float2 PixelSize;
float4 PS(vs2ps In): COLOR
{
    //sample the current pixel
    float4 center = tex2D(Samp, In.TexCd);
 
    //prepare pixel offsets for x and y
    float2 offX = float2 (PixelSize.x, 0);
    float2 offY = float2 (0, PixelSize.y);
 
    //sample neighbours and add up their states
    float alive = 0;
    alive += tex2D(Samp, In.TexCd - offY).r;
    alive += tex2D(Samp, In.TexCd - offY - offX).r;
    alive += tex2D(Samp, In.TexCd - offY + offX).r;
    alive += tex2D(Samp, In.TexCd + offY).r;
    alive += tex2D(Samp, In.TexCd + offY - offX).r;
    alive += tex2D(Samp, In.TexCd + offY + offX).r;
    alive += tex2D(Samp, In.TexCd - offX).r;
    alive += tex2D(Samp, In.TexCd + offX).r;
 
    //a dead cell with exactly three live neighbors becomes a live cell (birth).
    if (center.r == 0 && alive == 3) 
    {
      center.rgb = 1;
    } 
    //a live cell with two or three live neighbors stays alive (survival).  
    else if (center.r == 1 && (alive == 3 || alive == 2)) 
    {
      center.rgb = 1;
    } 
    //in all other cases, a cell dies or remains dead (overcrowding or loneliness).
    else 
    {
      center.rgb = 0;
    }
 
    return center;
}

sampler Samp = sampler_state    //sampler for doing the texture-lookup
{
    Texture   = (Tex);          //apply a texture to the sampler
    MipFilter = NONE;         //sampler states
    MinFilter = POINT;
    MagFilter = POINT;
};