C# 클래스 FarseerPhysics.Testbed.Tests.PolyShapesCallback
This tests stacking. It also shows how to use World.Query() and AABB.TestOverlap(). This callback is called by World.QueryAABB(). We find all the fixtures that overlap an AABB. Of those, we use AABB.TestOverlap() to determine which fixtures overlap a circle. Up to 4 overlapped fixtures will be highlighted with a yellow border.