Class Body

constructor

• new Body(type?: BodyType, position?: Vec2): Body

  Parameters

  • Optionaltype: BodyType

    Body type (DYNAMIC by default).

  • Optionalposition: Vec2

    Initial world-space position (defaults to origin).

  Returns Body

debugDraw

allowMovement

• get allowMovement(): boolean

  If false, translational motion is frozen (infinite effective mass).

  Returns boolean

• set allowMovement(value: boolean): void

  Parameters

  • value: boolean

  Returns void

allowRotation

• get allowRotation(): boolean

  If false, rotational motion is frozen (infinite effective inertia).

  Returns boolean

• set allowRotation(value: boolean): void

  Parameters

  • value: boolean

  Returns void

angularVel

• get angularVel(): number

  Angular velocity in radians per second.

  Returns number

• set angularVel(value: number): void

  Parameters

  • value: number

  Returns void

bounds

• get bounds(): AABB

  World-space AABB enclosing all shapes.

  Returns AABB

  Throws

  If this is the world body.

compound

• get compound(): Compound | null

  The Compound this body belongs to, or null.

  Returns Compound | null

• set compound(value: Compound | null): void

  Parameters

  • value: Compound | null

  Returns void

constraintInertia

• get constraintInertia(): number

  Effective inertia used by the constraint solver (accounts for allowRotation).

  Returns number

constraintMass

• get constraintMass(): number

  Effective mass used by the constraint solver (accounts for allowMovement).

  Returns number

constraintVelocity

• get constraintVelocity(): Vec2

  Constraint-solved velocity (read-only view used by the solver).

  Returns Vec2

disableCCD

• get disableCCD(): boolean

  If true, CCD is disabled even if isBullet is set.

  Returns boolean

• set disableCCD(value: boolean): void

  Parameters

  • value: boolean

  Returns void

force

• get force(): Vec2

  Accumulated force applied to this body for the current step (cleared after each step).

  Returns Vec2

• set force(value: Vec2): void

  Parameters

  • value: Vec2

  Returns void

gravMass

• get gravMass(): number

  Gravitational mass. Defaults to the same as mass.

  Returns number

• set gravMass(value: number): void

  Parameters

  • value: number

  Returns void

gravMassMode

• get gravMassMode(): GravMassMode

  Controls gravitational mass: DEFAULT, FIXED, or SCALED.

  Returns GravMassMode

• set gravMassMode(value: GravMassMode): void

  Parameters

  • value: GravMassMode

  Returns void

gravMassScale

• get gravMassScale(): number

  Scale factor applied to gravMass relative to the dynamic mass.

  Returns number

• set gravMassScale(value: number): void

  Parameters

  • value: number

  Returns void

inertia

• get inertia(): number

  Moment of inertia. Must be finite and > 0. Setting switches inertiaMode to FIXED.

  Returns number

  Throws

  If the body is the world body, or if no shapes are present in DEFAULT inertia mode.

• set inertia(value: number): void

  Parameters

  • value: number

  Returns void

inertiaMode

• get inertiaMode(): InertiaMode

  Controls how inertia is computed: DEFAULT or FIXED.

  Returns InertiaMode

• set inertiaMode(value: InertiaMode): void

  Parameters

  • value: InertiaMode

  Returns void

isBullet

• get isBullet(): boolean

  If true, continuous collision detection (CCD) is enabled for this body.

  Returns boolean

• set isBullet(value: boolean): void

  Parameters

  • value: boolean

  Returns void

isSleeping

• get isSleeping(): boolean

  True if the body is currently sleeping.

  Returns boolean

  Throws

  If the body is not in a Space.

kinAngVel

• get kinAngVel(): number

  Desired angular velocity for kinematic bodies.

  Returns number

• set kinAngVel(value: number): void

  Parameters

  • value: number

  Returns void

kinematicVel

• get kinematicVel(): Vec2

  Desired velocity for kinematic bodies; the engine tries to match this each step.

  Returns Vec2

• set kinematicVel(value: Vec2): void

  Parameters

  • value: Vec2

  Returns void

localCOM

• get localCOM(): Vec2

  Local-space centre of mass (read-only, lazy-computed from shapes).

  Returns Vec2

  Throws

  If this is the world body.

mass

• get mass(): number

  Mass in kg. Must be finite and > 0. Setting switches massMode to FIXED.

