b2Contact.cpp
上传用户:gb3593
上传日期:2022-01-07
资源大小:3028k
文件大小:6k
- /*
- * 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.
- */
- #include <Box2D/Dynamics/Contacts/b2Contact.h>
- #include <Box2D/Dynamics/Contacts/b2CircleContact.h>
- #include <Box2D/Dynamics/Contacts/b2PolygonAndCircleContact.h>
- #include <Box2D/Dynamics/Contacts/b2PolygonContact.h>
- #include <Box2D/Dynamics/Contacts/b2ContactSolver.h>
- #include <Box2D/Collision/b2Collision.h>
- #include <Box2D/Collision/b2TimeOfImpact.h>
- #include <Box2D/Collision/Shapes/b2Shape.h>
- #include <Box2D/Common/b2BlockAllocator.h>
- #include <Box2D/Dynamics/b2Body.h>
- #include <Box2D/Dynamics/b2Fixture.h>
- #include <Box2D/Dynamics/b2World.h>
- b2ContactRegister b2Contact::s_registers[b2Shape::e_typeCount][b2Shape::e_typeCount];
- bool b2Contact::s_initialized = false;
- void b2Contact::InitializeRegisters()
- {
- AddType(b2CircleContact::Create, b2CircleContact::Destroy, b2Shape::e_circle, b2Shape::e_circle);
- AddType(b2PolygonAndCircleContact::Create, b2PolygonAndCircleContact::Destroy, b2Shape::e_polygon, b2Shape::e_circle);
- AddType(b2PolygonContact::Create, b2PolygonContact::Destroy, b2Shape::e_polygon, b2Shape::e_polygon);
- }
- void b2Contact::AddType(b2ContactCreateFcn* createFcn, b2ContactDestroyFcn* destoryFcn,
- b2Shape::Type type1, b2Shape::Type type2)
- {
- b2Assert(b2Shape::e_unknown < type1 && type1 < b2Shape::e_typeCount);
- b2Assert(b2Shape::e_unknown < type2 && type2 < b2Shape::e_typeCount);
-
- s_registers[type1][type2].createFcn = createFcn;
- s_registers[type1][type2].destroyFcn = destoryFcn;
- s_registers[type1][type2].primary = true;
- if (type1 != type2)
- {
- s_registers[type2][type1].createFcn = createFcn;
- s_registers[type2][type1].destroyFcn = destoryFcn;
- s_registers[type2][type1].primary = false;
- }
- }
- b2Contact* b2Contact::Create(b2Fixture* fixtureA, b2Fixture* fixtureB, b2BlockAllocator* allocator)
- {
- if (s_initialized == false)
- {
- InitializeRegisters();
- s_initialized = true;
- }
- b2Shape::Type type1 = fixtureA->GetType();
- b2Shape::Type type2 = fixtureB->GetType();
- b2Assert(b2Shape::e_unknown < type1 && type1 < b2Shape::e_typeCount);
- b2Assert(b2Shape::e_unknown < type2 && type2 < b2Shape::e_typeCount);
-
- b2ContactCreateFcn* createFcn = s_registers[type1][type2].createFcn;
- if (createFcn)
- {
- if (s_registers[type1][type2].primary)
- {
- return createFcn(fixtureA, fixtureB, allocator);
- }
- else
- {
- return createFcn(fixtureB, fixtureA, allocator);
- }
- }
- else
- {
- return NULL;
- }
- }
- void b2Contact::Destroy(b2Contact* contact, b2BlockAllocator* allocator)
- {
- b2Assert(s_initialized == true);
- if (contact->m_manifold.pointCount > 0)
- {
- contact->GetFixtureA()->GetBody()->SetAwake(true);
- contact->GetFixtureB()->GetBody()->SetAwake(true);
- }
- b2Shape::Type typeA = contact->GetFixtureA()->GetType();
- b2Shape::Type typeB = contact->GetFixtureB()->GetType();
- b2Assert(b2Shape::e_unknown < typeA && typeB < b2Shape::e_typeCount);
- b2Assert(b2Shape::e_unknown < typeA && typeB < b2Shape::e_typeCount);
- b2ContactDestroyFcn* destroyFcn = s_registers[typeA][typeB].destroyFcn;
- destroyFcn(contact, allocator);
- }
- b2Contact::b2Contact(b2Fixture* fA, b2Fixture* fB)
- {
- m_flags = e_enabledFlag;
- m_fixtureA = fA;
- m_fixtureB = fB;
- m_manifold.pointCount = 0;
- m_prev = NULL;
- m_next = NULL;
- m_nodeA.contact = NULL;
- m_nodeA.prev = NULL;
- m_nodeA.next = NULL;
- m_nodeA.other = NULL;
- m_nodeB.contact = NULL;
- m_nodeB.prev = NULL;
- m_nodeB.next = NULL;
- m_nodeB.other = NULL;
- m_toiCount = 0;
- }
- // Update the contact manifold and touching status.
- // Note: do not assume the fixture AABBs are overlapping or are valid.
- void b2Contact::Update(b2ContactListener* listener)
- {
- b2Manifold oldManifold = m_manifold;
- // Re-enable this contact.
- m_flags |= e_enabledFlag;
- bool touching = false;
- bool wasTouching = (m_flags & e_touchingFlag) == e_touchingFlag;
- bool sensorA = m_fixtureA->IsSensor();
- bool sensorB = m_fixtureB->IsSensor();
- bool sensor = sensorA || sensorB;
- b2Body* bodyA = m_fixtureA->GetBody();
- b2Body* bodyB = m_fixtureB->GetBody();
- const b2Transform& xfA = bodyA->GetTransform();
- const b2Transform& xfB = bodyB->GetTransform();
- // Is this contact a sensor?
- if (sensor)
- {
- const b2Shape* shapeA = m_fixtureA->GetShape();
- const b2Shape* shapeB = m_fixtureB->GetShape();
- touching = b2TestOverlap(shapeA, shapeB, xfA, xfB);
- // Sensors don't generate manifolds.
- m_manifold.pointCount = 0;
- }
- else
- {
- Evaluate(&m_manifold, xfA, xfB);
- touching = m_manifold.pointCount > 0;
- // Match old contact ids to new contact ids and copy the
- // stored impulses to warm start the solver.
- for (int32 i = 0; i < m_manifold.pointCount; ++i)
- {
- b2ManifoldPoint* mp2 = m_manifold.points + i;
- mp2->normalImpulse = 0.0f;
- mp2->tangentImpulse = 0.0f;
- b2ContactID id2 = mp2->id;
- for (int32 j = 0; j < oldManifold.pointCount; ++j)
- {
- b2ManifoldPoint* mp1 = oldManifold.points + j;
- if (mp1->id.key == id2.key)
- {
- mp2->normalImpulse = mp1->normalImpulse;
- mp2->tangentImpulse = mp1->tangentImpulse;
- break;
- }
- }
- }
- if (touching != wasTouching)
- {
- bodyA->SetAwake(true);
- bodyB->SetAwake(true);
- }
- }
- if (touching)
- {
- m_flags |= e_touchingFlag;
- }
- else
- {
- m_flags &= ~e_touchingFlag;
- }
- if (wasTouching == false && touching == true && listener)
- {
- listener->BeginContact(this);
- }
- if (wasTouching == true && touching == false && listener)
- {
- listener->EndContact(this);
- }
- if (sensor == false && touching && listener)
- {
- listener->PreSolve(this, &oldManifold);
- }
- }