pathfinder/resources/shaders/gl3/tile_alpha_dodgeburn.fs.glsl

#version {{version}}
// Automatically generated from files in pathfinder/shaders/. Do not edit!














#extension GL_GOOGLE_include_directive : enable

precision highp float;

uniform int uBurn;

out vec4 oFragColor;












uniform sampler2D uStencilTexture;
uniform sampler2D uPaintTexture;
uniform sampler2D uDest;
uniform vec2 uFramebufferSize;

in vec2 vColorTexCoord;
in vec2 vMaskTexCoord;


vec4 sampleSrcColor(){
    float coverage = texture(uStencilTexture, vMaskTexCoord). r;
    vec4 srcRGBA = texture(uPaintTexture, vColorTexCoord);
    return vec4(srcRGBA . rgb, srcRGBA . a * coverage);
}

vec4 sampleDestColor(){
    vec2 destTexCoord = gl_FragCoord . xy / uFramebufferSize;
    return texture(uDest, destTexCoord);
}


vec4 blendColors(vec4 destRGBA, vec4 srcRGBA, vec3 blendedRGB){
    return vec4(srcRGBA . a *(1.0 - destRGBA . a)* srcRGBA . rgb +
                srcRGBA . a * destRGBA . a * blendedRGB +
                (1.0 - srcRGBA . a)* destRGBA . a * destRGBA . rgb,
                1.0);
}

vec3 select3(bvec3 cond, vec3 a, vec3 b){
    return vec3(cond . x ? a . x : b . x, cond . y ? a . y : b . y, cond . z ? a . z : b . z);
}


void main(){
    vec4 srcRGBA = sampleSrcColor();
    vec4 destRGBA = sampleDestColor();

    vec3 dest = uBurn == 0 ? destRGBA . rgb : vec3(1.0)- destRGBA . rgb;
    vec3 src = uBurn == 0 ? vec3(1.0)- srcRGBA . rgb : srcRGBA . rgb;

    bvec3 srcNonzero = notEqual(src, vec3(0.0));
    vec3 blended = min(vec3(srcNonzero . x ? dest . x / src . x : 1.0,
                            srcNonzero . y ? dest . y / src . y : 1.0,
                            srcNonzero . z ? dest . z / src . z : 1.0),
                       vec3(1.0));
    if(uBurn != 0)
        blended = vec3(1.0)- blended;

    oFragColor = blendColors(destRGBA, srcRGBA, blended);
}