Class: Manifold

physics/manifold.Manifold

Information about a collision which has occured between two objects.

Constructors

constructor

• new Manifold(a, b, collision, gravity, delta)

Creates a Manifold describing a collision between a and b in detail.

Parameters

Name	Type	Description
a	CollisionObject	First collision object
b	CollisionObject	Second collision object
collision	CollisionResult	CollisionResult from collision test
gravity	vec2	The collision world's gravity vector
delta	number	The time since the last update

Defined in

src/physics/manifold.ts:103

Properties

a

• a: CollisionObject

An object in the collision.

Defined in

src/physics/manifold.ts:40

---

b

• b: CollisionObject

Another object in the collision.

Defined in

src/physics/manifold.ts:45

---

contactPoints

• contactPoints: ContactPoint[]

The contact points of the collision.

Defined in

src/physics/manifold.ts:80

---

depth

• depth: number

The penetration depth of the collision.

Defined in

src/physics/manifold.ts:50

---

df

• df: number

dynamic friction scalar.

Defined in

src/physics/manifold.ts:75

---

edges

• edges: Edge[] = []

store used edges [inc, ref]

Defined in

src/physics/manifold.ts:85

---

epsilon

• epsilon: number

Minimum restitution between a and b.

Defined in

src/physics/manifold.ts:65

---

isDead

• isDead: boolean = false

Defined in

src/physics/manifold.ts:92

---

normal

• normal: vec2

The collision normal, should always point from a to b.

Defined in

src/physics/manifold.ts:55

---

penetration

• penetration: vec2

The penetration vector, this is the collision normal scaled by the penetration depth.

Defined in

src/physics/manifold.ts:60

---

positionImpulse

• positionImpulse: Object

Type declaration

Name	Type
a	vec2
b	vec2

Defined in

src/physics/manifold.ts:87

---

sf

• sf: number

static friction scalar.

Defined in

src/physics/manifold.ts:70

Methods

bestEdge

▸ Private bestEdge(obj, direction): Edge

Finds the best edge of a CollisionObject in a given direction.

The best edge is defined as the edge most perpendicular to the given direction.

Parameters

Name	Type	Description
obj	CollisionObject	The collision object to calculate the edge for
direction	vec2	The direction in which to calculate the edge

Returns

Edge

The best edge of obj for the direction given

Defined in

src/physics/manifold.ts:461

---

calculateContactPoints

▸ Private calculateContactPoints(): ContactPoint[]

Calculates the contact points of the collision.

see Dyn4j Contact Points

Returns

ContactPoint[]

The points of contact for the collision

Defined in

src/physics/manifold.ts:362

---

clipPoints

▸ Private clipPoints(p0, p1, direction, o): ContactPoint[]

Clips the edge points (p0, p1) if they are past o along the direction.

Parameters

Name	Type	Description
p0	ContactPoint	The first point to clip
p1	ContactPoint	The second point to clip
direction	vec2	The direction to clip in
o	number	The vector to clip past

Returns

ContactPoint[]

Defined in

src/physics/manifold.ts:499

---

compareContacts

▸ Private compareContacts(c1, c2): boolean

Compares two contact points using a distance heuristic to determine wether they should be considered the same contact.

Parameters

Name	Type	Description
c1	ContactPoint	A contact point
c2	ContactPoint	A contact point

Returns

boolean

If the 2 contact points match

Defined in

src/physics/manifold.ts:227

---

kill

▸ kill(): void

Marks the manifold as dead and decrements the objects involved's totalContacts counts.

Returns

void

Defined in

src/physics/manifold.ts:236

---

mergeManifold

▸ Private mergeManifold(m, contacts): void

Merge this manifold with the given manifold and contact points.

Parameters

Name	Type	Description
m	Manifold	The manifold to merge with
contacts	ContactPoint[]	The manifold's new contact points

Returns

void

Defined in

src/physics/manifold.ts:205

---

preStepImpulse

▸ preStepImpulse(delta): void

Precompute some additional information about the contact points for impulse resolution.

Calculates and applies accumulative impulse.

Parameters

Name	Type	Description
delta	number	The time since the last udpate

Returns

void

Defined in

src/physics/manifold.ts:296

---

solvePositionImpulse

▸ solvePositionImpulse(delta): void

Calculates the position impulse for objects a and b in the manifold.

see MatterJS Position Solving

Parameters

Name	Type	Description
delta	number	The time since the last update

Returns

void

Defined in

src/physics/manifold.ts:251

---

translateEdge

▸ Private translateEdge(edge, v): void

Translates the provided edge by the given vector.

Parameters

Name	Type	Description
edge	Edge	The edge to translate
v	vec2	The vector to translate by

Returns

void

Defined in

src/physics/manifold.ts:550

---

translateIncEdge

▸ translateIncEdge(v): void

Translates the manifold's incident edge by the given vector.

Parameters

Name	Type	Description
v	vec2	The vector to translate by

Returns

void

Defined in

src/physics/manifold.ts:540

---

update

▸ update(m): void

Parameters

Name	Type
m	Manifold

Returns

void

Defined in

src/physics/manifold.ts:158