# b2d.joint **Namespace:** `b2d.joint` **Language:** Lua **Type:** Defold Lua **File:** `script_box2d_joint_v2.cpp` **Source:** `engine/gamesys/src/gamesys/scripts/box2d/v2/script_box2d_joint_v2.cpp` Functions for interacting with native Box2D joints. ## API ### b2d.joint.create_distance *Type:* FUNCTION Create a distance joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, length, frequency, damping_ratio, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_distance *Type:* FUNCTION Create a distance joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, length, min_length, max_length, enable_spring, hertz or frequency, damping_ratio, enable_limit, enable_motor, max_motor_force, motor_speed, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_filter *Type:* FUNCTION Create a filter joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition table **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_friction *Type:* FUNCTION Create a friction joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, max_force, max_torque, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_gear *Type:* FUNCTION Create a gear joint. **Parameters** - `joint1` (b2Joint) - first revolute or prismatic joint - `joint2` (b2Joint) - second revolute or prismatic joint - `definition` (table) - optional definition with ratio **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_motor *Type:* FUNCTION Create a motor joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with linear_offset, angular_offset, max_force, max_torque, correction_factor, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_mouse *Type:* FUNCTION Create a mouse joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with target, max_force, frequency, damping_ratio, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_mouse *Type:* FUNCTION Create a mouse joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with target, hertz or frequency, damping_ratio, max_force, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_prismatic *Type:* FUNCTION Create a prismatic joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, local_axis_a, reference_angle, enable_limit, lower_translation, upper_translation, enable_motor, max_motor_force, motor_speed, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_prismatic *Type:* FUNCTION Create a prismatic joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, local_axis_a, reference_angle, enable_spring, hertz or frequency, damping_ratio, enable_limit, lower_translation, upper_translation, enable_motor, max_motor_force, motor_speed, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_pulley *Type:* FUNCTION Create a pulley joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with ground_anchor_a, ground_anchor_b, local_anchor_a, local_anchor_b, length_a, length_b, ratio, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_revolute *Type:* FUNCTION Create a revolute joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, reference_angle, enable_limit, lower_angle, upper_angle, enable_motor, max_motor_torque, motor_speed, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_revolute *Type:* FUNCTION Create a revolute joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, reference_angle, enable_spring, hertz or frequency, damping_ratio, enable_limit, lower_angle, upper_angle, enable_motor, max_motor_torque, motor_speed, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_rope *Type:* FUNCTION Create a rope joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, max_length, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_weld *Type:* FUNCTION Create a weld joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, reference_angle, frequency, damping_ratio, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_weld *Type:* FUNCTION Create a weld joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, reference_angle, linear_hertz, angular_hertz, linear_damping_ratio, angular_damping_ratio, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_wheel *Type:* FUNCTION Create a wheel joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, local_axis_a, enable_motor, max_motor_torque, motor_speed, frequency, damping_ratio, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.create_wheel *Type:* FUNCTION Create a wheel joint. **Parameters** - `body_a` (b2Body) - first body - `body_b` (b2Body) - second body - `definition` (table) - optional definition with local_anchor_a, local_anchor_b, local_axis_a, enable_spring, hertz or frequency, damping_ratio, enable_limit, lower_translation, upper_translation, enable_motor, max_motor_torque, motor_speed, and collide_connected **Returns** - `joint` (b2Joint) - created joint ### b2d.joint.destroy *Type:* FUNCTION Destroy a joint created by b2d.joint. **Parameters** - `joint` (b2Joint) - joint ### b2d.joint.destroy *Type:* FUNCTION Destroy a joint created by b2d.joint. **Parameters** - `joint` (b2Joint) - joint ### b2d.joint.enable_limit *Type:* FUNCTION Enable or disable joint limits. **Parameters** - `joint` (b2Joint) - prismatic or revolute joint - `enable` (boolean) - true to enable limits ### b2d.joint.enable_limit *Type:* FUNCTION Enable or disable joint limits. **Parameters** - `joint` (b2Joint) - distance, prismatic, revolute, or wheel joint - `enable` (boolean) - true to enable limits ### b2d.joint.enable_motor *Type:* FUNCTION Enable or disable the joint motor. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or wheel joint - `enable` (boolean) - true to enable the motor ### b2d.joint.enable_motor *Type:* FUNCTION Enable or disable the joint motor. **Parameters** - `joint` (b2Joint) - distance, prismatic, revolute, or wheel joint - `enable` (boolean) - true to enable the motor ### b2d.joint.enable_spring *Type:* FUNCTION Enable or disable joint spring behavior. **Parameters** - `joint` (b2Joint) - distance, prismatic, revolute, or wheel joint - `enable` (boolean) - true to enable the spring ### b2d.joint.get_anchor_a *Type:* FUNCTION Get the world anchor on body A. **Parameters** - `joint` (b2Joint) - joint **Returns** - `anchor` (vector3) - world anchor ### b2d.joint.get_anchor_a *Type:* FUNCTION Get the world anchor on body A. **Parameters** - `joint` (b2Joint) - joint **Returns** - `anchor` (vector3) - world anchor ### b2d.joint.get_anchor_b *Type:* FUNCTION Get the world anchor on body B. **Parameters** - `joint` (b2Joint) - joint **Returns** - `anchor` (vector3) - world anchor ### b2d.joint.get_anchor_b *Type:* FUNCTION Get the world anchor on body B. **Parameters** - `joint` (b2Joint) - joint **Returns** - `anchor` (vector3) - world anchor ### b2d.joint.get_angular_damping_ratio *Type:* FUNCTION Get weld joint angular damping ratio. **Parameters** - `joint` (b2Joint) - weld joint **Returns** - `ratio` (number) - damping ratio ### b2d.joint.get_angular_hertz *Type:* FUNCTION Get weld joint angular frequency. **Parameters** - `joint` (b2Joint) - weld joint **Returns** - `hertz` (number) - frequency in hertz ### b2d.joint.get_angular_offset *Type:* FUNCTION Get motor joint angular offset. **Parameters** - `joint` (b2Joint) - motor joint **Returns** - `offset` (number) - angular offset in radians ### b2d.joint.get_body_a *Type:* FUNCTION Get the first body connected to a joint. **Parameters** - `joint` (b2Joint) - joint **Returns** - `body` (b2Body) - body A ### b2d.joint.get_body_a *Type:* FUNCTION Get the first body connected to a joint. **Parameters** - `joint` (b2Joint) - joint **Returns** - `body` (b2Body) - body A ### b2d.joint.get_body_b *Type:* FUNCTION Get the second body connected to a joint. **Parameters** - `joint` (b2Joint) - joint **Returns** - `body` (b2Body) - body B ### b2d.joint.get_body_b *Type:* FUNCTION Get the second body connected to a