uniform half4 colorGreen;

inline half4 inner() {
    return half4(distance(colorGreen.ra, colorGreen.ra),
                 distance(colorGreen.ra, colorGreen.ga),
                 distance(colorGreen.ra, colorGreen.ba),
                 distance(colorGreen.ra, colorGreen.aa));
}

noinline half4 outer() {
    // The `distance` variable should not interfere with the `distance` intrinsic.
    half distance = colorGreen.a;
    half4 color = inner();
    return color * distance;
}

half4 main(float2 coords) {
    return outer();
}