How to make a ball move along the edge of a rotating rectangle in xcode?

Question

I wish to make a lever and rotate the lever using accelerometer. I have this problem trying to place the ball on top of the lever and slide the ball along the lever according to the rotation. Would anyone drop me some hints or refer me to sample codes?

Answer 1

how to delete answer?

Answer 2

You could have a look at Chipmunk which handles a lot of physics modelling.