#version 460 core

layout(location = 0) in vec2 inUV;

layout(location = 0) out vec4 outColor;

layout(binding = 0) uniform sampler2D sceneSampler;
layout(binding = 1) uniform sampler2D depthSampler;
layout(binding = 2) uniform sampler2D nearFieldSampler;
layout(binding = 3) uniform sampler2D farFieldSampler;

void main() {   
    vec3 sceneColor = texture(sceneSampler, inUV).rgb;  

    // alpha divide reconstruction
    vec3 farColor = texture(farFieldSampler, inUV).rgb / max(texture(farFieldSampler, inUV).a, 0.0001) * 0.02;
    vec3 nearColor = texture(nearFieldSampler, inUV).rgb / max(texture(nearFieldSampler, inUV).a, 0.0001) * 0.02;
    
    // read coc stored in the alpha channel
    float coc = texture(farFieldSampler, inUV).a;
    
    // transistion between out of focus and regular scene
    vec3 farColorBlurred = mix(sceneColor, farColor, clamp(coc, 0.0, 1.0));
    
    // smoother transistion between the normal scene and the "out of focus" portions
    farColorBlurred = mix(sceneColor, farColorBlurred, clamp(0.5 * coc + 1.0, 0.0, 1.0));
    
    //float coc2 = texture(nearFieldSampler, inUV).a;
    //vec3 finalColor = mix(farColorBlurred, nearColor, clamp(clamp(-coc2 - 1.0, 0.0, 1.0) + texture(nearFieldSampler, inUV).a * 8.0, 0.0, 1.0));
    
    outColor = vec4(farColorBlurred, 1.0);
}