uniform sampler2D frameSampler;
layout (std140) uniform Uniforms {
mat4 worldViewProjection;
vec2 invSize;
};
in vec2 texCoord;
out float outLum;
void main() {
float totalLum = 0.0;
for (float y = -0.5; y < 0.5; y += 0.5) {
for (float x = -0.5; x < 0.5; x += 0.5) {
totalLum += S_Luminance(texture(frameSampler, texCoord - vec2(x, y) * invSize).xyz);
}
}
outLum = totalLum / 9.0;
}