  Returns number

  Throws

  If the body is the world body, or if no shapes are present in DEFAULT mass mode.

• set mass(value: number): void

  Parameters

  • value: number

  Returns void

massMode

• get massMode(): MassMode

  Controls how mass is computed: DEFAULT (from shapes) or FIXED (manually set).

  Returns MassMode

• set massMode(value: MassMode): void

  Parameters

  • value: MassMode

  Returns void

position

• get position(): Vec2

  World-space position of the body's origin. Live Vec2 — mutating it moves the body.

  Returns Vec2

• set position(value: Vec2): void

  Parameters

  • value: Vec2

  Returns void

rotation

• get rotation(): number

  Rotation of the body in radians.

  Returns number

  Throws

  If set on a static body that is already in a space.

• set rotation(value: number): void

  Parameters

  • value: number

  Returns void

shapes

• get shapes(): NapeList<Shape>

  List of shapes attached to this body.

  Returns NapeList<Shape>

space

• get space(): Space

  The Space this body belongs to. Setting adds/removes it from the space.

  Returns Space

• set space(value: Space | null): void

  Parameters

  • value: Space | null

  Returns void

surfaceVel

• get surfaceVel(): Vec2

  Surface velocity used in friction calculations.

  Returns Vec2

• set surfaceVel(value: Vec2): void

  Parameters

  • value: Vec2

  Returns void

torque

• get torque(): number

  Accumulated torque applied to this body for the current step (only for DYNAMIC bodies).

  Returns number

• set torque(value: number): void

  Parameters

  • value: number

  Returns void

type

• get type(): BodyType

  The body type: DYNAMIC, STATIC, or KINEMATIC. Cannot be changed mid-step.

  Returns BodyType

• set type(value: BodyType): void

  Parameters

  • value: BodyType

  Returns void

velocity

• get velocity(): Vec2

  Linear velocity in world space (units/s). Live Vec2. Static bodies cannot have velocity.

  Returns Vec2

• set velocity(value: Vec2): void

  Parameters

  • value: Vec2

  Returns void

worldCOM

• get worldCOM(): Vec2

  World-space centre of mass (read-only, lazy-computed).

  Returns Vec2

  Throws

  If this is the world body.

align

• align(): Body

  Translate all shapes and adjust the body position so the local centre of mass coincides with the body origin.

  Returns Body

  this for chaining.

  Throws

  If the body has no shapes.

applyAngularImpulse

• applyAngularImpulse(impulse: number, sleepable?: boolean): Body

  Apply a direct angular impulse (change in angular velocity × inertia).

  Parameters

  • impulse: number

    The angular impulse magnitude.

  • sleepable: boolean = false

    If true, the body will not be woken if sleeping.

  Returns Body

  this for chaining.

applyImpulse

• applyImpulse(impulse: Vec2, pos?: Vec2, sleepable?: boolean): Body

  Apply a linear (and optionally angular) impulse to the body. If pos is given, it creates a torque about the body's centre. If sleepable is true, sleeping bodies are not woken.

  Parameters

  • impulse: Vec2

    The linear impulse vector (world space).

  • Optionalpos: Vec2

    Optional world-space point of application.

  • sleepable: boolean = false

    If true, the body will not be woken if sleeping.

  Returns Body

  this for chaining.

buoyancyImpulse

• buoyancyImpulse(body?: Body | null): Vec3

  Sum of buoyancy impulses received from fluid arbiters this step.

  Parameters

  • body: Body | null = null

    If provided, only arbiters shared with body are summed.

  Returns Vec3

  A Vec3 where x/y are the linear component and z is the angular component.

connectedBodies

• connectedBodies(depth?: number, output?: BodyList | null): BodyList

  Return the set of bodies connected to this body via constraints.

  Parameters

  • depth: number = -1

    Maximum traversal depth (-1 means unlimited).

  • output: BodyList | null = null

    Optional existing list to accumulate results into.

  Returns BodyList

  A BodyList of connected bodies.

constraintsImpulse

• constraintsImpulse(): Vec3

  Sum of impulses applied to this body by all attached constraints this step.

  Returns Vec3

  A Vec3 where x/y are the linear component and z is the angular component.

contains

• contains(point: Vec2): boolean

  Test whether a world-space point lies inside any shape attached to this body.

