/* ** Copyright (c) 2012, Romain Dura romain@shazbits.com ** ** Permission to use, copy, modify, and/or distribute this software for any ** purpose with or without fee is hereby granted, provided that the above ** copyright notice and this permission notice appear in all copies. ** ** THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES ** WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF ** MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY ** SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES ** WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ** ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR ** IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ /* ** Photoshop & misc math ** Blending modes, RGB/HSL/Contrast/Desaturate, levels control ** ** Romain Dura | Romz ** Blog: http://mouaif.wordpress.com ** Post: http://mouaif.wordpress.com/?p=94 */ /* ** Desaturation */ vec4 Desaturate(vec3 color, float Desaturation) { vec3 grayXfer = vec3(0.3, 0.59, 0.11); vec3 gray = vec3(dot(grayXfer, color)); return vec4(mix(color, gray, Desaturation), 1.0); } /* ** Hue, saturation, luminance */ vec3 RGBToHSL(vec3 color) { vec3 hsl; // init to 0 to avoid warnings ? (and reverse if + remove first part) float fmin = min(min(color.r, color.g), color.b); //Min. value of RGB float fmax = max(max(color.r, color.g), color.b); //Max. value of RGB float delta = fmax - fmin; //Delta RGB value hsl.z = (fmax + fmin) / 2.0; // Luminance if (delta == 0.0) //This is a gray, no chroma... { hsl.x = 0.0; // Hue hsl.y = 0.0; // Saturation } else //Chromatic data... { if (hsl.z < 0.5) hsl.y = delta / (fmax + fmin); // Saturation else hsl.y = delta / (2.0 - fmax - fmin); // Saturation float deltaR = (((fmax - color.r) / 6.0) + (delta / 2.0)) / delta; float deltaG = (((fmax - color.g) / 6.0) + (delta / 2.0)) / delta; float deltaB = (((fmax - color.b) / 6.0) + (delta / 2.0)) / delta; if (color.r == fmax ) hsl.x = deltaB - deltaG; // Hue else if (color.g == fmax) hsl.x = (1.0 / 3.0) + deltaR - deltaB; // Hue else if (color.b == fmax) hsl.x = (2.0 / 3.0) + deltaG - deltaR; // Hue if (hsl.x < 0.0) hsl.x += 1.0; // Hue else if (hsl.x > 1.0) hsl.x -= 1.0; // Hue } return hsl; } float HueToRGB(float f1, float f2, float hue) { if (hue < 0.0) hue += 1.0; else if (hue > 1.0) hue -= 1.0; float res; if ((6.0 * hue) < 1.0) res = f1 + (f2 - f1) * 6.0 * hue; else if ((2.0 * hue) < 1.0) res = f2; else if ((3.0 * hue) < 2.0) res = f1 + (f2 - f1) * ((2.0 / 3.0) - hue) * 6.0; else res = f1; return res; } vec3 HSLToRGB(vec3 hsl) { vec3 rgb; if (hsl.y == 0.0) rgb = vec3(hsl.z); // Luminance else { float f2; if (hsl.z < 0.5) f2 = hsl.z * (1.0 + hsl.y); else f2 = (hsl.z + hsl.y) - (hsl.y * hsl.z); float f1 = 2.0 * hsl.z - f2; rgb.r = HueToRGB(f1, f2, hsl.x + (1.0/3.0)); rgb.g = HueToRGB(f1, f2, hsl.x); rgb.b= HueToRGB(f1, f2, hsl.x - (1.0/3.0)); } return rgb; } /* ** Contrast, saturation, brightness ** Code of this function is from TGM's shader pack ** http://irrlicht.sourceforge.net/phpBB2/viewtopic.php?t=21057 */ // For all settings: 1.0 = 100% 0.5=50% 1.5 = 150% vec3 ContrastSaturationBrightness(vec3 color, float brt, float sat, float con) { // Increase or decrease theese values to adjust r, g and