144 lines
4.4 KiB
GLSL
144 lines
4.4 KiB
GLSL
// Colorgrading library functions - Inspired by UE4
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//No specific license (maybe zlib), but just do whatever
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#define LUMINANCE_PRESERVATION 0.75
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#define EPSILON 1e-10
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#define LUMA1 0.2722287168
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#define LUMA2 0.6740817658
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#define LUMA3 0.0536895174
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float saturate(float v) { return clamp(v, 0.0, 1.0); }
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vec2 saturate(vec2 v) { return clamp(v, vec2(0.0), vec2(1.0)); }
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vec3 saturate(vec3 v) { return clamp(v, vec3(0.0), vec3(1.0)); }
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vec4 saturate(vec4 v) { return clamp(v, vec4(0.0), vec4(1.0)); }
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float LumaKey (vec3 color) {
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return dot(color, vec3(LUMA1, LUMA2, LUMA3));
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}
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vec3 ColorTemperatureToRGB(float temperatureInKelvins)
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{
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vec3 retColor;
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temperatureInKelvins = clamp(temperatureInKelvins, 1000.0, 40000.0) / 100.0;
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if (temperatureInKelvins <= 66.0)
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{
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retColor.r = 1.0;
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retColor.g = saturate(0.39008157876901960784 * log(temperatureInKelvins) - 0.63184144378862745098);
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}
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else
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{
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float t = temperatureInKelvins - 60.0;
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retColor.r = saturate(1.29293618606274509804 * pow(t, -0.1332047592));
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retColor.g = saturate(1.12989086089529411765 * pow(t, -0.0755148492));
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}
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if (temperatureInKelvins >= 66.0)
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retColor.b = 1.0;
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else if(temperatureInKelvins <= 19.0)
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retColor.b = 0.0;
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else
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retColor.b = saturate(0.54320678911019607843 * log(temperatureInKelvins - 10.0) - 1.19625408914);
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return retColor;
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}
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float Luminance(vec3 color)
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{
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float fmin = min(min(color.r, color.g), color.b);
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float fmax = max(max(color.r, color.g), color.b);
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return (fmax + fmin) / 2.0;
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}
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vec3 HUEtoRGB(float H)
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{
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float R = abs(H * 6.0 - 3.0) - 1.0;
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float G = 2.0 - abs(H * 6.0 - 2.0);
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float B = 2.0 - abs(H * 6.0 - 4.0);
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return saturate(vec3(R,G,B));
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}
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vec3 HSLtoRGB(in vec3 HSL)
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{
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vec3 RGB = HUEtoRGB(HSL.x);
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float C = (1.0 - abs(2.0 * HSL.z - 1.0)) * HSL.y;
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return (RGB - 0.5) * C + vec3(HSL.z);
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}
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vec3 RGBtoHCV(vec3 RGB)
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{
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vec4 P = (RGB.g < RGB.b) ? vec4(RGB.bg, -1.0, 2.0/3.0) : vec4(RGB.gb, 0.0, -1.0/3.0);
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vec4 Q = (RGB.r < P.x) ? vec4(P.xyw, RGB.r) : vec4(RGB.r, P.yzx);
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float C = Q.x - min(Q.w, Q.y);
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float H = abs((Q.w - Q.y) / (6.0 * C + EPSILON) + Q.z);
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return vec3(H, C, Q.x);
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}
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vec3 RGBtoHSL(vec3 RGB)
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{
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vec3 HCV = RGBtoHCV(RGB);
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float L = HCV.z - HCV.y * 0.5;
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float S = HCV.y / (1.0 - abs(L * 2.0 - 1.0) + EPSILON);
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return vec3(HCV.x, S, L);
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}
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vec3 ToneColorCorrection(vec3 Color, vec3 ColorSaturation, vec3 ColorContrast, vec3 ColorGamma, vec3 ColorGain, vec3 ColorOffset) {
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//First initialize the colorluma key
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float ColorLuma = LumaKey(Color);
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//Add the saturation with the above key
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Color = max(vec3(0,0,0), mix(ColorLuma.xxx, Color, ColorSaturation));
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//Contrast with slight color correction (0.18 coefficient)
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float ContrastCorrectionCoefficient = 0.18;
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Color = pow(Color * (1.0 / ContrastCorrectionCoefficient), ColorContrast) * ContrastCorrectionCoefficient;
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//Gamma
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Color = pow(Color, 1.0 / ColorGamma);
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//Gain and Offset
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Color = Color.rgb * ColorGain + (ColorOffset - 1);
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//Return the color corrected profile
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return Color;
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}
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vec3 FinalizeColorCorrection(vec3 Color, mat3 ColorSaturation, mat3 ColorContrast, mat3 ColorGamma, mat3 ColorGain, mat3 ColorOffset, vec2 Toneweights) {
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float CCShadowsMax = Toneweights.x;
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float CCHighlightsMin = Toneweights.y;
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//First initialize the colorluma key and set color correction weights
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float ColorLuma = LumaKey(Color);
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float CCWeightShadows = 1 - smoothstep(0, CCShadowsMax, ColorLuma);
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float CCWeightHighlights = smoothstep(CCHighlightsMin, 1, ColorLuma);
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float CCWeightMidtones = 1 - CCWeightShadows - CCWeightHighlights;
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vec3 CCColorShadows = ToneColorCorrection (
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Color,
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ColorSaturation[0],
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ColorContrast[0],
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ColorGamma[0],
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ColorGain[0],
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ColorOffset[0]
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);
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vec3 CCColorMidtones = ToneColorCorrection (
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Color,
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ColorSaturation[1],
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ColorContrast[1],
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ColorGamma[1],
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ColorGain[1],
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ColorOffset[1]
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);
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vec3 CCColorHighlights = ToneColorCorrection (
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Color,
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ColorSaturation[2],
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ColorContrast[2],
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ColorGamma[2],
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ColorGain[2],
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ColorOffset[2]
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);
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vec3 CombinedCCProfile = CCColorShadows * CCWeightShadows + CCColorMidtones * CCWeightMidtones + CCColorHighlights * CCWeightHighlights;
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return vec3(CombinedCCProfile);
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} |