resources/sksl/compute/Desaturate.compute

layout(local_size_x = 16, local_size_y = 16) in;

layout(rgba8, binding=0) readonly texture2D src;
layout(rgba8, binding=1) writeonly texture2D dest;

half4 desaturate(half4 color) {
    color.rgb = half3(dot(color.rgb, half3(0.22, 0.67, 0.11)));
    return color;
}

void main() {
    if (sk_GlobalInvocationID.x < textureWidth(src) && sk_GlobalInvocationID.y < textureHeight(src)) {
        textureWrite(dest, sk_GlobalInvocationID.xy, desaturate(textureRead(src, sk_GlobalInvocationID.xy)));
    }
}