#version 450 core
out vec4 FragColor;
in vec3 WorldPos;

uniform samplerCube environmentMap;
uniform float exposure = 1;

vec3 ACESToneMapping(vec3 color)
{
    const float A = 2.51;
    const float B = 0.03;
    const float C = 2.43;
    const float D = 0.59;
    const float E = 0.14;
    return (color * (A * color + B)) / (color * (C * color + D) + E);
}

void main()
{		
    vec3 color = texture(environmentMap, WorldPos).rgb;
    
    // HDR tonemap
    //envColor = envColor / (envColor + vec3(1.0));

    color *= exposure;
	color = ACESToneMapping(color);

    // gamma correct
    color = pow(color, vec3(1.0/2.2)); 
    
    FragColor = vec4(color, 1.0);
}