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mirror of https://github.com/alliedmodders/hl2sdk.git synced 2024-12-23 01:59:43 +08:00
hl2sdk/tier1/bitbuf.cpp
2023-09-24 13:30:27 -04:00

1331 lines
28 KiB
C++

//========= Copyright © 1996-2005, Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
// $NoKeywords: $
//
//=============================================================================//
#include "bitbuf.h"
#include "coordsize.h"
#include "mathlib/vector.h"
#include "mathlib/mathlib.h"
#include "tier1/strtools.h"
#include "bitvec.h"
// FIXME: Can't use this until we get multithreaded allocations in tier0 working for tools
// This is used by VVIS and fails to link
// NOTE: This must be the last file included!!!
//#include "tier0/memdbgon.h"
#ifdef _X360
// mandatory ... wary of above comment and isolating, tier0 is built as MT though
#include "tier0/memdbgon.h"
#endif
#if _WIN32
#define FAST_BIT_SCAN 1
#if _X360
#define CountLeadingZeros(x) _CountLeadingZeros(x)
inline unsigned int CountTrailingZeros( unsigned int elem )
{
// this implements CountTrailingZeros() / BitScanForward()
unsigned int mask = elem-1;
unsigned int comp = ~elem;
elem = mask & comp;
return (32 - _CountLeadingZeros(elem));
}
#else
#include <intrin.h>
#pragma intrinsic(_BitScanReverse)
#pragma intrinsic(_BitScanForward)
inline unsigned int CountLeadingZeros(unsigned int x)
{
unsigned long firstBit;
if ( _BitScanReverse(&firstBit,x) )
return 31 - firstBit;
return 32;
}
inline unsigned int CountTrailingZeros(unsigned int elem)
{
unsigned long out;
if ( _BitScanForward(&out, elem) )
return out;
return 32;
}
#endif
#else
#define FAST_BIT_SCAN 0
#endif
static BitBufErrorHandler g_BitBufErrorHandler = 0;
inline int BitForBitnum(int bitnum)
{
return GetBitForBitnum(bitnum);
}
void InternalBitBufErrorHandler( BitBufErrorType errorType, const char *pDebugName )
{
if ( g_BitBufErrorHandler )
g_BitBufErrorHandler( errorType, pDebugName );
}
void SetBitBufErrorHandler( BitBufErrorHandler fn )
{
g_BitBufErrorHandler = fn;
}
// #define BB_PROFILING
// Precalculated bit masks for WriteUBitLong. Using these tables instead of
// doing the calculations gives a 33% speedup in WriteUBitLong.
unsigned long g_BitWriteMasks[32][33];
// (1 << i) - 1
unsigned long g_ExtraMasks[32];
class CBitWriteMasksInit
{
public:
CBitWriteMasksInit()
{
for( unsigned int startbit=0; startbit < 32; startbit++ )
{
for( unsigned int nBitsLeft=0; nBitsLeft < 33; nBitsLeft++ )
{
unsigned int endbit = startbit + nBitsLeft;
g_BitWriteMasks[startbit][nBitsLeft] = BitForBitnum(startbit) - 1;
if(endbit < 32)
g_BitWriteMasks[startbit][nBitsLeft] |= ~(BitForBitnum(endbit) - 1);
}
}
for ( unsigned int maskBit=0; maskBit < 32; maskBit++ )
g_ExtraMasks[maskBit] = BitForBitnum(maskBit) - 1;
}
};
CBitWriteMasksInit g_BitWriteMasksInit;
// ---------------------------------------------------------------------------------------- //
// bf_write
// ---------------------------------------------------------------------------------------- //
bf_write::bf_write()
{
m_pData = NULL;
m_nDataBytes = 0;
m_nDataBits = -1; // set to -1 so we generate overflow on any operation
m_iCurBit = 0;
m_bOverflow = false;
m_bAssertOnOverflow = true;
m_pDebugName = NULL;
}
bf_write::bf_write( void *pData, int nBytes, int nMaxBits )
{
m_bAssertOnOverflow = true;
m_pDebugName = NULL;
StartWriting( pData, nBytes, 0, nMaxBits );
}
bf_write::bf_write( const char *pDebugName, void *pData, int nBytes, int nMaxBits )
{
m_bAssertOnOverflow = true;
m_pDebugName = pDebugName;
StartWriting( pData, nBytes, 0, nMaxBits );
}
void bf_write::StartWriting( void *pData, int nBytes, int iStartBit, int nMaxBits )
{
// Make sure it's dword aligned and padded.
