title: cocos2d help find points on a circle
body: <p>I am trying to solve a tricky math problem, in a cocos2d for iphone context.</p>
  
  <p>Basically I have a roullette wheel which is rotating over time.</p>
  
  <p>I want to have a Sprite latch onto the wheel at certain points (like compass ordinal points N, S, E, W) and bounce off at all other points.</p>
  
  <p>I have the image of the wheel rotating, and just need to solve the part where I can test for whether a sprite has intersected with the circle at the right point on the circle as it is rotating.</p>
  
  <p>I think this question is going in the right direction, but I can't get my head around it. Can anyone help explain?</p>
  
  <p><a href="https://stackoverflow.com/questions/300871/best-way-to-find-a-point-on-a-circle-closest-to-a-given-point">Best way to find a point on a circle closest to a given point</a></p>