half4 helper();

void main() {
    sk_FragColor = helper();
}

enum class E {
    kBlack = 0,
    kGray  = 1,
    kWhite = 2
};

half4 helper() {
    E temp = E::kGray;
    switch (temp) {
        case E::kBlack: return half4(0, 0, 0, 1);
        case E::kGray:  return half4(0.5, 0.5, 0.5, 1);
        case E::kWhite: return half4(1);
        default:        return half4(1, 0, 0, 1);
    }
}