Overlapping shapes do not "resolve"

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Run the attached file (Just add it to the testbed folder and modify 
testbed.cpp to include the test)
Note: The polygon has 18 vertices so you need to modify Settings.h and change 
#define b2_maxPolygonVertices = 18;

What is the expected output? 
The overlapping shapes should repel each other.

What do you see instead?
The shapes stay overlapping.

What version of the product are you using? On what operating system?
I am using 2.1.2 but I have also tested it on 2.2.1 (which is what the testbed 
file is built for). All on Windows 7. 

Please provide any additional information below.
This only occurs at very specific shape orientations. The contact gets created, 
but for some reason it doesn't seem to think the shapes are overlapping. In 
b2CollidePolygons.cpp the lines
// Clip to negative box side 1
np = b2ClipSegmentToLine(clipPoints2, clipPoints1,  tangent, ideOffset2);

set np to 0 and so the manifold ends up with no contact points. Hope this 
helps. I can give more examples if needed.

Box2d is amazing, thank you Erin and everyone involved so much for your hard 
work.

Original issue reported on code.google.com by seanjeff...@gmail.com on 10 Apr 2012 at 10:32

Attachments:

• OverlapTest.h

[GoogleCodeExporter]

This issue was closed by revision r258.

Original comment by erinca...@gmail.com on 23 Oct 2013 at 7:09

• Changed state: Fixed