Paranoia2/game_shared/cubemap.h

64 lines
1.5 KiB
C++

//===== Copyright © 1996-2007, Valve Corporation, All rights reserved. ======//
//
// Purpose: a class for performing cube-mapped spherical sample lookups.
//
// $Workfile: $
// $Date: $
// $NoKeywords: $
//===========================================================================//
#ifndef CUBEMAP_H
#define CUBEMAP_H
#include "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 )
{
int nLargest = 0;
int nAxis0 = 1;
int nAxis1 = 2;
// find largest magnitude component
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