  Parameters

  • point: Vec2

    The point to test in world space.

  Returns boolean

  True if the point is inside at least one shape.

copy

• copy(): Body

  Create a deep copy of this body (shapes, mass properties, etc.).

  Returns Body

  A new Body with identical configuration.

  Throws

  If this is the world body.

crushFactor

• crushFactor(): number

  Compute a heuristic crush factor indicating how strongly this body is being compressed from multiple directions. A value near zero means balanced forces; larger values indicate compression.

  Returns number

  The crush factor (dimensionless).

  Throws

  If the body is not in a Space.

dragImpulse

• dragImpulse(body?: Body | null): Vec3

  Sum of fluid drag impulses received from fluid arbiters this step.

  Parameters

  • body: Body | null = null

    If provided, only arbiters shared with body are summed.

  Returns Vec3

  A Vec3 where x/y are the linear component and z is the angular component.

integrate

• integrate(deltaTime: number): Body

  Manually integrate the body's position and rotation by deltaTime seconds (outside of Space.step).

  Parameters

  • deltaTime: number

    Time in seconds to integrate over.

  Returns Body

  this for chaining.

  Throws

  If deltaTime is NaN.

interactingBodies

• interactingBodies(
      type?: InteractionType | null,
      _depth?: number,
      output?: BodyList | null,
  ): BodyList

  Return the set of bodies currently interacting with this body via arbiters.

  Parameters

  • type: InteractionType | null = null

    Filter by interaction type (COLLISION, FLUID, SENSOR), or null for all.

  • _depth: number = -1

    Unused; reserved for future use.

  • output: BodyList | null = null

    Optional existing list to accumulate results into.

  Returns BodyList

  A BodyList of interacting bodies.

isDynamic

• isDynamic(): boolean

  Return true if this body is dynamic.

  Returns boolean

isKinematic

• isKinematic(): boolean

  Return true if this body is kinematic.

  Returns boolean

isStatic

• isStatic(): boolean

  Return true if this body is static.

  Returns boolean

localPointToWorld

• localPointToWorld(point: Vec2, weak?: boolean): Vec2

  Transform a point from local body space to world space.

  Parameters

  • point: Vec2

    The point in local space.

  • weak: boolean = false

    If true, the returned Vec2 is a weak (pooled) reference.

  Returns Vec2

  The transformed point in world space.

localVectorToWorld

• localVectorToWorld(vector: Vec2, weak?: boolean): Vec2

  Rotate a vector from local body space to world space (no translation).

  Parameters

  • vector: Vec2

    The vector in local space.

  • weak: boolean = false

    If true, the returned Vec2 is a weak (pooled) reference.

  Returns Vec2

  The rotated vector in world space.

normalImpulse

• normalImpulse(body?: Body | null, freshOnly?: boolean): Vec3

  Sum of normal (penetration-resolving) impulses received from collision arbiters this step.

  Parameters

  • body: Body | null = null

    If provided, only arbiters shared with body are summed.

  • freshOnly: boolean = false

    If true, only newly created arbiters are considered.

  Returns Vec3

  A Vec3 where x/y are the linear component and z is the angular component.

rollingImpulse

• rollingImpulse(body?: Body | null, freshOnly?: boolean): number

  Sum of rolling (angular friction) impulses from collision arbiters this step.

  Parameters

  • body: Body | null = null

    If provided, only arbiters shared with body are summed.

  • freshOnly: boolean = false

    If true, only newly created arbiters are considered.

  Returns number

  The total rolling impulse scalar.

rotate

• rotate(centre: Vec2, angle: number): Body

  Rotate the body about a world-space pivot point by angle radians. Moves the body's position and increments its rotation.

  Parameters

  • centre: Vec2

    World-space pivot point.

  • angle: number

    Rotation in radians.

  Returns Body

  this for chaining.

  Throws

  If centre is null or angle is NaN.

rotateShapes

• rotateShapes(angle: number): Body

  Rotate all shapes attached to this body in local space by angle radians.

  Parameters

  • angle: number

    Rotation in radians.

  Returns Body

  this for chaining.

scaleShapes

• scaleShapes(scaleX: number, scaleY: number): Body

  Scale all shapes attached to this body in local space.

  Parameters

  • scaleX: number

    Horizontal scale factor.

  • scaleY: number

    Vertical scale factor.