Assert( (nBytes % 4) == 0 );
Assert(((unsigned long)pData & 3) == 0);
// The writing code will overrun the end of the buffer if it isn't dword aligned, so truncate to force alignment
nBytes &= ~3;
m_pData = (unsigned char*)pData;
m_nDataBytes = nBytes;
if ( nMaxBits == -1 )
{
m_nDataBits = nBytes << 3;
}
else
{
Assert( nMaxBits <= nBytes*8 );
m_nDataBits = nMaxBits;
}
m_iCurBit = iStartBit;
m_bOverflow = false;
}
void bf_write::Reset()
{
m_iCurBit = 0;
m_bOverflow = false;
}
void bf_write::SetAssertOnOverflow( bool bAssert )
{
m_bAssertOnOverflow = bAssert;
}
const char* bf_write::GetDebugName()
{
return m_pDebugName;
}
void bf_write::SetDebugName( const char *pDebugName )
{
m_pDebugName = pDebugName;
}
void bf_write::SeekToBit( int bitPos )
{
m_iCurBit = bitPos;
}
// Sign bit comes first
void bf_write::WriteSBitLong( int data, int numbits )
{
// Do we have a valid # of bits to encode with?
Assert( numbits >= 1 );
// Note: it does this wierdness here so it's bit-compatible with regular integer data in the buffer.
// (Some old code writes direct integers right into the buffer).
if(data < 0)
{
#ifdef _DEBUG
if( numbits < 32 )
{
// Make sure it doesn't overflow.
if( data < 0 )
{
Assert( data >= -(BitForBitnum(numbits-1)) );
}
else
{
Assert( data < (BitForBitnum(numbits-1)) );
}
}
#endif
WriteUBitLong( (unsigned int)(0x80000000 + data), numbits - 1, false );
WriteOneBit( 1 );
}
else
{
WriteUBitLong((unsigned int)data, numbits - 1);
WriteOneBit( 0 );
}
}
void bf_write::WriteVarInt32( uint32 data )
{
while ( data > 0x7F )
{
WriteUBitLong( (data & 0x7F) | 0x80, 8 );
data >>= 7;
}
WriteUBitLong( data & 0x7F, 8 );
}
int bf_write::ByteSizeVarInt32( uint32 data )
{
int size = 1;
while ( data > 0x7F )
{
size++;
data >>= 7;
}
return size;
}
#if _WIN32
inline unsigned int BitCountNeededToEncode(unsigned int data)
{
#if defined(_X360)
return (32 - CountLeadingZeros(data+1)) - 1;
#else
unsigned long firstBit;
_BitScanReverse(&firstBit,data+1);
return firstBit;
#endif
}
#endif // _WIN32
// writes an unsigned integer with variable bit length
void bf_write::WriteUBitVar( unsigned int data )
{
if ( ( data &0xf ) == data )
{
WriteUBitLong( 0, 2 );
WriteUBitLong( data, 4 );
}
else
{
if ( ( data & 0xff ) == data )
{
WriteUBitLong( 1, 2 );
WriteUBitLong( data, 8 );
}
else
{
if ( ( data & 0xfff ) == data )
{
WriteUBitLong( 2, 2 );
WriteUBitLong( data, 12 );
}
else
{
WriteUBitLong( 0x3, 2 );
WriteUBitLong( data, 32 );
}
}
}
#if 0
#if !FAST_BIT_SCAN
unsigned int bits = 0;
unsigned int base = 0;
while (data > (base<<1))
{
bits++;
base = BitForBitnum(bits)-1;
}
#else
unsigned int bits = BitCountNeededToEncode(data);
unsigned int base = GetBitForBitnum(bits)-1;
#endif
// how many bits do we use
WriteUBitLong( 0, bits );
// end marker
WriteOneBit( 1 );
// write the value
if ( bits > 0)
WriteUBitLong( data - base , bits );
#endif
}
void bf_write::WriteBitLong(unsigned int data, int numbits, bool bSigned)
{
if(bSigned)
WriteSBitLong((int)data, numbits);
else
WriteUBitLong(data, numbits);
}
bool bf_write::WriteBits(const void *pInData, int nBits)
{
#if defined( BB_PROFILING )
VPROF( "bf_write::WriteBits" );
#endif
unsigned char *pOut = (unsigned char*)pInData;
int nBitsLeft = nBits;
// Bounds checking..
