Class: RotarySpringConstraint

physics/constraints/rotarySpring.RotarySpringConstraint

Represents a damped rotary spring joint between two CollisionObjects or a CollisionObject and itself.

This joint will aim to maintain the provided angle between the 2 bodies.

When the joint only consists of one body it will aim to keep that bodies rotation at the specified angle.

Setting anchor points for this constraint will have no affect.

Hierarchy

• Constraint

  ↳ RotarySpringConstraint

Constructors

constructor

• new RotarySpringConstraint(a, b, angle, stiffness, damping?)

Creates a new RotarySpringConstraint between two bodies.

Parameters

Name	Type	Description
a	CollisionObject	The first body
b	CollisionObject	The second body
angle	number	The resting angle of the spring
stiffness	number	The stiffness of the spring
damping?	number	The damping of the spring

Overrides

Constraint.constructor

Defined in

src/physics/constraints/rotarySpring.ts:40

• new RotarySpringConstraint(opts)

Creates a new SpringConstraint with the given options.

Parameters

Name	Type	Description
opts	RotarySpringConstraintOptions	The constraint options

Overrides

Constraint.constructor

Defined in

src/physics/constraints/rotarySpring.ts:47

• new RotarySpringConstraint(a, angle, stiffness, damping?)

Creates a new RotarySpringConstraint between a body and a point.

Parameters

Name	Type	Description
a	CollisionObject	The body to constrain
angle	number	The resting angle of the spring.
stiffness	number	The stiffness of the spring
damping?	number	The damping of the spring

Overrides

Constraint.constructor

Defined in

src/physics/constraints/rotarySpring.ts:57

Properties

a

• a: CollisionObject

Inherited from

Constraint.a

Defined in

src/physics/constraints/constraint.ts:22

---

anchorA

• anchorA: vec2

Inherited from

Constraint.anchorA

Defined in

src/physics/constraints/constraint.ts:23

---

anchorB

• anchorB: vec2

Inherited from

Constraint.anchorB

Defined in

src/physics/constraints/constraint.ts:27

---

angle

• angle: number

Defined in

src/physics/constraints/rotarySpring.ts:22

---

b

• b: CollisionObject

Inherited from

Constraint.b

Defined in

src/physics/constraints/constraint.ts:26

---

damping

• damping: number

Defined in

src/physics/constraints/rotarySpring.ts:24

---

errorBias

• errorBias: number

Inherited from

Constraint.errorBias

Defined in

src/physics/constraints/constraint.ts:32

---

inertiaSum

• inertiaSum: number

Defined in

src/physics/constraints/rotarySpring.ts:26

---

jAcc

• jAcc: number

Defined in

src/physics/constraints/rotarySpring.ts:29

---

maxBias

• maxBias: number = Infinity

Inherited from

Constraint.maxBias

Defined in

src/physics/constraints/constraint.ts:33

---

maxForce

• maxForce: number = Infinity

Inherited from

Constraint.maxForce

Defined in

src/physics/constraints/constraint.ts:35

---

point

• point: vec2

Inherited from

Constraint.point

Defined in

src/physics/constraints/constraint.ts:30

---

rotA

• rotA: number = 0

Inherited from

Constraint.rotA

Defined in

src/physics/constraints/constraint.ts:24

---

rotB

• rotB: number = 0

Inherited from

Constraint.rotB

Defined in

src/physics/constraints/constraint.ts:28

---

stiffness

• stiffness: number

Defined in

src/physics/constraints/rotarySpring.ts:23

---

targetWrn

• targetWrn: number

Defined in

src/physics/constraints/rotarySpring.ts:27

---

wCoef

• wCoef: number

Defined in

src/physics/constraints/rotarySpring.ts:28

Methods

applyImpulses

▸ Protected applyImpulses(impulse, direction): void

Parameters

Name	Type
impulse	number
direction	vec2

Returns

void

Inherited from

Constraint.applyImpulses

Defined in

src/physics/constraints/constraint.ts:111

▸ Protected applyImpulses(impulse): void

Parameters

Name	Type
impulse	vec2

Returns

void

Inherited from

Constraint.applyImpulses

Defined in

src/physics/constraints/constraint.ts:113

---

biasCoef

▸ Protected biasCoef(dt): number

Calculates the velocity bias coefficient.

Parameters

Name	Type	Description
dt	number	The time since the last update

Returns

number

Inherited from

Constraint.biasCoef

Defined in

src/physics/constraints/constraint.ts:182

---

calcTorque

▸ Private calcTorque(): number

Calculates the torque required to correct the spring.

Returns

number

The torque required to correct the spring

Defined in

src/physics/constraints/rotarySpring.ts:140

---

calculateRelativeVelocity

▸ Protected calculateRelativeVelocity(pointA, pointB): vec2

Calculate the relative velocity of the bodies in the constraint.

Parameters

Name	Type	Description
pointA	vec2	The anchor point on body a
pointB	vec2	The anchor point on body b

Returns

vec2

The relative velocity between body a and b or body a and the anchor point

Inherited from

Constraint.calculateRelativeVelocity

Defined in

src/physics/constraints/constraint.ts:164

---

isBodyToPoint

▸ isBodyToPoint(): boolean

Determines wether or not the constraint is between a body and a point.

Returns

boolean

Wether or not the constraint is between a body and a point.

Inherited from

Constraint.isBodyToPoint

Defined in

src/physics/constraints/constraint.ts:107

---

kScalar

▸ Protected kScalar(n): number

Computes the k scalar value for the constraint.

Parameters

Name	Type	Description
n	vec2	The constraint's delta normal

Returns

number

The k scalar value for the constraint

Inherited from

Constraint.kScalar

Defined in

src/physics/constraints/constraint.ts:205

---

kScalarBody

▸ Protected kScalarBody(body, r, n): number

Computes the k scalar value for the given body.

Parameters

Name	Type	Description
body	CollisionObject	The body to calculate for
r	vec2	The anchor point on the body
n	vec2	The constraint's delta normal

Returns

number

The k scalar value for the given body

Inherited from

Constraint.kScalarBody

Defined in

src/physics/constraints/constraint.ts:194

---

kTensor

▸ Protected kTensor(): mat2

Computes the k tensor matrix for the constraint.

see Chipmunk2D kTensor

Returns

mat2

k tensor matrix

Inherited from

Constraint.kTensor

Defined in

src/physics/constraints/constraint.ts:220

---

postSolve

▸ postSolve(): void

Performs post solve operations.

Returns

void

Overrides

Constraint.postSolve

Defined in

src/physics/constraints/rotarySpring.ts:133

---

preSolve

▸ preSolve(dt): void

Prepares the spring for solving.

Parameters

Name	Type	Description
dt	number	The time since the last update

Returns

void

Overrides

Constraint.preSolve

Defined in

src/physics/constraints/rotarySpring.ts:95

---

solve

▸ solve(dt): void

Applies the spring forces to the attached bodies.

see Chipmunk2D Damped Spring

see Constraints and Solvers

Parameters

Name	Type	Description
dt	number	The time since the last update

Returns

void

Overrides

Constraint.solve

Defined in

src/physics/constraints/rotarySpring.ts:118

---

updateAnchors

▸ Protected updateAnchors(): void

Updates the constraint's anchor points to match the rotations of their bodies.

Returns

void

Inherited from

Constraint.updateAnchors

Defined in

src/physics/constraints/constraint.ts:141