26 lines
706 B
GLSL
26 lines
706 B
GLSL
#version 330 core
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uniform float exposure_compensation;
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const float one_over_log10 = 1.0 / log(10.0);
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float log10(float x)
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{
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return one_over_log10 * log(x);
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}
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// Exposure curve from 'Perceptual Effects in Real-time Tone Mapping'.
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// http://resources.mpi-inf.mpg.de/hdr/peffects/krawczyk05sccg.pdf
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float keyValue(float L)
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{
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return 1.03 - 2.0 / (log10(L + 1.0) + 2.0);
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}
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vec3 applyExposure(vec3 color, float avgLuminance, float threshold)
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{
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avgLuminance = max(avgLuminance, 0.001);
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float linearExposure = keyValue(avgLuminance) / avgLuminance;
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float exposure = log2(max(linearExposure, 0.0001));
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exposure += exposure_compensation - threshold;
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return color * exp2(exposure);
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}
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