title: snapping a puzzle piece to a hi view tile
body: <p>Hi I'm making a puzzle game and am stuck on the logic of "snapping" my puzzle pieces (UIImageVIew) to a tile board(Subview of the main UIView). I have the game where I can drag each puzzle piece around from the main view but when it comes time for me place it in the correct tile square I don't know how to have it snap to the correct tile. </p>
  
  <p>I read about using the centers as a way to determine where my puzzle piece is in the view but how can I determine how close it is to its "correct tile" and have it snap into its location. </p>
  
  <p>Thanks for any future responses.</p>