miketucker · March 6, 2015 23:19 · Mar 6, 2015
diff --git a/PhotoshopBlendModes b/PhotoshopBlendModes
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+/*
+** Copyright (c) 2012, Romain Dura [email protected]
+** 
+** 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)