if ( (m_iCurBit+nBits) > m_nDataBits )
{
SetOverflowFlag();
CallErrorHandler( BITBUFERROR_BUFFER_OVERRUN, GetDebugName() );
return false;
}
// Align output to dword boundary
while (((uintp)pOut & 3) != 0 && nBitsLeft >= 8)
{
WriteUBitLong( *pOut, 8, false );
++pOut;
nBitsLeft -= 8;
}
if ( IsPC() && (nBitsLeft >= 32) && (m_iCurBit & 7) == 0 )
{
// current bit is byte aligned, do block copy
int numbytes = nBitsLeft >> 3;
int numbits = numbytes << 3;
Q_memcpy( m_pData+(m_iCurBit>>3), pOut, numbytes );
pOut += numbytes;
nBitsLeft -= numbits;
m_iCurBit += numbits;
}
// X360TBD: Can't write dwords in WriteBits because they'll get swapped
if ( IsPC() && nBitsLeft >= 32 )
{
unsigned long iBitsRight = (m_iCurBit & 31);
unsigned long iBitsLeft = 32 - iBitsRight;
unsigned long bitMaskLeft = g_BitWriteMasks[iBitsRight][32];
unsigned long bitMaskRight = g_BitWriteMasks[0][iBitsRight];
unsigned long *pData = &((unsigned long*)m_pData)[m_iCurBit>>5];
// Read dwords.
while(nBitsLeft >= 32)
{
unsigned long curData = *(unsigned long*)pOut;
pOut += sizeof(unsigned long);
*pData &= bitMaskLeft;
*pData |= curData << iBitsRight;
pData++;
if ( iBitsLeft < 32 )
{
curData >>= iBitsLeft;
*pData &= bitMaskRight;
*pData |= curData;
}
nBitsLeft -= 32;
m_iCurBit += 32;
}
}
// write remaining bytes
while ( nBitsLeft >= 8 )
{
WriteUBitLong( *pOut, 8, false );
++pOut;
nBitsLeft -= 8;
}
// write remaining bits
if ( nBitsLeft )
{
WriteUBitLong( *pOut, nBitsLeft, false );
}
return !IsOverflowed();
}
bool bf_write::WriteBitsFromBuffer( bf_read *pIn, int nBits )
{
// This could be optimized a little by
while ( nBits > 32 )
{
WriteUBitLong( pIn->ReadUBitLong( 32 ), 32 );
nBits -= 32;
}
WriteUBitLong( pIn->ReadUBitLong( nBits ), nBits );
return !IsOverflowed() && !pIn->IsOverflowed();
}
void bf_write::WriteBitAngle( float fAngle, int numbits )
{
int d;
unsigned int mask;
unsigned int shift;
shift = BitForBitnum(numbits);
mask = shift - 1;
d = (int)( (fAngle / 360.0) * shift );
d &= mask;
WriteUBitLong((unsigned int)d, numbits);
}
void bf_write::WriteBitCoordMP( const float f, EBitCoordType coordType )
{
#if defined( BB_PROFILING )
VPROF( "bf_write::WriteBitCoordMP" );
#endif
int signbit = (f <= -( coordType == kCW_LowPrecision ? COORD_RESOLUTION_LOWPRECISION : COORD_RESOLUTION ));
int intval = (int)fabs(f);
int fractval = coordType == kCW_LowPrecision ?
( abs((int)(f*COORD_DENOMINATOR_LOWPRECISION)) & (COORD_DENOMINATOR_LOWPRECISION-1) ) :
( abs((int)(f*COORD_DENOMINATOR)) & (COORD_DENOMINATOR-1) );
bool bInBounds = intval < (1 << COORD_INTEGER_BITS_MP );
WriteOneBit( bInBounds );
if ( coordType == kCW_Integral )
{
// Send the sign bit
WriteOneBit( intval );
if ( intval )
{
WriteOneBit( signbit );
// Send the integer if we have one.
