#version 450

layout(location = 0) out vec4 FragColor;
layout(location = 0) in vec2 TexCoords;
layout(set = 0, binding = 0) uniform sampler2D bloomImage;

layout(push_constant) uniform PassConfig {
    int horizontal;
    float GAMMA_CONST;
    float Exposure;
    float blur_radius;
    vec2 bloomSize;
} config;

const float weight[5] = float[](0.227027, 0.1945946, 0.1216216, 0.054054, 0.016216);

vec3 safeBloomSample(vec2 uv) {
    return max(texture(bloomImage, uv).rgb, vec3(0.0));
}

void main() {
    vec2 tex_offset = config.blur_radius / vec2(textureSize(bloomImage, 0));
    vec2 direction = config.horizontal != 0 ? vec2(tex_offset.x, 0.0) : vec2(0.0, tex_offset.y);
    vec3 result = safeBloomSample(TexCoords) * weight[0];
    for (int i = 1; i < 5; i++) {
        result += safeBloomSample(TexCoords + direction * i) * weight[i];
        result += safeBloomSample(TexCoords - direction * i) * weight[i];
    }
    FragColor = vec4(result, 1.0);
}