private void PostSolve(Contact contact, ContactConstraint impulse)
{
if (!Broken)
{
if (Parts.Contains(contact.FixtureA) || Parts.Contains(contact.FixtureB))
{
float maxImpulse = 0.0f;
int count = contact.Manifold.PointCount;
for (int i = 0; i < count; ++i)
{
maxImpulse = Math.Max(maxImpulse, impulse.Points[i].NormalImpulse);
}
if (maxImpulse > Strength)
{
// Flag the body for breaking.
_break = true;
}
}
}
}
public void Add(Contact contact)
{
if (ContactCount < _contactCapacity) ;
_contacts[ContactCount++] = contact;
}
internal static Contact Create(Fixture fixtureA, int indexA, Fixture fixtureB, int indexB)
{
ShapeType type1 = fixtureA.ShapeType;
ShapeType type2 = fixtureB.ShapeType;
Debug.Assert(ShapeType.Unknown < type1 && type1 < ShapeType.TypeCount);
Debug.Assert(ShapeType.Unknown < type2 && type2 < ShapeType.TypeCount);
Contact c;
Queue<Contact> pool = fixtureA.Body.World.ContactPool;
if (pool.Count > 0)
{
c = pool.Dequeue();
if ((type1 >= type2 || (type1 == ShapeType.Edge && type2 == ShapeType.Polygon))
&&
!(type2 == ShapeType.Edge && type1 == ShapeType.Polygon))
{
c.Reset(fixtureA, indexA, fixtureB, indexB);
}
else
{
c.Reset(fixtureB, indexB, fixtureA, indexA);
}
}
else
{
// Edge+Polygon is non-symetrical due to the way Erin handles collision type registration.
if ((type1 >= type2 || (type1 == ShapeType.Edge && type2 == ShapeType.Polygon))
&&
!(type2 == ShapeType.Edge && type1 == ShapeType.Polygon))
{
c = new Contact(fixtureA, indexA, fixtureB, indexB);
}
else
{
c = new Contact(fixtureB, indexB, fixtureA, indexA);
}
}
c._type = _registers[(int)type1, (int)type2];
return c;
}
public void Reset(Contact[] contacts, int contactCount, float impulseRatio, bool warmstarting)
{
_contacts = contacts;
_constraintCount = contactCount;
// grow the array
if (Constraints == null || Constraints.Length < _constraintCount)
{
Constraints = new ContactConstraint[_constraintCount * 2];
for (int i = 0; i < Constraints.Length; i++)
{
Constraints[i] = new ContactConstraint();
}
}
// Initialize position independent portions of the constraints.
for (int i = 0; i < _constraintCount; ++i)
{
Contact contact = contacts[i];
Fixture fixtureA = contact.FixtureA;
Fixture fixtureB = contact.FixtureB;
Shape shapeA = fixtureA.Shape;
Shape shapeB = fixtureB.Shape;
float radiusA = shapeA.Radius;
float radiusB = shapeB.Radius;
PhysicsBody bodyA = fixtureA.Body;
PhysicsBody bodyB = fixtureB.Body;
Manifold manifold = contact.Manifold;
Debug.Assert(manifold.PointCount > 0);
ContactConstraint cc = Constraints[i];
cc.Friction = Settings.MixFriction(fixtureA.Friction, fixtureB.Friction);
cc.Restitution = Settings.MixRestitution(fixtureA.Restitution, fixtureB.Restitution);
cc.BodyA = bodyA;
cc.BodyB = bodyB;
cc.Manifold = manifold;
cc.Normal = Vector2.Zero;
cc.PointCount = manifold.PointCount;
cc.LocalNormal = manifold.LocalNormal;
cc.LocalPoint = manifold.LocalPoint;
cc.RadiusA = radiusA;
cc.RadiusB = radiusB;
cc.Type = manifold.Type;
for (int j = 0; j < cc.PointCount; ++j)
{
ManifoldPoint cp = manifold.Points[j];
ContactConstraintPoint ccp = cc.Points[j];
if (warmstarting)
{
ccp.NormalImpulse = impulseRatio * cp.NormalImpulse;
ccp.TangentImpulse = impulseRatio * cp.TangentImpulse;
}
else
{
ccp.NormalImpulse = 0.0f;
ccp.TangentImpulse = 0.0f;
}
ccp.LocalPoint = cp.LocalPoint;
ccp.rA = Vector2.Zero;
ccp.rB = Vector2.Zero;
ccp.NormalMass = 0.0f;
ccp.TangentMass = 0.0f;
ccp.VelocityBias = 0.0f;
}
cc.K.SetZero();
cc.NormalMass.SetZero();
}
}
internal void Destroy(Contact contact)
{
Fixture fixtureA = contact.FixtureA;
Fixture fixtureB = contact.FixtureB;
PhysicsBody bodyA = fixtureA.Body;
PhysicsBody bodyB = fixtureB.Body;
if (EndContact != null && contact.IsTouching())
{
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;
}
contact.Destroy();
}
