Beispiel #1
0
        // Remove contacts without broadphase overlap
        // Solves contact manifolds
        public void TestCollisions()
        {
            for (int h = 0; h < ContactList.Count; h++)
            {
                var  constraint = ContactList[h];
                Box  A          = constraint.A;
                Box  B          = constraint.B;
                Body bodyA      = A.body;
                Body bodyB      = B.body;

                constraint.Flags &= ~ContactFlags.eIsland;

                if (!bodyA.IsAwake() && !bodyB.IsAwake())
                {
                    continue;
                }

                if (!bodyA.CanCollide(bodyB))
                {
                    RemoveContact(constraint);
                    continue;
                }

                // Check if contact should persist
                if (!Broadphase.TestOverlap(A.broadPhaseIndex, B.broadPhaseIndex))
                {
                    RemoveContact(constraint);
                    continue;
                }
                Manifold manifold    = constraint.manifold;
                Manifold oldManifold = constraint.manifold;
                Vec3     ot0         = oldManifold.tangentVectors;
                Vec3     ot1         = oldManifold.bitangentVectors;
                constraint.SolveCollision();
                AABB.ComputeBasis(manifold.normal, ref manifold.tangentVectors, ref manifold.bitangentVectors);

                for (int i = 0; i < manifold.contactCount; ++i)
                {
                    Contact c = manifold.contacts[i];
                    c.tangentImpulse = c.bitangentImpulse = c.normalImpulse = 0;
                    byte oldWarmStart = c.warmStarted;
                    c.warmStarted = 0;

                    for (int j = 0; j < oldManifold.contactCount; ++j)
                    {
                        Contact oc = oldManifold.contacts[j];
                        if (c.fp.key == oc.fp.key)
                        {
                            c.normalImpulse = oc.normalImpulse;

                            // Attempt to re-project old friction solutions
                            Vec3 friction = ot0 * oc.tangentImpulse + ot1 * oc.bitangentImpulse;
                            c.tangentImpulse   = Vec3.Dot(friction, manifold.tangentVectors);
                            c.bitangentImpulse = Vec3.Dot(friction, manifold.bitangentVectors);
                            c.warmStarted      = Math.Max(oldWarmStart, (byte)(oldWarmStart + 1));
                            break;
                        }
                    }
                }

                if (ContactListener != null)
                {
                    var now_colliding = constraint.Flags & ContactFlags.eColliding;
                    var was_colliding = constraint.Flags & ContactFlags.eWasColliding;

                    if (now_colliding > 0 && was_colliding == 0)
                    {
                        ContactListener.BeginContact(constraint);
                    }

                    else if (now_colliding == 0 && was_colliding > 0)
                    {
                        ContactListener.EndContact(constraint);
                    }
                }
            }
        }