55 lines
1.2 KiB
C
55 lines
1.2 KiB
C
//----------------------------------------------------------------------------
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//
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// texdiff.h
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//
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// TextureDiff base code for inclusion as an inline function or
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// regular function from common code.
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//
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// Copyright (C) Microsoft Corporation, 1997.
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//
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//----------------------------------------------------------------------------
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//----------------------------------------------------------------------------
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//
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// TextureDiff
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//
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// Computes the difference between two texture coordinates according
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// to the given texture wrap mode.
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//
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//----------------------------------------------------------------------------
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{
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FLOAT fDiff1 = fTb - fTa;
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if (iMode == 0)
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{
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// Wrap not set, return plain difference.
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return fDiff1;
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}
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else
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{
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FLOAT fDiff2;
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// Wrap set, compute shortest distance of plain difference
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// and wrap difference.
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fDiff2 = fDiff1;
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if (FLOAT_LTZ(fDiff1))
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{
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fDiff2 += g_fOne;
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}
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else if (FLOAT_GTZ(fDiff1))
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{
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fDiff2 -= g_fOne;
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}
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if (ABSF(fDiff1) < ABSF(fDiff2))
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{
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return fDiff1;
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}
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else
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{
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return fDiff2;
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}
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}
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}
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