title: Are there any examples of quadtrees being used in HTML5 Canvas?
body: <p>Quadtrees are used as an optimisation in games and elsewhere for spatial organisation of entities <a href="http://en.wikipedia.org/wiki/Quadtree" rel="nofollow">http://en.wikipedia.org/wiki/Quadtree</a>.</p>
  
  <p>Are there any examples of quadtrees being used for HTML5 Canvas?</p>