Gaussian2.dctl

// Gaussian Blur
// Resolution: 3x3
// Sigma^2 = 1



__DEVICE__ float3 transform(int p_Width, int p_Height, int p_X, int p_Y, __TEXTURE__ p_TexR, __TEXTURE__ p_TexG, __TEXTURE__ p_TexB)
{
    
    const float e = 2.718281828459f;
    const float sqrtTwoPI = 2.506628274631f;
    const float sigma = 1.0f;



    const float a = (1.0f / (sqrtTwoPI * sigma));
    const float b = _powf(e, -1.0f*( 1.0f / (2.0f * sigma * sigma))) * (1.0f / (sqrtTwoPI * sigma));
    const float c = _powf(e, -1.0f*( 2.0f / (2.0f * sigma * sigma))) * (1.0f / (sqrtTwoPI * sigma));
        
    const float N = a + (b * 4.0f) + (c * 4.0f);
    const float A = a / N;
    const float B = b / N;
    const float C = c / N;

    const float Gaus[9] =  {C, B, C,
							B, A, B,
							C, B, C};

    
    float3 result; 
    
    
    result.x = (Gaus[0] * _tex2D(p_TexR, p_X - 1, p_Y + 1)) + (Gaus[1] * _tex2D(p_TexR, p_X, p_Y + 1)) + (Gaus[2] * _tex2D(p_TexR, p_X + 1, p_Y + 1)) + (Gaus[3] * _tex2D(p_TexR, p_X - 1, p_Y)) + (Gaus[4] * _tex2D(p_TexR, p_X, p_Y))
                     + (Gaus[5] * _tex2D(p_TexR, p_X + 1, p_Y)) + (Gaus[6] * _tex2D(p_TexR, p_X - 1, p_Y - 1)) + (Gaus[7] * _tex2D(p_TexR, p_X, p_Y - 1)) + (Gaus[8] * _tex2D(p_TexR, p_X - 1, p_Y - 1));
    
    result.y = (Gaus[0] * _tex2D(p_TexG, p_X - 1, p_Y + 1)) + (Gaus[1] * _tex2D(p_TexG, p_X, p_Y + 1)) + (Gaus[2] * _tex2D(p_TexG, p_X + 1, p_Y + 1)) + (Gaus[3] * _tex2D(p_TexG, p_X - 1, p_Y)) + (Gaus[4] * _tex2D(p_TexG, p_X, p_Y))
                     + (Gaus[5] * _tex2D(p_TexG, p_X + 1, p_Y)) + (Gaus[6] * _tex2D(p_TexG, p_X - 1, p_Y - 1)) + (Gaus[7] * _tex2D(p_TexG, p_X, p_Y - 1)) + (Gaus[8] * _tex2D(p_TexG, p_X - 1, p_Y - 1));
    
    
    result.z = (Gaus[0] * _tex2D(p_TexB, p_X - 1, p_Y + 1)) + (Gaus[1] * _tex2D(p_TexB, p_X, p_Y + 1)) + (Gaus[2] * _tex2D(p_TexB, p_X + 1, p_Y + 1)) + (Gaus[3] * _tex2D(p_TexB, p_X - 1, p_Y)) + (Gaus[4] * _tex2D(p_TexB, p_X, p_Y))
                     + (Gaus[5] * _tex2D(p_TexB, p_X + 1, p_Y)) + (Gaus[6] * _tex2D(p_TexB, p_X - 1, p_Y - 1)) + (Gaus[7] * _tex2D(p_TexB, p_X, p_Y - 1)) + (Gaus[8] * _tex2D(p_TexB, p_X - 1, p_Y - 1));
    

    return result;
}