b2d.chain

Namespace: b2d.chain Language: Lua Type: Defold Lua File: script_box2d_chain_v3.cpp Source: engine/gamesys/src/gamesys/scripts/box2d/v3/script_box2d_chain_v3.cpp

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

API

b2Chain

Type: TYPEDEF Box2D chain

Parameters

• value (userdata)

b2d.chain.destroy

Type: FUNCTION 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

Type: FUNCTION 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

Type: FUNCTION Get chain friction.

Parameters

• chain (b2Chain) - chain

Returns

• friction (number) - chain friction

b2d.chain.get_geometry

Type: FUNCTION 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

Type: FUNCTION Get chain material id.

Parameters

• chain (b2Chain) - chain

Returns

• material (number) - chain material id

b2d.chain.get_restitution

Type: FUNCTION Get chain restitution.

Parameters

• chain (b2Chain) - chain

Returns

• restitution (number) - chain restitution

b2d.chain.get_segment_count

Type: FUNCTION Get the number of segment shapes in a chain.

Parameters

• chain (b2Chain) - chain

Returns

• count (number) - segment count

b2d.chain.get_segments

Type: FUNCTION 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

Type: FUNCTION Get the world owning a chain.

Parameters

• chain (b2Chain) - chain

Returns

• world (b2World) - owning world

b2d.chain.is_valid

Type: FUNCTION 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

Type: FUNCTION Set chain friction.

Parameters

• chain (b2Chain) - chain
• friction (number) - chain friction

b2d.chain.set_material

Type: FUNCTION Set chain material id.

Parameters

• chain (b2Chain) - chain
• material (number) - chain material id

b2d.chain.set_restitution

Type: FUNCTION Set chain restitution.

Parameters

• chain (b2Chain) - chain
• restitution (number) - chain restitution