// 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;
	float4 shape = -2.0f * x_cu + 3.0f * x_sq;
	//return shape;

//	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) ;
}