import postprocess;
import ambientocclusion;

#pragma MSP stage(fragment)
void main()
{
	vec4 rv = texture(rotate, gl_FragCoord.xy/4.0)*2.0-1.0;
	mat3 transform = mat3(rv.xy, 0.0, rv.zx, 0.0, 0.0, 0.0, rv.w)*occlusion_radius;
	vec3 center = unproject(vec3(vertex.xy, texture(depth, texcoord).r));
	float min_depth = project(vec3(center.xy, center.z+occlusion_radius)).z;
	float occlusion_sum = 0.0;
	float count = 0.0;
	for(int i=0; i<n_samples; ++i)
	{
		vec3 psp = project(center+transform*sample_points[i]);
		float sample = texture(depth, psp.xy*0.5+0.5).r;
		if(sample>=min_depth)
		{
			if(sample<psp.z)
				occlusion_sum += 1.0;
			count += 1.0;
		}
	}
	frag_color = vec4(1.0-occlusion_sum/count, 0.0, 0.0, 1.0);
}