title: Cocos2D: increasing Sprite Brightness
body: <p>Is there a good way to adjust the brightness of a CCSprite without using an overlay sprite or creating a separate texture? The color property doesn't work since it can only decrease the brightness.</p>
  
  <p>I am thinking this is possible by overriding the draw method and adding some opengl calls similar to what is found in <a href="http://developer.apple.com/library/ios/#samplecode/GLImageProcessing/Introduction/Intro.html" rel="nofollow">http://developer.apple.com/library/ios/#samplecode/GLImageProcessing/Introduction/Intro.html</a> , but all of my attempts have failed and I am very novice at writing raw opengl. Does anyone know if this is possible and what calls need to be made?</p>