uniform sampler2D taccum;
uniform sampler2D trevealage;
uniform sampler2DMS tcolor;

uniform int samples;

out vec4 fragColor;

void main() {
	ivec2 C = ivec2(gl_FragCoord.xy);
	vec4 accum = texelFetch(taccum, C, 0);
	float aa = texelFetch(trevealage, C, 0).r;
	vec4 col = texelFetch(tcolor, C, 0);

	for (int i = 1; i < samples; i++) {
		col += texelFetch(tcolor, C, i);
	}
	col /= float(samples);

	float r = accum.a;
	accum.a = aa;
	if (r >= 1.0) {
		fragColor = vec4(col.rgb, 0.0);
	} else {
		vec3 alp = clamp(accum.rgb / clamp(accum.a, 1e-4, 5e4), 0.0, 1.0);
		fragColor = vec4(col.rgb * r  + alp * (1.0 - r), 0.0);
	}
}