30 lines
1,007 B
GLSL
30 lines
1,007 B
GLSL
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float RadicalInverse_VdC(uint bits)
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{
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bits = (bits << 16u) | (bits >> 16u);
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bits = ((bits & 0x55555555u) << 1u) | ((bits & 0xAAAAAAAAu) >> 1u);
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bits = ((bits & 0x33333333u) << 2u) | ((bits & 0xCCCCCCCCu) >> 2u);
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bits = ((bits & 0x0F0F0F0Fu) << 4u) | ((bits & 0xF0F0F0F0u) >> 4u);
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bits = ((bits & 0x00FF00FFu) << 8u) | ((bits & 0xFF00FF00u) >> 8u);
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return float(bits) * 2.3283064365386963e-10f; // / 0x100000000
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}
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vec2 Hammersley(uint i, uint N)
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{
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return vec2(float(i) / float(N), RadicalInverse_VdC(i));
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}
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vec2 getVogelDiskSample(int sampleIndex, int sampleCount, float phi)
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{
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const float goldenAngle = radians(180.0) * (3.0 - sqrt(5.0));
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float sampleIndexF = float(sampleIndex);
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float sampleCountF = float(sampleCount);
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float r = sqrt((sampleIndexF + 0.5) / sampleCountF); // Assuming index and count are positive
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float theta = sampleIndexF * goldenAngle + phi;
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float sine = sin(theta);
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float cosine = cos(theta);
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return vec2(cosine, sine) * r;
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}
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