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 An opaque handle to a chain of connected segment shapes attached to a b2Body. Create one with b2d.body.create_chain, use the functions in b2d.chain to inspect or configure it, and release it with b2d.chain.destroy. Destroying its body also destroys the chain.

Parameters

• value (userdata) - Box2D chain handle

Examples

local body = b2d.get_body("#collisionobject")
local chain = b2d.body.create_chain(body, {
    vertices = {
        vmath.vector3(-64, 0, 0),
        vmath.vector3(0, 16, 0),
        vmath.vector3(64, 0, 0),
    },
})
print(b2d.chain.get_segment_count(chain))

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 Get the chain geometry.

Parameters

• chain (b2Chain) - chain

Returns

• geometry (b2d.chain_geometry) - chain geometry

b2d.chain.get_material

Type: FUNCTION Get chain material id.

Parameters

• chain (b2Chain) - chain

Returns

• material (integer) - 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 (integer) - segment count

b2d.chain.get_segments

Type: FUNCTION Get the segment shapes owned by a chain.

Parameters

• chain (b2Chain) - chain

Returns

• segments (b2d.shape_info[]) - chain segment shapes

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 (integer) - chain material id

b2d.chain.set_restitution

Type: FUNCTION Set chain restitution.

Parameters

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