b color channels seperately const float AvgLumR = 0.5; const float AvgLumG = 0.5; const float AvgLumB = 0.5; const vec3 LumCoeff = vec3(0.2125, 0.7154, 0.0721); vec3 AvgLumin = vec3(AvgLumR, AvgLumG, AvgLumB); vec3 brtColor = color * brt; vec3 intensity = vec3(dot(brtColor, LumCoeff)); vec3 satColor = mix(intensity, brtColor, sat); vec3 conColor = mix(AvgLumin, satColor, con); return conColor; } /* ** Float blending modes ** Adapted from here: http://www.nathanm.com/photoshop-blending-math/ ** But I modified the HardMix (wrong condition), Overlay, SoftLight, ColorDodge, ColorBurn, VividLight, PinLight (inverted layers) ones to have correct results */ #define BlendLinearDodgef BlendAddf #define BlendLinearBurnf BlendSubstractf #define BlendAddf(base, blend) min(base + blend, 1.0) #define BlendSubstractf(base, blend) max(base + blend - 1.0, 0.0) #define BlendLightenf(base, blend) max(blend, base) #define BlendDarkenf(base, blend) min(blend, base) #define BlendLinearLightf(base, blend) (blend < 0.5 ? BlendLinearBurnf(base, (2.0 * blend)) : BlendLinearDodgef(base, (2.0 * (blend - 0.5)))) #define BlendScreenf(base, blend) (1.0 - ((1.0 - base) * (1.0 - blend))) #define BlendOverlayf(base, blend) (base < 0.5 ? (2.0 * base * blend) : (1.0 - 2.0 * (1.0 - base) * (1.0 - blend))) #define BlendSoftLightf(base, blend) ((blend < 0.5) ? (2.0 * base * blend + base * base * (1.0 - 2.0 * blend)) : (sqrt(base) * (2.0 * blend - 1.0) + 2.0 * base * (1.0 - blend))) #define BlendColorDodgef(base, blend) ((blend == 1.0) ? blend : min(base / (1.0 - blend), 1.0)) #define BlendColorBurnf(base, blend) ((blend == 0.0) ? blend : max((1.0 - ((1.0 - base) / blend)), 0.0)) #define BlendVividLightf(base, blend) ((blend < 0.5) ? BlendColorBurnf(base, (2.0 * blend)) : BlendColorDodgef(base, (2.0 * (blend - 0.5)))) #define BlendPinLightf(base, blend) ((blend < 0.5) ? BlendDarkenf(base, (2.0 * blend)) : BlendLightenf(base, (2.0 *(blend - 0.5)))) #define BlendHardMixf(base, blend) ((BlendVividLightf(base, blend) < 0.5) ? 0.0 : 1.0) #define BlendReflectf(base, blend) ((blend == 1.0) ? blend : min(base * base / (1.0 - blend), 1.0)) /* ** Vector3 blending modes */ // Component wise blending #define Blend(base, blend, funcf) vec3(funcf(base.r, blend.r), funcf(base.g, blend.g), funcf(base.b, blend.b)) #define BlendNormal(base, blend) (blend) #define BlendLighten BlendLightenf #define BlendDarken BlendDarkenf #define BlendMultiply(base, blend) (base * blend) #define BlendAverage(base, blend) ((base + blend) / 2.0) #define BlendAdd(base, blend) min(base + blend, vec3(1.0)) #define BlendSubstract(base, blend) max(base + blend - vec3(1.0), vec3(0.0)) #define BlendDifference(base, blend) abs(base - blend) #define BlendNegation(base, blend) (vec3(1.0) - abs(vec3(1.0) - base - blend)) #define BlendExclusion(base, blend) (base + blend - 2.0 * base * blend) #define BlendScreen(base, blend) Blend(base, blend, BlendScreenf) #define BlendOverlay(base, blend) Blend(base, blend, BlendOverlayf) #define BlendSoftLight(base, blend) Blend(base, blend, BlendSoftLightf) #define BlendHardLight(base, blend) BlendOverlay(blend, base) #define BlendColorDodge(base, blend) Blend(base, blend, BlendColorDodgef) #define