title: Why can a control draw outside its bounding box?
body: <p>Here's an example image of what I mean: <a href="https://i.stack.imgur.com/yUFwN.png" rel="noreferrer">example</a></p>
  
  <p>The gray rectangle is the bounding box of a control that draws the blue lines and dots in it's <code>OnRender(...)</code> method. The red ovals mark places where it happens.</p>
  
  <ul>
  <li>Why is that possible?</li>
  <li>How can it be avoided?</li>
  </ul>