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