joint. **Parameters** - `joint` (b2Joint) - joint **Returns** - `body` (b2Body) - body B ### b2d.joint.get_collide_connected *Type:* FUNCTION Get whether connected bodies can collide. **Parameters** - `joint` (b2Joint) - joint **Returns** - `collide` (boolean) - true if connected bodies can collide ### b2d.joint.get_collide_connected *Type:* FUNCTION Get whether connected bodies can collide. **Parameters** - `joint` (b2Joint) - joint **Returns** - `collide` (boolean) - true if connected bodies can collide ### b2d.joint.get_correction_factor *Type:* FUNCTION Get motor joint correction factor. **Parameters** - `joint` (b2Joint) - motor joint **Returns** - `factor` (number) - correction factor ### b2d.joint.get_current_length *Type:* FUNCTION Get the current distance joint length. **Parameters** - `joint` (b2Joint) - distance joint **Returns** - `length` (number) - current length in project units ### b2d.joint.get_damping_ratio *Type:* FUNCTION Get spring damping ratio. **Parameters** - `joint` (b2Joint) - distance, mouse, weld, or wheel joint **Returns** - `ratio` (number) - damping ratio ### b2d.joint.get_damping_ratio *Type:* FUNCTION Alias for b2d.joint.get_spring_damping_ratio. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint **Returns** - `ratio` (number) - damping ratio ### b2d.joint.get_frequency *Type:* FUNCTION Get spring frequency. **Parameters** - `joint` (b2Joint) - distance, mouse, weld, or wheel joint **Returns** - `frequency` (number) - frequency in hertz ### b2d.joint.get_frequency *Type:* FUNCTION Alias for b2d.joint.get_spring_hertz. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint **Returns** - `frequency` (number) - frequency in hertz ### b2d.joint.get_ground_anchor_a *Type:* FUNCTION Get pulley ground anchor A. **Parameters** - `joint` (b2Joint) - pulley joint **Returns** - `anchor` (vector3) - world anchor ### b2d.joint.get_ground_anchor_b *Type:* FUNCTION Get pulley ground anchor B. **Parameters** - `joint` (b2Joint) - pulley joint **Returns** - `anchor` (vector3) - world anchor ### b2d.joint.get_hertz *Type:* FUNCTION Alias for b2d.joint.get_frequency. **Parameters** - `joint` (b2Joint) - distance, mouse, weld, or wheel joint **Returns** - `hertz` (number) - frequency in hertz ### b2d.joint.get_hertz *Type:* FUNCTION Alias for b2d.joint.get_spring_hertz. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint **Returns** - `hertz` (number) - frequency in hertz ### b2d.joint.get_joint1 *Type:* FUNCTION Get the first joint connected to a gear joint. **Parameters** - `joint` (b2Joint) - gear joint **Returns** - `joint1` (b2Joint) - first connected joint ### b2d.joint.get_joint2 *Type:* FUNCTION Get the second joint connected to a gear joint. **Parameters** - `joint` (b2Joint) - gear joint **Returns** - `joint2` (b2Joint) - second connected joint ### b2d.joint.get_joint_angle *Type:* FUNCTION Get revolute joint angle. **Parameters** - `joint` (b2Joint) - revolute joint **Returns** - `angle` (number) - angle in radians ### b2d.joint.get_joint_angle *Type:* FUNCTION Get revolute joint angle. **Parameters** - `joint` (b2Joint) - revolute joint **Returns** - `angle` (number) - angle in radians ### b2d.joint.get_joint_speed *Type:* FUNCTION Get joint speed. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or wheel joint **Returns** - `speed` (number) - joint speed ### b2d.joint.get_joint_speed *Type:* FUNCTION Get joint speed. **Parameters** - `joint` (b2Joint) - prismatic joint **Returns** - `speed` (number) - joint speed ### b2d.joint.get_joint_translation *Type:* FUNCTION Get joint translation. **Parameters** - `joint` (b2Joint) - prismatic or wheel joint **Returns** - `translation` (number) - translation in project units ### b2d.joint.get_joint_translation *Type:* FUNCTION Get joint translation. **Parameters** - `joint` (b2Joint) - prismatic joint **Returns** - `translation` (number) - translation