Box2D b2Chain documentation

Functions for Box2D v3 chains. A chain owns multiple connected segment shapes, so it is represented by a separate b2Chain handle.

Version: beta

FUNCTIONS
b2d.chain.destroy()	Destroy a chain.
b2d.chain.from_shape()	Get the parent chain for a chain segment shape.
b2d.chain.get_friction()	Get chain friction.
b2d.chain.get_geometry()	Get the chain geometry.
b2d.chain.get_material()	Get chain material id.
b2d.chain.get_restitution()	Get chain restitution.
b2d.chain.get_segment_count()	Get the number of segment shapes in a chain.
b2d.chain.get_segments()	Get the segment shapes owned by a chain.
b2d.chain.get_world()	Get the world owning a chain.
b2d.chain.is_valid()	Validate a chain handle.
b2d.chain.set_friction()	Set chain friction.
b2d.chain.set_material()	Set chain material id.
b2d.chain.set_restitution()	Set chain restitution.

Functions

b2d.chain.destroy()

b2d.chain.destroy(chain)

Destroying a chain removes all segment shapes owned by the chain. Destroying any segment shape through b2d.body.destroy_shape also destroys its parent chain.

PARAMETERS

chain b2Chain chain

b2d.chain.from_shape()

b2d.chain.from_shape(shape_id)

Returns nil if the shape is not a chain segment.

PARAMETERS

shape_id b2Shape shape handle from a shape info table, or pass body, shape_index

RETURNS

chain b2Chain
nil parent chain, or nil if the shape is not a chain segment

b2d.chain.get_friction()

b2d.chain.get_friction(chain)

Get chain friction.

PARAMETERS

chain b2Chain chain

RETURNS

friction number chain friction

b2d.chain.get_geometry()

b2d.chain.get_geometry(chain)

Returns a chain geometry table with loop, segment_count, and vertices. Open chains also include prev_vertex and next_vertex ghost vertices.

PARAMETERS

chain b2Chain chain

RETURNS

geometry table chain geometry table

b2d.chain.get_material()

b2d.chain.get_material(chain)

Get chain material id.

PARAMETERS

chain b2Chain chain

RETURNS

material number chain material id

b2d.chain.get_restitution()

b2d.chain.get_restitution(chain)

Get chain restitution.

PARAMETERS

chain b2Chain chain

RETURNS

restitution number chain restitution

b2d.chain.get_segment_count()

b2d.chain.get_segment_count(chain)

Get the number of segment shapes in a chain.

PARAMETERS

chain b2Chain chain

RETURNS

count number segment count

b2d.chain.get_segments()

b2d.chain.get_segments(chain)

Get the segment shapes owned by a chain.

PARAMETERS

chain b2Chain chain

RETURNS

segments table array of shape info tables for the chain segments. Each entry includes shape_id.

b2d.chain.get_world()

b2d.chain.get_world(chain)

Get the world owning a chain.

PARAMETERS

chain b2Chain chain

RETURNS

world b2World owning world

b2d.chain.is_valid()

b2d.chain.is_valid(chain)

Validate a chain handle.

PARAMETERS

chain b2Chain chain

RETURNS

valid boolean true if the chain handle still refers to a live Box2D chain

b2d.chain.set_friction()

b2d.chain.set_friction(chain,friction)

Set chain friction.

PARAMETERS

`chain`	`b2Chain`	chain
`friction`	`number`	chain friction

b2d.chain.set_material()

b2d.chain.set_material(chain,material)

Set chain material id.

PARAMETERS

`chain`	`b2Chain`	chain
`material`	`number`	chain material id

b2d.chain.set_restitution()

b2d.chain.set_restitution(chain,restitution)

Set chain restitution.

PARAMETERS

`chain`	`b2Chain`	chain
`restitution`	`number`	chain restitution