// Adjust the integers from [1..MAX_COORD_VALUE] to [0..MAX_COORD_VALUE-1]
intval--;
if ( bInBounds )
{
WriteUBitLong( (unsigned int)intval, COORD_INTEGER_BITS_MP );
}
else
{
WriteUBitLong( (unsigned int)intval, COORD_INTEGER_BITS );
}
}
}
else
{
// Send the bit flags that indicate whether we have an integer part and/or a fraction part.
WriteOneBit( intval );
// Send the sign bit
WriteOneBit( signbit );
if ( intval )
{
// Adjust the integers from [1..MAX_COORD_VALUE] to [0..MAX_COORD_VALUE-1]
intval--;
if ( bInBounds )
{
WriteUBitLong( (unsigned int)intval, COORD_INTEGER_BITS_MP );
}
else
{
WriteUBitLong( (unsigned int)intval, COORD_INTEGER_BITS );
}
}
WriteUBitLong( (unsigned int)fractval, coordType == kCW_LowPrecision ? COORD_FRACTIONAL_BITS_MP_LOWPRECISION : COORD_FRACTIONAL_BITS );
}
}
void bf_write::WriteBitCellCoord( const float f, int bits, EBitCoordType coordType )
{
#if defined( BB_PROFILING )
VPROF( "bf_write::WriteCellBitCoordMP" );
#endif
int intval = (int)fabs(f);
int fractval = coordType == kCW_LowPrecision ?
( abs((int)(f*COORD_DENOMINATOR_LOWPRECISION)) & (COORD_DENOMINATOR_LOWPRECISION-1) ) :
( abs((int)(f*COORD_DENOMINATOR)) & (COORD_DENOMINATOR-1) );
if ( coordType == kCW_Integral )
{
WriteUBitLong( (unsigned int)intval, bits );
}
else
{
WriteUBitLong( (unsigned int)intval, bits );
WriteUBitLong( (unsigned int)fractval, coordType == kCW_LowPrecision ? COORD_FRACTIONAL_BITS_MP_LOWPRECISION : COORD_FRACTIONAL_BITS );
}
}
void bf_write::WriteBitCoord (const float f)
{
#if defined( BB_PROFILING )
VPROF( "bf_write::WriteBitCoord" );
#endif
int signbit = (f <= -COORD_RESOLUTION);
int intval = (int)fabs(f);
int fractval = abs((int)(f*COORD_DENOMINATOR)) & (COORD_DENOMINATOR-1);
// Send the bit flags that indicate whether we have an integer part and/or a fraction part.
WriteOneBit( intval );
WriteOneBit( fractval );
if ( intval || fractval )
{
// Send the sign bit
WriteOneBit( signbit );
// Send the integer if we have one.
if ( intval )
{
// Adjust the integers from [1..MAX_COORD_VALUE] to [0..MAX_COORD_VALUE-1]
intval--;
WriteUBitLong( (unsigned int)intval, COORD_INTEGER_BITS );
}
// Send the fraction if we have one
if ( fractval )
{
WriteUBitLong( (unsigned int)fractval, COORD_FRACTIONAL_BITS );
}
}
}
void bf_write::WriteBitFloat(float val)
{
long intVal;
Assert(sizeof(long) == sizeof(float));
Assert(sizeof(float) == 4);
intVal = *((long*)&val);
WriteUBitLong( intVal, 32 );
}
void bf_write::WriteBitVec3Coord( const Vector& fa )
{
int xflag, yflag, zflag;
xflag = (fa[0] >= COORD_RESOLUTION) || (fa[0] <= -COORD_RESOLUTION);
yflag = (fa[1] >= COORD_RESOLUTION) || (fa[1] <= -COORD_RESOLUTION);
zflag = (fa[2] >= COORD_RESOLUTION) || (fa[2] <= -COORD_RESOLUTION);
WriteOneBit( xflag );
WriteOneBit( yflag );
WriteOneBit( zflag );
if ( xflag )
WriteBitCoord( fa[0] );
if ( yflag )
WriteBitCoord( fa[1] );
if ( zflag )
WriteBitCoord( fa[2] );
}
void bf_write::WriteBitNormal( float f )
{
int signbit = (f <= -NORMAL_RESOLUTION);
// NOTE: Since +/-1 are valid values for a normal, I'm going to encode that as all ones
unsigned int fractval = abs( (int)(f*NORMAL_DENOMINATOR) );
// clamp..
