/* Copyright (c) 2018-2024, Sascha Willems
 *
 * SPDX-License-Identifier: MIT
 *
 */

// From http://filmicworlds.com/blog/filmic-tonemapping-operators/
vec3 Uncharted2Tonemap(vec3 color)
{
	float A = 0.15;
	float B = 0.50;
	float C = 0.10;
	float D = 0.20;
	float E = 0.02;
	float F = 0.30;
	float W = 11.2;
	return ((color*(A*color+C*B)+D*E)/(color*(A*color+B)+D*F))-E/F;
}

// HDR颜色 + 曝光、gamma -> 屏幕颜色
vec4 tonemap(vec4 color)
{
	vec3 outcol = Uncharted2Tonemap(color.rgb * pass.exposure);
	outcol = outcol * (1.0f / Uncharted2Tonemap(vec3(11.2f)));	
	return vec4(pow(outcol, vec3(1.0f / pass.gamma)), color.a);
}