title: Problem with huge objects in a quad tree
body: <p>Let's say I have circular objects. Each object has a diameter of 64 pixels.</p>
  
  <p>The cells of my quad tree are let's say 96x96 pixels.</p>
  
  <p>Everything will be fine and working well when I check collision from the cell a circle is residing in + all it's neighbor cells.</p>
  
  <p>BUT what if I have one circle that has a diameter of 512 pixels? It would cover many cells and thus this would be a problem when checking only the neighbor cells. But I can't re-size my quad-tree-grid every time a much larger object is inserted into the tree...</p>