title: What is the best way to make a bouncing ball animation with infinite loop on iPhone?
body: <p>I am developing an iPhone game in which birds bounce.</p>
  
  <p>I have set up the images for animating the wings of the flying bird like this: </p>
  
  <pre><code>[imgBird[i] setAnimationImages:birdArrayConstant];
  [imgBird[i] setAnimationDuration:1.0];
  [imgBird[i] startAnimating];
  </code></pre>
  
  <p>Now how I make the bird move is to use an NSTimer to fire every 0.03 seconds which adds/subtracts 1 from the x or y coordinate from imgBird[i].center. </p>
  
  <p>I learnt about doing it like this from here. <a href="http://icodeblog.com/2008/10/28/iphone-programming-tutorial-animating-a-ball-using-an-nstimer/" rel="nofollow noreferrer">http://icodeblog.com/2008/10/28/iphone-programming-tutorial-animating-a-ball-using-an-nstimer/</a></p>
  
  <p>But the issue is the birds slow down as soon as another timer (for moving my ship the same way) fires and returns back to original speed as i stop moving the ship. </p>
  
  <p>Is there a better way to keep the bird moving except NSTimer?</p>
  
  <p>The movement of bird is an infinite loop. </p>