b2Contact.h
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00001 /*
00002 * Copyright (c) 2006-2009 Erin Catto http://www.box2d.org
00003 *
00004 * This software is provided 'as-is', without any express or implied
00005 * warranty.  In no event will the authors be held liable for any damages
00006 * arising from the use of this software.
00007 * Permission is granted to anyone to use this software for any purpose,
00008 * including commercial applications, and to alter it and redistribute it
00009 * freely, subject to the following restrictions:
00010 * 1. The origin of this software must not be misrepresented; you must not
00011 * claim that you wrote the original software. If you use this software
00012 * in a product, an acknowledgment in the product documentation would be
00013 * appreciated but is not required.
00014 * 2. Altered source versions must be plainly marked as such, and must not be
00015 * misrepresented as being the original software.
00016 * 3. This notice may not be removed or altered from any source distribution.
00017 */
00018 
00019 #ifndef B2_CONTACT_H
00020 #define B2_CONTACT_H
00021 
00022 #include <Box2D/Common/b2Math.h>
00023 #include <Box2D/Collision/b2Collision.h>
00024 #include <Box2D/Collision/Shapes/b2Shape.h>
00025 #include <Box2D/Dynamics/b2Fixture.h>
00026 
00027 class b2Body;
00028 class b2Contact;
00029 class b2Fixture;
00030 class b2World;
00031 class b2BlockAllocator;
00032 class b2StackAllocator;
00033 class b2ContactListener;
00034 
00037 inline float32 b2MixFriction(float32 friction1, float32 friction2)
00038 {
00039         return b2Sqrt(friction1 * friction2);
00040 }
00041 
00044 inline float32 b2MixRestitution(float32 restitution1, float32 restitution2)
00045 {
00046         return restitution1 > restitution2 ? restitution1 : restitution2;
00047 }
00048 
00049 typedef b2Contact* b2ContactCreateFcn(  b2Fixture* fixtureA, int32 indexA,
00050                                                                                 b2Fixture* fixtureB, int32 indexB,
00051                                                                                 b2BlockAllocator* allocator);
00052 typedef void b2ContactDestroyFcn(b2Contact* contact, b2BlockAllocator* allocator);
00053 
00054 struct b2ContactRegister
00055 {
00056         b2ContactCreateFcn* createFcn;
00057         b2ContactDestroyFcn* destroyFcn;
00058         bool primary;
00059 };
00060 
00066 struct b2ContactEdge
00067 {
00068         b2Body* other;                  
00069         b2Contact* contact;             
00070         b2ContactEdge* prev;    
00071         b2ContactEdge* next;    
00072 };
00073 
00077 class b2Contact
00078 {
00079 public:
00080 
00083         b2Manifold* GetManifold();
00084         const b2Manifold* GetManifold() const;
00085 
00087         void GetWorldManifold(b2WorldManifold* worldManifold) const;
00088 
00090         bool IsTouching() const;
00091 
00095         void SetEnabled(bool flag);
00096 
00098         bool IsEnabled() const;
00099 
00101         b2Contact* GetNext();
00102         const b2Contact* GetNext() const;
00103 
00105         b2Fixture* GetFixtureA();
00106         const b2Fixture* GetFixtureA() const;
00107 
00109         int32 GetChildIndexA() const;
00110 
00112         b2Fixture* GetFixtureB();
00113         const b2Fixture* GetFixtureB() const;
00114 
00116         int32 GetChildIndexB() const;
00117 
00120         void SetFriction(float32 friction);
00121 
00123         float32 GetFriction() const;
00124 
00126         void ResetFriction();
00127 
00130         void SetRestitution(float32 restitution);
00131 
00133         float32 GetRestitution() const;
00134 
00136         void ResetRestitution();
00137 
00139         void SetTangentSpeed(float32 speed);
00140 
00142         float32 GetTangentSpeed() const;
00143 
00145         virtual void Evaluate(b2Manifold* manifold, const b2Transform& xfA, const b2Transform& xfB) = 0;
00146 
00147 protected:
00148         friend class b2ContactManager;
00149         friend class b2World;
00150         friend class b2ContactSolver;
00151         friend class b2Body;
00152         friend class b2Fixture;
00153 
00154         // Flags stored in m_flags
00155         enum
00156         {
00157                 // Used when crawling contact graph when forming islands.
00158                 e_islandFlag            = 0x0001,
00159 
00160         // Set when the shapes are touching.
00161                 e_touchingFlag          = 0x0002,
00162 
00163                 // This contact can be disabled (by user)
00164                 e_enabledFlag           = 0x0004,
00165 
00166                 // This contact needs filtering because a fixture filter was changed.
