It's usually done to combine multiple flags using bitwise or, but I don't think it's the case here(unless glass can be shattered and not shattered at the same t

It's usually done to combine multiple flags using bitwise or, but I don't think it's the case here(unless glass can be shattered and not shattered at the same time). Or are you saying that you usually write 0, 1, 2, 4 and so on?