#version 450
#extension GL_ARB_separate_shader_objects : enable
#extension GL_ARB_shading_language_420pack : enable

layout(push_constant) uniform PushConsts {
	float exposure;
	float gamma;
};

vec3 Uncharted2Tonemap(vec3 color)
{
	const float A = 0.15;
	const float B = 0.50;
	const float C = 0.10;
	const float D = 0.20;
	const float E = 0.02;
	const float F = 0.30;
	const float W = 11.2;
	return ((color*(A*color+C*B)+D*E)/(color*(A*color+B)+D*F))-E/F;
}

vec4 tonemap(vec4 color, float exposure, float gamma)
{
	vec3 outcol = Uncharted2Tonemap(color.rgb * exposure);
	outcol = outcol * (1.0f / Uncharted2Tonemap(vec3(11.2f)));
	return vec4(pow(outcol, vec3(1.0f / gamma)), color.a);
}

vec4 SRGBtoLINEAR(vec4 srgbIn)
{
	#ifdef MANUAL_SRGB
	#ifdef SRGB_FAST_APPROXIMATION
	vec3 linOut = pow(srgbIn.xyz,vec3(2.2));
	#else //SRGB_FAST_APPROXIMATION
	vec3 bLess = step(vec3(0.04045),srgbIn.xyz);
	vec3 linOut = mix( srgbIn.xyz/vec3(12.92), pow((srgbIn.xyz+vec3(0.055))/vec3(1.055),vec3(2.4)), bLess );
	#endif //SRGB_FAST_APPROXIMATION
	return vec4(linOut,srgbIn.w);;
	#else //MANUAL_SRGB
	return srgbIn;
	#endif //MANUAL_SRGB
}

layout (constant_id = 0) const float NEAR_PLANE = 0.1f;
layout (constant_id = 1) const float FAR_PLANE = 32.0f;

layout (set = 0, binding = 0) uniform sampler2D uiImage;
layout (set = 0, binding = 1) uniform sampler2DMS samplerHDR;

layout (location = 0) in vec2 inUV;
layout (location = 0) out vec4 outColor;

void main()
{
		//vec4 hdrColor = texture(samplerHDR, inUV);
		vec4 hdrColor = texelFetch (samplerHDR, ivec2(gl_FragCoord.xy), gl_SampleID);
		
		vec4 uiColor = texture(uiImage, inUV);
		outColor = tonemap(hdrColor, exposure, gamma);
		outColor = vec4(outColor.rgb * (1 - uiColor.a) + uiColor.rgb * uiColor.a, 1);
}