00167                 e_filterFlag            = 0x0008,
00168 
00169                 // This bullet contact had a TOI event
00170                 e_bulletHitFlag         = 0x0010,
00171 
00172                 // This contact has a valid TOI in m_toi
00173                 e_toiFlag                       = 0x0020
00174         };
00175 
00177         void FlagForFiltering();
00178 
00179         static void AddType(b2ContactCreateFcn* createFcn, b2ContactDestroyFcn* destroyFcn,
00180                                                 b2Shape::Type typeA, b2Shape::Type typeB);
00181         static void InitializeRegisters();
00182         static b2Contact* Create(b2Fixture* fixtureA, int32 indexA, b2Fixture* fixtureB, int32 indexB, b2BlockAllocator* allocator);
00183         static void Destroy(b2Contact* contact, b2Shape::Type typeA, b2Shape::Type typeB, b2BlockAllocator* allocator);
00184         static void Destroy(b2Contact* contact, b2BlockAllocator* allocator);
00185 
00186         b2Contact() : m_fixtureA(NULL), m_fixtureB(NULL) {}
00187         b2Contact(b2Fixture* fixtureA, int32 indexA, b2Fixture* fixtureB, int32 indexB);
00188         virtual ~b2Contact() {}
00189 
00190         void Update(b2ContactListener* listener);
00191 
00192         static b2ContactRegister s_registers[b2Shape::e_typeCount][b2Shape::e_typeCount];
00193         static bool s_initialized;
00194 
00195         uint32 m_flags;
00196 
00197         // World pool and list pointers.
00198         b2Contact* m_prev;
00199         b2Contact* m_next;
00200 
00201         // Nodes for connecting bodies.
00202         b2ContactEdge m_nodeA;
00203         b2ContactEdge m_nodeB;
00204 
00205         b2Fixture* m_fixtureA;
00206         b2Fixture* m_fixtureB;
00207 
00208         int32 m_indexA;
00209         int32 m_indexB;
00210 
00211         b2Manifold m_manifold;
00212 
00213         int32 m_toiCount;
00214         float32 m_toi;
00215 
00216         float32 m_friction;
00217         float32 m_restitution;
00218 
00219         float32 m_tangentSpeed;
00220 };
00221 
00222 inline b2Manifold* b2Contact::GetManifold()
00223 {
00224         return &m_manifold;
00225 }
00226 
00227 inline const b2Manifold* b2Contact::GetManifold() const
00228 {
00229         return &m_manifold;
00230 }
00231 
00232 inline void b2Contact::GetWorldManifold(b2WorldManifold* worldManifold) const
00233 {
00234         const b2Body* bodyA = m_fixtureA->GetBody();
00235         const b2Body* bodyB = m_fixtureB->GetBody();
00236         const b2Shape* shapeA = m_fixtureA->GetShape();
00237         const b2Shape* shapeB = m_fixtureB->GetShape();
00238 
00239         worldManifold->Initialize(&m_manifold, bodyA->GetTransform(), shapeA->m_radius, bodyB->GetTransform(), shapeB->m_radius);
00240 }
00241 
00242 inline void b2Contact::SetEnabled(bool flag)
00243 {
00244         if (flag)
00245         {
00246                 m_flags |= e_enabledFlag;
00247         }
00248         else
00249         {
00250                 m_flags &= ~e_enabledFlag;
00251         }
00252 }
00253 
00254 inline bool b2Contact::IsEnabled() const
00255 {
00256         return (m_flags & e_enabledFlag) == e_enabledFlag;
00257 }
00258 
00259 inline bool b2Contact::IsTouching() const
00260 {
00261         return (m_flags & e_touchingFlag) == e_touchingFlag;
00262 }
00263 
00264 inline b2Contact* b2Contact::GetNext()
00265 {
00266         return m_next;
00267 }
00268 
00269 inline const b2Contact* b2Contact::GetNext() const
00270 {
00271         return m_next;
00272 }
00273 
00274 inline b2Fixture* b2Contact::GetFixtureA()
00275 {
00276         return m_fixtureA;
00277 }
00278 
00279 inline const b2Fixture* b2Contact::GetFixtureA() const
00280 {
00281         return m_fixtureA;
00282 }
00283 
00284 inline b2Fixture* b2Contact::GetFixtureB()
00285 {
00286         return m_fixtureB;
00287 }
00288 
00289 inline int32 b2Contact::GetChildIndexA() const
00290 {
00291         return m_indexA;
00292 }
00293 
00294 inline const b2Fixture* b2Contact::GetFixtureB() const
00295 {
00296         return m_fixtureB;
00297 }
00298 
00299 inline int32 b2Contact::GetChildIndexB() const
00300 {
00301         return m_indexB;
00302 }
00303 
00304 inline void b2Contact::FlagForFiltering()
00305 {
00306         m_flags |= e_filterFlag;
00307 }
00308 
00309 inline void b2Contact::SetFriction(float32 friction)
00310 {
00311         m_friction = friction;
00312 }
00313 
00314 inline float32 b2Contact::GetFriction() const
00315 {
00316         return m_friction;
00317 }
00318 
00319 inline void b2Contact::ResetFriction()
00320 {
00321         m_friction = b2MixFriction(m_fixtureA->m_friction, m_fixtureB->m_friction);
00322 }
00323 
00324 inline void b2Contact::SetRestitution(float32 restitution)
00325 {
00326         m_restitution = restitution;
00327 }
00328 
00329 inline float32 b2Contact::GetRestitution() const
00330 {
00331         return m_restitution;
00332 }
00333 
00334 inline void b2Contact::ResetRestitution()
00335 {
00336         m_restitution = b2MixRestitution(m_fixtureA->m_restitution, m_fixtureB->m_restitution);
00337 }
00338 
00339 inline void b2Contact::SetTangentSpeed(float32 speed)
00340 {
00341         m_tangentSpeed = speed;
00342 }
00343 
00344 inline float32 b2Contact::GetTangentSpeed() const
00345 {
00346         return m_tangentSpeed;
00347 }
00348 
00349 #endif


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autogenerated on Thu Jun 6 2019 22:08:34