sampler2D RT : register(s0);
sampler2D pattern : register(s1);

half4 Dither_ps(float4 pos : POSITION, float2 TexCoord : TEXCOORD0) : COLOR
{	
	half c = dot(tex2D(RT, TexCoord),half4(0.30,0.11,0.59,0.00));
	half n = tex2D(pattern, TexCoord).r*2 - 1.0;
	c += n;
	if (c > 0.5)
	{
		c = 0.0;
	}
	else
	{
		c = 1.0;
	}   
	return half4(c,c,c,1.0);
}