public void glow(int index) {
		if (alpha[index] < maximum[index] && increasing[index]) {
			alpha[index] += rate[index];
		}
		if (alpha[index] > maximum[index]) {
			alpha[index] = maximum[index];
		}
		if (alpha[index] == maximum[index]) {
			increasing[index] = false;
		}
		if (alpha[index] > minimum[index] && !increasing[index]) {
			alpha[index] -= rate[index];
		}
		if (alpha[index] <= minimum[index]) {
			increasing[index] = true;
			alpha[index] = minimum[index];
		}
	}