source: downloads/Samples/Media/materials/programs/Blur0_ps20.hlsl @ 3

sampler RT: register(s0);
// Simple blur filter

float4 main(float2 texCoord: TEXCOORD0) : COLOR {

        float2 samples[12] = {
        -0.326212, -0.405805,
        -0.840144, -0.073580,
        -0.695914,  0.457137,
        -0.203345,  0.620716,
        0.962340, -0.194983,
        0.473434, -0.480026,
        0.519456,  0.767022,
        0.185461, -0.893124,
        0.507431,  0.064425,
        0.896420,  0.412458,
        -0.321940, -0.932615,
        -0.791559, -0.597705,
        };

   float4 sum = tex2D(RT, texCoord);
   for (int i = 0; i < 12; i++){
      sum += tex2D(RT, texCoord + 0.025 * samples[i]);
   }
   return sum / 13;

}