BlendColorBurn(base, blend) Blend(base, blend, BlendColorBurnf) #define BlendLinearDodge BlendAdd #define BlendLinearBurn BlendSubstract // Linear Light is another contrast-increasing mode // If the blend color is darker than midgray, Linear Light darkens the image by decreasing the brightness. If the blend color is lighter than midgray, the result is a brighter image due to increased brightness. #define BlendLinearLight(base, blend) Blend(base, blend, BlendLinearLightf) #define BlendVividLight(base, blend) Blend(base, blend, BlendVividLightf) #define BlendPinLight(base, blend) Blend(base, blend, BlendPinLightf) #define BlendHardMix(base, blend) Blend(base, blend, BlendHardMixf) #define BlendReflect(base, blend) Blend(base, blend, BlendReflectf) #define BlendGlow(base, blend) BlendReflect(blend, base) #define BlendPhoenix(base, blend) (min(base, blend) - max(base, blend) + vec3(1.0)) #define BlendOpacity(base, blend, F, O) (F(base, blend) * O + blend * (1.0 - O)) // Hue Blend mode creates the result color by combining the luminance and saturation of the base color with the hue of the blend color. vec3 BlendHue(vec3 base, vec3 blend) { vec3 baseHSL = RGBToHSL(base); return HSLToRGB(vec3(RGBToHSL(blend).r, baseHSL.g, baseHSL.b)); } // Saturation Blend mode creates the result color by combining the luminance and hue of the base color with the saturation of the blend color. vec3 BlendSaturation(vec3 base, vec3 blend) { vec3 baseHSL = RGBToHSL(base); return HSLToRGB(vec3(baseHSL.r, RGBToHSL(blend).g, baseHSL.b)); } // Color Mode keeps the brightness of the base color and applies both the hue and saturation of the blend color. vec3 BlendColor(vec3 base, vec3 blend) { vec3 blendHSL = RGBToHSL(blend); return HSLToRGB(vec3(blendHSL.r, blendHSL.g, RGBToHSL(base).b)); } // Luminosity Blend mode creates the result color by combining the hue and saturation of the base color with the luminance of the blend color. vec3 BlendLuminosity(vec3 base, vec3 blend) { vec3 baseHSL = RGBToHSL(base); return HSLToRGB(vec3(baseHSL.r, baseHSL.g, RGBToHSL(blend).b)); } /* ** Gamma correction ** Details: http://blog.mouaif.org/2009/01/22/photoshop-gamma-correction-shader/ */ #define GammaCorrection(color, gamma) pow(color, 1.0 / gamma) /* ** Levels control (input (+gamma), output) ** Details: http://blog.mouaif.org/2009/01/28/levels-control-shader/ */ #define LevelsControlInputRange(color, minInput, maxInput) min(max(color - vec3(minInput), vec3(0.0)) / (vec3(maxInput) - vec3(minInput)), vec3(1.0)) #define LevelsControlInput(color, minInput, gamma, maxInput) GammaCorrection(LevelsControlInputRange(color, minInput, maxInput), gamma) #define LevelsControlOutputRange(color, minOutput, maxOutput) mix(vec3(minOutput), vec3(maxOutput), color) #define LevelsControl(color, minInput, gamma, maxInput, minOutput, maxOutput) LevelsControlOutputRange(LevelsControlInput(color, minInput, gamma, maxInput), minOutput, maxOutput) // added by Eric so it works in Magic: void main() { vec4 col1 = texture2D(iChannel0, gl_FragCoord.xy / iResolution.xy); vec4 col2 = texture2D(iChannel1, gl_FragCoord.xy / iResolution.xy); // replace BlendPhoenix with any other mode from above: gl_FragColor = vec4( BlendPhoenix(col1.rgb, col2.rgb), (col1.a+col2.a)/2.0); }