png_uint_32 i; + + sp = row; + dp = row; + shift = 4; + v = 0; + for (i = 0; i < row_info->width; i++) + { + png_byte value; + + value = (png_byte)(*sp & 0xf); + v |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp = (png_byte)v; + dp++; + v = 0; + } + else + shift -= 4; + + sp++; + } + if (shift != 4) + *dp = (png_byte)v; + break; + } + } + row_info->bit_depth = (png_byte)bit_depth; + row_info->pixel_depth = (png_byte)(bit_depth * row_info->channels); + row_info->rowbytes = + ((row_info->width * row_info->pixel_depth + 7) >> 3); + } +} +#endif + +#if defined(PNG_WRITE_SHIFT_SUPPORTED) +/* Shift pixel values to take advantage of whole range. Pass the + * true number of bits in bit_depth. The row should be packed + * according to row_info->bit_depth. Thus, if you had a row of + * bit depth 4, but the pixels only had values from 0 to 7, you + * would pass 3 as bit_depth, and this routine would translate the + * data to 0 to 15. + */ +void +png_do_shift(png_row_infop row_info, png_bytep row, png_color_8p bit_depth) +{ + png_debug(1, "in png_do_shift\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL && +#else + if ( +#endif + row_info->color_type != PNG_COLOR_TYPE_PALETTE) + { + int shift_start[4], shift_dec[4]; + png_uint_32 channels; + + channels = 0; + if (row_info->color_type & PNG_COLOR_MASK_COLOR) + { + shift_start[channels] = row_info->bit_depth - bit_depth->red; + shift_dec[channels] = bit_depth->red; + channels++; + shift_start[channels] = row_info->bit_depth - bit_depth->green; + shift_dec[channels] = bit_depth->green; + channels++; + shift_start[channels] = row_info->bit_depth - bit_depth->blue; + shift_dec[channels] = bit_depth->blue; + channels++; + } + else + { + shift_start[channels] = row_info->bit_depth - bit_depth->gray; + shift_dec[channels] = bit_depth->gray; + channels++; + } + if (row_info->color_type & PNG_COLOR_MASK_ALPHA) + { + shift_start[channels] = row_info->bit_depth - bit_depth->alpha; + shift_dec[channels] = bit_depth->alpha; + channels++; + } + + /* with low row depths, could only be grayscale, so one channel */ + if (row_info->bit_depth < 8) + { + png_bytep bp; + png_uint_32 i; + png_byte mask; + + if (bit_depth->gray == 1 && row_info->bit_depth == 2) + mask = 0x55; + else if (row_info->bit_depth == 4 && bit_depth->gray == 3) + mask = 0x11; + else + mask = 0xff; + + for (bp = row, i = 0; i < row_info->rowbytes; i++, bp++) + { + png_uint_16 v; + int j; + + v = *bp; + *bp = 0; + for (j = shift_start[0]; j > -shift_dec[0]; j -= shift_dec[0]) + { + if (j > 0) + *bp |= (png_byte)((v << j) & 0xff); + else + *bp |= (png_byte)((v >> (-j)) & mask); + } + } + } + else if (row_info->bit_depth == 8) + { + png_bytep bp; + png_uint_32 i; + + for (bp = row, i = 0; i < row_info->width; i++) + { + png_uint_32 c; + + for (c = 0; c < channels; c++, bp++) + { + png_uint_16 v; + int j; + + v = *bp; + *bp = 0; + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) + { + if (j > 0) + *bp |= (png_byte)((v << j) & 0xff); + else + *bp |= (png_byte)((v >> (-j)) & 0xff); + } + } + } + } + else + { + png_bytep bp; + png_uint_32 i; + + for (bp = row, i = 0; i < row_info->width * row_info->channels; i++) + { + png_uint_32 c; + + for (c = 0; c < channels; c++, bp += 2) + { + png_uint_16 value, v; + int j; + + v = ((png_uint_16)(*bp) << 8) + *(bp + 1); + value = 0; + for (j = shift_start[c]; j > -shift_dec[c]; j -= shift_dec[c]) + { + if (j > 0) + value |= (png_uint_16)((v << j) & (png_uint_16)0xffff); + else + value |= (png_uint_16)((v >> (-j)) & (png_uint_16)0xffff); + } + *bp = (png_byte)(value >> 8); + *(bp + 1) = (png_byte)(value & 0xff); + } + } + } + } +} +#endif + +#if defined(PNG_WRITE_SWAP_ALPHA_SUPPORTED) +void +png_do_write_swap_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_swap_alpha\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL) +#endif + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + /* This converts from ARGB to RGBA */ + if (row_info->bit_depth == 8) + { + png_bytep sp, dp; + png_byte save; + png_uint_32 i; + + for (i = 0, sp = dp = row; i < row_info->width; i++) + { + save = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save; + } + } + /* This converts from AARRGGBB to RRGGBBAA */ + else + { + png_bytep sp, dp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0, sp = dp = row; i < row_info->width; i++) + { + save[0] = *(sp++); + save[1] = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save[0]; + *(dp++) = save[1]; + } + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + /* This converts from AG to GA */ + if (row_info->bit_depth == 8) + { + png_bytep sp, dp; + png_byte save; + png_uint_32 i; + + for (i = 0, sp = dp = row; i < row_info->width; i++) + { + save = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save; + } + } + /* This converts from AAGG to GGAA */ + else + { + png_bytep sp, dp; + png_byte save[2]; + png_uint_32 i; + + for (i = 0, sp = dp = row; i < row_info->width; i++) + { + save[0] = *(sp++); + save[1] = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = save[0]; + *(dp++) = save[1]; + } + } + } + } +} +#endif + +#if defined(PNG_WRITE_INVERT_ALPHA_SUPPORTED) +void +png_do_write_invert_alpha(png_row_infop row_info, png_bytep row) +{ + png_debug(1, "in png_do_write_invert_alpha\n"); +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL) +#endif + { + if (row_info->color_type == PNG_COLOR_TYPE_RGB_ALPHA) + { + /* This inverts the alpha channel in RGBA */ + if (row_info->bit_depth == 8) + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = dp = row; i < row_info->width; i++) + { + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = 255 - *(sp++); + } + } + /* This inverts the alpha channel in RRGGBBAA */ + else + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = dp = row; i < row_info->width; i++) + { + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = 255 - *(sp++); + *(dp++) = 255 - *(sp++); + } + } + } + else if (row_info->color_type == PNG_COLOR_TYPE_GRAY_ALPHA) + { + /* This inverts the alpha channel in GA */ + if (row_info->bit_depth == 8) + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = dp = row; i < row_info->width; i++) + { + *(dp++) = *(sp++); + *(dp++) = 255 - *(sp++); + } + } + /* This inverts the alpha channel in GGAA */ + else + { + png_bytep sp, dp; + png_uint_32 i; + + for (i = 0, sp = dp = row; i < row_info->width; i++) + { + *(dp++) = *(sp++); + *(dp++) = *(sp++); + *(dp++) = 255 - *(sp++); + *(dp++) = 255 - *(sp++); + } + } + } + } +} +#endif diff --git a/thirdparty/libpng/pngwutil.c b/thirdparty/libpng/pngwutil.c new file mode 100644 index 00000000..17faf8f3 --- /dev/null +++ b/thirdparty/libpng/pngwutil.c @@ -0,0 +1,1934 @@ + +/* pngwutil.c - utilities to write a PNG file + * + * libpng 1.0.1 + * For conditions of distribution and use, see copyright notice in png.h + * Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc. + * Copyright (c) 1996, 1997 Andreas Dilger + * Copyright (c) 1998, Glenn Randers-Pehrson + * March 9, 1998 + */ + +#define PNG_INTERNAL +#include "png.h" + +/* Place a 32-bit number into a buffer in PNG byte order. We work + * with unsigned numbers for convenience, although one supported + * ancillary chunk uses signed (two's complement) numbers. + */ +void +png_save_uint_32(png_bytep buf, png_uint_32 i) +{ + buf[0] = (png_byte)((i >> 24) & 0xff); + buf[1] = (png_byte)((i >> 16) & 0xff); + buf[2] = (png_byte)((i >> 8) & 0xff); + buf[3] = (png_byte)(i & 0xff); +} + +#if defined(PNG_WRITE_pCAL_SUPPORTED) +/* The png_save_int_32 function assumes integers are stored in two's + * complement format. If this isn't the case, then this routine needs to + * be modified to write data in two's complement format. + */ +void +png_save_int_32(png_bytep buf, png_int_32 i) +{ + buf[0] = (png_byte)((i >> 24) & 0xff); + buf[1] = (png_byte)((i >> 16) & 0xff); + buf[2] = (png_byte)((i >> 8) & 0xff); + buf[3] = (png_byte)(i & 0xff); +} +#endif + +/* Place a 16-bit number into a buffer in PNG byte order. + * The parameter is declared unsigned int, not png_uint_16, + * just to avoid potential problems on pre-ANSI C compilers. + */ +void +png_save_uint_16(png_bytep buf, unsigned int i) +{ + buf[0] = (png_byte)((i >> 8) & 0xff); + buf[1] = (png_byte)(i & 0xff); +} + +/* Write a PNG chunk all at once. The type is an array of ASCII characters + * representing the chunk name. The array must be at least 4 bytes in + * length, and does not need to be null terminated. To be safe, pass the + * pre-defined chunk names here, and if you need a new one, define it + * where the others are defined. The length is the length of the data. + * All the data must be present. If that is not possible, use the + * png_write_chunk_start(), png_write_chunk_data(), and png_write_chunk_end() + * functions instead. + */ +void +png_write_chunk(png_structp png_ptr, png_bytep chunk_name, + png_bytep data, png_size_t length) +{ + png_write_chunk_start(png_ptr, chunk_name, (png_uint_32)length); + png_write_chunk_data(png_ptr, data, length); + png_write_chunk_end(png_ptr); +} + +/* Write the start of a PNG chunk. The type is the chunk type. + * The total_length is the sum of the lengths of all the data you will be + * passing in png_write_chunk_data(). + */ +void +png_write_chunk_start(png_structp png_ptr, png_bytep chunk_name, + png_uint_32 length) +{ + png_byte buf[4]; + png_debug2(0, "Writing %s chunk (%d bytes)\n", chunk_name, length); + + /* write the length */ + png_save_uint_32(buf, length); + png_write_data(png_ptr, buf, (png_size_t)4); + + /* write the chunk name */ + png_write_data(png_ptr, chunk_name, (png_size_t)4); + /* reset the crc and run it over the chunk name */ + png_reset_crc(png_ptr); + png_calculate_crc(png_ptr, chunk_name, (png_size_t)4); +} + +/* Write the data of a PNG chunk started with png_write_chunk_start(). + * Note that multiple calls to this function are allowed, and that the + * sum of the lengths from these calls *must* add up to the total_length + * given to png_write_chunk_start(). + */ +void +png_write_chunk_data(png_structp png_ptr, png_bytep data, png_size_t length) +{ + /* write the data, and run the CRC over it */ + if (data != NULL && length > 0) + { + png_calculate_crc(png_ptr, data, length); + png_write_data(png_ptr, data, length); + } +} + +/* Finish a chunk started with png_write_chunk_start(). */ +void +png_write_chunk_end(png_structp png_ptr) +{ + png_byte buf[4]; + + /* write the crc */ + png_save_uint_32(buf, png_ptr->crc); + + png_write_data(png_ptr, buf, (png_size_t)4); +} + +/* Simple function to write the signature. If we have already written + * the magic bytes of the signature, or more likely, the PNG stream is + * being embedded into another stream and doesn't need its own signature, + * we should call png_set_sig_bytes() to tell libpng how many of the + * bytes have already been written. + */ +void +png_write_sig(png_structp png_ptr) +{ + /* write the rest of the 8 byte signature */ + png_write_data(png_ptr, &png_sig[png_ptr->sig_bytes], + (png_size_t)8 - png_ptr->sig_bytes); +} + +/* Write the IHDR chunk, and update the png_struct with the necessary + * information. Note that the rest of this code depends upon this + * information being correct. + */ +void +png_write_IHDR(png_structp png_ptr, png_uint_32 width, png_uint_32 height, + int bit_depth, int color_type, int