import postprocess;

uniform sampler1D curve;
uniform ToneMapping
{
	float peak;
	float brightness;
};

////// fragment
void main()
{
	vec4 sample = texture(source, texcoord);
	float maxc = max(sample.r, max(sample.g, sample.b));
	if(maxc>1.0-peak)
	{
		vec3 saturated = sample.rgb/maxc;
		if(maxc>1.0+peak)
		{
			sample.rgb = mix(vec3(1.0), saturated, 1.0/pow(brightness, maxc-1.0-peak));
		}
		else
		{
			float x = (1.0+peak-maxc)/(2.0*peak);
			sample.rgb = saturated.rgb*(1.0-peak+(1.0-x*x)*peak);
		}
	}
	frag_color = vec4(texture(curve, sample.r).r, texture(curve, sample.g).r, texture(curve, sample.b).r, sample.a);
}