// MinecraftPT — Depth of Field
// Circle of confusion computation and bokeh blur.

#ifndef DOF_GLSL
#define DOF_GLSL

// Compute CoC (circle of confusion) for a fragment
float GetCoC(float depth, float focalDepth){
	float focus = focalDepth;
	float aperture = DOF_BLUR;
	float coc = abs(depth - focus) / focus * aperture * DOF_MAX_COC;
	return clamp(coc, 0.0, DOF_MAX_COC);
}

// Simple bokeh blur (gather)
vec3 DofBlur(vec2 texelCoord, float coc){
	vec3 color = vec3(0.0);
	float weight = 0.0;

	int radius = int(min(coc, 8.0)) + 1;
	for (int i = -radius; i <= radius; i++){
	for (int j = -radius; j <= radius; j++){
		float dist = length(vec2(i, j));
		if (dist > coc) continue;

		vec2 coord = texelCoord + vec2(i, j);
		vec3 sampleColor = texelFetch(colortex12, ivec2(coord), 0).rgb;
		float w = max(0.0, 1.0 - dist / coc);

		color += sampleColor * w;
		weight += w;
	}}

	return weight > 0.0 ? color / weight : color;
}

#endif