compression_type, int filter_type, + int interlace_type) +{ + png_byte buf[13]; /* buffer to store the IHDR info */ + + png_debug(1, "in png_write_IHDR\n"); + /* Check that we have valid input data from the application info */ + switch (color_type) + { + case PNG_COLOR_TYPE_GRAY: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: + case 16: png_ptr->channels = 1; break; + default: png_error(png_ptr,"Invalid bit depth for grayscale image"); + } + break; + case PNG_COLOR_TYPE_RGB: + if (bit_depth != 8 && bit_depth != 16) + png_error(png_ptr, "Invalid bit depth for RGB image"); + png_ptr->channels = 3; + break; + case PNG_COLOR_TYPE_PALETTE: + switch (bit_depth) + { + case 1: + case 2: + case 4: + case 8: png_ptr->channels = 1; break; + default: png_error(png_ptr, "Invalid bit depth for paletted image"); + } + break; + case PNG_COLOR_TYPE_GRAY_ALPHA: + if (bit_depth != 8 && bit_depth != 16) + png_error(png_ptr, "Invalid bit depth for grayscale+alpha image"); + png_ptr->channels = 2; + break; + case PNG_COLOR_TYPE_RGB_ALPHA: + if (bit_depth != 8 && bit_depth != 16) + png_error(png_ptr, "Invalid bit depth for RGBA image"); + png_ptr->channels = 4; + break; + default: + png_error(png_ptr, "Invalid image color type specified"); + } + + if (compression_type != PNG_COMPRESSION_TYPE_BASE) + { + png_warning(png_ptr, "Invalid compression type specified"); + compression_type = PNG_COMPRESSION_TYPE_BASE; + } + + if (filter_type != PNG_FILTER_TYPE_BASE) + { + png_warning(png_ptr, "Invalid filter type specified"); + filter_type = PNG_FILTER_TYPE_BASE; + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + if (interlace_type != PNG_INTERLACE_NONE && + interlace_type != PNG_INTERLACE_ADAM7) + { + png_warning(png_ptr, "Invalid interlace type specified"); + interlace_type = PNG_INTERLACE_ADAM7; + } +#else + interlace_type=PNG_INTERLACE_NONE; +#endif + + /* save off the relevent information */ + png_ptr->bit_depth = (png_byte)bit_depth; + png_ptr->color_type = (png_byte)color_type; + png_ptr->interlaced = (png_byte)interlace_type; + png_ptr->width = width; + png_ptr->height = height; + + png_ptr->pixel_depth = (png_byte)(bit_depth * png_ptr->channels); + png_ptr->rowbytes = ((width * (png_size_t)png_ptr->pixel_depth + 7) >> 3); + /* set the usr info, so any transformations can modify it */ + png_ptr->usr_width = png_ptr->width; + png_ptr->usr_bit_depth = png_ptr->bit_depth; + png_ptr->usr_channels = png_ptr->channels; + + /* pack the header information into the buffer */ + png_save_uint_32(buf, width); + png_save_uint_32(buf + 4, height); + buf[8] = (png_byte)bit_depth; + buf[9] = (png_byte)color_type; + buf[10] = (png_byte)compression_type; + buf[11] = (png_byte)filter_type; + buf[12] = (png_byte)interlace_type; + + /* write the chunk */ + png_write_chunk(png_ptr, png_IHDR, buf, (png_size_t)13); + + /* initialize zlib with PNG info */ + png_ptr->zstream.zalloc = png_zalloc; + png_ptr->zstream.zfree = png_zfree; + png_ptr->zstream.opaque = (voidpf)png_ptr; + if (!(png_ptr->do_filter)) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE || + png_ptr->bit_depth < 8) + png_ptr->do_filter = PNG_FILTER_NONE; + else + png_ptr->do_filter = PNG_ALL_FILTERS; + } + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_STRATEGY)) + { + if (png_ptr->do_filter != PNG_FILTER_NONE) + png_ptr->zlib_strategy = Z_FILTERED; + else + png_ptr->zlib_strategy = Z_DEFAULT_STRATEGY; + } + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_LEVEL)) + png_ptr->zlib_level = Z_DEFAULT_COMPRESSION; + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_MEM_LEVEL)) + png_ptr->zlib_mem_level = 8; + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_WINDOW_BITS)) + png_ptr->zlib_window_bits = 15; + if (!(png_ptr->flags & PNG_FLAG_ZLIB_CUSTOM_METHOD)) + png_ptr->zlib_method = 8; + deflateInit2(&png_ptr->zstream, png_ptr->zlib_level, + png_ptr->zlib_method, png_ptr->zlib_window_bits, + png_ptr->zlib_mem_level, png_ptr->zlib_strategy); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + + png_ptr->mode = PNG_HAVE_IHDR; +} + +/* write the palette. We are careful not to trust png_color to be in the + * correct order for PNG, so people can redefine it to any convient + * structure. + */ +void +png_write_PLTE(png_structp png_ptr, png_colorp palette, png_uint_32 num_pal) +{ + png_uint_32 i; + png_colorp pal_ptr; + png_byte buf[3]; + + png_debug(1, "in png_write_PLTE\n"); + if (num_pal == 0 || num_pal > 256) + { + if (png_ptr->color_type == PNG_COLOR_TYPE_PALETTE) + { + png_error(png_ptr, "Invalid number of colors in palette"); + } + else + { + png_warning(png_ptr, "Invalid number of colors in palette"); + return; + } + } + + png_ptr->num_palette = (png_uint_16)num_pal; + png_debug1(3, "num_palette = %d\n", png_ptr->num_palette); + + png_write_chunk_start(png_ptr, png_PLTE, num_pal * 3); + for (i = 0, pal_ptr = palette; i < num_pal; i++, pal_ptr++) + { + buf[0] = pal_ptr->red; + buf[1] = pal_ptr->green; + buf[2] = pal_ptr->blue; + png_write_chunk_data(png_ptr, buf, (png_size_t)3); + } + png_write_chunk_end(png_ptr); + png_ptr->mode |= PNG_HAVE_PLTE; +} + +/* write an IDAT chunk */ +void +png_write_IDAT(png_structp png_ptr, png_bytep data, png_size_t length) +{ + png_debug(1, "in png_write_IDAT\n"); + png_write_chunk(png_ptr, png_IDAT, data, length); + png_ptr->mode |= PNG_HAVE_IDAT; +} + +/* write an IEND chunk */ +void +png_write_IEND(png_structp png_ptr) +{ + png_debug(1, "in png_write_IEND\n"); + png_write_chunk(png_ptr, png_IEND, NULL, (png_size_t)0); + png_ptr->mode |= PNG_HAVE_IEND; +} + +#if defined(PNG_WRITE_gAMA_SUPPORTED) +/* write a gAMA chunk */ +void +png_write_gAMA(png_structp png_ptr, double file_gamma) +{ + png_uint_32 igamma; + png_byte buf[4]; + + png_debug(1, "in png_write_gAMA\n"); + /* file_gamma is saved in 1/1.0.100ths */ + igamma = (png_uint_32)(file_gamma * 1.0.10.0 + 0.5); + png_save_uint_32(buf, igamma); + png_write_chunk(png_ptr, png_gAMA, buf, (png_size_t)4); +} +#endif + +#if defined(PNG_WRITE_sRGB_SUPPORTED) +/* write a sRGB chunk */ +void +png_write_sRGB(png_structp png_ptr, int srgb_intent) +{ + png_byte buf[1]; + + png_debug(1, "in png_write_sRGB\n"); + if(srgb_intent >= PNG_sRGB_INTENT_LAST) + png_warning(png_ptr, + "Invalid sRGB rendering intent specified"); + buf[0]=(png_byte)srgb_intent; + png_write_chunk(png_ptr, png_sRGB, buf, (png_size_t)1); +} +#endif + +#if defined(PNG_WRITE_sBIT_SUPPORTED) +/* write the sBIT chunk */ +void +png_write_sBIT(png_structp png_ptr, png_color_8p sbit, int color_type) +{ + png_byte buf[4]; + png_size_t size; + + png_debug(1, "in png_write_sBIT\n"); + /* make sure we don't depend upon the order of PNG_COLOR_8 */ + if (color_type & PNG_COLOR_MASK_COLOR) + { + png_byte maxbits; + + maxbits = color_type==PNG_COLOR_TYPE_PALETTE ? 8:png_ptr->usr_bit_depth; + if (sbit->red == 0 || sbit->red > maxbits || + sbit->green == 0 || sbit->green > maxbits || + sbit->blue == 0 || sbit->blue > maxbits) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + buf[0] = sbit->red; + buf[1] = sbit->green; + buf[2] = sbit->blue; + size = 3; + } + else + { + if (sbit->gray == 0 || sbit->gray > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + buf[0] = sbit->gray; + size = 1; + } + + if (color_type & PNG_COLOR_MASK_ALPHA) + { + if (sbit->alpha == 0 || sbit->alpha > png_ptr->usr_bit_depth) + { + png_warning(png_ptr, "Invalid sBIT depth specified"); + return; + } + buf[size++] = sbit->alpha; + } + + png_write_chunk(png_ptr, png_sBIT, buf, size); +} +#endif + +#if defined(PNG_WRITE_cHRM_SUPPORTED) +/* write the cHRM chunk */ +void +png_write_cHRM(png_structp png_ptr, double white_x, double white_y, + double red_x, double red_y, double green_x, double green_y, + double blue_x, double blue_y) +{ + png_uint_32 itemp; + png_byte buf[32]; + + png_debug(1, "in png_write_cHRM\n"); + /* each value is saved int 1/1.0.100ths */ + if (white_x < 0 || white_x > 0.8 || white_y < 0 || white_y > 0.8 || + white_x + white_y > 1.0) + { + png_warning(png_ptr, "Invalid cHRM white point specified"); + return; + } + itemp = (png_uint_32)(white_x * 1.0.10.0 + 0.5); + png_save_uint_32(buf, itemp); + itemp = (png_uint_32)(white_y * 1.0.10.0 + 0.5); + png_save_uint_32(buf + 4, itemp); + + if (red_x < 0 || red_x > 0.8 || red_y < 0 || red_y > 0.8 || + red_x + red_y > 1.0) + { + png_warning(png_ptr, "Invalid cHRM red point specified"); + return; + } + itemp = (png_uint_32)(red_x * 1.0.10.0 + 0.5); + png_save_uint_32(buf + 8, itemp); + itemp = (png_uint_32)(red_y * 1.0.10.0 + 0.5); + png_save_uint_32(buf + 12, itemp); + + if (green_x < 0 || green_x > 0.8 || green_y < 0 || green_y > 0.8 || + green_x + green_y > 1.0) + { + png_warning(png_ptr, "Invalid cHRM green point specified"); + return; + } + itemp = (png_uint_32)(green_x * 1.0.10.0 + 0.5); + png_save_uint_32(buf + 16, itemp); + itemp = (png_uint_32)(green_y * 1.0.10.0 + 0.5); + png_save_uint_32(buf + 20, itemp); + + if (blue_x < 0 || blue_x > 0.8 || blue_y < 0 || blue_y > 0.8 || + blue_x + blue_y > 1.0) + { + png_warning(png_ptr, "Invalid cHRM blue point specified"); + return; + } + itemp = (png_uint_32)(blue_x * 1.0.10.0 + 0.5); + png_save_uint_32(buf + 24, itemp); + itemp = (png_uint_32)(blue_y * 1.0.10.0 + 0.5); + png_save_uint_32(buf + 28, itemp); + + png_write_chunk(png_ptr, png_cHRM, buf, (png_size_t)32); +} +#endif + +#if defined(PNG_WRITE_tRNS_SUPPORTED) +/* write the tRNS chunk */ +void +png_write_tRNS(png_structp png_ptr, png_bytep trans, png_color_16p tran, + int num_trans, int color_type) +{ + png_byte buf[6]; + + png_debug(1, "in png_write_tRNS\n"); + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if (num_trans <= 0 || num_trans > (int)png_ptr->num_palette) + { + png_warning(png_ptr,"Invalid number of transparent colors specified"); + return; + } + /* write the chunk out as it is */ + png_write_chunk(png_ptr, png_tRNS, trans, (png_size_t)num_trans); + } + else if (color_type == PNG_COLOR_TYPE_GRAY) + { + /* one 16 bit value */ + png_save_uint_16(buf, tran->gray); + png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)2); + } + else if (color_type == PNG_COLOR_TYPE_RGB) + { + /* three 16 bit values */ + png_save_uint_16(buf, tran->red); + png_save_uint_16(buf + 2, tran->green); + png_save_uint_16(buf + 4, tran->blue); + png_write_chunk(png_ptr, png_tRNS, buf, (png_size_t)6); + } + else + { + png_warning(png_ptr, "Can't write tRNS with an alpha channel"); + } +} +#endif + +#if defined(PNG_WRITE_bKGD_SUPPORTED) +/* write the background chunk */ +void +png_write_bKGD(png_structp png_ptr, png_color_16p back, int color_type) +{ + png_byte buf[6]; + + png_debug(1, "in png_write_bKGD\n"); + if (color_type == PNG_COLOR_TYPE_PALETTE) + { + if (back->index > png_ptr->num_palette) + { + png_warning(png_ptr, "Invalid background palette index"); + return; + } + buf[0] = back->index; + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)1); + } + else if (color_type & PNG_COLOR_MASK_COLOR) + { + png_save_uint_16(buf, back->red); + png_save_uint_16(buf + 2, back->green); + png_save_uint_16(buf + 4, back->blue); + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)6); + } + else + { + png_save_uint_16(buf, back->gray); + png_write_chunk(png_ptr, png_bKGD, buf, (png_size_t)2); + } +} +#endif + +#if defined(PNG_WRITE_hIST_SUPPORTED) +/* write the histogram */ +void +png_write_hIST(png_structp png_ptr, png_uint_16p