#version 450

layout(std140, set = 0, binding = 0) uniform UBO
{
    mat4 MVP;
    vec4 OutputSize;
    vec4 OriginalSize;
    vec4 SourceSize;
} global;

#pragma stage vertex
layout(location = 0) in vec4 Position;
layout(location = 1) in vec2 TexCoord;
layout(location = 0) out vec2 vTexCoord;

void main()
{
    gl_Position = global.MVP * Position;
    vTexCoord   = TexCoord;
}

#pragma stage fragment
layout(location = 0) in vec2 vTexCoord;
layout(location = 0) out vec4 FragColor;
layout(set = 0, binding = 2) uniform sampler2D Source;
layout(set = 0, binding = 3) uniform sampler2D OriginalHistory1;
layout(set = 0, binding = 4) uniform sampler2D OriginalHistory2;
layout(set = 0, binding = 5) uniform sampler2D OriginalHistory3;
layout(set = 0, binding = 6) uniform sampler2D OriginalHistory4;
layout(set = 0, binding = 7) uniform sampler2D OriginalHistory5;
layout(set = 0, binding = 8) uniform sampler2D OriginalHistory6;
layout(set = 0, binding = 9) uniform sampler2D OriginalHistory7;

void main()
{
    float blue_result = 
        texture(OriginalHistory1, vTexCoord).b +
        texture(OriginalHistory2, vTexCoord).b +
        texture(OriginalHistory3, vTexCoord).b +
        texture(OriginalHistory4, vTexCoord).b +
        texture(OriginalHistory5, vTexCoord).b +
        texture(OriginalHistory6, vTexCoord).b +
        texture(OriginalHistory7, vTexCoord).b -
        texture(Source,           vTexCoord).b * 7.0;

    blue_result = clamp(blue_result, 0.0, 1.0);
    
    FragColor = clamp(
        texture(Source, vTexCoord) + 0.4 * vec4(0.0, 0.0, blue_result, 1.0),
        0.0, 1.0
    );
}
