but here is the kicker… it is NOT a simple convert radians to nearest multple of 45 degrees.

I have a control that has 8 allowed directions (corresponding to compass points)

If I do a touch gesture on an iPhone, it returns delta radians as I rotate my two fingers.

I need to figure out somehow when during that event to issue a +1 or -1 to the control

The gesture turns in fractional degrees but the control needs to “click” at the right time.

One idea (which I havent tested yet) is to do nothing until the gesture delta is exactly 45 degrees either direction. then tell the control to move 1 compass point … and reset the gesture delta to zero.

any other ideas?