hist, int num_hist) +{ + int i; + png_byte buf[3]; + + png_debug(1, "in png_write_hIST\n"); + if (num_hist > (int)png_ptr->num_palette) + { + png_debug2(3, "num_hist = %d, num_palette = %d\n", num_hist, + png_ptr->num_palette); + png_warning(png_ptr, "Invalid number of histogram entries specified"); + return; + } + + png_write_chunk_start(png_ptr, png_hIST, (png_uint_32)(num_hist * 2)); + for (i = 0; i < num_hist; i++) + { + png_save_uint_16(buf, hist[i]); + png_write_chunk_data(png_ptr, buf, (png_size_t)2); + } + png_write_chunk_end(png_ptr); +} +#endif + +#if defined(PNG_WRITE_tEXt_SUPPORTED) || defined(PNG_WRITE_zTXt_SUPPORTED) +/* Check that the tEXt or zTXt keyword is valid per PNG 1.0 specification, + * and if invalid, correct the keyword rather than discarding the entire + * chunk. The PNG 1.0 specification requires keywords 1-79 characters in + * length, forbids leading or trailing whitespace, multiple internal spaces, + * and the non-break space (0x80) from ISO 8859-1. Returns keyword length. + * + * The new_key is allocated to hold the corrected keyword and must be freed + * by the calling routine. This avoids problems with trying to write to + * static keywords without having to have duplicate copies of the strings. + */ +png_size_t +png_check_keyword(png_structp png_ptr, png_charp key, png_charpp new_key) +{ + png_size_t key_len; + png_charp kp, dp; + int kflag; + + png_debug(1, "in png_check_keyword\n"); + *new_key = NULL; + + if (key == NULL || (key_len = png_strlen(key)) == 0) + { + png_chunk_warning(png_ptr, "zero length keyword"); + return ((png_size_t)0); + } + + png_debug1(2, "Keyword to be checked is '%s'\n", key); + + *new_key = (png_charp)png_malloc(png_ptr, (png_uint_32)(key_len + 1)); + + /* Replace non-printing characters with a blank and print a warning */ + for (kp = key, dp = *new_key; *kp != '\0'; kp++, dp++) + { + if (*kp < 0x20 || (*kp > 0x7E && (png_byte)*kp < 0xA1)) + { +#if !defined(PNG_NO_STDIO) + char msg[40]; + + sprintf(msg, "invalid keyword character 0x%02X", *kp); + png_chunk_warning(png_ptr, msg); +#else + png_chunk_warning(png_ptr, "invalid character in keyword"); +#endif + *dp = ' '; + } + else + { + *dp = *kp; + } + } + *dp = '\0'; + + /* Remove any trailing white space. */ + kp = *new_key + key_len - 1; + if (*kp == ' ') + { + png_chunk_warning(png_ptr, "trailing spaces removed from keyword"); + + while (*kp == ' ') + { + *(kp--) = '\0'; + key_len--; + } + } + + /* Remove any leading white space. */ + kp = *new_key; + if (*kp == ' ') + { + png_chunk_warning(png_ptr, "leading spaces removed from keyword"); + + while (*kp == ' ') + { + kp++; + key_len--; + } + } + + png_debug1(2, "Checking for multiple internal spaces in '%s'\n", kp); + + /* Remove multiple internal spaces. */ + for (kflag = 0, dp = *new_key; *kp != '\0'; kp++) + { + if (*kp == ' ' && kflag == 0) + { + *(dp++) = *kp; + kflag = 1; + } + else if (*kp == ' ') + { + key_len--; + } + else + { + *(dp++) = *kp; + kflag = 0; + } + } + *dp = '\0'; + + if (key_len == 0) + { + png_chunk_warning(png_ptr, "zero length keyword"); + } + + if (key_len > 79) + { + png_chunk_warning(png_ptr, "keyword length must be 1 - 79 characters"); + new_key[79] = '\0'; + key_len = 79; + } + + return (key_len); +} +#endif + +#if defined(PNG_WRITE_tEXt_SUPPORTED) +/* write a tEXt chunk */ +void +png_write_tEXt(png_structp png_ptr, png_charp key, png_charp text, + png_size_t text_len) +{ + png_size_t key_len; + png_charp new_key; + + png_debug(1, "in png_write_tEXt\n"); + if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0) + { + png_warning(png_ptr, "Empty keyword in tEXt chunk"); + return; + } + + if (text == NULL || *text == '\0') + text_len = 0; + + /* make sure we include the 0 after the key */ + png_write_chunk_start(png_ptr, png_tEXt, (png_uint_32)key_len+text_len+1); + png_write_chunk_data(png_ptr, (png_bytep)new_key, key_len + 1); + if (text_len) + png_write_chunk_data(png_ptr, (png_bytep)text, text_len); + + png_write_chunk_end(png_ptr); + png_free(png_ptr, new_key); +} +#endif + +#if defined(PNG_WRITE_zTXt_SUPPORTED) +/* write a compressed text chunk */ +void +png_write_zTXt(png_structp png_ptr, png_charp key, png_charp text, + png_size_t text_len, int compression) +{ + png_size_t key_len; + char buf[1]; + png_charp new_key; + int i, ret; + png_charpp output_ptr = NULL; /* array of pointers to output */ + int num_output_ptr = 0; /* number of output pointers used */ + int max_output_ptr = 0; /* size of output_ptr */ + + png_debug(1, "in png_write_zTXt\n"); + + if (key == NULL || (key_len = png_check_keyword(png_ptr, key, &new_key))==0) + { + png_warning(png_ptr, "Empty keyword in zTXt chunk"); + return; + } + + if (text == NULL || *text == '\0' || compression==PNG_TEXT_COMPRESSION_NONE) + { + png_write_tEXt(png_ptr, new_key, text, (png_size_t)0); + png_free(png_ptr, new_key); + return; + } + + png_free(png_ptr, new_key); + + if (compression >= PNG_TEXT_COMPRESSION_LAST) + { +#if !defined(PNG_NO_STDIO) + char msg[50]; + sprintf(msg, "Unknown zTXt compression type %d", compression); + png_warning(png_ptr, msg); +#else + png_warning(png_ptr, "Unknown zTXt compression type"); +#endif + compression = PNG_TEXT_COMPRESSION_zTXt; + } + + /* We can't write the chunk until we find out how much data we have, + * which means we need to run the compressor first, and save the + * output. This shouldn't be a problem, as the vast majority of + * comments should be reasonable, but we will set up an array of + * malloc'd pointers to be sure. + * + * If we knew the application was well behaved, we could simplify this + * greatly by assuming we can always malloc an output buffer large + * enough to hold the compressed text ((1001 * text_len / 1000) + 12) + * and malloc this directly. The only time this would be a bad idea is + * if we can't malloc more than 64K and we have 64K of random input + * data, or if the input string is incredibly large (although this + * wouldn't cause a failure, just a slowdown due to swapping). + */ + + /* set up the compression buffers */ + png_ptr->zstream.avail_in = (uInt)text_len; + png_ptr->zstream.next_in = (Bytef *)text; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = (Bytef *)png_ptr->zbuf; + + /* this is the same compression loop as in png_write_row() */ + do + { + /* compress the data */ + ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); + if (ret != Z_OK) + { + /* error */ + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + else + png_error(png_ptr, "zlib error"); + } + /* check to see if we need more room */ + if (!png_ptr->zstream.avail_out && png_ptr->zstream.avail_in) + { + /* make sure the output array has room */ + if (num_output_ptr >= max_output_ptr) + { + int old_max; + + old_max = max_output_ptr; + max_output_ptr = num_output_ptr + 4; + if (output_ptr != NULL) + { + png_charpp old_ptr; + + old_ptr = output_ptr; + output_ptr = (png_charpp)png_malloc(png_ptr, + (png_uint_32)(max_output_ptr * sizeof (png_charpp))); + png_memcpy(output_ptr, old_ptr, old_max * sizeof (png_charp)); + png_free(png_ptr, old_ptr); + } + else + output_ptr = (png_charpp)png_malloc(png_ptr, + (png_uint_32)(max_output_ptr * sizeof (png_charp))); + } + + /* save the data */ + output_ptr[num_output_ptr] = (png_charp)png_malloc(png_ptr, + (png_uint_32)png_ptr->zbuf_size); + png_memcpy(output_ptr[num_output_ptr], png_ptr->zbuf, + png_ptr->zbuf_size); + num_output_ptr++; + + /* and reset the buffer */ + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + } + /* continue until we don't have anymore to compress */ + } while (png_ptr->zstream.avail_in); + + /* finish the compression */ + do + { + /* tell zlib we are finished */ + ret = deflate(&png_ptr->zstream, Z_FINISH); + if (ret != Z_OK && ret != Z_STREAM_END) + { + /* we got an error */ + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + else + png_error(png_ptr, "zlib error"); + } + + /* check to see if we need more room */ + if (!(png_ptr->zstream.avail_out) && ret == Z_OK) + { + /* check to make sure our output array has room */ + if (num_output_ptr >= max_output_ptr) + { + int old_max; + + old_max = max_output_ptr; + max_output_ptr = num_output_ptr + 4; + if (output_ptr != NULL) + { + png_charpp old_ptr; + + old_ptr = output_ptr; + /* This could be optimized to realloc() */ + output_ptr = (png_charpp)png_malloc(png_ptr, + (png_uint_32)(max_output_ptr * sizeof (png_charpp))); + png_memcpy(output_ptr, old_ptr, old_max * sizeof (png_charp)); + png_free(png_ptr, old_ptr); + } + else + output_ptr = (png_charpp)png_malloc(png_ptr, + (png_uint_32)(max_output_ptr * sizeof (png_charp))); + } + + /* save off the data */ + output_ptr[num_output_ptr] = (png_charp)png_malloc(png_ptr, + (png_uint_32)png_ptr->zbuf_size); + png_memcpy(output_ptr[num_output_ptr], png_ptr->zbuf, + png_ptr->zbuf_size); + num_output_ptr++; + + /* and reset the buffer pointers */ + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; + } + } while (ret != Z_STREAM_END); + + /* text length is number of buffers plus last buffer */ + text_len = png_ptr->zbuf_size * num_output_ptr; + if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) + text_len += png_ptr->zbuf_size - (png_size_t)png_ptr->zstream.avail_out; + + /* write start of chunk */ + png_write_chunk_start(png_ptr, png_zTXt, (png_uint_32)(key_len+text_len+2)); + /* write key */ + png_write_chunk_data(png_ptr, (png_bytep)key, key_len + 1); + buf[0] = (png_byte)compression; + /* write compression */ + png_write_chunk_data(png_ptr, (png_bytep)buf, (png_size_t)1); + + /* write saved output buffers, if any */ + for (i = 0; i < num_output_ptr; i++) + { + png_write_chunk_data(png_ptr,(png_bytep)output_ptr[i],png_ptr->zbuf_size); + png_free(png_ptr, output_ptr[i]); + } + if (max_output_ptr != 0) + png_free(png_ptr, output_ptr); + /* write anything left in zbuf */ + if (png_ptr->zstream.avail_out < (png_uint_32)png_ptr->zbuf_size) + png_write_chunk_data(png_ptr, png_ptr->zbuf, + png_ptr->zbuf_size - png_ptr->zstream.avail_out); + /* close the chunk */ + png_write_chunk_end(png_ptr); + + /* reset zlib for another zTXt or the image data */ + deflateReset(&png_ptr->zstream); +} +#endif + + +#if defined(PNG_WRITE_oFFs_SUPPORTED) +/* write the oFFs chunk */ +void +png_write_oFFs(png_structp png_ptr, png_uint_32 x_offset, + png_uint_32 y_offset, + int unit_type) +{ + png_byte buf[9]; + + png_debug(1, "in png_write_oFFs\n"); + if (unit_type >= PNG_OFFSET_LAST) + png_warning(png_ptr, "Unrecognized unit type for oFFs chunk"); + + png_save_uint_32(buf, x_offset); + png_save_uint_32(buf + 4, y_offset); + buf[8] = (png_byte)unit_type; + + png_write_chunk(png_ptr, png_oFFs, buf, (png_size_t)9); +} +#endif + +#if defined(PNG_WRITE_pCAL_SUPPORTED) +/* write the pCAL chunk (png-scivis-19970203) */ +void +png_write_pCAL(png_structp png_ptr, png_charp purpose, png_int_32 X0, + png_int_32 X1, int type, int nparams, png_charp units, png_charpp params) +{ + png_size_t purpose_len, units_len, total_len; + png_uint_32p params_len; + png_byte buf[10]; + png_charp new_purpose; + int i; + + png_debug1(1, "in png_write_pCAL (%d parameters)\n", nparams); + if (type >= PNG_EQUATION_LAST) + png_warning(png_ptr, "Unrecognized equation type for pCAL chunk"); + + purpose_len = png_check_keyword(png_ptr, purpose, &new_purpose) + 1; + png_debug1(3, "pCAL purpose length = %d\n", purpose_len); + units_len = png_strlen(units) + (nparams == 0 ? 