if (fractval > NORMAL_DENOMINATOR)
fractval = NORMAL_DENOMINATOR;
// Send the sign bit
WriteOneBit( signbit );
// Send the fractional component
WriteUBitLong( fractval, NORMAL_FRACTIONAL_BITS );
}
void bf_write::WriteBitVec3Normal( const Vector& fa )
{
int xflag, yflag;
xflag = (fa[0] >= NORMAL_RESOLUTION) || (fa[0] <= -NORMAL_RESOLUTION);
yflag = (fa[1] >= NORMAL_RESOLUTION) || (fa[1] <= -NORMAL_RESOLUTION);
WriteOneBit( xflag );
WriteOneBit( yflag );
if ( xflag )
WriteBitNormal( fa[0] );
if ( yflag )
WriteBitNormal( fa[1] );
// Write z sign bit
int signbit = (fa[2] <= -NORMAL_RESOLUTION);
WriteOneBit( signbit );
}
void bf_write::WriteBitAngles( const QAngle& fa )
{
// FIXME:
Vector tmp( fa.x, fa.y, fa.z );
WriteBitVec3Coord( tmp );
}
void bf_write::WriteChar(int val)
{
WriteSBitLong(val, sizeof(char) << 3);
}
void bf_write::WriteByte(unsigned int val)
{
WriteUBitLong(val, sizeof(unsigned char) << 3);
}
void bf_write::WriteShort(int val)
{
WriteSBitLong(val, sizeof(short) << 3);
}
void bf_write::WriteWord(unsigned int val)
{
WriteUBitLong(val, sizeof(unsigned short) << 3);
}
void bf_write::WriteLong(long val)
{
WriteSBitLong(val, sizeof(long) << 3);
}
void bf_write::WriteLongLong(int64 val)
{
uint *pLongs = (uint*)&val;
// Insert the two DWORDS according to network endian
const short endianIndex = 0x0100;
byte *idx = (byte*)&endianIndex;
WriteUBitLong(pLongs[*idx++], sizeof(long) << 3);
WriteUBitLong(pLongs[*idx], sizeof(long) << 3);
}
void bf_write::WriteFloat(float val)
{
// Pre-swap the float, since WriteBits writes raw data
LittleFloat( &val, &val );
WriteBits(&val, sizeof(val) << 3);
}
bool bf_write::WriteBytes( const void *pBuf, int nBytes )
{
return WriteBits(pBuf, nBytes << 3);
}
bool bf_write::WriteString(const char *pStr)
{
if(pStr)
{
do
{
WriteChar( *pStr );
++pStr;
} while( *(pStr-1) != 0 );
}
else
{
WriteChar( 0 );
}
return !IsOverflowed();
}
bool bf_write::WriteString(const wchar_t *pStr)
{
if(pStr)
{
do
{
WriteSBitLong( *pStr, 16 );
++pStr;
} while ( (*pStr-1) != 0 );
}
else
{
WriteUBitLong( 0, 15 );
WriteOneBit( 0 );
}
return !IsOverflowed();
}
// ---------------------------------------------------------------------------------------- //
// old_bf_read
// ---------------------------------------------------------------------------------------- //
old_bf_read::old_bf_read()
{
m_pData = NULL;
m_nDataBytes = 0;
m_nDataBits = -1; // set to -1 so we overflow on any operation
m_iCurBit = 0;
m_bOverflow = false;
m_bAssertOnOverflow = true;
m_pDebugName = NULL;
}
old_bf_read::old_bf_read( const void *pData, int nBytes, int nBits )
{
m_bAssertOnOverflow = true;
StartReading( pData, nBytes, 0, nBits );
}
old_bf_read::old_bf_read( const char *pDebugName, const void *pData, int nBytes, int nBits )
{
m_bAssertOnOverflow = true;
m_pDebugName = pDebugName;
StartReading( pData, nBytes, 0, nBits );
}
void old_bf_read::StartReading( const void *pData, int nBytes, int iStartBit, int nBits )
{
// Make sure we're dword aligned.
