float4 Combine_fp
(
    in float2 texCoord: TEXCOORD0,
    
    uniform sampler2D RT : register(s0),
    uniform sampler2D Sum : register(s1),

    uniform float blur
) : COLOR
{
   float4 render = tex2D(RT, texCoord);
   float4 sum = tex2D(Sum, texCoord);

   return lerp(render, sum, blur);
}