paulxstretch/deps/juce/modules/juce_box2d/box2d/Dynamics/b2ContactManager.cpp

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/*
* Copyright (c) 2006-2009 Erin Catto http://www.box2d.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 "b2ContactManager.h"
#include "b2Body.h"
#include "b2Fixture.h"
#include "b2WorldCallbacks.h"
#include "Contacts/b2Contact.h"
b2ContactFilter b2_defaultFilter;
b2ContactListener b2_defaultListener;
b2ContactManager::b2ContactManager()
{
m_contactList = NULL;
m_contactCount = 0;
m_contactFilter = &b2_defaultFilter;
m_contactListener = &b2_defaultListener;
m_allocator = NULL;
}
void b2ContactManager::Destroy(b2Contact* c)
{
b2Fixture* fixtureA = c->GetFixtureA();
b2Fixture* fixtureB = c->GetFixtureB();
b2Body* bodyA = fixtureA->GetBody();
b2Body* bodyB = fixtureB->GetBody();
if (m_contactListener && c->IsTouching())
{
m_contactListener->EndContact(c);
}
// Remove from the world.
if (c->m_prev)
{
c->m_prev->m_next = c->m_next;
}
if (c->m_next)
{
c->m_next->m_prev = c->m_prev;
}
if (c == m_contactList)
{
m_contactList = c->m_next;
}
// Remove from body 1
if (c->m_nodeA.prev)
{
c->m_nodeA.prev->next = c->m_nodeA.next;
}
if (c->m_nodeA.next)
{
c->m_nodeA.next->prev = c->m_nodeA.prev;
}
if (&c->m_nodeA == bodyA->m_contactList)
{
bodyA->m_contactList = c->m_nodeA.next;
}
// Remove from body 2
if (c->m_nodeB.prev)
{
c->m_nodeB.prev->next = c->m_nodeB.next;
}
if (c->m_nodeB.next)
{
c->m_nodeB.next->prev = c->m_nodeB.prev;
}
if (&c->m_nodeB == bodyB->m_contactList)
{
bodyB->m_contactList = c->m_nodeB.next;
}
// Call the factory.
b2Contact::Destroy(c, m_allocator);
--m_contactCount;
}
// This is the top level collision call for the time step. Here
// all the narrow phase collision is processed for the world
// contact list.
void b2ContactManager::Collide()
{
// Update awake contacts.
b2Contact* c = m_contactList;
while (c)
{
b2Fixture* fixtureA = c->GetFixtureA();
b2Fixture* fixtureB = c->GetFixtureB();
int32 indexA = c->GetChildIndexA();
int32 indexB = c->GetChildIndexB();
b2Body* bodyA = fixtureA->GetBody();
b2Body* bodyB = fixtureB->GetBody();
// Is this contact flagged for filtering?
if (c->m_flags & b2Contact::e_filterFlag)
{
// Should these bodies collide?
if (bodyB->ShouldCollide(bodyA) == false)
{
b2Contact* cNuke = c;
c = cNuke->GetNext();
Destroy(cNuke);
continue;
}
// Check user filtering.
if (m_contactFilter && m_contactFilter->ShouldCollide(fixtureA, fixtureB) == false)
{
b2Contact* cNuke = c;
c = cNuke->GetNext();
Destroy(cNuke);
continue;
}
// Clear the filtering flag.
c->m_flags &= ~b2Contact::e_filterFlag;
}
bool activeA = bodyA->IsAwake() && bodyA->m_type != b2_staticBody;
bool activeB = bodyB->IsAwake() && bodyB->m_type != b2_staticBody;
// At least one body must be awake and it must be dynamic or kinematic.
if (activeA == false && activeB == false)
{
c = c->GetNext();
continue;
}
int32 proxyIdA = fixtureA->m_proxies[indexA].proxyId;
int32 proxyIdB = fixtureB->m_proxies[indexB].proxyId;
bool overlap = m_broadPhase.TestOverlap(proxyIdA, proxyIdB);
// Here we destroy contacts that cease to overlap in the broad-phase.
if (overlap == false)
{
b2Contact* cNuke = c;
c = cNuke->GetNext();
Destroy(cNuke);
continue;
}
// The contact persists.
c->Update(m_contactListener);
c = c->GetNext();
}
}
void b2ContactManager::FindNewContacts()
{
m_broadPhase.UpdatePairs(this);
}
void b2ContactManager::AddPair(void* proxyUserDataA, void* proxyUserDataB)
{
b2FixtureProxy* proxyA = (b2FixtureProxy*)proxyUserDataA;
b2FixtureProxy* proxyB = (b2FixtureProxy*)proxyUserDataB;
b2Fixture* fixtureA = proxyA->fixture;
b2Fixture* fixtureB = proxyB->fixture;
int32 indexA = proxyA->childIndex;
int32 indexB = proxyB->childIndex;
b2Body* bodyA = fixtureA->GetBody();
b2Body* bodyB = fixtureB->GetBody();
// Are the fixtures on the same body?
if (bodyA == bodyB)
{
return;
}
// TODO_ERIN use a hash table to remove a potential bottleneck when both
// bodies have a lot of contacts.
// Does a contact already exist?
b2ContactEdge* edge = bodyB->GetContactList();
while (edge)
{
if (edge->other == bodyA)
{
b2Fixture* fA = edge->contact->GetFixtureA();
b2Fixture* fB = edge->contact->GetFixtureB();
int32 iA = edge->contact->GetChildIndexA();
int32 iB = edge->contact->GetChildIndexB();
if (fA == fixtureA && fB == fixtureB && iA == indexA && iB == indexB)
{
// A contact already exists.
return;
}
if (fA == fixtureB && fB == fixtureA && iA == indexB && iB == indexA)
{
// A contact already exists.
return;
}
}
edge = edge->next;
}
// Does a joint override collision? Is at least one body dynamic?
if (bodyB->ShouldCollide(bodyA) == false)
{
return;
}
// Check user filtering.
if (m_contactFilter && m_contactFilter->ShouldCollide(fixtureA, fixtureB) == false)
{
return;
}
// Call the factory.
b2Contact* c = b2Contact::Create(fixtureA, indexA, fixtureB, indexB, m_allocator);
if (c == NULL)
{
return;
}
// Contact creation may swap fixtures.
fixtureA = c->GetFixtureA();
fixtureB = c->GetFixtureB();
// indexA = c->GetChildIndexA();
// indexB = c->GetChildIndexB();
bodyA = fixtureA->GetBody();
bodyB = fixtureB->GetBody();
// Insert into the world.
c->m_prev = NULL;
c->m_next = m_contactList;
if (m_contactList != NULL)
{
m_contactList->m_prev = c;
}
m_contactList = c;
// Connect to island graph.
// Connect to body A
c->m_nodeA.contact = c;
c->m_nodeA.other = bodyB;
c->m_nodeA.prev = NULL;
c->m_nodeA.next = bodyA->m_contactList;
if (bodyA->m_contactList != NULL)
{
bodyA->m_contactList->prev = &c->m_nodeA;
}
bodyA->m_contactList = &c->m_nodeA;
// Connect to body B
c->m_nodeB.contact = c;
c->m_nodeB.other = bodyA;
c->m_nodeB.prev = NULL;
c->m_nodeB.next = bodyB->m_contactList;
if (bodyB->m_contactList != NULL)
{
bodyB->m_contactList->prev = &c->m_nodeB;
}
bodyB->m_contactList = &c->m_nodeB;
// Wake up the bodies
bodyA->SetAwake(true);
bodyB->SetAwake(true);
++m_contactCount;
}