Assert(((unsigned long)pData & 3) == 0);
m_pData = (unsigned char*)pData;
m_nDataBytes = nBytes;
if ( nBits == -1 )
{
m_nDataBits = m_nDataBytes << 3;
}
else
{
Assert( nBits <= nBytes*8 );
m_nDataBits = nBits;
}
m_iCurBit = iStartBit;
m_bOverflow = false;
}
void old_bf_read::Reset()
{
m_iCurBit = 0;
m_bOverflow = false;
}
void old_bf_read::SetAssertOnOverflow( bool bAssert )
{
m_bAssertOnOverflow = bAssert;
}
const char* old_bf_read::GetDebugName()
{
return m_pDebugName;
}
void old_bf_read::SetDebugName( const char *pName )
{
m_pDebugName = pName;
}
unsigned int old_bf_read::CheckReadUBitLong(int numbits)
{
// Ok, just read bits out.
int i, nBitValue;
unsigned int r = 0;
for(i=0; i < numbits; i++)
{
nBitValue = ReadOneBitNoCheck();
r |= nBitValue << i;
}
m_iCurBit -= numbits;
return r;
}
void old_bf_read::ReadBits(void *pOutData, int nBits)
{
#if defined( BB_PROFILING )
VPROF( "old_bf_write::ReadBits" );
#endif
unsigned char *pOut = (unsigned char*)pOutData;
int nBitsLeft = nBits;
// align output to dword boundary
while( ((uintp)pOut & 3) != 0 && nBitsLeft >= 8 )
{
*pOut = (unsigned char)ReadUBitLong(8);
++pOut;
nBitsLeft -= 8;
}
// X360TBD: Can't read dwords in ReadBits because they'll get swapped
if ( IsPC() )
{
// read dwords
while ( nBitsLeft >= 32 )
{
*((unsigned long*)pOut) = ReadUBitLong(32);
pOut += sizeof(unsigned long);
nBitsLeft -= 32;
}
}
// read remaining bytes
while ( nBitsLeft >= 8 )
{
*pOut = ReadUBitLong(8);
++pOut;
nBitsLeft -= 8;
}
// read remaining bits
if ( nBitsLeft )
{
*pOut = ReadUBitLong(nBitsLeft);
}
}
float old_bf_read::ReadBitAngle( int numbits )
{
float fReturn;
int i;
float shift;
shift = (float)( BitForBitnum(numbits) );
i = ReadUBitLong( numbits );
fReturn = (float)i * (360.0 / shift);
return fReturn;
}
unsigned int old_bf_read::PeekUBitLong( int numbits )
{
unsigned int r;
int i, nBitValue;
#ifdef BIT_VERBOSE
int nShifts = numbits;
#endif
old_bf_read savebf;
savebf = *this; // Save current state info
r = 0;
for(i=0; i < numbits; i++)
{
nBitValue = ReadOneBit();
// Append to current stream
if ( nBitValue )
{
r |= BitForBitnum(i);
}
}
*this = savebf;
#ifdef BIT_VERBOSE
Con_Printf( "PeekBitLong: %i %i\n", nShifts, (unsigned int)r );
#endif
return r;
}
// Append numbits least significant bits from data to the current bit stream
int old_bf_read::ReadSBitLong( int numbits )
{
int r, sign;
r = ReadUBitLong(numbits - 1);
// Note: it does this wierdness here so it's bit-compatible with regular integer data in the buffer.
// (Some old code writes direct integers right into the buffer).
sign = ReadOneBit();
if(sign)
r = -((BitForBitnum(numbits-1)) - r);
return r;
}
const byte g_BitMask[8] = {0x1, 0x2, 0x4, 0x8, 0x10, 0x20, 0x40, 0x80};
const byte g_TrailingMask[8] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
inline int old_bf_read::CountRunOfZeros()
{
int bits = 0;
if ( m_iCurBit + 32 < m_nDataBits )
{
#if !FAST_BIT_SCAN
while (true)
{
int value = (m_pData[m_iCurBit >> 3] & g_BitMask[m_iCurBit & 7]);
++m_iCurBit;
if ( value )
return bits;
++bits;
}
#else
while (true)
{
int value = (m_pData[m_iCurBit >> 3] & g_TrailingMask[m_iCurBit & 7]);
if ( !value )
{
int zeros = (8-(m_iCurBit&7));
bits += zeros;
m_iCurBit += zeros;
}
else
{
int zeros = CountTrailingZeros(value) - (m_iCurBit & 7);
m_iCurBit += zeros + 1;
bits += zeros;
return bits;
}
}
#endif
}
else
{
while ( ReadOneBit() == 0 )
bits++;
}
return bits;
}
unsigned int old_bf_read::ReadUBitVar()
{
switch( ReadUBitLong( 2 ) )
{
case 0:
return ReadUBitLong( 4 );
case 1:
return ReadUBitLong( 8 );
case 2:
return ReadUBitLong( 12 );
default:
case 3:
return ReadUBitLong( 32 );
}
#if 0
int bits = CountRunOfZeros();
unsigned int data = BitForBitnum(bits)-1;
// read the value
if ( bits > 0)
data += ReadUBitLong( bits );
return data;
#endif
}
unsigned int old_bf_read::ReadBitLong(int numbits, bool bSigned)
{
if(bSigned)
return (unsigned int)ReadSBitLong(numbits);
else
return ReadUBitLong(numbits);
}
// Basic Coordinate Routines (these contain bit-field size AND fixed point scaling constants)
float old_bf_read::ReadBitCoord (void)
{
#if defined( BB_PROFILING )
VPROF( "old_bf_write::ReadBitCoord" );
#endif
int intval=0,fractval=0,signbit=0;
float value = 0.0;
// Read the required integer and fraction flags
intval = ReadOneBit();
fractval = ReadOneBit();
// If we got either parse them, otherwise it's a zero.
