title: ccDrawLine opacity?
body: <p>I am very new to all those OpenGL calls, but fortunately cocos2d will easily let me draw lines on the screen, like this:</p>
  
  <pre><code>-(void)draw {
      glColor4f(255, 255, 255,255);
      ccDrawLine(ccp(150,110), ccp(280,230));
  }
  </code></pre>
  
  <p>And I get a white line.</p>
  
  <p>But now, I want to make it a bit transparent, so I change the alpha value to 100. However, the line is still bright and white. Then I assumed that the values could actually range from 0.0 to 1.0. I set it to 0.2 but still no change.</p>
  
  <p>Why is that?</p>