// LFS Pixel Shader : PostProcess


// Vertex shader output

struct VS_OUTPUT
{
	float4 Position		: POSITION;
	float4 Color		: COLOR0;
	float2 Texture		: TEXCOORD0;
};


// Global variables

sampler2D Tex0;


// Main function

float4 ps_main( in VS_OUTPUT In ) : COLOR
{
	// look up colour 

	float4 tex_col = tex2D(Tex0, In.Texture);
	
//	NO CHANGE
//	return tex_col;
	
//	S-SHAPE	
	float4 x_sq = tex_col * tex_col;
	float4 x_cu = x_sq * tex_col;
//	return -2.0f * x_cu + 3.0f * x_sq;

//	GAMMA	
//	return pow(tex_col, 0.5f);

//	CONTRAST
	return (tex_col - float4(0.5f, 0.5f, 0.5f, 0.0f)) * 1.0f + float4(0.5f, 0.5f, 0.5f, 0.0f); // contrast

//	SIMPLE HDR
//	return tex_col / (1.0f + tex_col);
}