in project units ### b2d.joint.get_length *Type:* FUNCTION Get the distance joint length. **Parameters** - `joint` (b2Joint) - distance joint **Returns** - `length` (number) - length in project units ### b2d.joint.get_length *Type:* FUNCTION Get the distance joint length. **Parameters** - `joint` (b2Joint) - distance joint **Returns** - `length` (number) - length in project units ### b2d.joint.get_length_a *Type:* FUNCTION Get pulley segment length A. **Parameters** - `joint` (b2Joint) - pulley joint **Returns** - `length` (number) - length in project units ### b2d.joint.get_length_b *Type:* FUNCTION Get pulley segment length B. **Parameters** - `joint` (b2Joint) - pulley joint **Returns** - `length` (number) - length in project units ### b2d.joint.get_limit_state *Type:* FUNCTION Get rope limit state. **Parameters** - `joint` (b2Joint) - rope joint **Returns** - `state` (number) - one of the LIMIT_STATE_* constants ### b2d.joint.get_linear_damping_ratio *Type:* FUNCTION Get weld joint linear damping ratio. **Parameters** - `joint` (b2Joint) - weld joint **Returns** - `ratio` (number) - damping ratio ### b2d.joint.get_linear_hertz *Type:* FUNCTION Get weld joint linear frequency. **Parameters** - `joint` (b2Joint) - weld joint **Returns** - `hertz` (number) - frequency in hertz ### b2d.joint.get_linear_offset *Type:* FUNCTION Get motor joint linear offset. **Parameters** - `joint` (b2Joint) - motor joint **Returns** - `offset` (vector3) - linear offset in project units ### b2d.joint.get_local_anchor_a *Type:* FUNCTION Get the local anchor on body A. **Parameters** - `joint` (b2Joint) - joint **Returns** - `anchor` (vector3) - local anchor ### b2d.joint.get_local_anchor_a *Type:* FUNCTION Get the local anchor on body A. **Parameters** - `joint` (b2Joint) - joint **Returns** - `anchor` (vector3) - local anchor ### b2d.joint.get_local_anchor_b *Type:* FUNCTION Get the local anchor on body B. **Parameters** - `joint` (b2Joint) - joint **Returns** - `anchor` (vector3) - local anchor ### b2d.joint.get_local_anchor_b *Type:* FUNCTION Get the local anchor on body B. **Parameters** - `joint` (b2Joint) - joint **Returns** - `anchor` (vector3) - local anchor ### b2d.joint.get_local_axis_a *Type:* FUNCTION Get the local axis on body A. **Parameters** - `joint` (b2Joint) - prismatic or wheel joint **Returns** - `axis` (vector3) - local axis ### b2d.joint.get_lower_limit *Type:* FUNCTION Get the lower joint limit. **Parameters** - `joint` (b2Joint) - prismatic or revolute joint **Returns** - `lower` (number) - lower limit ### b2d.joint.get_lower_limit *Type:* FUNCTION Get the lower joint limit. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or wheel joint **Returns** - `lower` (number) - lower limit ### b2d.joint.get_max_force *Type:* FUNCTION Get maximum force. **Parameters** - `joint` (b2Joint) - mouse or friction joint **Returns** - `force` (number) - maximum force ### b2d.joint.get_max_force *Type:* FUNCTION Get maximum force. **Parameters** - `joint` (b2Joint) - mouse or motor joint **Returns** - `force` (number) - maximum force ### b2d.joint.get_max_length *Type:* FUNCTION Get rope maximum length. **Parameters** - `joint` (b2Joint) - rope joint **Returns** - `length` (number) - maximum length in project units ### b2d.joint.get_max_length *Type:* FUNCTION Get the distance joint maximum length. **Parameters** - `joint` (b2Joint) - distance joint **Returns** - `length` (number) - maximum length in project units ### b2d.joint.get_max_motor_force *Type:* FUNCTION Get maximum motor force. **Parameters** - `joint` (b2Joint) - prismatic joint **Returns** - `force` (number) - maximum motor force ### b2d.joint.get_max_motor_force *Type:* FUNCTION Get maximum motor force. **Parameters** - `joint` (b2Joint) - distance or prismatic joint **Returns** - `force` (number) - maximum motor force ### b2d.joint.get_max_motor_torque *Type:* FUNCTION Get maximum motor torque. **Parameters** - `joint` (b2Joint) - revolute or wheel joint **Returns** - `torque` (number) - maximum motor torque ### b2d.joint.get_max_motor_torque *Type:* FUNCTION Get maximum motor torque. **Parameters** - `joint` (b2Joint) - revolute or wheel joint **Returns** - `torque` (number) - maximum motor torque ### b2d.joint.get_max_torque *Type:* FUNCTION Get maximum torque. **Parameters** - `joint` (b2Joint) - friction joint **Returns** - `torque` (number) - maximum torque ### b2d.joint.get_max_torque *Type:* FUNCTION Get maximum torque. **Parameters** - `joint` (b2Joint) - motor joint **Returns** - `torque` (number) - maximum torque ### b2d.joint.get_min_length *Type:* FUNCTION Get the distance joint minimum length. **Parameters** - `joint` (b2Joint) - distance joint **Returns** - `length` (number) - minimum length in project units ### b2d.joint.get_motor_force *Type:* FUNCTION Get current motor force. **Parameters** - `joint` (b2Joint) - prismatic joint - `inv_dt` (number) - inverse time step **Returns** - `force` (number) - motor force ### b2d.joint.get_motor_force *Type:* FUNCTION Get current motor force. **Parameters** - `joint` (b2Joint) - distance or prismatic joint **Returns** - `force` (number) - motor force ### b2d.joint.get_motor_speed *Type:* FUNCTION Get motor speed. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or wheel joint **Returns** - `speed` (number) - motor speed ### b2d.joint.get_motor_speed *Type:* FUNCTION Get motor speed. **Parameters** - `joint` (b2Joint) - distance, prismatic, revolute, or wheel joint **Returns** - `speed` (number) - motor speed ### b2d.joint.get_motor_torque *Type:* FUNCTION Get current motor torque. **Parameters** - `joint` (b2Joint) - revolute or wheel joint - `inv_dt` (number) - inverse time step **Returns** - `torque` (number) - motor torque ### b2d.joint.get_motor_torque *Type:* FUNCTION Get current motor torque. **Parameters** - `joint` (b2Joint) - revolute or wheel joint **Returns** - `torque` (number) - motor torque ### b2d.joint.get_mouse_target *Type:* FUNCTION Get the target for a mouse joint. **Parameters** - `joint` (b2Joint) - mouse joint **Returns** - `target` (vector3) - world target ### b2d.joint.get_mouse_target *Type:* FUNCTION Get the target for a mouse joint. **Parameters** - `joint` (b2Joint) - mouse joint **Returns** - `target` (vector3) - world target ### b2d.joint.get_ratio *Type:* FUNCTION Get joint ratio. **Parameters** - `joint` (b2Joint) - pulley or gear joint **Returns** - `ratio` (number) - joint ratio ### b2d.joint.get_reaction_force *Type:* FUNCTION Get reaction force. **Parameters** - `joint` (b2Joint) - joint - `inv_dt` (number) - inverse time step **Returns** - `force` (vector3) - reaction force ### b2d.joint.get_reaction_force *Type:* FUNCTION Get reaction force. **Parameters** - `joint` (b2Joint) - joint **Returns** - `force` (vector3) - reaction force ### b2d.joint.get_reaction_torque *Type:* FUNCTION Get reaction torque. **Parameters** - `joint` (b2Joint) - joint - `inv_dt` (number) - inverse time step **Returns** - `torque` (number) - reaction torque ### b2d.joint.get_reaction_torque *Type:* FUNCTION Get reaction torque. **Parameters** - `joint` (b2Joint) - joint **Returns** - `torque` (number) - reaction torque ### b2d.joint.get_reference_angle *Type:* FUNCTION Get the reference angle. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or weld joint **Returns** - `angle` (number) - reference angle in radians ### b2d.joint.get_reference_angle *Type:* FUNCTION Get weld joint reference angle. **Parameters** - `joint` (b2Joint) - weld joint **Returns** - `angle` (number) - reference angle in radians ### b2d.joint.get_spring_damping_ratio *Type:* FUNCTION Alias for b2d.joint.get_damping_ratio. **Parameters** - `joint` (b2Joint) - distance, mouse, weld, or wheel joint **Returns** - `ratio` (number) - damping ratio ### b2d.joint.get_spring_damping_ratio *Type:* FUNCTION Get spring damping ratio. