void UnsharpMask_fp
(
    in float4 position : POSITION,
    in float2 iTexCoord : TEXCOORD0, 
    
    out float4 oColor0 : COLOR0,
    
    uniform sampler blurred: register(s0),
    uniform sampler mrt0: register(s1),
    uniform float cLambda
)
{
    float spacialImportance = tex2D(blurred, iTexCoord).w - tex2D(mrt0, iTexCoord).w;
    float4 color = float4(1,1,1,1);
    if (spacialImportance < 0) // darkening only
    {
        oColor0 = float4(color.rgb + (cLambda * spacialImportance), 1);
    } else 
    {
        oColor0 = color;
    }
}

void GaussianBlurX_fp
(
    in float4 position : POSITION,
    in float2 uv : TEXCOORD0,
    
    out float4 oColor0 : COLOR0,
    
    uniform sampler mrt1 : register(s0),
    uniform float stepX,
    uniform const float cKernelWidthBias
)
{
    const int kernelWidth = 19;
    float sigma = (kernelWidth - 1) / 6; // make the kernel span 6 sigma

    float weights = 0;
    float blurredDepth = 0;
    
    for (float i = -(kernelWidth - 1) / 2; i < (kernelWidth - 1) / 2; i++)
    {
        float geometricWeight = exp(-pow(i, 2) / (2 * pow(sigma, 2)));
        weights += geometricWeight;
        blurredDepth += tex2D(mrt1, float2(uv.x - i * stepX * cKernelWidthBias, uv.y)).w * geometricWeight;
    }

    blurredDepth /= weights;
    oColor0 = float4(tex2D(mrt1, uv).xyz, blurredDepth);
}

void GaussianBlurY_fp
(
    in float4 position : POSITION,
    in float2 uv : TEXCOORD0,
    
    out float4 oColor0 : COLOR0,
    
    uniform sampler mrt1 : register(s0),
    uniform const float stepY,
    uniform const float cKernelWidthBias
)
{
    const int kernelWidth = 19;
    float sigma = (kernelWidth - 1) / 6; // make the kernel span 6 sigma

    float weights = 0;
    float blurredDepth = 0;
    
    for (float i = -(kernelWidth - 1) / 2; i < (kernelWidth - 1) / 2; i++)
    {
        float geometricWeight = exp(-pow(i, 2) / (2 * pow(sigma, 2)));
        weights += geometricWeight;
        blurredDepth += tex2D(mrt1, float2(uv.x, uv.y - i * stepY * cKernelWidthBias)).w * geometricWeight;
    }

    blurredDepth /= weights;
    oColor0 = float4(tex2D(mrt1, uv).xyz, blurredDepth);
}