title: Get center of Shape intersection (2D)
body: <p>I'm using the Slick java game lib and I've used the Slick implementation of <a href="http://slick.cokeandcode.com/javadoc/org/newdawn/slick/geom/Shape.html" rel="nofollow">Shape</a> as a hit-box for collision and that's working fine. I use <code>shape1.intersects(shape2)</code> for checking if two shapes overlap. Now what I want to do is get the center point of the intersecting shape to use as a place to generate particles showing the collision between the 2 objects.</p>
  
  <p>I can't find any explanations of algorithms that calculate shape intersections, maybe because I don't know if it has a specific name or not.</p>