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hl2sdk/public/bitmap/cubemap.h
2013-06-26 15:22:04 -07:00

69 lines
1.6 KiB
C++

//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose: a class for performing cube-mapped spherical sample lookups.
//
// $Workfile: $
// $Date: $
// $NoKeywords: $
//===========================================================================//
#ifndef CUBEMAP_H
#define CUBEMAP_H
#ifdef _WIN32
#pragma once
#endif
#include "tier0/platform.h"
#include "tier1/utlmemory.h"
#include "mathlib/mathlib.h"
template<class T, int RES> struct CCubeMap
{
T m_Samples[6][RES][RES];
public:
FORCEINLINE void GetCoords( Vector const &vecNormalizedDirection, int &nX, int &nY, int &nFace )
{
// find largest magnitude component
int nLargest = 0;
int nAxis0 = 1;
int nAxis1 = 2;
if ( fabs( vecNormalizedDirection[1] ) > fabs( vecNormalizedDirection[0] ) )
{
nLargest = 1;
nAxis0 = 0;
nAxis1 = 2;
}
if ( fabs( vecNormalizedDirection[2] ) > fabs( vecNormalizedDirection[nLargest] ) )
{
nLargest = 2;
nAxis0 = 0;
nAxis1 = 1;
}
float flZ = vecNormalizedDirection[nLargest];
if ( flZ < 0 )
{
flZ = - flZ;
nLargest += 3;
}
nFace = nLargest;
flZ = 1.0 / flZ;
nX = RemapValClamped( vecNormalizedDirection[nAxis0] * flZ, -1, 1, 0, RES - 1 );
nY = RemapValClamped( vecNormalizedDirection[nAxis1] * flZ, -1, 1, 0, RES - 1 );
}
FORCEINLINE T & GetSample( Vector const &vecNormalizedDirection )
{
int nX, nY, nFace;
GetCoords( vecNormalizedDirection, nX, nY, nFace );
return m_Samples[nFace][nX][nY];
}
};
#endif // CUBEMAP_H