title: erasing sprite graphics?
body: <p>If I have a sprite, with which I have drawn some stuff, how do I erase part of what I have drawn?  Preferably I could use <code>drawRect()</code> with some "alpha=0" paint.</p>
  
  <p>However, I don't believe the <code>beginFill()</code> method lets you set an RGBA color (like you can in <code>bitmapData</code>).  Setting <code>alpha = 0</code> in the graphics method of <code>beginFill()</code> doesn't really do anything -- it just draws nothing.</p>
  
  <p>In my particular use case, masking isn't an option.</p>
  
  <p>Also, calling <code>clear()</code> isn't a good solution, since it clears away everything.</p>