public SinCosTable(int number_of_angles){
		na = number_of_angles;
		a = new Vec2u[na];
		a[0] = new Vec2u(1,0);
		for(int i = 1;i<na-1;i++){
			a[i] = new Vec2u((float)Math.cos(i*(2*Math.PI)/na), (float)Math.sin(i*(2*Math.PI)/na));
		}
	}