b2Contact.h
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上传日期:2022-01-07
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- /*
- * Copyright (c) 2006-2009 Erin Catto http://www.gphysics.com
- *
- * 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 B2_CONTACT_H
- #define B2_CONTACT_H
- #include <Box2D/Common/b2Math.h>
- #include <Box2D/Collision/b2Collision.h>
- #include <Box2D/Collision/Shapes/b2Shape.h>
- #include <Box2D/Dynamics/Contacts/b2Contact.h>
- #include <Box2D/Dynamics/b2Fixture.h>
- class b2Body;
- class b2Contact;
- class b2Fixture;
- class b2World;
- class b2BlockAllocator;
- class b2StackAllocator;
- class b2ContactListener;
- typedef b2Contact* b2ContactCreateFcn(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator);
- typedef void b2ContactDestroyFcn(b2Contact* contact, b2BlockAllocator* allocator);
- struct b2ContactRegister
- {
- b2ContactCreateFcn* createFcn;
- b2ContactDestroyFcn* destroyFcn;
- bool primary;
- };
- /// 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. A contact edge belongs to a doubly linked list
- /// maintained in each attached body. Each contact has two contact
- /// nodes, one for each attached body.
- struct b2ContactEdge
- {
- b2Body* other; ///< provides quick access to the other body attached.
- b2Contact* contact; ///< the contact
- b2ContactEdge* prev; ///< the previous contact edge in the body's contact list
- b2ContactEdge* next; ///< the next contact edge in the body's contact list
- };
- /// The class manages contact between two shapes. A contact exists for each overlapping
- /// AABB in the broad-phase (except if filtered). Therefore a contact object may exist
- /// that has no contact points.
- class b2Contact
- {
- public:
- /// Get the contact manifold. Do not modify the manifold unless you understand the
- /// internals of Box2D.
- b2Manifold* GetManifold();
- const b2Manifold* GetManifold() const;
- /// Get the world manifold.
- void GetWorldManifold(b2WorldManifold* worldManifold) const;
- /// Is this contact touching?
- bool IsTouching() const;
- /// Enable/disable this contact. This can be used inside the pre-solve
- /// contact listener. The contact is only disabled for the current
- /// time step (or sub-step in continuous collisions).
- void SetEnabled(bool flag);
- /// Has this contact been disabled?
- bool IsEnabled() const;
- /// Get the next contact in the world's contact list.
- b2Contact* GetNext();
- const b2Contact* GetNext() const;
- /// Get the first fixture in this contact.
- b2Fixture* GetFixtureA();
- const b2Fixture* GetFixtureA() const;
- /// Get the second fixture in this contact.
- b2Fixture* GetFixtureB();
- const b2Fixture* GetFixtureB() const;
- /// Evaluate this contact with your own manifold and transforms.
- virtual void Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB) = 0;
- protected:
- friend class b2ContactManager;
- friend class b2World;
- friend class b2ContactSolver;
- friend class b2Body;
- friend class b2Fixture;
- // Flags stored in m_flags
- enum
- {
- // Used when crawling contact graph when forming islands.
- e_islandFlag = 0x0001,
- // Set when the shapes are touching.
- e_touchingFlag = 0x0002,
- // This contact can be disabled (by user)
- e_enabledFlag = 0x0004,
- // This contact needs filtering because a fixture filter was changed.
- e_filterFlag = 0x0008,
- // This bullet contact had a TOI event
- e_bulletHitFlag = 0x0010,
- };
- /// Flag this contact for filtering. Filtering will occur the next time step.
- void FlagForFiltering();
- static void AddType(b2ContactCreateFcn* createFcn, b2ContactDestroyFcn* destroyFcn,
- b2Shape::Type typeA, b2Shape::Type typeB);
- static void InitializeRegisters();
- static b2Contact* Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator);
- static void Destroy(b2Contact* contact, b2Shape::Type typeA, b2Shape::Type typeB, b2BlockAllocator* allocator);
- static void Destroy(b2Contact* contact, b2BlockAllocator* allocator);
- b2Contact() : m_fixtureA(NULL), m_fixtureB(NULL) {}
- b2Contact(b2Fixture* fixtureA, b2Fixture* fixtureB);
- virtual ~b2Contact() {}
- void Update(b2ContactListener* listener);
- static b2ContactRegister s_registers[b2Shape::e_typeCount][b2Shape::e_typeCount];
- static bool s_initialized;
- uint32 m_flags;
- // World pool and list pointers.
- b2Contact* m_prev;
- b2Contact* m_next;
- // Nodes for connecting bodies.
- b2ContactEdge m_nodeA;
- b2ContactEdge m_nodeB;
- b2Fixture* m_fixtureA;
- b2Fixture* m_fixtureB;
- b2Manifold m_manifold;
- int32 m_toiCount;
- // float32 m_toi;
- };
- inline b2Manifold* b2Contact::GetManifold()
- {
- return &m_manifold;
- }
- inline const b2Manifold* b2Contact::GetManifold() const
- {
- return &m_manifold;
- }
- inline void b2Contact::GetWorldManifold(b2WorldManifold* worldManifold) const
- {
- const b2Body* bodyA = m_fixtureA->GetBody();
- const b2Body* bodyB = m_fixtureB->GetBody();
- const b2Shape* shapeA = m_fixtureA->GetShape();
- const b2Shape* shapeB = m_fixtureB->GetShape();
- worldManifold->Initialize(&m_manifold, bodyA->GetTransform(), shapeA->m_radius, bodyB->GetTransform(), shapeB->m_radius);
- }
- inline void b2Contact::SetEnabled(bool flag)
- {
- if (flag)
- {
- m_flags |= e_enabledFlag;
- }
- else
- {
- m_flags &= ~e_enabledFlag;
- }
- }
- inline bool b2Contact::IsEnabled() const
- {
- return (m_flags & e_enabledFlag) == e_enabledFlag;
- }
- inline bool b2Contact::IsTouching() const
- {
- return (m_flags & e_touchingFlag) == e_touchingFlag;
- }
- inline b2Contact* b2Contact::GetNext()
- {
- return m_next;
- }
- inline const b2Contact* b2Contact::GetNext() const
- {
- return m_next;
- }
- inline b2Fixture* b2Contact::GetFixtureA()
- {
- return m_fixtureA;
- }
- inline const b2Fixture* b2Contact::GetFixtureA() const
- {
- return m_fixtureA;
- }
- inline b2Fixture* b2Contact::GetFixtureB()
- {
- return m_fixtureB;
- }
- inline const b2Fixture* b2Contact::GetFixtureB() const
- {
- return m_fixtureB;
- }
- inline void b2Contact::FlagForFiltering()
- {
- m_flags |= e_filterFlag;
- }
- #endif