Box2D  2.4.1
A 2D physics engine for games
b2GearJoint Class Reference

#include <b2_gear_joint.h>

Inheritance diagram for b2GearJoint:

Public Member Functions

b2Vec2 GetAnchorA () const override
 Get the anchor point on bodyA in world coordinates.
b2Vec2 GetAnchorB () const override
 Get the anchor point on bodyB in world coordinates.
b2Vec2 GetReactionForce (float inv_dt) const override
 Get the reaction force on bodyB at the joint anchor in Newtons.
float GetReactionTorque (float inv_dt) const override
 Get the reaction torque on bodyB in N*m.
b2JointGetJoint1 ()
 Get the first joint.
b2JointGetJoint2 ()
 Get the second joint.
void SetRatio (float ratio)
 Set/Get the gear ratio.
float GetRatio () const
void Dump () override
 Dump joint to dmLog.
- Public Member Functions inherited from b2Joint
b2JointType GetType () const
 Get the type of the concrete joint.
b2BodyGetBodyA ()
 Get the first body attached to this joint.
b2BodyGetBodyB ()
 Get the second body attached to this joint.
b2JointGetNext ()
 Get the next joint the world joint list.
const b2JointGetNext () const
b2JointUserDataGetUserData ()
 Get the user data pointer.
bool IsEnabled () const
 Short-cut function to determine if either body is enabled.
bool GetCollideConnected () const
virtual void ShiftOrigin (const b2Vec2 &newOrigin)
 Shift the origin for any points stored in world coordinates.
virtual void Draw (b2Draw *draw) const
 Debug draw this joint.

Protected Member Functions

 b2GearJoint (const b2GearJointDef *data)
void InitVelocityConstraints (const b2SolverData &data) override
void SolveVelocityConstraints (const b2SolverData &data) override
bool SolvePositionConstraints (const b2SolverData &data) override
- Protected Member Functions inherited from b2Joint
 b2Joint (const b2JointDef *def)

Protected Attributes

b2JointType m_typeA
b2JointType m_typeB
b2Vec2 m_localAnchorA
b2Vec2 m_localAnchorB
b2Vec2 m_localAnchorC
b2Vec2 m_localAnchorD
b2Vec2 m_localAxisC
b2Vec2 m_localAxisD
float m_referenceAngleA
float m_referenceAngleB
float m_constant
float m_ratio
float m_impulse
int32 m_indexA
int32 m_indexB
int32 m_indexC
int32 m_indexD
b2Vec2 m_lcA
b2Vec2 m_lcB
b2Vec2 m_lcC
b2Vec2 m_lcD
float m_mA
float m_mB
float m_mC
float m_mD
float m_iA
float m_iB
float m_iC
float m_iD
b2Vec2 m_JvAC
b2Vec2 m_JvBD
float m_JwA
float m_JwB
float m_JwC
float m_JwD
float m_mass
- Protected Attributes inherited from b2Joint
b2JointType m_type
b2JointEdge m_edgeA
b2JointEdge m_edgeB
int32 m_index
bool m_islandFlag
bool m_collideConnected
b2JointUserData m_userData


class b2Joint

Additional Inherited Members

- Static Protected Member Functions inherited from b2Joint
static b2JointCreate (const b2JointDef *def, b2BlockAllocator *allocator)
static void Destroy (b2Joint *joint, b2BlockAllocator *allocator)

Detailed Description

A gear joint is used to connect two joints together. Either joint can be a revolute or prismatic joint. You specify a gear ratio to bind the motions together: coordinate1 + ratio * coordinate2 = constant The ratio can be negative or positive. If one joint is a revolute joint and the other joint is a prismatic joint, then the ratio will have units of length or units of 1/length.

You have to manually destroy the gear joint if joint1 or joint2 is destroyed.

The documentation for this class was generated from the following file: