pb2zig/rollup-plugin-pb2zig/demos/demo-1/pbk/difference-key.pbk at main · chung-leong/pb2zig · GitHub

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<languageVersion : 1.0;>

kernel DifferenceKey
<   namespace : "com.quasimondo";
    vendor : "Quasimondo";
    version : 1;
    description : "A simple difference key for chroma keying";
>
{
    input image4 src;
    output pixel4 dst;

    parameter float3 keyColor;

    parameter float tolerance
    <
        minValue: 0.0;
        maxValue: 3.0;
        defaultValue: 0.02;
    >;

    parameter float ramp
    <
        minValue: 0.0;
        maxValue: 1.0;
        defaultValue: 0.005;
    >;

     parameter float gamma
    <
        minValue: 0.0;
        maxValue: 10.0;
        defaultValue: 1.00;
    >;

    void
    evaluatePixel()
    {
        dst = sampleNearest(src,outCoord());
        float diff = length( dst.rgb - keyColor );
        if ( diff < tolerance )
        {
            dst.a = 0.0;
        } else if ( diff < tolerance + ramp )
        {
            dst.a = pow( (diff - tolerance) / ramp, gamma );
        }

    }
}