private ChainAndCircleContact(Fixture fixtureA, int indexA, Fixture fixtureB, int indexB) : base(
fixtureA,
indexA,
fixtureB,
indexB)
{
Debug.Assert(FixtureA.GetShapeType() == ShapeType.Chain);
Debug.Assert(FixtureB.GetShapeType() == ShapeType.Circle);
}
/// <summary>
/// Computes the toi using the specified sweep a
/// </summary>
/// <param name="sweepA">The sweep</param>
/// <param name="sweepB">The sweep</param>
/// <returns>The float</returns>
public float ComputeToi(Sweep sweepA, Sweep sweepB)
{
ToiInput input = new ToiInput();
input.SweepA = sweepA;
input.SweepB = sweepB;
input.SweepRadiusA = FixtureA.ComputeSweepRadius(sweepA.LocalCenter);
input.SweepRadiusB = FixtureB.ComputeSweepRadius(sweepB.LocalCenter);
input.Tolerance = Settings.LinearSlop;
return(Collision.Collision.TimeOfImpact(input, FixtureA.Shape, FixtureB.Shape));
}
/// <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;
}
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.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)
{
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;
}
}
// Report the collision to both bodies:
if (FixtureA.Body != null && FixtureA.Body.onCollisionEventHandler != null)
{
foreach (OnCollisionEventHandler handler in FixtureA.Body.onCollisionEventHandler.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.Body != null && FixtureB.Body.onCollisionEventHandler != null)
{
foreach (OnCollisionEventHandler handler in FixtureB.Body.onCollisionEventHandler.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);
}
// 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, this);
}
//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, this);
}
//Report the separation to both bodies:
if (FixtureA != null && FixtureA.Body != null && FixtureA.Body.onSeparationEventHandler != null)
{
FixtureA.Body.onSeparationEventHandler(FixtureA, FixtureB, this);
}
//Reverse the order of the reported fixtures. The first fixture is always the one that the
//user subscribed to.
if (FixtureB != null && FixtureB.Body != null && FixtureB.Body.onSeparationEventHandler != null)
{
FixtureB.Body.onSeparationEventHandler(FixtureB, FixtureA, this);
}
if (contactManager.EndContact != null)
{
contactManager.EndContact(this);
}
}
}
if (sensor)
{
return;
}
if (contactManager.PreSolve != null)
{
contactManager.PreSolve(this, ref oldManifold);
}
}
private EdgeAndPolygonContact(Fixture fixtureA, Fixture fixtureB) : base(fixtureA, 0, fixtureB, 0)
{
Debug.Assert(FixtureA.GetShapeType() == ShapeType.Edge);
Debug.Assert(FixtureB.GetShapeType() == ShapeType.Polygon);
}
private PolygonAndCircleContact(Fixture fixtureA, Fixture fixtureB) : base(fixtureA, 0, fixtureB, 0)
{
Debug.Assert(FixtureA.GetShapeType() == ShapeType.Polygon);
Debug.Assert(FixtureB.GetShapeType() == ShapeType.Circle);
}