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint **Returns** - `ratio` (number) - damping ratio ### b2d.joint.get_spring_hertz *Type:* FUNCTION Get spring frequency. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint **Returns** - `hertz` (number) - frequency in hertz ### b2d.joint.get_type *Type:* FUNCTION Get the joint type. **Parameters** - `joint` (b2Joint) - joint **Returns** - `type` (number) - one of the JOINT_TYPE_* constants ### b2d.joint.get_type *Type:* FUNCTION Get the joint type. **Parameters** - `joint` (b2Joint) - joint **Returns** - `type` (number) - one of the JOINT_TYPE_* constants ### b2d.joint.get_upper_limit *Type:* FUNCTION Get the upper joint limit. **Parameters** - `joint` (b2Joint) - prismatic or revolute joint **Returns** - `upper` (number) - upper limit ### b2d.joint.get_upper_limit *Type:* FUNCTION Get the upper joint limit. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or wheel joint **Returns** - `upper` (number) - upper limit ### b2d.joint.get_world *Type:* FUNCTION Get the world owning a joint. **Parameters** - `joint` (b2Joint) - joint **Returns** - `world` (b2World) - owning world ### b2d.joint.is_active *Type:* FUNCTION Get whether the joint is active. **Parameters** - `joint` (b2Joint) - joint **Returns** - `active` (boolean) - true if the joint is active ### b2d.joint.is_limit_enabled *Type:* FUNCTION Get whether joint limits are enabled. **Parameters** - `joint` (b2Joint) - prismatic or revolute joint **Returns** - `enabled` (boolean) - true if limits are enabled ### b2d.joint.is_limit_enabled *Type:* FUNCTION Get whether joint limits are enabled. **Parameters** - `joint` (b2Joint) - distance, prismatic, revolute, or wheel joint **Returns** - `enabled` (boolean) - true if limits are enabled ### b2d.joint.is_motor_enabled *Type:* FUNCTION Get whether the joint motor is enabled. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or wheel joint **Returns** - `enabled` (boolean) - true if the motor is enabled ### b2d.joint.is_motor_enabled *Type:* FUNCTION Get whether the joint motor is enabled. **Parameters** - `joint` (b2Joint) - distance, prismatic, revolute, or wheel joint **Returns** - `enabled` (boolean) - true if the motor is enabled ### b2d.joint.is_spring_enabled *Type:* FUNCTION Get whether joint spring behavior is enabled. **Parameters** - `joint` (b2Joint) - distance, prismatic, revolute, or wheel joint **Returns** - `enabled` (boolean) - true if the spring is enabled ### b2d.joint.is_valid *Type:* FUNCTION Validate a joint handle. **Parameters** - `joint` (b2Joint) - joint **Returns** - `valid` (boolean) - true if the joint handle still refers to a live Box2D joint ### b2d.joint.JOINT_TYPE_DISTANCE *Type:* CONSTANT Distance joint type. ### b2d.joint.JOINT_TYPE_DISTANCE *Type:* CONSTANT Distance joint type. ### b2d.joint.JOINT_TYPE_FILTER *Type:* CONSTANT Filter joint type. ### b2d.joint.JOINT_TYPE_FRICTION *Type:* CONSTANT Friction joint type. ### b2d.joint.JOINT_TYPE_GEAR *Type:* CONSTANT Gear joint type. ### b2d.joint.JOINT_TYPE_MOTOR *Type:* CONSTANT Motor joint type. ### b2d.joint.JOINT_TYPE_MOUSE *Type:* CONSTANT Mouse joint type. ### b2d.joint.JOINT_TYPE_MOUSE *Type:* CONSTANT Mouse joint type. ### b2d.joint.JOINT_TYPE_PRISMATIC *Type:* CONSTANT Prismatic joint type. ### b2d.joint.JOINT_TYPE_PRISMATIC *Type:* CONSTANT Prismatic joint type. ### b2d.joint.JOINT_TYPE_PULLEY *Type:* CONSTANT Pulley joint type. ### b2d.joint.JOINT_TYPE_REVOLUTE *Type:* CONSTANT Revolute joint type. ### b2d.joint.JOINT_TYPE_REVOLUTE *Type:* CONSTANT Revolute joint type. ### b2d.joint.JOINT_TYPE_ROPE *Type:* CONSTANT Rope joint type. ### b2d.joint.JOINT_TYPE_UNKNOWN *Type:* CONSTANT Unknown joint type. ### b2d.joint.JOINT_TYPE_WELD *Type:* CONSTANT Weld joint type. ### b2d.joint.JOINT_TYPE_WELD *Type:* CONSTANT Weld joint type. ### b2d.joint.JOINT_TYPE_WHEEL *Type:* CONSTANT Wheel joint type. ### b2d.joint.JOINT_TYPE_WHEEL *Type:* CONSTANT Wheel joint type. ### b2d.joint.LIMIT_STATE_AT_LOWER *Type:* CONSTANT At lower limit state. ### b2d.joint.LIMIT_STATE_AT_UPPER *Type:* CONSTANT At upper limit state. ### b2d.joint.LIMIT_STATE_EQUAL *Type:* CONSTANT Equal limits state. ### b2d.joint.LIMIT_STATE_INACTIVE *Type:* CONSTANT Inactive limit state. ### b2d.joint.set_angular_damping_ratio *Type:* FUNCTION Set weld joint angular damping ratio. **Parameters** - `joint` (b2Joint) - weld joint - `ratio` (number) - damping ratio ### b2d.joint.set_angular_hertz *Type:* FUNCTION Set weld joint angular frequency. **Parameters** - `joint` (b2Joint) - weld joint - `hertz` (number) - frequency in hertz ### b2d.joint.set_angular_offset *Type:* FUNCTION Set motor joint angular offset. **Parameters** - `joint` (b2Joint) - motor joint - `offset` (number) - angular offset in radians ### b2d.joint.set_collide_connected *Type:* FUNCTION Set whether connected bodies can collide. **Parameters** - `joint` (b2Joint) - joint - `collide` (boolean) - true if connected bodies can collide ### b2d.joint.set_correction_factor *Type:* FUNCTION Set motor joint correction factor. **Parameters** - `joint` (b2Joint) - motor joint - `factor` (number) - correction factor ### b2d.joint.set_damping_ratio *Type:* FUNCTION Set spring damping ratio. **Parameters** - `joint` (b2Joint) - distance, mouse, weld, or wheel joint - `ratio` (number) - damping ratio ### b2d.joint.set_damping_ratio *Type:* FUNCTION Alias for b2d.joint.set_spring_damping_ratio. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint - `ratio` (number) - damping ratio ### b2d.joint.set_frequency *Type:* FUNCTION Set spring frequency. **Parameters** - `joint` (b2Joint) - distance, mouse, weld, or wheel joint - `frequency` (number) - frequency in hertz ### b2d.joint.set_frequency *Type:* FUNCTION Alias for b2d.joint.set_spring_hertz. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint - `frequency` (number) - frequency in hertz ### b2d.joint.set_hertz *Type:* FUNCTION Alias for b2d.joint.set_frequency. **Parameters** - `joint` (b2Joint) - distance, mouse, weld, or wheel joint - `hertz` (number) - frequency in hertz ### b2d.joint.set_hertz *Type:* FUNCTION Alias for b2d.joint.set_spring_hertz. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint - `hertz` (number) - frequency in hertz ### b2d.joint.set_length *Type:* FUNCTION Set the distance joint length. **Parameters** - `joint` (b2Joint) - distance joint - `length` (number) - length in project units ### b2d.joint.set_length *Type:* FUNCTION Set the distance joint length. **Parameters** - `joint` (b2Joint) - distance joint - `length` (number) - length in project units ### b2d.joint.set_length_range *Type:* FUNCTION Set the distance joint length range. **Parameters** - `joint` (b2Joint) - distance joint - `min_length` (number) - minimum length in project units - `max_length` (number) - maximum length in project units ### b2d.joint.set_limits *Type:* FUNCTION Set joint limits. **Parameters** - `joint` (b2Joint) - prismatic or revolute joint - `lower` (number) - lower limit - `upper` (number) - upper limit ### b2d.joint.set_limits *Type:* FUNCTION Set joint limits. