package com.marshalchen.common.uimodule.imageprocessing.filter.blend;
import com.marshalchen.common.uimodule.imageprocessing.filter.MultiInputFilter;
/**
* Applies a luminosity blend of two images
* @author Chris Batt
*/
public class LuminosityBlendFilter extends MultiInputFilter {
public LuminosityBlendFilter() {
super(2);
}
@Override
protected String getFragmentShader() {
return
"precision mediump float;\n"
+"uniform sampler2D "+UNIFORM_TEXTURE0+";\n"
+"uniform sampler2D "+UNIFORM_TEXTUREBASE+1+";\n"
+"varying vec2 "+VARYING_TEXCOORD+";\n"
+"highp float lum(lowp vec3 c) {\n"
+" return dot(c, vec3(0.3, 0.59, 0.11));\n"
+"}\n"
+"vec3 setlum(lowp vec3 c, highp float l2) {\n"
+" float d = l2 - lum(c);\n"
+" c = c + vec3(d);\n"
+" float l = lum(c);\n"
+" float n = min(min(c.r, c.g), c.b);\n"
+" float x = max(max(c.r, c.g), c.b);\n"
+" if (n < 0.0) {\n"
+" c.r = l + ((c.r - l) * l) / (l - n);\n"
+" c.g = l + ((c.g - l) * l) / (l - n);\n"
+" c.b = l + ((c.b - l) * l) / (l - n);\n"
+" }\n"
+" if (x > 1.0) {\n"
+" c.r = l + ((c.r - l) * (1.0 - l)) / (x - l);\n"
+" c.g = l + ((c.g - l) * (1.0 - l)) / (x - l);\n"
+" c.b = l + ((c.b - l) * (1.0 - l)) / (x - l);\n"
+" }\n"
+" return c;\n"
+"}\n"
+"void main(){\n"
+" vec4 color1 = texture2D("+UNIFORM_TEXTURE0+","+VARYING_TEXCOORD+");\n"
+" vec4 color2 = texture2D("+UNIFORM_TEXTUREBASE+1+","+VARYING_TEXCOORD+");\n"
+" gl_FragColor = vec4(color1.rgb * (1.0 - color2.a) + setlum(color1.rgb, lum(color2.rgb)) * color2.a, color1.a);\n"
+"}\n";
}
}