Classes
 ClassDescription
 b2CircleContact 
 b2Contact typedef b2Contactb2ContactCreateFcn(b2Shapeshape1, b2Shapeshape2, b2BlockAllocatorallocator); typedef void b2ContactDestroyFcn(b2Contactcontact, b2BlockAllocatorallocator);
 b2ContactConstraint 
 b2ContactConstraintPoint 
 b2ContactEdge A contact edge is used to connect bodies and contacts together in a contact graph where each body is a node and each contact is an edge.
 b2ContactRegister 
 b2ContactResult This structure is used to report contact point results.
 b2ContactSolver 
 b2NullContact 
 b2PolyAndCircleContact 
 b2PolygonContact