0 : 1); + png_debug1(3, "pCAL units length = %d\n", units_len); + total_len = purpose_len + units_len + 10; + + params_len = (png_uint_32p)png_malloc(png_ptr, (png_uint_32)(nparams + *sizeof(png_uint_32))); + + /* Find the length of each parameter, making sure we don't count the + null terminator for the last parameter. */ + for (i = 0; i < nparams; i++) + { + params_len[i] = png_strlen(params[i]) + (i == nparams - 1 ? 0 : 1); + png_debug2(3, "pCAL parameter %d length = %d\n", i, params_len[i]); + total_len += (png_size_t)params_len[i]; + } + + png_debug1(3, "pCAL total length = %d\n", total_len); + png_write_chunk_start(png_ptr, png_pCAL, (png_uint_32)total_len); + png_write_chunk_data(png_ptr, (png_bytep)new_purpose, purpose_len); + png_save_int_32(buf, X0); + png_save_int_32(buf + 4, X1); + buf[8] = (png_byte)type; + buf[9] = (png_byte)nparams; + png_write_chunk_data(png_ptr, buf, (png_size_t)10); + png_write_chunk_data(png_ptr, (png_bytep)units, (png_size_t)units_len); + + png_free(png_ptr, new_purpose); + + for (i = 0; i < nparams; i++) + { + png_write_chunk_data(png_ptr, (png_bytep)params[i], + (png_size_t)params_len[i]); + } + + png_free(png_ptr, params_len); + png_write_chunk_end(png_ptr); +} +#endif + +#if defined(PNG_WRITE_pHYs_SUPPORTED) +/* write the pHYs chunk */ +void +png_write_pHYs(png_structp png_ptr, png_uint_32 x_pixels_per_unit, + png_uint_32 y_pixels_per_unit, + int unit_type) +{ + png_byte buf[9]; + + png_debug(1, "in png_write_pHYs\n"); + if (unit_type >= PNG_RESOLUTION_LAST) + png_warning(png_ptr, "Unrecognized unit type for pHYs chunk"); + + png_save_uint_32(buf, x_pixels_per_unit); + png_save_uint_32(buf + 4, y_pixels_per_unit); + buf[8] = (png_byte)unit_type; + + png_write_chunk(png_ptr, png_pHYs, buf, (png_size_t)9); +} +#endif + +#if defined(PNG_WRITE_tIME_SUPPORTED) +/* Write the tIME chunk. Use either png_convert_from_struct_tm() + * or png_convert_from_time_t(), or fill in the structure yourself. + */ +void +png_write_tIME(png_structp png_ptr, png_timep mod_time) +{ + png_byte buf[7]; + + png_debug(1, "in png_write_tIME\n"); + if (mod_time->month > 12 || mod_time->month < 1 || + mod_time->day > 31 || mod_time->day < 1 || + mod_time->hour > 23 || mod_time->second > 60) + { + png_warning(png_ptr, "Invalid time specified for tIME chunk"); + return; + } + + png_save_uint_16(buf, mod_time->year); + buf[2] = mod_time->month; + buf[3] = mod_time->day; + buf[4] = mod_time->hour; + buf[5] = mod_time->minute; + buf[6] = mod_time->second; + + png_write_chunk(png_ptr, png_tIME, buf, (png_size_t)7); +} +#endif + +/* initializes the row writing capability of libpng */ +void +png_write_start_row(png_structp png_ptr) +{ + png_size_t buf_size; + + png_debug(1, "in png_write_start_row\n"); + buf_size = (png_size_t)(((png_ptr->width * png_ptr->usr_channels * + png_ptr->usr_bit_depth + 7) >> 3) + 1); + + /* set up row buffer */ + png_ptr->row_buf = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size); + png_ptr->row_buf[0] = PNG_FILTER_VALUE_NONE; + + /* set up filtering buffer, if using this filter */ + if (png_ptr->do_filter & PNG_FILTER_SUB) + { + png_ptr->sub_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->sub_row[0] = PNG_FILTER_VALUE_SUB; + } + + /* We only need to keep the previous row if we are using one of these. */ + if (png_ptr->do_filter & (PNG_FILTER_AVG | PNG_FILTER_UP | PNG_FILTER_PAETH)) + { + /* set up previous row buffer */ + png_ptr->prev_row = (png_bytep)png_malloc(png_ptr, (png_uint_32)buf_size); + png_memset(png_ptr->prev_row, 0, buf_size); + + if (png_ptr->do_filter & PNG_FILTER_UP) + { + png_ptr->up_row = (png_bytep )png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->up_row[0] = PNG_FILTER_VALUE_UP; + } + + if (png_ptr->do_filter & PNG_FILTER_AVG) + { + png_ptr->avg_row = (png_bytep)png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->avg_row[0] = PNG_FILTER_VALUE_AVG; + } + + if (png_ptr->do_filter & PNG_FILTER_PAETH) + { + png_ptr->paeth_row = (png_bytep )png_malloc(png_ptr, + (png_ptr->rowbytes + 1)); + png_ptr->paeth_row[0] = PNG_FILTER_VALUE_PAETH; + } + } + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* if interlaced, we need to set up width and height of pass */ + if (png_ptr->interlaced) + { + if (!(png_ptr->transformations & PNG_INTERLACE)) + { + png_ptr->num_rows = (png_ptr->height + png_pass_yinc[0] - 1 - + png_pass_ystart[0]) / png_pass_yinc[0]; + png_ptr->usr_width = (png_ptr->width + png_pass_inc[0] - 1 - + png_pass_start[0]) / png_pass_inc[0]; + } + else + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } + } + else +#endif + { + png_ptr->num_rows = png_ptr->height; + png_ptr->usr_width = png_ptr->width; + } + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + png_ptr->zstream.next_out = png_ptr->zbuf; +} + +/* Internal use only. Called when finished processing a row of data. */ +void +png_write_finish_row(png_structp png_ptr) +{ + int ret; + + png_debug(1, "in png_write_finish_row\n"); + /* next row */ + png_ptr->row_number++; + + /* see if we are done */ + if (png_ptr->row_number < png_ptr->num_rows) + return; + +#ifdef PNG_WRITE_INTERLACING_SUPPORTED + /* if interlaced, go to next pass */ + if (png_ptr->interlaced) + { + png_ptr->row_number = 0; + if (png_ptr->transformations & PNG_INTERLACE) + { + png_ptr->pass++; + } + else + { + /* loop until we find a non-zero width or height pass */ + do + { + png_ptr->pass++; + if (png_ptr->pass >= 7) + break; + png_ptr->usr_width = (png_ptr->width + + png_pass_inc[png_ptr->pass] - 1 - + png_pass_start[png_ptr->pass]) / + png_pass_inc[png_ptr->pass]; + png_ptr->num_rows = (png_ptr->height + + png_pass_yinc[png_ptr->pass] - 1 - + png_pass_ystart[png_ptr->pass]) / + png_pass_yinc[png_ptr->pass]; + if (png_ptr->transformations & PNG_INTERLACE) + break; + } while (png_ptr->usr_width == 0 || png_ptr->num_rows == 0); + + } + + /* reset the row above the image for the next pass */ + if (png_ptr->pass < 7) + { + if (png_ptr->prev_row != NULL) + png_memset(png_ptr->prev_row, 0, + (png_size_t) (((png_uint_32)png_ptr->usr_channels * + (png_uint_32)png_ptr->usr_bit_depth * + png_ptr->width + 7) >> 3) + 1); + return; + } + } +#endif + + /* if we get here, we've just written the last row, so we need + to flush the compressor */ + do + { + /* tell the compressor we are done */ + ret = deflate(&png_ptr->zstream, Z_FINISH); + /* check for an error */ + if (ret != Z_OK && ret != Z_STREAM_END) + { + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + else + png_error(png_ptr, "zlib error"); + } + /* check to see if we need more room */ + if (!(png_ptr->zstream.avail_out) && ret == Z_OK) + { + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + } while (ret != Z_STREAM_END); + + /* write any extra space */ + if (png_ptr->zstream.avail_out < png_ptr->zbuf_size) + { + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size - + png_ptr->zstream.avail_out); + } + + deflateReset(&png_ptr->zstream); +} + +#if defined(PNG_WRITE_INTERLACING_SUPPORTED) +/* Pick out the correct pixels for the interlace pass. + * The basic idea here is to go through the row with a source + * pointer and a destination pointer (sp and dp), and copy the + * correct pixels for the pass. As the row gets compacted, + * sp will always be >= dp, so we should never overwrite anything. + * See the default: case for the easiest code to understand. + */ +void +png_do_write_interlace(png_row_infop row_info, png_bytep row, int pass) +{ + png_debug(1, "in png_do_write_interlace\n"); + /* we don't have to do anything on the last pass (6) */ +#if defined(PNG_USELESS_TESTS_SUPPORTED) + if (row != NULL && row_info != NULL && pass < 6) +#else + if (pass < 6) +#endif + { + /* each pixel depth is handled seperately */ + switch (row_info->pixel_depth) + { + case 1: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + + dp = row; + d = 0; + shift = 7; + for (i = png_pass_start[pass]; i < row_info->width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 3); + value = (int)(*sp >> (7 - (int)(i & 7))) & 0x1; + d |= (value << shift); + + if (shift == 0) + { + shift = 7; + *dp++ = (png_byte)d; + d = 0; + } + else + shift--; + + } + if (shift != 7) + *dp = (png_byte)d; + break; + } + case 2: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + + dp = row; + shift = 6; + d = 0; + for (i = png_pass_start[pass]; i < row_info->width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 2); + value = (*sp >> ((3 - (int)(i & 3)) << 1)) & 0x3; + d |= (value << shift); + + if (shift == 0) + { + shift = 6; + *dp++ = (png_byte)d; + d = 0; + } + else + shift -= 2; + } + if (shift != 6) + *dp = (png_byte)d; + break; + } + case 4: + { + png_bytep sp; + png_bytep dp; + int shift; + int d; + int value; + png_uint_32 i; + + dp = row; + shift = 4; + d = 0; + for (i = png_pass_start[pass]; i < row_info->width; + i += png_pass_inc[pass]) + { + sp = row + (png_size_t)(i >> 1); + value = (*sp >> ((1 - (int)(i & 1)) << 2)) & 0xf; + d |= (value << shift); + + if (shift == 0) + { + shift = 4; + *dp++ = (png_byte)d; + d = 0; + } + else + shift -= 4; + } + if (shift != 4) + *dp = (png_byte)d; + break; + } + default: + { + png_bytep sp; + png_bytep dp; + png_uint_32 i; + png_size_t pixel_bytes; + + /* start at the beginning */ + dp = row; + /* find out how many bytes each pixel takes up */ + pixel_bytes = (row_info->pixel_depth >> 3); + /* loop through the row, only looking at the pixels that + matter */ + for (i = png_pass_start[pass]; i < row_info->width; + i += png_pass_inc[pass]) + { + /* find out where the original pixel is */ + sp = row + (png_size_t)i * pixel_bytes; + /* move the pixel */ + if (dp != sp) + png_memcpy(dp, sp, pixel_bytes); + /* next pixel */ + dp += pixel_bytes; + } + break; + } + } + /* set new row width */ + row_info->width = (row_info->width + + png_pass_inc[pass] - 1 - + png_pass_start[pass]) / + png_pass_inc[pass]; + row_info->rowbytes = ((row_info->width * + row_info->pixel_depth + 7) >> 3); + } +} +#endif + +/* This filters the row, chooses which filter to use, if it has not already + * been specified by the application, and then writes the row out with the + * chosen filter. + */ +#define PNG_MAXSUM (~((png_uint_32)0) >> 1) +#define PNG_HISHIFT 10 +#define PNG_LOMASK ((png_uint_32)0xffffL) +#define PNG_HIMASK ((png_uint_32)(~PNG_LOMASK >> PNG_HISHIFT)) +void +png_write_find_filter(png_structp png_ptr, png_row_infop row_info) +{ + png_bytep prev_row, best_row, row_buf; + png_uint_32 mins, bpp; + + png_debug(1, "in png_write_find_filter\n"); + /* find out how many bytes offset each pixel is */ + bpp = (row_info->pixel_depth + 7) / 8; + + prev_row = png_ptr->prev_row; + best_row = row_buf = png_ptr->row_buf; + mins = PNG_MAXSUM; + + /* The prediction method we use is to find which method provides the + * smallest value when summing the absolute values of the distances + * from zero using anything >= 128 as negative numbers. This is known + * as the "minimum sum of absolute differences" heuristic. Other + * heuristics are the "weighted minumum sum of absolute differences" + * (experimental and can in theory improve compression), and the "zlib + * predictive" method (not implemented in libpng 0.95), which does test + * compressions of lines using different filter methods, and then chooses + * the (series of) filter(s) which give minimum compressed data size (VERY + * computationally expensive). + */ + + /* We don't need to test the 'no filter' case if this is the only filter + * that has been chosen, as it doesn't actually do anything to the data. + */ + if (png_ptr->do_filter & PNG_FILTER_NONE && + png_ptr->do_filter != PNG_FILTER_NONE) + { + png_bytep rp; + png_uint_32 sum = 0; + png_uint_32 i; + int v; + + for (i = 0, rp = row_buf + 1; i < row_info->rowbytes; i++, rp++) + { + v = *rp; + sum += (v < 128) ? v : 256 - v; + } + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; /* Gives us some footroom */ + + /* Reduce the sum if we match any of the previous rows */ + for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_NONE) + { + sumlo = (sumlo * png_ptr->filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + /* Factor in the cost of this filter (this is here for completeness, + * but it makes no sense to have a "cost" for the NONE filter, as + * it has the minimum possible computational cost - none). + */ + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_NONE]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + mins = sum; + } + + /* sub filter */ + if (png_ptr->do_filter & PNG_FILTER_SUB) + { + png_bytep rp, dp, lp; + png_uint_32 sum = 0, lmins = mins; + png_uint_32 i; + int v; + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + /* We temporarily increase the "minumum sum" by the factor we + * would reduce the sum of this filter, so that we can do the + * early exit comparison without scaling the sum each time. + */ + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_SUB) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->sub_row + 1; i < bpp; + i++, rp++, dp++) + { + v = *dp = *rp; + + sum += (v < 128) ? v : 256 - v; + } + for (lp = row_buf + 1; i < row_info->rowbytes; + i++, rp++, lp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*lp) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_SUB) + { + sumlo = (sumlo * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_SUB]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->sub_row; + } + } + + /* up filter */ + if (png_ptr->do_filter & PNG_FILTER_UP) + { + png_bytep rp, dp, pp; + png_uint_32 sum = 0, lmins = mins; + png_uint_32 i; + int v; + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_UP) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->up_row + 1, + pp = prev_row + 1; i < row_info->rowbytes; + i++, rp++, pp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_UP) + { + sumlo = (sumlo * png_ptr->filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_UP]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->up_row; + } + } + + /* avg filter */ + if (png_ptr->do_filter & PNG_FILTER_AVG) + { + png_bytep rp, dp, pp, lp; + png_uint_32 sum = 0, lmins = mins; + png_uint_32 i; + int v; + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (i = 0; i < (png_uint_32)png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_AVG) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->avg_row + 1, + pp = prev_row + 1; i < bpp; i++, rp++, pp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - ((int)*pp / 2)) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + for (lp = row_buf + 1; i < row_info->rowbytes; + i++, rp++, pp++, lp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (((int)*pp + (int)*lp) / 2)) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (i = 0; i < png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_NONE) + { + sumlo = (sumlo * png_ptr->filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_AVG]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + mins = sum; + best_row = png_ptr->avg_row; + } + } + + /* Paeth filter */ + if (png_ptr->do_filter & PNG_FILTER_PAETH) + { + png_bytep rp, dp, pp, cp, lp; + png_uint_32 sum = 0, lmins = mins; + png_uint_32 i; + int v; + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 lmhi, lmlo; + lmlo = lmins & PNG_LOMASK; + lmhi = (lmins >> PNG_HISHIFT) & PNG_HIMASK; + + for (i = 0; i < png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_VALUE_PAETH) + { + lmlo = (lmlo * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + lmlo = (lmlo * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + lmhi = (lmhi * png_ptr->inv_filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + if (lmhi > PNG_HIMASK) + lmins = PNG_MAXSUM; + else + lmins = (lmhi << PNG_HISHIFT) + lmlo; + } +#endif + + for (i = 0, rp = row_buf + 1, dp = png_ptr->paeth_row + 1, + pp = prev_row + 1; (unsigned)i < bpp; i++, rp++, pp++, dp++) + { + v = *dp = (png_byte)(((int)*rp - (int)*pp) & 0xff); + + sum += (v < 128) ? v : 256 - v; + } + for (lp = row_buf + 1, cp = prev_row + 1; i < row_info->rowbytes; + i++, rp++, pp++, lp++, dp++, cp++) + { + int a, b, c, pa, pb, pc, p; + + b = *pp; + c = *cp; + a = *lp; + + p = a + b - c; + pa = abs(p - a); + pb = abs(p - b); + pc = abs(p - c); + + if (pa <= pb && pa <= pc) + p = a; + else if (pb <= pc) + p = b; + else + p = c; + + v = *dp = (png_byte)(((int)*rp - p) & 0xff); + + sum += (v < 128) ? v : 256 - v; + + if (sum > lmins) /* We are already worse, don't continue. */ + break; + } + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + if (png_ptr->heuristic_method == PNG_FILTER_HEURISTIC_WEIGHTED) + { + png_uint_32 sumhi, sumlo; + sumlo = sum & PNG_LOMASK; + sumhi = (sum >> PNG_HISHIFT) & PNG_HIMASK; + + for (i = 0; i < png_ptr->num_prev_filters; i++) + { + if (png_ptr->prev_filters[i] == PNG_FILTER_PAETH) + { + sumlo = (sumlo * png_ptr->filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + sumhi = (sumhi * png_ptr->filter_weights[i]) >> + PNG_WEIGHT_SHIFT; + } + } + + sumlo = (sumlo * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + sumhi = (sumhi * png_ptr->filter_costs[PNG_FILTER_VALUE_PAETH]) >> + PNG_COST_SHIFT; + + if (sumhi > PNG_HIMASK) + sum = PNG_MAXSUM; + else + sum = (sumhi << PNG_HISHIFT) + sumlo; + } +#endif + + if (sum < mins) + { + best_row = png_ptr->paeth_row; + } + } + + /* Do the actual writing of the filtered row data from the chosen filter. */ + png_write_filtered_row(png_ptr, best_row); + +#if defined(PNG_WRITE_WEIGHTED_FILTER_SUPPORTED) + /* Save the type of filter we picked this time for future calculations */ + if (png_ptr->num_prev_filters > 0) + { + int i; + + for (i = 1; i < (int)png_ptr->num_prev_filters; i++) + { + png_ptr->prev_filters[i] = png_ptr->prev_filters[i - 1]; + } + png_ptr->prev_filters[i] = best_row[0]; + } +#endif +} + + +/* Do the actual writing of a previously filtered row. */ +void +png_write_filtered_row(png_structp png_ptr, png_bytep filtered_row) +{ + png_debug(1, "in png_write_filtered_row\n"); + png_debug1(2, "filter = %d\n", filtered_row[0]); + /* set up the zlib input buffer */ + png_ptr->zstream.next_in = filtered_row; + png_ptr->zstream.avail_in = (uInt)png_ptr->row_info.rowbytes + 1; + /* repeat until we have compressed all the data */ + do + { + int ret; /* return of zlib */ + + /* compress the data */ + ret = deflate(&png_ptr->zstream, Z_NO_FLUSH); + /* check for compression errors */ + if (ret != Z_OK) + { + if (png_ptr->zstream.msg != NULL) + png_error(png_ptr, png_ptr->zstream.msg); + else + png_error(png_ptr, "zlib error"); + } + + /* see if it is time to write another IDAT */ + if (!(png_ptr->zstream.avail_out)) + { + /* write the IDAT and reset the zlib output buffer */ + png_write_IDAT(png_ptr, png_ptr->zbuf, png_ptr->zbuf_size); + png_ptr->zstream.next_out = png_ptr->zbuf; + png_ptr->zstream.avail_out = (uInt)png_ptr->zbuf_size; + } + /* repeat until all data has been compressed */ + } while (png_ptr->zstream.avail_in); + + /* swap the current and previous rows */ + if (png_ptr->prev_row != NULL) + { + png_bytep tptr; + + tptr = png_ptr->prev_row; + png_ptr->prev_row = png_ptr->row_buf; + png_ptr->row_buf = tptr; + } + + /* finish row - updates counters and flushes zlib if last row */ + png_write_finish_row(png_ptr); + +#if defined(PNG_WRITE_FLUSH_SUPPORTED) + png_ptr->flush_rows++; + + if (png_ptr->flush_dist > 0 && + png_ptr->flush_rows >= png_ptr->flush_dist) + { + png_write_flush(png_ptr); + } +#endif /* PNG_WRITE_FLUSH_SUPPORTED */ +} diff --git a/thirdparty/libpng/scripts/SCOPTIONS.ppc b/thirdparty/libpng/scripts/SCOPTIONS.ppc new file mode 100644 index 00000000..2c3503e9 --- /dev/null +++ b/thirdparty/libpng/scripts/SCOPTIONS.ppc @@ -0,0 +1,7 @@ +OPTIMIZE +OPTPEEP +OPTTIME +OPTSCHED +AUTOREGISTER +PARMS=REGISTERS +INCLUDEDIR=hlp:ppc/include diff --git a/thirdparty/libpng/scripts/build.bat b/thirdparty/libpng/scripts/build.bat new file mode 100644 index 00000000..ec34b6f0 --- /dev/null +++ b/thirdparty/libpng/scripts/build.bat @@ -0,0 +1,2 @@ +make -fmakefile.bor -B -DMODEL=m %1 %2 %3 libpng >buildm.out +make -fmakefile.bor -B -DMODEL=l %1 %2 %3 libpng >buildl.out diff --git a/thirdparty/libpng/scripts/descrip.mms b/thirdparty/libpng/scripts/descrip.mms new file mode 100644 index 00000000..3584b0d7 --- /dev/null +++ b/thirdparty/libpng/scripts/descrip.mms @@ -0,0 +1,52 @@ + +cc_defs = /inc=$(ZLIBSRC) +c_deb = + +.ifdef __DECC__ +pref = /prefix=all +.endif + + + +OBJS = png.obj, pngset.obj, pngget.obj, pngrutil.obj, pngtrans.obj,\ + pngwutil.obj, pngread.obj, pngmem.obj, pngwrite.obj, pngrtran.obj,\ + pngwtran.obj, pngrio.obj, pngwio.obj, pngerror.obj, pngpread.obj + + +CFLAGS= $(C_DEB) $(CC_DEFS) $(PREF) + +all : pngtest.exe libpng.olb + @ write sys$output " pngtest available" + +libpng.olb : libpng.olb($(OBJS)) + @ write sys$output " Libpng available" + + +pngtest.exe : pngtest.obj libpng.olb + link pngtest,libpng.olb/lib,$(ZLIBSRC)libz.olb/lib + +test : pngtest.exe + run pngtest + +clean : + delete *.obj;*,*.exe;* + + +# Other dependencies. +png.obj : png.h, pngconf.h +pngpread.obj : png.h, pngconf.h +pngset.obj : png.h, pngconf.h +pngget.obj : png.h, pngconf.h +pngread.obj : png.h, pngconf.h +pngrtran.obj : png.h, pngconf.h +pngrutil.obj : png.h, pngconf.h +pngerror.obj : png.h, pngconf.h +pngmem.obj : png.h, pngconf.h +pngrio.obj : png.h, pngconf.h +pngwio.obj : png.h, pngconf.h +pngtest.obj : png.h, pngconf.h +pngtrans.obj : png.h, pngconf.h +pngwrite.obj : png.h, pngconf.h +pngwtran.obj : png.h, pngconf.h +pngwutil.obj : png.h, pngconf.h + diff --git a/thirdparty/libpng/scripts/makefile.aco b/thirdparty/libpng/scripts/makefile.aco new file mode 100644 index 00000000..2cb08987 --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.aco @@ -0,0 +1,221 @@ +# Project: libpng + + +# Toolflags: +CCflags = -c -depend !Depend -IC:,Zlib: -g -throwback -DRISCOS -fnah +C++flags = -c -depend !Depend -IC: -throwback +Linkflags = -aif -c++ -o $@ +ObjAsmflags = -throwback -NoCache -depend !Depend +CMHGflags = +LibFileflags = -c -l -o $@ +Squeezeflags = -o $@ + + +# Final targets: +@.libpng-lib: @.o.png @.o.pngerror @.o.pngrio @.o.pngwio @.o.pngmem \ + @.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngrtran \ + @.