Frequent calling of method EdgePairs.toList() significantly reduce performance of entire engine.

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What steps will reproduce the problem?
1. Start some demo with many polygons in it.
2. Open visualvm, and make cpu sampling.
3. EdgePairs.toList() - on the top 1 position using many CPU time.

What is the expected output? What do you see instead?
-

What version of the product are you using? On what operating system?
2008-04-06

Please provide any additional information below.
I looked in code. And found that it is not nesessary to convert EdgePairs to 
int[][]. Creation of int[][] is heavy operation. We can simply pass iterator of 
EdgePairs where it needed instead of int[][].  Here is code of iterator:

private class EdgeParisIterator implements Iterator<EdgePair>
      {
         private EdgePair current;

         @Override
         public boolean hasNext()
         {
            if (current != null)
            {
               return current.next != null;
            }

            return first != null;
         }

         @Override
         public EdgePair next()
         {
            current = current == null ? first : current.next;
            return current;
         }

         @Override
         public void remove()
         {
            throw new RuntimeException("Method not supported!");
         }
      }

Example of use in LinePolygonCollider:

Iterator<EdgeSweep.EdgePairs.EdgePair> collEdgeCands = 
sweep.getOverlappingEdges();

IntersectionGatherer intGath = new IntersectionGatherer(vertsA, vertsB);
while (collEdgeCands.hasNext())
{
    EdgeSweep.EdgePairs.EdgePair pair = collEdgeCands.next();
    intGath.intersect(pair.a, pair.b);
}

Patched code shows much greater performance.
code of all engine with my patch in attachment.

Original issue reported on code.google.com by good.guy...@gmail.com on 28 Jul 2012 at 8:56

Attachments:

• net.zip