if ( intval || fractval )
{
// Read the sign bit
signbit = ReadOneBit();
// If there's an integer, read it in
if ( intval )
{
// Adjust the integers from [0..MAX_COORD_VALUE-1] to [1..MAX_COORD_VALUE]
intval = ReadUBitLong( COORD_INTEGER_BITS ) + 1;
}
// If there's a fraction, read it in
if ( fractval )
{
fractval = ReadUBitLong( COORD_FRACTIONAL_BITS );
}
// Calculate the correct floating point value
value = intval + ((float)fractval * COORD_RESOLUTION);
// Fixup the sign if negative.
if ( signbit )
value = -value;
}
return value;
}
float old_bf_read::ReadBitCoordMP( EBitCoordType coordType )
{
#if defined( BB_PROFILING )
VPROF( "old_bf_write::ReadBitCoordMP" );
#endif
int intval=0,fractval=0,signbit=0;
float value = 0.0;
bool bInBounds = ReadOneBit() ? true : false;
if ( coordType == kCW_Integral )
{
// Read the required integer and fraction flags
intval = ReadOneBit();
// If we got either parse them, otherwise it's a zero.
if ( intval )
{
// Read the sign bit
signbit = ReadOneBit();
// If there's an integer, read it in
// Adjust the integers from [0..MAX_COORD_VALUE-1] to [1..MAX_COORD_VALUE]
if ( bInBounds )
{
value = ReadUBitLong( COORD_INTEGER_BITS_MP ) + 1;
}
else
{
value = ReadUBitLong( COORD_INTEGER_BITS ) + 1;
}
}
}
else
{
// Read the required integer and fraction flags
intval = ReadOneBit();
// Read the sign bit
signbit = ReadOneBit();
// If we got either parse them, otherwise it's a zero.
if ( intval )
{
if ( bInBounds )
{
intval = ReadUBitLong( COORD_INTEGER_BITS_MP ) + 1;
}
else
{
intval = ReadUBitLong( COORD_INTEGER_BITS ) + 1;
}
}
// If there's a fraction, read it in
fractval = ReadUBitLong( coordType == kCW_LowPrecision ? COORD_FRACTIONAL_BITS_MP_LOWPRECISION : COORD_FRACTIONAL_BITS );
// Calculate the correct floating point value
value = intval + ((float)fractval * ( coordType == kCW_LowPrecision ? COORD_RESOLUTION_LOWPRECISION : COORD_RESOLUTION ) );
}
// Fixup the sign if negative.
if ( signbit )
value = -value;
return value;
}
void old_bf_read::ReadBitVec3Coord( Vector& fa )
{
int xflag, yflag, zflag;
// This vector must be initialized! Otherwise, If any of the flags aren't set,
// the corresponding component will not be read and will be stack garbage.
fa.Init( 0, 0, 0 );
xflag = ReadOneBit();
yflag = ReadOneBit();
zflag = ReadOneBit();
if ( xflag )
fa[0] = ReadBitCoord();
if ( yflag )
fa[1] = ReadBitCoord();
if ( zflag )
fa[2] = ReadBitCoord();
}
float old_bf_read::ReadBitNormal (void)
{
// Read the sign bit
int signbit = ReadOneBit();
// Read the fractional part
unsigned int fractval = ReadUBitLong( NORMAL_FRACTIONAL_BITS );
// Calculate the correct floating point value
float value = (float)fractval * NORMAL_RESOLUTION;
// Fixup the sign if negative.
