Contact.md

Contact

The class manages contact between two shapes. A contact exists for each overlapping AABB in the broad-phase (except if filtered). Therefore a contact object may exist that has no contact points.

Constructor

Never constructed. Sent as a parameter in the contact listener functions: BeginContact, EndContact, PreSolve, and PostSolve (see World:SetContactListener).

Methods

• Box2dContact:GetManifold ()
• Box2dContact:GetNext ()
• Box2dContact:GetWorldManifold ()
• Box2dContact:IsTouching ()
• Box2dContact:SetEnabled (flag)
• Box2dContact:IsEnabled ()
• Box2dContact:GetFixtureA ()
• Box2dContact:GetChildIndexA ()
• Box2dContact:GetFixtureB ()
• Box2dContact:GetChildIndexB ()
• Box2dContact:SetFriction (friction)
• Box2dContact:GetFriction ()
• Box2dContact:ResetFriction ()
• Box2dContact:SetRestitution (restitution)
• Box2dContact:GetRestitution ()
• Box2dContact:ResetRestitution ()
• Box2dContact:SetRestitutionThreshold (threshold)
• Box2dContact:GetRestitutionThreshold ()
• Box2dContact:ResetRestitutionThreshold ()
• Box2dContact:SetTangentSpeed (speed)
• Box2dContact:GetTangentSpeed ()

---

Box2dContact:GetNext()

Get the next contact in the world's contact list.

RETURN

• (Box2dConctact)|(nil)

---

Box2dContact:GetManifold()

Get the local manifold.

RETURN

• (Box2dManifold)

---

Box2dContact:GetWorldManifold()

Get the world manifold.

RETURN

• (Box2dWorldManifold)

---

Box2dContact:IsTouching()

Is this contact touching?

RETURN

• (boolean)

---

Box2dContact:SetEnabled(flag)

Enable/disable this contact. This can be used inside the pre-solve contact listener. The contact is only disabled for the current time step (or sub-step in continuous collisions).

PARAMETERS

• flag (boolean)

---

Box2dContact:IsEnabled()

Has this contact been disabled?

RETURN

• (boolean)

---

Box2dContact:GetFixtureA()

Get fixture A in this contact.

RETURN

• (Box2dFixture)

---

Box2dContact:GetChildIndexA()

Get the child primitive index for fixture A.

RETURN

• (number)

---

Box2dContact:GetFixtureB()

Get fixture B in this contact.

RETURN

• (Box2dFixture)

---

Box2dContact:GetChildIndexB()

Get the child primitive index for fixture B.

RETURN

• (number)

---

Box2dContact:SetFriction(friction)

Override the default friction mixture. You can call this in b2ContactListener::PreSolve. This value persists until set or reset.

PARAMETERS

• friction (number)

---

Box2dContact:GetFriction()

Get the friction.

RETURN

• (number)

---

Box2dContact:ResetFriction()

Reset the friction mixture to the default value.

---

Box2dContact:SetRestitution(restitution)

Override the default restitution mixture. You can call this in b2ContactListener::PreSolve. The value persists until you set or reset.

PARAMETERS

• restitution (number)

---

Box2dContact:GetRestitution()

Get the restitution.

RETURN

• (number)

---

Box2dContact:ResetRestitution()

Reset the restitution to the default value.

---

Box2dContact:SetRestitutionThreshold(threshold)

Override the default restitution velocity threshold mixture. You can call this in b2ContactListener::PreSolve. The value persists until you set or reset.

PARAMETERS

• threshold (number)

---

Box2dContact:GetRestitutionThreshold()

Get the restitution threshold.

RETURN

• (number)

---

Box2dContact:ResetRestitutionThreshold()

Reset the restitution threshold to the default value.

---

Box2dContact:SetTangentSpeed(speed)

Set the desired tangent speed for a conveyor belt behavior. In meters per second.

PARAMETERS

• speed (number)

---

Box2dContact:GetTangentSpeed()

Get the desired tangent speed. In meters per second.

RETURN

• (number)