How to check for Shape intersection using GeneralPath? Java

Question

I have a program that allows you to move various Shapes about. I want to be able to return a boolean that returns true if two shapes are intersecting. This is what I have thus far:

   public boolean overlaps(MyShape s){
   Rectangle2D.Double otherShapeBoundary
         = new Rectangle2D.Double(s.getX(), s.getY(), s.getWidth(), s.getHeight());
   PathIterator pi = path.getPathIterator(null);
   return path.intersects(pi,otherShapeBoundary);
   }

...where path is a GeneralPath (these are all straight from the API, except MyShape).

One thing I'm unsure on is how PathIterator works, which might be the problem. I've also tried this, but I was getting a similar error:

   public boolean overlaps(OverlappableSceneShape s){
   Rectangle2D.Double otherShapeBoundary
         = new Rectangle2D.Double(s.getX(), s.getY(), s.getWidth(), s.getHeight());
   return path.intersects(otherShapeBoundary);
   }

The error is that this method almost always returns false. I'm unsure when/why it is returning true, but it is very infrequent.

For better help sooner, post an [SSCCE](http://sscce.org/). – Andrew Thompson Nov 28 '11 at 00:44 — Andrew Thompson, Nov 28 '11 at 00:44
^^Kk. I'll try to get around to doing it – varatis Nov 28 '11 at 00:46 — varatis, Nov 28 '11 at 00:46

score 2 · Accepted Answer · answered Jan 15 '12 at 01:14

What I tried second was actually the correct answer. Just to be clear:

public boolean overlaps(OverlappableSceneShape s){
  Rectangle2D.Double otherShapeBoundary
     = new Rectangle2D.Double(s.getX(), s.getY(), s.getWidth(), s.getHeight());
  return path.intersects(otherShapeBoundary);
}

is the best method of determining intersection.

How to check for Shape intersection using GeneralPath? Java

1 Answers1