title: 2d coordinate system: Math vs. Screen
body: <p>We're working on a library that does calculations in 2D space.  However, the 'natural' interpretation of the 2D coordinate system is where increasing Y values represent points that lie higher, while the <code>awt</code> coordinates do the reverse.  This reflects in <code>Rectangle(10,100).maxY()</code> returning 0, while the mathematician would expect it to return 100.</p>
  
  <p>How can we properly deal with that difference?  Is there another java library to do geometrical calculations?</p>