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or wheel joint - `lower` (number) - lower limit - `upper` (number) - upper limit ### b2d.joint.set_linear_damping_ratio *Type:* FUNCTION Set weld joint linear damping ratio. **Parameters** - `joint` (b2Joint) - weld joint - `ratio` (number) - damping ratio ### b2d.joint.set_linear_hertz *Type:* FUNCTION Set weld joint linear frequency. **Parameters** - `joint` (b2Joint) - weld joint - `hertz` (number) - frequency in hertz ### b2d.joint.set_linear_offset *Type:* FUNCTION Set motor joint linear offset. **Parameters** - `joint` (b2Joint) - motor joint - `offset` (vector3) - linear offset in project units ### b2d.joint.set_max_force *Type:* FUNCTION Set maximum force. **Parameters** - `joint` (b2Joint) - mouse or friction joint - `force` (number) - maximum force ### b2d.joint.set_max_force *Type:* FUNCTION Set maximum force. **Parameters** - `joint` (b2Joint) - mouse or motor joint - `force` (number) - maximum force ### b2d.joint.set_max_length *Type:* FUNCTION Set rope maximum length. **Parameters** - `joint` (b2Joint) - rope joint - `length` (number) - maximum length in project units ### b2d.joint.set_max_length *Type:* FUNCTION Set the distance joint maximum length. **Parameters** - `joint` (b2Joint) - distance joint - `length` (number) - maximum length in project units ### b2d.joint.set_max_motor_force *Type:* FUNCTION Set maximum motor force. **Parameters** - `joint` (b2Joint) - prismatic joint - `force` (number) - maximum motor force ### b2d.joint.set_max_motor_force *Type:* FUNCTION Set maximum motor force. **Parameters** - `joint` (b2Joint) - distance or prismatic joint - `force` (number) - maximum motor force ### b2d.joint.set_max_motor_torque *Type:* FUNCTION Set maximum motor torque. **Parameters** - `joint` (b2Joint) - revolute or wheel joint - `torque` (number) - maximum motor torque ### b2d.joint.set_max_motor_torque *Type:* FUNCTION Set maximum motor torque. **Parameters** - `joint` (b2Joint) - revolute or wheel joint - `torque` (number) - maximum motor torque ### b2d.joint.set_max_torque *Type:* FUNCTION Set maximum torque. **Parameters** - `joint` (b2Joint) - friction joint - `torque` (number) - maximum torque ### b2d.joint.set_max_torque *Type:* FUNCTION Set maximum torque. **Parameters** - `joint` (b2Joint) - motor joint - `torque` (number) - maximum torque ### b2d.joint.set_min_length *Type:* FUNCTION Set the distance joint minimum length. **Parameters** - `joint` (b2Joint) - distance joint - `length` (number) - minimum length in project units ### b2d.joint.set_motor_speed *Type:* FUNCTION Set motor speed. **Parameters** - `joint` (b2Joint) - prismatic, revolute, or wheel joint - `speed` (number) - motor speed ### b2d.joint.set_motor_speed *Type:* FUNCTION Set motor speed. **Parameters** - `joint` (b2Joint) - distance, prismatic, revolute, or wheel joint - `speed` (number) - motor speed ### b2d.joint.set_mouse_target *Type:* FUNCTION Set the target for a mouse joint. **Parameters** - `joint` (b2Joint) - mouse joint - `target` (vector3) - world target ### b2d.joint.set_mouse_target *Type:* FUNCTION Set the target for a mouse joint. **Parameters** - `joint` (b2Joint) - mouse joint - `target` (vector3) - world target ### b2d.joint.set_ratio *Type:* FUNCTION Set gear joint ratio. **Parameters** - `joint` (b2Joint) - gear joint - `ratio` (number) - gear ratio ### b2d.joint.set_reference_angle *Type:* FUNCTION Set weld joint reference angle. **Parameters** - `joint` (b2Joint) - weld joint - `angle` (number) - reference angle in radians ### b2d.joint.set_spring_damping_ratio *Type:* FUNCTION Alias for b2d.joint.set_damping_ratio. **Parameters** - `joint` (b2Joint) - distance, mouse, weld, or wheel joint - `ratio` (number) - damping ratio ### b2d.joint.set_spring_damping_ratio *Type:* FUNCTION Set spring damping ratio. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint - `ratio` (number) - damping ratio ### b2d.joint.set_spring_hertz *Type:* FUNCTION Set spring frequency. **Parameters** - `joint` (b2Joint) - distance, mouse, prismatic, revolute, or wheel joint - `hertz` (number) - frequency in hertz ### b2d.joint.wake_bodies *Type:* FUNCTION Wake the bodies connected to a joint. **Parameters** - `joint` (b2Joint) - joint ### b2Joint *Type:* TYPEDEF Box2D joint **Parameters** - `value` (userdata) ### b2Joint *Type:* TYPEDEF Box2D joint **Parameters** - `value` (userdata)