title: Cocos2d-x - how to set part of CCLayer transparent?
body: <p>I'm newbie in <code>cocos2d-x</code> and I need your help.</p>
  
  <p>I need to make transparent a touched portion of the layer. </p>
  
  <p>How to make a portion of the layer transparent? I had thought to use <code>ССClippingNode</code>, but I'm not find examples or docs.</p>
  
  <p>I use C++. Thanks.</p>