forked from 0ad/0ad
65 lines
1.9 KiB
C++
Executable File
65 lines
1.9 KiB
C++
Executable File
//----------------------------------------------------------------
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//
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// Name: SHCoeffs.h
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// Last Update: 25/11/03
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// Author: Rich Cross
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// Contact: rich@0ad.wildfiregames.com
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//
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// Description: implementation of 9 component spherical harmonic
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// lighting
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//----------------------------------------------------------------
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#include "SHCoeffs.h"
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CSHCoeffs::CSHCoeffs()
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{
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for (int i=0;i<9;i++) {
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_data[i].Clear();
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}
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}
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void CSHCoeffs::AddAmbientLight(const RGBColor& color)
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{
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_data[0]+=color;
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}
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void CSHCoeffs::AddDirectionalLight(const CVector3D& lightDir,const RGBColor& lightColor)
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{
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CVector3D dirToLight(-lightDir.X,-lightDir.Y,-lightDir.Z);
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const float normalisation = PI*16/17;
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const float c1 = SQR(0.282095f) * normalisation * 1.0f;
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const float c2 = SQR(0.488603f) * normalisation * (2.0f/3.0f);
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const float c3 = SQR(1.092548f) * normalisation * (1.0f/4.0f);
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const float c4 = SQR(0.315392f) * normalisation * (1.0f/4.0f);
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const float c5 = SQR(0.546274f) * normalisation * (1.0f/4.0f);
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_data[0]+=lightColor*c1;
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_data[1]+=lightColor*c2*dirToLight.X;
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_data[2]+=lightColor*c2*dirToLight.Y;
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_data[3]+=lightColor*c2*dirToLight.Z;
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_data[4]+=lightColor*c3*dirToLight.X*dirToLight.Z;
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_data[5]+=lightColor*c3*dirToLight.Z*dirToLight.Y;
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_data[6]+=lightColor*c3*dirToLight.Y*dirToLight.X;
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_data[7]+=lightColor*c4*(3.0f*SQR(dirToLight.Z)-1.0f);
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_data[8]+=lightColor*c5*(SQR(dirToLight.X)-SQR(dirToLight.Y));
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}
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void CSHCoeffs::Evaluate(const CVector3D& normal,RGBColor& color)
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{
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#if 1
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color=_data[0];
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color+=_data[1]*normal.X;
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color+=_data[2]*normal.Y;
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color+=_data[3]*normal.Z;
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color+=_data[4]*(normal.X*normal.Z);
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color+=_data[5]*(normal.Z*normal.Y);
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color+=_data[6]*(normal.Y*normal.X);
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color+=_data[7]*(3*SQR(normal.Z)-1.0f);
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color+=_data[8]*(SQR(normal.X)-SQR(normal.Y));
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#else
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// debug aid: output quantised normal
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color=RGBColor((normal.X+1)*0.5,(normal.Y+1)*0.5,(normal.Z+1)*0.5);
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#endif
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}
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