Add support for generic 2d convex shapes, through wrapper class btConvex2dShape. See Bullet/Demos/Box2dDemo for example wrapping a btCylinderShape and 2d btConvexHullShape.

Add some extra degeneracy debugging check in btGjkPairDetector

src/BulletCollision/CollisionShapes/btConvex2dShape.cpp

@@ -0,0 +1,92 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2009 Erwin Coumans  http://bulletphysics.org
+
+This software is provided 'as-is', without any express or implied warranty.
+In no event will the authors be held liable for any damages arising from the use of this software.
+Permission is granted to anyone to use this software for any purpose, 
+including commercial applications, and to alter it and redistribute it freely, 
+subject to the following restrictions:
+
+1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include "btConvex2dShape.h"
+
+btConvex2dShape::btConvex2dShape(	btConvexShape* convexChildShape):
+btConvexShape (), m_childConvexShape(convexChildShape)
+{
+	m_shapeType = CONVEX_2D_SHAPE_PROXYTYPE;
+}
+	
+btConvex2dShape::~btConvex2dShape()
+{
+}
+
+	
+
+btVector3	btConvex2dShape::localGetSupportingVertexWithoutMargin(const btVector3& vec)const
+{
+	return m_childConvexShape->localGetSupportingVertexWithoutMargin(vec);
+}
+
+void	btConvex2dShape::batchedUnitVectorGetSupportingVertexWithoutMargin(const btVector3* vectors,btVector3* supportVerticesOut,int numVectors) const
+{
+	m_childConvexShape->batchedUnitVectorGetSupportingVertexWithoutMargin(vectors,supportVerticesOut,numVectors);
+}
+
+
+btVector3	btConvex2dShape::localGetSupportingVertex(const btVector3& vec)const
+{
+	return m_childConvexShape->localGetSupportingVertex(vec);
+}
+
+
+void	btConvex2dShape::calculateLocalInertia(btScalar mass,btVector3& inertia) const
+{
+	///this linear upscaling is not realistic, but we don't deal with large mass ratios...
+	m_childConvexShape->calculateLocalInertia(mass,inertia);
+}
+
+
+	///getAabb's default implementation is brute force, expected derived classes to implement a fast dedicated version
+void btConvex2dShape::getAabb(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const
+{
+	m_childConvexShape->getAabb(t,aabbMin,aabbMax);
+}
+
+void btConvex2dShape::getAabbSlow(const btTransform& t,btVector3& aabbMin,btVector3& aabbMax) const
+{
+	m_childConvexShape->getAabbSlow(t,aabbMin,aabbMax);
+}
+
+void	btConvex2dShape::setLocalScaling(const btVector3& scaling) 
+{
+	m_childConvexShape->setLocalScaling(scaling);
+}
+
+const btVector3& btConvex2dShape::getLocalScaling() const
+{
+	return m_childConvexShape->getLocalScaling();
+}
+
+void	btConvex2dShape::setMargin(btScalar margin)
+{
+	m_childConvexShape->setMargin(margin);
+}
+btScalar	btConvex2dShape::getMargin() const
+{
+	return m_childConvexShape->getMargin();
+}
+
+int		btConvex2dShape::getNumPreferredPenetrationDirections() const
+{
+	return m_childConvexShape->getNumPreferredPenetrationDirections();
+}
+	
+void	btConvex2dShape::getPreferredPenetrationDirection(int index, btVector3& penetrationVector) const
+{
+	m_childConvexShape->getPreferredPenetrationDirection(index,penetrationVector);
+}