Ejemplo n.º 1
0
        // Broad-phase callback.
        internal void AddPair(FixtureProxy proxyA, FixtureProxy proxyB)
        {
            Fixture fixtureA = proxyA.fixture;
            Fixture fixtureB = proxyB.fixture;

            int indexA = proxyA.childIndex;
            int indexB = proxyB.childIndex;

            Body bodyA = fixtureA.GetBody();
            Body bodyB = fixtureB.GetBody();

            // Are the fixtures on the same body?
            if (bodyA == bodyB)
            {
                return;
            }

            // Does a contact already exist?
            ContactEdge edge = bodyB.GetContactList();

            while (edge != null)
            {
                if (edge.Other == bodyA)
                {
                    Fixture fA = edge.Contact.GetFixtureA();
                    Fixture fB = edge.Contact.GetFixtureB();
                    int     iA = edge.Contact.GetChildIndexA();
                    int     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 (ContactFilter != null && ContactFilter.ShouldCollide(fixtureA, fixtureB) == false)
            {
                return;
            }

            // Call the factory.
            Contact c = Contact.Create(fixtureA, indexA, fixtureB, indexB);

            // 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._prev = null;
            c._next = _contactList;
            if (_contactList != null)
            {
                _contactList._prev = c;
            }
            _contactList = c;

            // Connect to island graph.

            // Connect to body A
            c._nodeA.Contact = c;
            c._nodeA.Other   = bodyB;

            c._nodeA.Prev = null;
            c._nodeA.Next = bodyA._contactList;
            if (bodyA._contactList != null)
            {
                bodyA._contactList.Prev = c._nodeA;
            }
            bodyA._contactList = c._nodeA;

            // Connect to body B
            c._nodeB.Contact = c;
            c._nodeB.Other   = bodyA;

            c._nodeB.Prev = null;
            c._nodeB.Next = bodyB._contactList;
            if (bodyB._contactList != null)
            {
                bodyB._contactList.Prev = c._nodeB;
            }
            bodyB._contactList = c._nodeB;

            ++_contactCount;
        }
Ejemplo n.º 2
0
        internal void Collide()
        {
            // Update awake contacts.
            Contact c = _contactList;

            while (c != null)
            {
                Fixture fixtureA = c.GetFixtureA();
                Fixture fixtureB = c.GetFixtureB();
                int     indexA   = c.GetChildIndexA();
                int     indexB   = c.GetChildIndexB();
                Body    bodyA    = fixtureA.GetBody();
                Body    bodyB    = fixtureB.GetBody();

                if (bodyA.IsAwake() == false && bodyB.IsAwake() == false)
                {
                    c = c.GetNext();
                    continue;
                }

                // Is this contact flagged for filtering?
                if ((c._flags & ContactFlags.Filter) == ContactFlags.Filter)
                {
                    // Should these bodies collide?
                    if (bodyB.ShouldCollide(bodyA) == false)
                    {
                        Contact cNuke = c;
                        c = cNuke.GetNext();
                        Destroy(cNuke);
                        continue;
                    }

                    // Check user filtering.
                    if (ContactFilter != null && ContactFilter.ShouldCollide(fixtureA, fixtureB) == false)
                    {
                        Contact cNuke = c;
                        c = cNuke.GetNext();
                        Destroy(cNuke);
                        continue;
                    }

                    // Clear the filtering flag.
                    c._flags &= ~ContactFlags.Filter;
                }

                int proxyIdA = fixtureA._proxies[indexA].proxyId;
                int proxyIdB = fixtureB._proxies[indexB].proxyId;

                bool overlap = _broadPhase.TestOverlap(proxyIdA, proxyIdB);

                // Here we destroy contacts that cease to overlap in the broad-phase.
                if (overlap == false)
                {
                    Contact cNuke = c;
                    c = cNuke.GetNext();
                    Destroy(cNuke);
                    continue;
                }

                // The contact persists.
                c.Update(ContactListener);
                c = c.GetNext();
            }
        }