if ( signbit )
value = -value;
return value;
}
void old_bf_read::ReadBitVec3Normal( Vector& fa )
{
int xflag = ReadOneBit();
int yflag = ReadOneBit();
if (xflag)
fa[0] = ReadBitNormal();
else
fa[0] = 0.0f;
if (yflag)
fa[1] = ReadBitNormal();
else
fa[1] = 0.0f;
// The first two imply the third (but not its sign)
int znegative = ReadOneBit();
float fafafbfb = fa[0] * fa[0] + fa[1] * fa[1];
if (fafafbfb < 1.0f)
fa[2] = sqrt( 1.0f - fafafbfb );
else
fa[2] = 0.0f;
if (znegative)
fa[2] = -fa[2];
}
void old_bf_read::ReadBitAngles( QAngle& fa )
{
Vector tmp;
ReadBitVec3Coord( tmp );
fa.Init( tmp.x, tmp.y, tmp.z );
}
int old_bf_read::ReadChar()
{
return ReadSBitLong(sizeof(char) << 3);
}
int old_bf_read::ReadByte()
{
return ReadUBitLong(sizeof(unsigned char) << 3);
}
int old_bf_read::ReadShort()
{
return ReadSBitLong(sizeof(short) << 3);
}
int old_bf_read::ReadWord()
{
return ReadUBitLong(sizeof(unsigned short) << 3);
}
long old_bf_read::ReadLong()
{
return ReadSBitLong(sizeof(long) << 3);
}
int64 old_bf_read::ReadLongLong()
{
int64 retval;
uint *pLongs = (uint*)&retval;
// Read the two DWORDs according to network endian
const short endianIndex = 0x0100;
byte *idx = (byte*)&endianIndex;
pLongs[*idx++] = ReadUBitLong(sizeof(long) << 3);
pLongs[*idx] = ReadUBitLong(sizeof(long) << 3);
return retval;
}
float old_bf_read::ReadFloat()
{
float ret;
Assert( sizeof(ret) == 4 );
ReadBits(&ret, 32);
// Swap the float, since ReadBits reads raw data
LittleFloat( &ret, &ret );
return ret;
}
bool old_bf_read::ReadBytes(void *pOut, int nBytes)
{
ReadBits(pOut, nBytes << 3);
return !IsOverflowed();
}
bool old_bf_read::ReadString( char *pStr, int maxLen, bool bLine, int *pOutNumChars )
{
Assert( maxLen != 0 );
bool bTooSmall = false;
int iChar = 0;
while(1)
{
char val = ReadChar();
if ( val == 0 )
break;
else if ( bLine && val == '\n' )
break;
if ( iChar < (maxLen-1) )
{
pStr[iChar] = val;
++iChar;
}
else
{
bTooSmall = true;
}
}
// Make sure it's null-terminated.
Assert( iChar < maxLen );
pStr[iChar] = 0;
if ( pOutNumChars )
*pOutNumChars = iChar;
return !IsOverflowed() && !bTooSmall;
}
char* old_bf_read::ReadAndAllocateString( bool *pOverflow )
{
char str[2048];
int nChars;
bool bOverflow = !ReadString( str, sizeof( str ), false, &nChars );
if ( pOverflow )
*pOverflow = bOverflow;
// Now copy into the output and return it;
char *pRet = new char[ nChars + 1 ];
for ( int i=0; i <= nChars; i++ )
pRet[i] = str[i];
return pRet;
}
void old_bf_read::ExciseBits( int startbit, int bitstoremove )
{
int endbit = startbit + bitstoremove;
int remaining_to_end = m_nDataBits - endbit;
bf_write temp;
temp.StartWriting( (void *)m_pData, m_nDataBits << 3, startbit );
Seek( endbit );
for ( int i = 0; i < remaining_to_end; i++ )
{
temp.WriteOneBit( ReadOneBit() );
}
Seek( startbit );
m_nDataBits -= bitstoremove;
m_nDataBytes = m_nDataBits >> 3;
}