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil + LibFile $(LibFileflags) @.o.png @.o.pngerror @.o.pngrio @.o.pngrtran \ + @.o.pngmem @.o.pngpread @.o.pngset @.o.pngget @.o.pngread @.o.pngwio \ + @.o.pngrutil @.o.pngtrans @.o.pngwrite @.o.pngwtran @.o.pngwutil +@.mm-libpng-lib: @.mm.png @.mm.pngerror @.mm.pngrio @.mm.pngwio @.mm.pngmem \ + @.mm.pngpread @.mm.pngset @.mm.pngget @.mm.pngread @.mm.pngrtran \ + @.mm.pngrutil @.mm.pngtrans @.mm.pngwrite @.mm.pngwtran @.mm.pngwutil + LibFile $(LibFileflags) @.mm.png @.mm.pngerror @.mm.pngrio \ + @.mm.pngwio @.mm.pngmem @.mm.pngpread @.mm.pngset @.mm.pngget \ + @.mm.pngread @.mm.pngrtran @.mm.pngrutil @.mm.pngtrans @.mm.pngwrite \ + @.mm.pngwtran @.mm.pngwutil + + +# User-editable dependencies: +# (C) Copyright 1997 Tom Tanner +Test: @.pngtest + .pngtest + @remove .pngtest + +#It would be nice if you could stop "make" listing from here on! +@.pngtest: @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib + Link $(Linkflags) @.o.pngtest @.libpng-lib C:o.Stubs Zlib:zlib_lib + +.SUFFIXES: .o .mm .c + +.c.mm: + MemCheck.CC cc $(ccflags) -o $@ LibPng:$< +.c.o: + cc $(ccflags) -o $@ $< + + +# Static dependencies: + + +# Dynamic dependencies: +o.pngtest: c.pngtest +o.pngtest: h.png +o.pngtest: Zlib:h.zlib +o.pngtest: Zlib:h.zconf +o.pngtest: h.pngconf +mm.png: LibPng:c.png +mm.png: LibPng:h.png +mm.png: Zlib:h.zlib +mm.png: Zlib:h.zconf +mm.png: LibPng:h.pngconf +mm.png: MemCheck:ANSI.h.stdio +mm.pngerror: LibPng:c.pngerror +mm.pngerror: LibPng:h.png +mm.pngerror: Zlib:h.zlib +mm.pngerror: Zlib:h.zconf +mm.pngerror: LibPng:h.pngconf +mm.pngerror: MemCheck:ANSI.h.stdio +mm.pngrio: LibPng:c.pngrio +mm.pngrio: LibPng:h.png +mm.pngrio: Zlib:h.zlib +mm.pngrio: Zlib:h.zconf +mm.pngrio: LibPng:h.pngconf +mm.pngrio: MemCheck:ANSI.h.stdio +mm.pngwio: LibPng:c.pngwio +mm.pngwio: LibPng:h.png +mm.pngwio: Zlib:h.zlib +mm.pngwio: Zlib:h.zconf +mm.pngwio: LibPng:h.pngconf +mm.pngwio: MemCheck:ANSI.h.stdio +mm.pngmem: LibPng:c.pngmem +mm.pngmem: LibPng:h.png +mm.pngmem: Zlib:h.zlib +mm.pngmem: Zlib:h.zconf +mm.pngmem: LibPng:h.pngconf +mm.pngmem: MemCheck:ANSI.h.stdio +mm.pngpread: LibPng:c.pngpread +mm.pngpread: LibPng:h.png +mm.pngpread: Zlib:h.zlib +mm.pngpread: Zlib:h.zconf +mm.pngpread: LibPng:h.pngconf +mm.pngpread: MemCheck:ANSI.h.stdio +mm.pngset: LibPng:c.pngset +mm.pngset: LibPng:h.png +mm.pngset: Zlib:h.zlib +mm.pngset: Zlib:h.zconf +mm.pngset: LibPng:h.pngconf +mm.pngset: MemCheck:ANSI.h.stdio +mm.pngget: LibPng:c.pngget +mm.pngget: LibPng:h.png +mm.pngget: Zlib:h.zlib +mm.pngget: Zlib:h.zconf +mm.pngget: LibPng:h.pngconf +mm.pngget: MemCheck:ANSI.h.stdio +mm.pngread: LibPng:c.pngread +mm.pngread: LibPng:h.png +mm.pngread: Zlib:h.zlib +mm.pngread: Zlib:h.zconf +mm.pngread: LibPng:h.pngconf +mm.pngread: MemCheck:ANSI.h.stdio +mm.pngrtran: LibPng:c.pngrtran +mm.pngrtran: LibPng:h.png +mm.pngrtran: Zlib:h.zlib +mm.pngrtran: Zlib:h.zconf +mm.pngrtran: LibPng:h.pngconf +mm.pngrtran: MemCheck:ANSI.h.stdio +mm.pngrutil: LibPng:c.pngrutil +mm.pngrutil: LibPng:h.png +mm.pngrutil: Zlib:h.zlib +mm.pngrutil: Zlib:h.zconf +mm.pngrutil: LibPng:h.pngconf +mm.pngrutil: MemCheck:ANSI.h.stdio +mm.pngtrans: LibPng:c.pngtrans +mm.pngtrans: LibPng:h.png +mm.pngtrans: Zlib:h.zlib +mm.pngtrans: Zlib:h.zconf +mm.pngtrans: LibPng:h.pngconf +mm.pngtrans: MemCheck:ANSI.h.stdio +mm.pngwrite: LibPng:c.pngwrite +mm.pngwrite: LibPng:h.png +mm.pngwrite: Zlib:h.zlib +mm.pngwrite: Zlib:h.zconf +mm.pngwrite: LibPng:h.pngconf +mm.pngwrite: MemCheck:ANSI.h.stdio +mm.pngwtran: LibPng:c.pngwtran +mm.pngwtran: LibPng:h.png +mm.pngwtran: Zlib:h.zlib +mm.pngwtran: Zlib:h.zconf +mm.pngwtran: LibPng:h.pngconf +mm.pngwtran: MemCheck:ANSI.h.stdio +mm.pngwutil: LibPng:c.pngwutil +mm.pngwutil: LibPng:h.png +mm.pngwutil: Zlib:h.zlib +mm.pngwutil: Zlib:h.zconf +mm.pngwutil: LibPng:h.pngconf +mm.pngwutil: MemCheck:ANSI.h.stdio +o.png: c.png +o.png: h.png +o.png: Zlib:h.zlib +o.png: Zlib:h.zconf +o.png: h.pngconf +o.pngerror: c.pngerror +o.pngerror: h.png +o.pngerror: Zlib:h.zlib +o.pngerror: Zlib:h.zconf +o.pngerror: h.pngconf +o.pngrio: c.pngrio +o.pngrio: h.png +o.pngrio: Zlib:h.zlib +o.pngrio: Zlib:h.zconf +o.pngrio: h.pngconf +o.pngwio: c.pngwio +o.pngwio: h.png +o.pngwio: Zlib:h.zlib +o.pngwio: Zlib:h.zconf +o.pngwio: h.pngconf +o.pngmem: c.pngmem +o.pngmem: h.png +o.pngmem: Zlib:h.zlib +o.pngmem: Zlib:h.zconf +o.pngmem: h.pngconf +o.pngpread: c.pngpread +o.pngpread: h.png +o.pngpread: Zlib:h.zlib +o.pngpread: Zlib:h.zconf +o.pngpread: h.pngconf +o.pngset: c.pngset +o.pngset: h.png +o.pngset: Zlib:h.zlib +o.pngset: Zlib:h.zconf +o.pngset: h.pngconf +o.pngget: c.pngget +o.pngget: h.png +o.pngget: Zlib:h.zlib +o.pngget: Zlib:h.zconf +o.pngget: h.pngconf +o.pngread: c.pngread +o.pngread: h.png +o.pngread: Zlib:h.zlib +o.pngread: Zlib:h.zconf +o.pngread: h.pngconf +o.pngrtran: c.pngrtran +o.pngrtran: h.png +o.pngrtran: Zlib:h.zlib +o.pngrtran: Zlib:h.zconf +o.pngrtran: h.pngconf +o.pngrutil: c.pngrutil +o.pngrutil: h.png +o.pngrutil: Zlib:h.zlib +o.pngrutil: Zlib:h.zconf +o.pngrutil: h.pngconf +o.pngtrans: c.pngtrans +o.pngtrans: h.png +o.pngtrans: Zlib:h.zlib +o.pngtrans: Zlib:h.zconf +o.pngtrans: h.pngconf +o.pngwrite: c.pngwrite +o.pngwrite: h.png +o.pngwrite: Zlib:h.zlib +o.pngwrite: Zlib:h.zconf +o.pngwrite: h.pngconf +o.pngwtran: c.pngwtran +o.pngwtran: h.png +o.pngwtran: Zlib:h.zlib +o.pngwtran: Zlib:h.zconf +o.pngwtran: h.pngconf +o.pngwutil: c.pngwutil +o.pngwutil: h.png +o.pngwutil: Zlib:h.zlib +o.pngwutil: Zlib:h.zconf +o.pngwutil: h.pngconf diff --git a/thirdparty/libpng/scripts/makefile.ama b/thirdparty/libpng/scripts/makefile.ama new file mode 100644 index 00000000..366524d5 --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.ama @@ -0,0 +1,42 @@ +# Commodore Amiga Makefile +# makefile for libpng and SAS C V6.55 compiler +# Copyright (C) 1995 Wolf Faust + +#compiler +CC=sc +#compiler flags +# WARNING: a bug in V6.51 causes bad code with OPTGO +# So use V6.55 or set NOOPTGO!!!!!!!!! +CFLAGS= NOSTKCHK PARMS=REG OPTIMIZE OPTGO OPTPEEP OPTINLOCAL OPTINL\ + OPTLOOP OPTRDEP=4 OPTDEP=4 OPTCOMP=4 DEFINE=PNG_INTERNAL +#linker flags +LDFLAGS= SD ND BATCH +#link libs +LDLIBS= libpng.lib libgz.lib LIB:scm.lib LIB:sc.lib Lib:amiga.lib +# linker +LN= slink +# file deletion command +RM= delete quiet +# library (.lib) file creation command +AR= oml +# make directory command +MKDIR= makedir + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o pngpread.o \ +pngread.o pngerror.o pngwrite.o pngrtran.o pngwtran.o pngrio.o pngwio.o pngmem.o + +all: libpng.lib pngtest + +libpng.lib: $(OBJS) +-$(RM) libpng.lib +$(AR) libpng.lib r $(OBJS) + +pngtest: pngtest.o libpng.lib +$(LN) > pngerrs + +# variables +OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O) +OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O) +OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O) + +all: libpng.lib + +png$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngset$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngget$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngread$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngpread$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngrtran$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngrutil$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngerror$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngmem$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngrio$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngwio$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngtest$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngtrans$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngwrite$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngwtran$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +pngwutil$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c $(ERRFILE) + +libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3) + del libpng.lib + lib libpng $(OBJS1); + lib libpng $(OBJS2); + lib libpng $(OBJS3); + +pngtest.exe: pngtest.obj libpng.lib + $(LD) $(LDFLAGS) pngtest.obj,,,libpng.lib ..\zlib\zlib.lib ; + +test: pngtest.exe + pngtest + +# End of makefile for libpng + diff --git a/thirdparty/libpng/scripts/makefile.os2 b/thirdparty/libpng/scripts/makefile.os2 new file mode 100644 index 00000000..a3ff2dca --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.os2 @@ -0,0 +1,69 @@ +# makefile for libpng on OS/2 with gcc +# For conditions of distribution and use, see copyright notice in png.h + +# Related files: pngos2.def + +CC=gcc -Zomf -s + +# Where the zlib library and include files are located +ZLIBLIB=../zlib +ZLIBINC=../zlib + +WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \ + -Wmissing-declarations -Wtraditional -Wcast-align \ + -Wstrict-prototypes -Wmissing-prototypes #-Wconversion +CFLAGS=-I$(ZLIBINC) -Wall -O6 -funroll-loops -malign-loops=2 \ + -malign-functions=2 #$(WARNMORE) -g -DPNG_DEBUG=5 +LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lzdll -Zcrtdll +AR=emxomfar + +PNGLIB=png.lib +IMPLIB=emximp +SHAREDLIB=png.dll +SHAREDLIBIMP=pngdll.lib + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \ + pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \ + pngwtran.o pngmem.o pngerror.o pngpread.o + +.SUFFIXES: .c .o + +all: $(PNGLIB) $(SHAREDLIB) $(SHAREDLIBIMP) + +$(PNGLIB): $(OBJS) + $(AR) rc $@ $(OBJS) + +$(SHAREDLIB): $(OBJS) pngos2.def + $(CC) $(LDFLAGS) -Zdll -o $@ $^ + +$(SHAREDLIBIMP): pngos2.def + $(IMPLIB) -o $@ $^ + +pngtest.exe: pngtest.o png.dll pngdll.lib + $(CC) -o $@ $(CFLAGS) $< $(LDFLAGS) + +test: pngtest.exe + ./pngtest.exe + +clean: + rm -f *.o $(PNGLIB) png.dll pngdll.lib pngtest.exe pngout.png + +# DO NOT DELETE THIS LINE -- make depend depends on it. + +png.o png.pic.o: png.h pngconf.h +pngerror.o pngerror.pic.o: png.h pngconf.h +pngrio.o pngrio.pic.o: png.h pngconf.h +pngwio.o pngwio.pic.o: png.h pngconf.h +pngmem.o pngmem.pic.o: png.h pngconf.h +pngset.o pngset.pic.o: png.h pngconf.h +pngget.o pngget.pic.o: png.h pngconf.h +pngread.o pngread.pic.o: png.h pngconf.h +pngrtran.o pngrtran.pic.o: png.h pngconf.h +pngrutil.o pngrutil.pic.o: png.h pngconf.h +pngtrans.o pngtrans.pic.o: png.h pngconf.h +pngwrite.o pngwrite.pic.o: png.h pngconf.h +pngwtran.o pngwtran.pic.o: png.h pngconf.h +pngwutil.o pngwutil.pic.o: png.h pngconf.h +pngpread.o pngpread.pic.o: png.h pngconf.h + +pngtest.o: png.h pngconf.h diff --git a/thirdparty/libpng/scripts/makefile.s2x b/thirdparty/libpng/scripts/makefile.s2x new file mode 100644 index 00000000..0503890a --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.s2x @@ -0,0 +1,98 @@ + makefile for libpng on Solaris 2.x with gcc +# Contributed by William L. Sebok, based on makefile.lnx +# Copyright (C) 1996, 1997 Andreas Dilger +# Copyright (C) 1998 Greg Roelofs +# For conditions of distribution and use, see copyright notice in png.h + +CC=gcc + +# Where the zlib library and include files are located +ZLIBLIB=/usr/local/lib +ZLIBINC=/usr/local/include + +WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \ + -Wmissing-declarations -Wtraditional -Wcast-align \ + -Wstrict-prototypes -Wmissing-prototypes #-Wconversion +CFLAGS=-I$(ZLIBINC) -Wall -O3 \ + #$(WARNMORE) -g -DPNG_DEBUG=5 +LDFLAGS=-L. -R. -L$(ZLIBLIB) -R$(ZLIBLIB) -lpng -lz -lm + +#RANLIB=ranlib +RANLIB=echo + +# read libpng.txt or png.h to see why PNGMAJ is 2. You should not +# have to change it. +PNGMAJ = 2 +PNGMIN = 1.0 +PNGVER = $(PNGMAJ).$(PNGMIN) + +# where make install puts libpng.a, libpng.so*, and png.h +prefix=/local +INCPATH=$(prefix)/include +LIBPATH=$(prefix)/lib + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \ + pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \ + pngwtran.o pngmem.o pngerror.o pngpread.o + +OBJSDLL = $(OBJS:.o=.pic.o) + +.SUFFIXES: .c .o .pic.o + +.c.pic.o: + $(CC) -c $(CFLAGS) -fPIC -o $@ $*.c + +all: libpng.a libpng.so pngtest + +libpng.a: $(OBJS) + ar rc $@ $(OBJS) + $(RANLIB) $@ + +libpng.so: libpng.so.