skia2/tests/sksl/intrinsics/Distance.metal

struct Inputs {
    float a;
    float b;
    float4 c;
    float4 d;
};
struct Outputs {
    float4 sk_FragColor [[color(0)]];
};

fragment Outputs fragmentMain(Inputs _in [[stage_in]], bool _frontFacing [[front_facing]], float4 _fragCoord [[position]]) {
    Outputs _out;
    (void)_out;
    _out.sk_FragColor.x = abs(_in.a - _in.b);
    _out.sk_FragColor.x = distance(_in.c, _in.d);
    return _out;
}