Alternative sphere-sphere collision algorithm

Extras/AlternativeCollisionAlgorithms/SphereSphereCollisionAlgorithm.cpp

@@ -0,0 +1,79 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
+
+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 "SphereSphereCollisionAlgorithm.h"
+#include "CollisionDispatch/CollisionDispatcher.h"
+#include "CollisionShapes/SphereShape.h"
+#include "CollisionDispatch/CollisionObject.h"
+
+SphereSphereCollisionAlgorithm::SphereSphereCollisionAlgorithm(PersistentManifold* mf,const CollisionAlgorithmConstructionInfo& ci,BroadphaseProxy* proxy0,BroadphaseProxy* proxy1)
+: CollisionAlgorithm(ci),
+m_ownManifold(false),
+m_manifoldPtr(mf)
+{
+	if (!m_manifoldPtr && m_dispatcher->NeedsCollision(*proxy0,*proxy1))
+	{
+		m_manifoldPtr = m_dispatcher->GetNewManifold(proxy0->m_clientObject,proxy1->m_clientObject);
+		m_ownManifold = true;
+	}
+}
+
+SphereSphereCollisionAlgorithm::~SphereSphereCollisionAlgorithm()
+{
+	if (m_ownManifold)
+	{
+		if (m_manifoldPtr)
+			m_dispatcher->ReleaseManifold(m_manifoldPtr);
+	}
+}
+
+void SphereSphereCollisionAlgorithm::ProcessCollision (BroadphaseProxy* proxy0,BroadphaseProxy* proxy1,const DispatcherInfo& dispatchInfo)
+{
+
+	if (!m_manifoldPtr)
+		return;
+
+	CollisionObject*	col0 = static_cast<CollisionObject*>(proxy0->m_clientObject);
+	CollisionObject*	col1 = static_cast<CollisionObject*>(proxy1->m_clientObject);
+
+	SphereShape* sphere0 = (SphereShape*)col0->m_collisionShape;
+	SphereShape* sphere1 = (SphereShape*)col1->m_collisionShape;
+
+	SimdScalar radius0 = sphere0->GetRadius();
+	SimdScalar radius1 = sphere1->GetRadius();
+
+	SimdVector3 diff = col0->m_worldTransform.getOrigin()- 
+		col1->m_worldTransform.getOrigin();
+
+	float len = diff.length();
+	if ( len > (radius0+radius1))
+		return;
+
+	SimdScalar dist = len - (radius0+radius1);
+
+	SimdVector3 normalOnSurfaceB = diff / len;
+	SimdVector3 pos0 = col0->m_worldTransform.getOrigin() - radius0 * normalOnSurfaceB;
+	SimdVector3 pos1 = col1->m_worldTransform.getOrigin() + radius1* normalOnSurfaceB;
+
+	ManifoldResult* resultOut = m_dispatcher->GetNewManifoldResult(col0,col1,m_manifoldPtr);
+	resultOut->AddContactPoint(normalOnSurfaceB,pos1,dist);
+
+}
+
+float SphereSphereCollisionAlgorithm::CalculateTimeOfImpact(BroadphaseProxy* proxy0,BroadphaseProxy* proxy1,const DispatcherInfo& dispatchInfo)
+{
+	//not yet
+	return 1.f;
+}

Extras/AlternativeCollisionAlgorithms/SphereSphereCollisionAlgorithm.h

@@ -0,0 +1,54 @@
+/*
+Bullet Continuous Collision Detection and Physics Library
+Copyright (c) 2003-2006 Erwin Coumans  http://continuousphysics.com/Bullet/
+
+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.
+*/
+
+#ifndef SPHERE_SPHERE_COLLISION_ALGORITHM_H
+#define SPHERE_SPHERE_COLLISION_ALGORITHM_H
+
+#include "BroadphaseCollision/CollisionAlgorithm.h"
+#include "BroadphaseCollision/BroadphaseProxy.h"
+#include "CollisionDispatch/CollisionCreateFunc.h"
+class PersistentManifold;
+
+/// SphereSphereCollisionAlgorithm  provides sphere-sphere collision detection.
+/// Other features are frame-coherency (persistent data) and collision response.
+/// Also provides the most basic sample for custom/user CollisionAlgorithm
+class SphereSphereCollisionAlgorithm : public CollisionAlgorithm
+{
+	bool	m_ownManifold;
+	PersistentManifold*	m_manifoldPtr;
+	
+public:
+	SphereSphereCollisionAlgorithm(const CollisionAlgorithmConstructionInfo& ci)
+		: CollisionAlgorithm(ci) {}
+
+	virtual void ProcessCollision (BroadphaseProxy* proxy0,BroadphaseProxy* proxy1,const DispatcherInfo& dispatchInfo);
+
+	virtual float CalculateTimeOfImpact(BroadphaseProxy* proxy0,BroadphaseProxy* proxy1,const DispatcherInfo& dispatchInfo);
+
+	SphereSphereCollisionAlgorithm(PersistentManifold* mf,const CollisionAlgorithmConstructionInfo& ci,BroadphaseProxy* proxy0,BroadphaseProxy* proxy1);
+
+	virtual ~SphereSphereCollisionAlgorithm();
+
+	struct CreateFunc :public 	CollisionAlgorithmCreateFunc
+	{
+		virtual	CollisionAlgorithm* CreateCollisionAlgorithm(CollisionAlgorithmConstructionInfo& ci, BroadphaseProxy* proxy0,BroadphaseProxy* proxy1)
+		{
+			return new SphereSphereCollisionAlgorithm(0,ci,proxy0,proxy1);
+		}
+	};
+
+};
+
+#endif //SPHERE_SPHERE_COLLISION_ALGORITHM_H