$(PNGMAJ) + ln -sf libpng.so.$(PNGMAJ) libpng.so + +libpng.so.$(PNGMAJ): libpng.so.$(PNGVER) + ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ) + +libpng.so.$(PNGVER): $(OBJSDLL) + $(LD) -G -L$(LIBPATH) -R$(LIBPATH) -h libpng.so.$(PNGMAJ) \ + -o libpng.so.$(PNGVER) $(OBJSDLL) -lz + +pngtest: pngtest.o libpng.so + $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS) + +test: pngtest + ./pngtest + +install: libpng.a libpng.so.$(PNGVER) + -@mkdir $(INCPATH) $(LIBPATH) + cp png.h pngconf.h $(INCPATH) + chmod 644 $(INCPATH)/png.h $(INCPATH)/pngconf.h + cp libpng.a libpng.so.$(PNGVER) $(LIBPATH) + chmod 755 $(LIBPATH)/libpng.so.$(PNGVER) + -@/bin/rm -f $(LIBPATH)/libpng.so.$(PNGMAJ) $(LIBPATH)/libpng.so + (cd $(LIBPATH); ln -sf libpng.so.$(PNGVER) libpng.so.$(PNGMAJ); \ + ln -sf libpng.so.$(PNGMAJ) libpng.so) + +clean: + /bin/rm -f *.o libpng.a libpng.so* pngtest pngout.png + +# DO NOT DELETE THIS LINE -- make depend depends on it. + +png.o png.pic.o: png.h pngconf.h +pngerror.o pngerror.pic.o: png.h pngconf.h +pngrio.o pngrio.pic.o: png.h pngconf.h +pngwio.o pngwio.pic.o: png.h pngconf.h +pngmem.o pngmem.pic.o: png.h pngconf.h +pngset.o pngset.pic.o: png.h pngconf.h +pngget.o pngget.pic.o: png.h pngconf.h +pngread.o pngread.pic.o: png.h pngconf.h +pngrtran.o pngrtran.pic.o: png.h pngconf.h +pngrutil.o pngrutil.pic.o: png.h pngconf.h +pngtrans.o pngtrans.pic.o: png.h pngconf.h +pngwrite.o pngwrite.pic.o: png.h pngconf.h +pngwtran.o pngwtran.pic.o: png.h pngconf.h +pngwutil.o pngwutil.pic.o: png.h pngconf.h +pngpread.o pngpread.pic.o: png.h pngconf.h + +pngtest.o: png.h pngconf.h diff --git a/thirdparty/libpng/scripts/makefile.sgi b/thirdparty/libpng/scripts/makefile.sgi new file mode 100644 index 00000000..965cf91f --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.sgi @@ -0,0 +1,69 @@ +# makefile for libpng +# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc. +# For conditions of distribution and use, see copyright notice in png.h + +# Where the zlib library and include files are located +#ZLIBLIB=/usr/local/lib +#ZLIBINC=/usr/local/include +ZLIBLIB=../zlib +ZLIBINC=../zlib + +CC=cc + +CFLAGS=-I$(ZLIBINC) -O -fullwarn # -g -DPNG_DEBUG=1 +LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm + +RANLIB=echo +#RANLIB=ranlib + +# where make install puts libpng.a and png.h +prefix=/usr/local + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \ + pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \ + pngwtran.o pngmem.o pngerror.o pngpread.o + +all: libpng.a pngtest + +libpng.a: $(OBJS) + ar rc $@ $(OBJS) + $(RANLIB) $@ + +pngtest: pngtest.o libpng.a + $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS) + +test: pngtest + ./pngtest + +install: libpng.a + -@mkdir $(prefix)/include + -@mkdir $(prefix)/lib + cp png.h $(prefix)/include + cp pngconf.h $(prefix)/include + chmod 644 $(prefix)/include/png.h + chmod 644 $(prefix)/include/pngconf.h + cp libpng.a $(prefix)/lib + chmod 644 $(prefix)/lib/libpng.a + +clean: + rm -f *.o libpng.a pngtest pngout.png + +# DO NOT DELETE THIS LINE -- make depend depends on it. + +png.o: png.h pngconf.h +pngerror.o: png.h pngconf.h +pngrio.o: png.h pngconf.h +pngwio.o: png.h pngconf.h +pngmem.o: png.h pngconf.h +pngset.o: png.h pngconf.h +pngget.o: png.h pngconf.h +pngread.o: png.h pngconf.h +pngrtran.o: png.h pngconf.h +pngrutil.o: png.h pngconf.h +pngtest.o: png.h pngconf.h +pngtrans.o: png.h pngconf.h +pngwrite.o: png.h pngconf.h +pngwtran.o: png.h pngconf.h +pngwutil.o: png.h pngconf.h +pngpread.o: png.h pngconf.h + diff --git a/thirdparty/libpng/scripts/makefile.std b/thirdparty/libpng/scripts/makefile.std new file mode 100644 index 00000000..7cc60599 --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.std @@ -0,0 +1,68 @@ +# makefile for libpng +# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc. +# For conditions of distribution and use, see copyright notice in png.h + +# Where the zlib library and include files are located +#ZLIBLIB=/usr/local/lib +#ZLIBINC=/usr/local/include +ZLIBLIB=../zlib +ZLIBINC=../zlib + +CC=cc +CFLAGS=-I$(ZLIBINC) -O # -g -DPNG_DEBUG=1 +LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm + +#RANLIB=echo +RANLIB=ranlib + +# where make install puts libpng.a and png.h +prefix=/usr/local + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \ + pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \ + pngwtran.o pngmem.o pngerror.o pngpread.o + +all: libpng.a pngtest + +libpng.a: $(OBJS) + ar rc $@ $(OBJS) + $(RANLIB) $@ + +pngtest: pngtest.o libpng.a + $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS) + +test: pngtest + ./pngtest + +install: libpng.a + -@mkdir $(prefix)/include + -@mkdir $(prefix)/lib + cp png.h $(prefix)/include + cp pngconf.h $(prefix)/include + chmod 644 $(prefix)/include/png.h + chmod 644 $(prefix)/include/pngconf.h + cp libpng.a $(prefix)/lib + chmod 644 $(prefix)/lib/libpng.a + +clean: + rm -f *.o libpng.a pngtest pngout.png + +# DO NOT DELETE THIS LINE -- make depend depends on it. + +png.o: png.h pngconf.h +pngerror.o: png.h pngconf.h +pngrio.o: png.h pngconf.h +pngwio.o: png.h pngconf.h +pngmem.o: png.h pngconf.h +pngset.o: png.h pngconf.h +pngget.o: png.h pngconf.h +pngread.o: png.h pngconf.h +pngrtran.o: png.h pngconf.h +pngrutil.o: png.h pngconf.h +pngtest.o: png.h pngconf.h +pngtrans.o: png.h pngconf.h +pngwrite.o: png.h pngconf.h +pngwtran.o: png.h pngconf.h +pngwutil.o: png.h pngconf.h +pngpread.o: png.h pngconf.h + diff --git a/thirdparty/libpng/scripts/makefile.sun b/thirdparty/libpng/scripts/makefile.sun new file mode 100644 index 00000000..975ca172 --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.sun @@ -0,0 +1,72 @@ +# makefile for libpng +# Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc. +# For conditions of distribution and use, see copyright notice in png.h + +# Where the zlib library and include files are located +#ZLIBLIB=/usr/local/lib +#ZLIBINC=/usr/local/include +ZLIBLIB=../zlib +ZLIBINC=../zlib + + +WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow -Wconversion \ + -Wmissing-declarations -Wtraditional -Wcast-align \ + -Wstrict-prototypes -Wmissing-prototypes +CC=gcc +CFLAGS=-I$(ZLIBINC) -O $(WARNMORE) -DPNG_DEBUG=4 +LDFLAGS=-L. -L$(ZLIBLIB) -lpng -lz -lm + +RANLIB=ranlib +#RANLIB=echo + +# where make install puts libpng.a and png.h +prefix=/usr/local + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \ + pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \ + pngwtran.o pngmem.o pngerror.o pngpread.o + +all: libpng.a pngtest + +libpng.a: $(OBJS) + ar rc $@ $(OBJS) + $(RANLIB) $@ + +pngtest: pngtest.o libpng.a + $(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS) + +test: pngtest + ./pngtest + +install: libpng.a + -@mkdir $(prefix)/include + -@mkdir $(prefix)/lib + cp png.h $(prefix)/include + cp pngconf.h $(prefix)/include + chmod 644 $(prefix)/include/png.h + chmod 644 $(prefix)/include/pngconf.h + cp libpng.a $(prefix)/lib + chmod 644 $(prefix)/lib/libpng.a + +clean: + rm -f *.o libpng.a pngtest pngout.png + +# DO NOT DELETE THIS LINE -- make depend depends on it. + +png.o: png.h pngconf.h +pngerror.o: png.h pngconf.h +pngrio.o: png.h pngconf.h +pngwio.o: png.h pngconf.h +pngmem.o: png.h pngconf.h +pngset.o: png.h pngconf.h +pngget.o: png.h pngconf.h +pngread.o: png.h pngconf.h +pngrtran.o: png.h pngconf.h +pngrutil.o: png.h pngconf.h +pngtest.o: png.h pngconf.h +pngtrans.o: png.h pngconf.h +pngwrite.o: png.h pngconf.h +pngwtran.o: png.h pngconf.h +pngwutil.o: png.h pngconf.h +pngpread.o: png.h pngconf.h + diff --git a/thirdparty/libpng/scripts/makefile.tc3 b/thirdparty/libpng/scripts/makefile.tc3 new file mode 100644 index 00000000..6f8f3666 --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.tc3 @@ -0,0 +1,82 @@ +# Makefile for libpng +# TurboC++ 3.0 (Note: All modules are compiled in C mode) + +# To use, do "make -fmakefile.tc3" + +# ------------- Turbo C++ 3.0 ------------- +MODEL=-ml +CFLAGS=-O2 -Z $(MODEL) -I..\zlib +CC=tcc +LD=tcc +LIB=tlib +LDFLAGS=$(MODEL) -L..\zlib +O=.obj +E=.exe + +# variables +OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O) +OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O) +OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O) +OBJSL1 = +png$(O) +pngset$(O) +pngget$(O) +pngrutil$(O) +pngtrans$(O) +OBJSL2 = +pngwutil$(O) +pngmem$(O) +pngpread$(O) +pngread$(O) +pngerror$(O) +OBJSL3 = +pngwrite$(O) +pngrtran$(O) +pngwtran$(O) +pngrio$(O) +pngwio$(O) + +all: libpng.lib pngtest.exe + +png$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngset$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngget$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngread$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngpread$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngrtran$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngrutil$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngerror$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngmem$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngrio$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngwio$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngtest$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngtrans$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngwrite$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngwtran$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +pngwutil$(O): png.h pngconf.h + $(CC) -c $(CFLAGS) $*.c + +libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3) + $(LIB) libpng +$(OBJSL1) + $(LIB) libpng +$(OBJSL2) + $(LIB) libpng +$(OBJSL3) + +pngtest$(E): pngtest$(O) libpng.lib + $(CC) $(LDFLAGS) pngtest.obj libpng.lib zlib.lib + +# End of makefile for libpng diff --git a/thirdparty/libpng/scripts/makefile.wat b/thirdparty/libpng/scripts/makefile.wat new file mode 100644 index 00000000..a715acbc --- /dev/null +++ b/thirdparty/libpng/scripts/makefile.wat @@ -0,0 +1,88 @@ +# Makefile for libpng +# Watcom 10a and later 32-bit protected mode flat memory model + +# Adapted by Pawel Mrochen, based on makefile.msc +# For conditions of distribution and use, see copyright notice in png.h +# Assumes that zlib.lib, zconf.h, and zlib.h have been copied to ..\zlib + +# To use, do "wmake -f makefile.wat" + +# ------------- Watcom 10a and later ------------- +MODEL=-mf +CFLAGS= $(MODEL) -fpi87 -fp5 -5r -oaeilmnrt -s -zp4 -i=..\zlib +CC=wcc386 +LD=wcl386 +LIB=wlib -b -c +LDFLAGS= +O=.obj + +#uncomment next to put error messages in a file +#ERRFILE= >> pngerrs + +# variables +OBJS1 = png$(O) pngset$(O) pngget$(O) pngrutil$(O) pngtrans$(O) pngwutil$(O) +OBJS2 = pngmem$(O) pngpread$(O) pngread$(O) pngerror$(O) pngwrite$(O) +OBJS3 = pngrtran$(O) pngwtran$(O) pngrio$(O) pngwio$(O) + +all: test + +png$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngset$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngget$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngread$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngpread$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngrtran$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngrutil$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngerror$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngmem$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngrio$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngwio$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngtest$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngtrans$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngwrite$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngwtran$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +pngwutil$(O): png.h pngconf.h + $(CC) $(CFLAGS) $*.c $(ERRFILE) + +libpng.lib: $(OBJS1) $(OBJS2) $(OBJS3) + $(LIB) -n libpng.lib +$(OBJS1) + $(LIB) libpng.lib +$(OBJS2) + $(LIB) libpng.lib +$(OBJS3) + +pngtest.exe: pngtest.obj libpng.lib + $(LD) $(LDFLAGS) pngtest.obj libpng.lib ..