title: Reduce overhead for sprite outside the screen
body: <p>For my game I am working on a 2  player mode where the player can swipe left to see what the other player is doing. Effectively 2 iPhone screens. </p>
  
  <p>My question is, are any sprites, particles outside the screen (I.e. for player 2) being rendered and processed as if they are on screen? If so, is there a way to get cocos2d to handle these differently so that they do not slow down the overall game performance? (fps)</p>