HLSL snippet

sampler2D input : register(s0);

float4 main(float2 uv : TEXCOORD) : COLOR
{

	//colorin is the original color of the pixel, colorout the altered color

	float4 colorin, colorout;
	colorin = tex2D( input , uv.xy);
	colorout = colorin;

	if((colorin.g + colorin.b) < colorin.r )
	{
		colorout.r = colorin.r;
		colorout.g = 0;
		colorout.b = 0;

	}else
	{
		colorout.rgb = dot(colorin.rgb, colorin.rgb ) * dot(colorin.rgb, float4(2, 1, 2, 1) );
	}

	return colorout;
}