\zlib\zlib.lib + +test: pngtest.exe + pngtest + +# End of makefile for libpng diff --git a/thirdparty/libpng/scripts/makevms.com b/thirdparty/libpng/scripts/makevms.com new file mode 100644 index 00000000..15f305a6 --- /dev/null +++ b/thirdparty/libpng/scripts/makevms.com @@ -0,0 +1,125 @@ +$! make libpng under VMS +$! +$! +$! Look for the compiler used +$! +$ zlibsrc = "[-.zlib]" +$ ccopt="/include=''zlibsrc'" +$ if f$getsyi("HW_MODEL").ge.1024 +$ then +$ ccopt = "/prefix=all"+ccopt +$ comp = "__decc__=1" +$ if f$trnlnm("SYS").eqs."" then define sys sys$library: +$ else +$ if f$search("SYS$SYSTEM:DECC$COMPILER.EXE").eqs."" +$ then +$ if f$trnlnm("SYS").eqs."" then define sys sys$library: +$ if f$search("SYS$SYSTEM:VAXC.EXE").eqs."" +$ then +$ comp = "__gcc__=1" +$ CC :== GCC +$ else +$ comp = "__vaxc__=1" +$ endif +$ else +$ if f$trnlnm("SYS").eqs."" then define sys decc$library_include: +$ ccopt = "/decc/prefix=all"+ccopt +$ comp = "__decc__=1" +$ endif +$ endif +$! +$! Build the thing plain or with mms +$! +$ write sys$output "Compiling Libpng sources ..." +$ if f$search("SYS$SYSTEM:MMS.EXE").eqs."" +$ then +$ dele pngtest.obj;* +$ CALL MAKE png.OBJ "cc ''CCOPT' png" - + png.c png.h pngconf.h +$ CALL MAKE pngpread.OBJ "cc ''CCOPT' pngpread" - + pngpread.c png.h pngconf.h +$ CALL MAKE pngset.OBJ "cc ''CCOPT' pngset" - + pngset.c png.h pngconf.h +$ CALL MAKE pngget.OBJ "cc ''CCOPT' pngget" - + pngget.c png.h pngconf.h +$ CALL MAKE pngread.OBJ "cc ''CCOPT' pngread" - + pngread.c png.h pngconf.h +$ CALL MAKE pngpread.OBJ "cc ''CCOPT' pngpread" - + pngpread.c png.h pngconf.h +$ CALL MAKE pngrtran.OBJ "cc ''CCOPT' pngrtran" - + pngrtran.c png.h pngconf.h +$ CALL MAKE pngrutil.OBJ "cc ''CCOPT' pngrutil" - + pngrutil.c png.h pngconf.h +$ CALL MAKE pngerror.OBJ "cc ''CCOPT' pngerror" - + pngerror.c png.h pngconf.h +$ CALL MAKE pngmem.OBJ "cc ''CCOPT' pngmem" - + pngmem.c png.h pngconf.h +$ CALL MAKE pngrio.OBJ "cc ''CCOPT' pngrio" - + pngrio.c png.h pngconf.h +$ CALL MAKE pngwio.OBJ "cc ''CCOPT' pngwio" - + pngwio.c png.h pngconf.h +$ CALL MAKE pngtrans.OBJ "cc ''CCOPT' pngtrans" - + pngtrans.c png.h pngconf.h +$ CALL MAKE pngwrite.OBJ "cc ''CCOPT' pngwrite" - + pngwrite.c png.h pngconf.h +$ CALL MAKE pngwtran.OBJ "cc ''CCOPT' pngwtran" - + pngwtran.c png.h pngconf.h +$ CALL MAKE pngwutil.OBJ "cc ''CCOPT' pngwutil" - + pngwutil.c png.h pngconf.h +$ write sys$output "Building Libpng ..." +$ CALL MAKE libpng.OLB "lib/crea libpng.olb *.obj" *.OBJ +$ write sys$output "Building pngtest..." +$ CALL MAKE pngtest.OBJ "cc ''CCOPT' pngtest" - + pngtest.c png.h pngconf.h +$ call make pngtest.exe - + "LINK pngtest,libpng.olb/lib,''zlibsrc'libgz.olb/lib" - + pngtest.obj libpng.olb +$ write sys$output "Testing Libpng..." +$ run pngtest +$ else +$ mms/macro=('comp',zlibsrc='zlibsrc') +$ endif +$ write sys$output "Libpng build completed" +$ exit +$! +$! +$MAKE: SUBROUTINE !SUBROUTINE TO CHECK DEPENDENCIES +$ V = 'F$Verify(0) +$! P1 = What we are trying to make +$! P2 = Command to make it +$! P3 - P8 What it depends on +$ +$ If F$Search(P1) .Eqs. "" Then Goto Makeit +$ Time = F$CvTime(F$File(P1,"RDT")) +$arg=3 +$Loop: +$ Argument = P'arg +$ If Argument .Eqs. "" Then Goto Exit +$ El=0 +$Loop2: +$ File = F$Element(El," ",Argument) +$ If File .Eqs. " " Then Goto Endl +$ AFile = "" +$Loop3: +$ OFile = AFile +$ AFile = F$Search(File) +$ If AFile .Eqs. "" .Or. AFile .Eqs. OFile Then Goto NextEl +$ If F$CvTime(F$File(AFile,"RDT")) .Ges. Time Then Goto Makeit +$ Goto Loop3 +$NextEL: +$ El = El + 1 +$ Goto Loop2 +$EndL: +$ arg=arg+1 +$ If arg .Le. 8 Then Goto Loop +$ Goto Exit +$ +$Makeit: +$ VV=F$VERIFY(0) +$ write sys$output P2 +$ 'P2 +$ VV='F$Verify(VV) +$Exit: +$ If V Then Set Verify +$ENDSUBROUTINE + diff --git a/thirdparty/libpng/scripts/pngos2.def b/thirdparty/libpng/scripts/pngos2.def new file mode 100644 index 00000000..ba2d3e3d --- /dev/null +++ b/thirdparty/libpng/scripts/pngos2.def @@ -0,0 +1,286 @@ +;---------------------------------------- +; PNGLIB module definition file for OS/2 +;---------------------------------------- + +LIBRARY PNG +DESCRIPTION "PNG image compression library for OS/2" +CODE PRELOAD MOVEABLE DISCARDABLE +DATA PRELOAD MOVEABLE MULTIPLE + +EXPORTS + png_set_sig_bytes + png_sig_cmp + png_check_sig + png_create_read_struct + png_create_write_struct + png_write_chunk + png_write_chunk_start + png_write_chunk_data + png_write_chunk_end + png_create_info_struct + png_info_init + png_write_info + png_read_info + png_convert_to_rfc1123 + png_convert_from_struct_tm + png_convert_from_time_t + png_set_expand + png_set_bgr + png_set_gray_to_rgb +; png_set_rgb_to_gray + png_build_grayscale_palette + png_set_strip_alpha + png_set_swap_alpha + png_set_invert_alpha + png_set_filler + png_set_swap + png_set_packing + png_set_packswap + png_set_shift + png_set_interlace_handling + png_set_invert_mono + png_set_background + png_set_strip_16 + png_set_dither + png_set_gamma + png_set_flush + png_write_flush + png_start_read_image + png_read_update_info + png_read_rows + png_read_row + png_read_image + png_write_row + png_write_rows + png_write_image + png_write_end + png_read_end + png_destroy_info_struct + png_destroy_read_struct + png_read_destroy + png_destroy_write_struct +; png_write_destroy_info + png_write_destroy + png_set_crc_action + png_set_filter + png_set_filter_heuristics + png_set_compression_level + png_set_compression_mem_level + png_set_compression_strategy + png_set_compression_window_bits + png_set_compression_method + png_init_io + png_set_error_fn + png_get_error_ptr + png_set_write_fn + png_set_read_fn + png_set_write_status_fn + png_set_read_status_fn + png_get_io_ptr + png_set_progressive_read_fn + png_set_read_status_fn + png_set_read_user_transform_fn + png_set_write_status_fn + png_set_write_user_transform_fn + png_get_progressive_ptr + png_process_data + png_progressive_combine_row + png_malloc + png_free + png_memcpy_check + png_memset_check +; png_debug_malloc +; png_debug_free +; png_far_to_near + png_error + png_chunk_error + png_warning + png_chunk_warning + png_get_valid + png_get_rowbytes + png_get_channels + png_get_image_width + png_get_image_height + png_get_bit_depth + png_get_color_type + png_get_filter_type + png_get_interlace_type + png_get_compression_type + png_get_pixels_per_meter + png_get_pixel_aspect_ratio + png_get_x_offset_pixels + png_get_y_offset_pixels + png_get_x_offset_microns + png_get_y_offset_microns + png_get_signature + png_get_bKGD + png_set_bKGD + png_get_cHRM + png_set_cHRM + png_get_gAMA + png_set_gAMA + png_get_hIST + png_set_hIST + png_get_IHDR + png_set_IHDR + png_get_oFFs + png_set_oFFs + png_get_pCAL + png_set_pCAL + png_get_pHYs + png_set_pHYs + png_get_PLTE + png_set_PLTE + png_get_sBIT + png_set_sBIT + png_get_sRGB + png_set_sRGB + png_set_sRGB_gAMA_and_cHRM + png_get_text + png_set_text + png_get_tIME + png_set_tIME + png_get_tRNS + png_set_tRNS + + png_create_struct + png_destroy_struct + png_info_destroy + png_zalloc + png_zfree + png_reset_crc + png_write_data + png_read_data + png_crc_read + png_crc_finish + png_crc_error + png_calculate_crc + png_flush + png_save_uint_32 + png_save_int_32 + png_save_uint_16 + png_write_sig + png_write_IHDR + png_write_PLTE + png_write_IDAT + png_write_IEND + png_write_gAMA + png_write_sBIT + png_write_cHRM + png_write_sRGB + png_write_tRNS + png_write_bKGD + png_write_hIST + png_check_keyword + png_write_tEXt + png_write_zTXt + png_write_oFFs + png_write_pCAL + png_write_pHYs + png_write_tIME + png_write_finish_row + png_write_start_row + png_build_gamma_table + png_combine_row + png_do_read_interlace + png_do_write_interlace + png_read_filter_row + png_write_find_filter + png_write_filtered_row + png_read_finish_row + png_read_start_row + png_read_transform_info + png_do_read_filler + png_do_read_swap_alpha + png_do_write_swap_alpha + png_do_read_invert_alpha + png_do_write_invert_alpha + png_do_strip_filler + png_do_swap + png_do_packswap +; png_do_rgb_to_gray + png_do_gray_to_rgb + png_do_unpack + png_do_unshift + png_do_invert + png_do_chop + png_do_dither +; png_correct_palette + png_do_bgr + png_do_pack + png_do_shift + png_do_background + png_do_gamma + png_do_expand_palette + png_do_expand + png_handle_IHDR + png_handle_PLTE + png_handle_IEND + png_handle_gAMA + png_handle_sBIT + png_handle_cHRM + png_handle_sRGB + png_handle_tRNS + png_handle_bKGD + png_handle_hIST + png_handle_oFFs + png_handle_pCAL + png_handle_pHYs + png_handle_tIME + png_handle_tEXt + png_handle_zTXt + png_handle_unknown + png_check_chunk_name + png_do_read_transformations + png_do_write_transformations + png_init_read_transformations + png_push_read_chunk + png_push_read_sig +; png_push_check_crc + png_push_crc_skip + png_push_crc_finish + png_push_fill_buffer + png_push_save_buffer + png_push_restore_buffer + png_push_read_IDAT + png_process_IDAT_data + png_push_process_row + png_push_handle_unknown + png_push_have_info + png_push_have_end + png_push_have_row +; png_push_read_end + png_process_some_data + png_read_push_finish_row + png_push_handle_tEXt + png_push_read_tEXt + png_push_handle_zTXt + png_push_read_zTXt + + png_libpng_ver + png_pass_start + png_pass_inc + png_pass_ystart + png_pass_yinc + png_pass_mask + png_pass_dsp_mask +; png_pass_width +; png_pass_height + + png_IHDR + png_IDAT + png_IEND + png_PLTE + png_bKGD + png_cHRM + png_gAMA + png_hIST + png_oFFs + png_pCAL + png_pHYs + png_sBIT + png_sRGB + png_tEXt + png_tIME + png_tRNS + png_zTXt diff --git a/thirdparty/libpng/scripts/smakefile.ppc b/thirdparty/libpng/scripts/smakefile.ppc new file mode 100644 index 00000000..fa3cad44 --- /dev/null +++ b/thirdparty/libpng/scripts/smakefile.ppc @@ -0,0 +1,29 @@ +# Amiga powerUP (TM) Makefile +# makefile for libpng and SAS C V6.58/7.00 PPC compiler +# Copyright (C) 1998 by Andreas R. Kleinert + +CC = scppc +CFLAGS = NOSTKCHK NOSINT OPTIMIZE OPTGO OPTPEEP OPTINLOCAL OPTINL IDIR /zlib \ + OPTLOOP OPTRDEP=8 OPTDEP=8 OPTCOMP=8 +LIBNAME = libpng.a +AR = ppc-amigaos-ar +AR_FLAGS = cr +RANLIB = ppc-amigaos-ranlib +LDFLAGS = -r -o +LDLIBS = ../zlib/libzip.a LIB:scppc.a +LN = ppc-amigaos-ld +RM = delete quiet +MKDIR = makedir + +OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o pngread.o \ +pngerror.o pngpread.o pngwrite.o pngrtran.o pngwtran.o pngrio.o pngwio.o pngmem.o + +all: $(LIBNAME) pngtest + +$(LIBNAME): $(OBJS) + $(AR) $(AR_FLAGS) $@ $(OBJS) + $(RANLIB) $@ + +pngtest: pngtest.o $(LIBNAME) + $(LN) $(LDFLAGS) pngtest LIB:c_ppc.o pngtest.o $(LIBNAME) $(LDLIBS) \ +LIB:end.o