/// <summary>
/// Update the contact manifold and touching status.
/// Note: do not assume the fixture AABBs are overlapping or are valid.
/// </summary>
/// <param name="contactManager">The contact manager.</param>
internal void Update(ContactManager contactManager)
{
Body bodyA = FixtureA.Body;
Body bodyB = FixtureB.Body;
if (FixtureA == null || FixtureB == null)
{
return;
}
if (!ContactManager.CheckCollisionConditions(FixtureA, FixtureB))
{
Enabled = false;
return;
}
Manifold oldManifold = Manifold;
// Re-enable this contact.
Enabled = true;
bool touching;
bool wasTouching = IsTouching;
bool sensor = FixtureA.IsSensor || FixtureB.IsSensor;
// Is this contact a sensor?
if (sensor)
{
Shape shapeA = FixtureA.Shape;
Shape shapeB = FixtureB.Shape;
touching = Collision.TestOverlap(shapeA, ChildIndexA, shapeB, ChildIndexB, ref bodyA._xf, ref bodyB._xf);
// Sensors don't generate manifolds.
Manifold.PointCount = 0;
}
else
{
Evaluate(ref Manifold, ref bodyA._xf, ref bodyB._xf);
touching = Manifold.PointCount > 0;
// Match old contact ids to new contact ids and copy the
// stored impulses to warm start the solver.
for (int i = 0; i < Manifold.PointCount; ++i)
{
ManifoldPoint mp2 = Manifold.Points[i];
mp2.NormalImpulse = 0.0f;
mp2.TangentImpulse = 0.0f;
ContactID id2 = mp2.Id;
for (int j = 0; j < oldManifold.PointCount; ++j)
{
ManifoldPoint mp1 = oldManifold.Points[j];
if (mp1.Id.Key == id2.Key)
{
mp2.NormalImpulse = mp1.NormalImpulse;
mp2.TangentImpulse = mp1.TangentImpulse;
break;
}
}
Manifold.Points[i] = mp2;
}
if (touching != wasTouching)
{
bodyA.Awake = true;
bodyB.Awake = true;
}
}
IsTouching = touching;
if (wasTouching == false)
{
if (touching)
{
if (Settings.AllCollisionCallbacksAgree)
{
bool enabledA = true, enabledB = true;
// Report the collision to both participants. Track which ones returned true so we can
// later call OnSeparation if the contact is disabled for a different reason.
if (FixtureA.OnCollision != null)
{
foreach (OnCollisionEventHandler handler in FixtureA.OnCollision.GetInvocationList())
{
enabledA = handler(FixtureA, FixtureB, this) && enabledA;
}
}
// Reverse the order of the reported fixtures. The first fixture is always the one that the
// user subscribed to.
if (FixtureB.OnCollision != null)
{
foreach (OnCollisionEventHandler handler in FixtureB.OnCollision.GetInvocationList())
{
enabledB = handler(FixtureB, FixtureA, this) && enabledB;
}
}
Enabled = enabledA && enabledB;
// BeginContact can also return false and disable the contact
if (enabledA && enabledB && contactManager.BeginContact != null)
{
Enabled = contactManager.BeginContact(this);
}
}
else
{
//Report the collision to both participants:
if (FixtureA.OnCollision != null)
{
foreach (OnCollisionEventHandler handler in FixtureA.OnCollision.GetInvocationList())
{
Enabled = handler(FixtureA, FixtureB, this);
}
}
//Reverse the order of the reported fixtures. The first fixture is always the one that the
//user subscribed to.
if (FixtureB.OnCollision != null)
{
foreach (OnCollisionEventHandler handler in FixtureB.OnCollision.GetInvocationList())
{
Enabled = handler(FixtureB, FixtureA, this);
}
}
//BeginContact can also return false and disable the contact
if (contactManager.BeginContact != null)
{
Enabled = contactManager.BeginContact(this);
}
}
// If the user disabled the contact (needed to exclude it in TOI solver) at any point by
// any of the callbacks, we need to mark it as not touching and call any separation
// callbacks for fixtures that didn't explicitly disable the collision.
if (!Enabled)
{
IsTouching = false;
}
}
}
else
{
if (touching == false)
{
//Report the separation to both participants:
if (FixtureA != null && FixtureA.OnSeparation != null)
{
FixtureA.OnSeparation(FixtureA, FixtureB);
}
//Reverse the order of the reported fixtures. The first fixture is always the one that the
//user subscribed to.
if (FixtureB != null && FixtureB.OnSeparation != null)
{
FixtureB.OnSeparation(FixtureB, FixtureA);
}
if (contactManager.EndContact != null)
{
contactManager.EndContact(this);
}
}
else
{
if (contactManager.StayContact != null)
{
contactManager.StayContact(this);
}
}
}
if (sensor)
{
return;
}
if (contactManager.PreSolve != null)
{
contactManager.PreSolve(this, ref oldManifold);
}
}
internal void Destroy(Contact contact)
{
Fixture fixtureA = contact.FixtureA;
Fixture fixtureB = contact.FixtureB;
Body bodyA = fixtureA.Body;
Body bodyB = fixtureB.Body;
if (contact.IsTouching)
{
//Report the separation to both participants:
if (fixtureA != null && fixtureA.OnSeparation != null)
{
fixtureA.OnSeparation(fixtureA, fixtureB);
}
//Reverse the order of the reported fixtures. The first fixture is always the one that the
//user subscribed to.
if (fixtureB != null && fixtureB.OnSeparation != null)
{
fixtureB.OnSeparation(fixtureB, fixtureA);
}
if (EndContact != null)
{
EndContact(contact);
}
}
// Remove from the world.
ContactList.Remove(contact);
// Remove from body 1
if (contact._nodeA.Prev != null)
{
contact._nodeA.Prev.Next = contact._nodeA.Next;
}
if (contact._nodeA.Next != null)
{
contact._nodeA.Next.Prev = contact._nodeA.Prev;
}
if (contact._nodeA == bodyA.ContactList)
{
bodyA.ContactList = contact._nodeA.Next;
}
// Remove from body 2
if (contact._nodeB.Prev != null)
{
contact._nodeB.Prev.Next = contact._nodeB.Next;
}
if (contact._nodeB.Next != null)
{
contact._nodeB.Next.Prev = contact._nodeB.Prev;
}
if (contact._nodeB == bodyB.ContactList)
{
bodyB.ContactList = contact._nodeB.Next;
}
#if USE_ACTIVE_CONTACT_SET
if (ActiveContacts.Contains(contact))
{
ActiveContacts.Remove(contact);
}
#endif
contact.Destroy();
}
