code: public static <P extends Point2D> Comparator<P> createPointComparator (final P origin)
      {
          return new Comparator<P>() {
              public int compare (P p1, P p2)
              {
                  double dist1 = origin.distance(p1);
                  double dist2 = origin.distance(p2);
                  return (dist1 > dist2) ? 1 : ((dist1 < dist2) ? -1 : 0);
              }
          };
      }
docs: Create a comparator that compares against the distance from the specified point.
  
  Note: The comparator will continue to sort by distance from the origin point, even if the
  origin point's coordinates are modified after the comparator is created.
  
  Used by positionRect().