How to wrap around a range

Question

Angles in my program are expressed in 0 to 2pi. I want a way to add two angles and have it wrap around the 2pi to 0 if the result is higher than 2pi. Or if I subtracted an a

Answer 1

You can use something like this:

while (angle > 2pi)
    angle -= 2pi;

while (angle < 0)
    angle += 2pi;

Basically, you have to change the angle by 2pi until you are assured that it doesn't exceed 2pi or fall below 0.