title: Unable to get OpenGL ES 'draw' functions to work (+ C99 error) with Cocos2d
body: <p>I'm trying to compile some example code from the <strong>Cocos2d for iPhone 0.99 Beginner's Guide</strong>.:</p>
  
  <pre><code>-(void)draw
  {
      if(isSelected)
      {
          [self.mySprite setOpacity:100];
          glColor4f(255 / 255.0f, 0 / 255.0f, 0 / 255.0f, 255 / 255.0f);
          glPointSize( 30.0 );
          ccDrawPoint( self.mySprite.position);
      }
      [super draw];
  }
  </code></pre>
  
  <p>Apart from this not actually drawing a rectangular highlight on top of the sprite when isSelected = YES, the gl functions are also giving me warnings:</p>
  
  <ul>
  <li>Implicit declaration of function 'glPointSize' is invalid in C99</li>
  <li>Implicit declaration of function 'glColor4f' is invalid in C99</li>
  </ul>