#version 150

uniform sampler2D colortex0;
in vec2 texCoord;
out vec4 fragColor;

void main() {
	ivec2 pixelSizeInt = textureSize(colortex0, 0);
	vec2 pixelSizeFloat = vec2(pixelSizeInt);
	vec2 texelSize = vec2(1.0) / vec2(textureSize(colortex0, 0));



	// Following is made by Claude, that works (27.5.26)
    /*
	vec3 scene = texture(colortex0, texCoord).rgb;
    float gray = dot(scene, vec3(2.5000, 0.5000, 0.5000)); // Farbkontrolle (Auch genannt, luma weiter oben)
    fragColor = vec4(vec3(gray), 1.0);
	*/
}

squareBottomRight() {
	float lumaSum_br = 0.0;
	float lumaSquaredSum_br = 0.0;
	vec3 colorSum_br = vec3(0.0);
	vec3 mean_br = vec3(0.0);
	vec3 mean_luma_br = vec3(0.0);
	float variance_br = 0.0;
	for (int i = 0; i <= 2; i++) {
		for (int j = -2; j <= 0; j++) {
			vec2 offset_br = vec2(float(i), float(j)) * texelSize_br;
			vec3 neighborColor_br = texture(colortex0, texCoord + offset_br).rgb;
			float luma_br = dot(neighborColor_br, vec3(0.299, 0.587, 0.114)); // Basically dasselbe wie float gray weiter unten
			colorSum_br += neighborColor_br;
			lumaSum_br += luma_br;
			lumaSquaredSum_br += (luma_br * luma_br);
		}
	}
	mean_br = (colorSum_br / 9.0);
	mean_luma_br = (lumaSum_br / 9.0);
	variance_br = (lumaSquaredSum_br / 9.0 - (mean_luma_br * mean_luma_br)); 
}

squareBottomLeft() {
	float lumaSum_bl = 0.0;
	float lumaSquaredSum_bl = 0.0;
	vec3 colorSum_bl = vec3(0.0);
	vec3 mean_bl = vec3(0.0);
	vec3 mean_luma_bl = vec3(0.0);
	float variance_bl = 0.0;
	for (int i = -2; i <= 0; i++) {
		for (int j = -2; j <= 0; j++) {
			vec2 offset_bl = vec2(float(i), float(j)) * texelSize_bl;
			vec3 neighborColor_bl = texture(colortex0, texCoord + offset_bl).rgb;
			float luma_bl = dot(neighborColor_bl, vec3(0.299, 0.587, 0.114)); // Basically dasselbe wie float gray weiter unten
			colorSum_bl += neighborColor_bl;
			lumaSum_bl += luma_bl;
			lumaSquaredSum_bl += (luma_bl * luma_bl);
		}
	}
	mean_bl = (colorSum_bl / 9.0);
	mean_luma_bl = (lumaSum_bl / 9.0);
	variance_bl = (lumaSquaredSum_bl / 9.0 - (mean_luma_bl * mean_luma_bl)); 
}