  Returns Body

  this for chaining.

setShapeFilters

• setShapeFilters(filter: InteractionFilter): Body

  Set the same InteractionFilter on every shape attached to this body.

  Parameters

  • filter: InteractionFilter

    The interaction filter to apply.

  Returns Body

  this for chaining.

setShapeFluidProperties

• setShapeFluidProperties(fluidProperties: FluidProperties): Body

  Set the same FluidProperties on every shape attached to this body.

  Parameters

  • fluidProperties: FluidProperties

    The fluid properties to apply.

  Returns Body

  this for chaining.

setShapeMaterials

• setShapeMaterials(material: Material): Body

  Set the same Material on every shape attached to this body.

  Parameters

  • material: Material

    The material to apply.

  Returns Body

  this for chaining.

setVelocityFromTarget

• setVelocityFromTarget(
      targetPosition: Vec2,
      targetRotation: number,
      deltaTime: number,
  ): Body

  Set linear and angular velocity so the body reaches the given target pose in deltaTime seconds. Useful for kinematic or manually driven bodies.

  Parameters

  • targetPosition: Vec2

    Desired world-space position.

  • targetRotation: number

    Desired rotation in radians.

  • deltaTime: number

    Time in seconds over which to reach the target.

  Returns Body

  this for chaining.

  Throws

  If targetPosition is null or deltaTime is zero.

tangentImpulse

• tangentImpulse(body?: Body | null, freshOnly?: boolean): Vec3

  Sum of tangent (friction) impulses received from collision arbiters this step.

  Parameters

  • body: Body | null = null

    If provided, only arbiters shared with body are summed.

  • freshOnly: boolean = false

    If true, only newly created arbiters are considered.

  Returns Vec3

  A Vec3 where x/y are the linear component and z is the angular component.

toString

• toString(): string

  String identifier like (dynamic)#42.

  Returns string

  A human-readable description of this body.

totalContactsImpulse

• totalContactsImpulse(body?: Body | null, freshOnly?: boolean): Vec3

  Sum of total contact impulses (normal + tangent) from collision arbiters this step.

  Parameters

  • body: Body | null = null

    If provided, only arbiters shared with body are summed.

  • freshOnly: boolean = false

    If true, only newly created arbiters are considered.

  Returns Vec3

  A Vec3 where x/y are the linear component and z is the angular component.

totalFluidImpulse

• totalFluidImpulse(body?: Body | null): Vec3

  Sum of total fluid impulses (buoyancy + drag) from fluid arbiters this step.

  Parameters

  • body: Body | null = null

    If provided, only arbiters shared with body are summed.

  Returns Vec3

  A Vec3 where x/y are the linear component and z is the angular component.

totalImpulse

• totalImpulse(body?: Body | null, freshOnly?: boolean): Vec3

  Sum of all impulses (contacts + constraints) applied to this body this step, excluding sensor arbiters.

  Parameters

  • body: Body | null = null

    If provided, only arbiters shared with body are summed.

  • freshOnly: boolean = false

    If true, only newly created contact arbiters are considered.

  Returns Vec3

  A Vec3 where x/y are the linear component and z is the angular component.

transformShapes

• transformShapes(matrix: Mat23): Body

  Apply an affine transform matrix to all shapes in local space.

  Parameters

  • matrix: Mat23

    The 2D affine transformation matrix.

  Returns Body

  this for chaining.

translateShapes

• translateShapes(translation: Vec2): Body

  Translate all shapes attached to this body in local space by translation.

  Parameters

  • translation: Vec2

    Offset vector in local space.

  Returns Body

  this for chaining.

worldPointToLocal

• worldPointToLocal(point: Vec2, weak?: boolean): Vec2

  Transform a point from world space to local body space.

  Parameters

  • point: Vec2

    The point in world space.

  • weak: boolean = false

    If true, the returned Vec2 is a weak (pooled) reference.

  Returns Vec2

  The transformed point in local space.

worldVectorToLocal

• worldVectorToLocal(vector: Vec2, weak?: boolean): Vec2

  Rotate a vector from world space to local body space (no translation).

  Parameters

  • vector: Vec2

    The vector in world space.

  • weak: boolean = false

    If true, the returned Vec2 is a weak (pooled) reference.

  Returns Vec2

  The rotated vector in local space.