title: libGDX, detect side touching between rectangles (side collision)
body: <p>I use libGDX library for my game. I user <code>overlap</code> method for detecting collision detection between two rectangles.</p>
  
  <pre><code>...
  if (r1.overlaps(r2)) collisionTest();
  ...
  </code></pre>
  
  <p>I want to detect touching side on rectangle (top, bottom, left or right): </p>
  
  <pre><code>r1 overlap r2 on the left side
  </code></pre>
  
  <p>Can anyone give me code for this, but this need to be fast method.</p>
  
  <p>Thanks</p>