java.lang.Object
- org.jbox2d.dynamics.joints.Joint
- - org.jbox2d.dynamics.joints.GearJoint

```
public class GearJoint
extends Joint
```
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.

Field Summary

Fields
Modifier and Type	Field	Description
`private Body`	`m_bodyC`
`private Body`	`m_bodyD`
`private float`	`m_constant`
`private float`	`m_iA`
`private float`	`m_iB`
`private float`	`m_iC`
`private float`	`m_iD`
`private float`	`m_impulse`
`private int`	`m_indexA`
`private int`	`m_indexB`
`private int`	`m_indexC`
`private int`	`m_indexD`
`private Joint`	`m_joint1`
`private Joint`	`m_joint2`
`private Vec2`	`m_JvAC`
`private Vec2`	`m_JvBD`
`private float`	`m_JwA`
`private float`	`m_JwB`
`private float`	`m_JwC`
`private float`	`m_JwD`
`private Vec2`	`m_lcA`
`private Vec2`	`m_lcB`
`private Vec2`	`m_lcC`
`private Vec2`	`m_lcD`
`private Vec2`	`m_localAnchorA`
`private Vec2`	`m_localAnchorB`
`private Vec2`	`m_localAnchorC`
`private Vec2`	`m_localAnchorD`
`private Vec2`	`m_localAxisC`
`private Vec2`	`m_localAxisD`
`private float`	`m_mA`
`private float`	`m_mass`
`private float`	`m_mB`
`private float`	`m_mC`
`private float`	`m_mD`
`private float`	`m_ratio`
`private float`	`m_referenceAngleA`
`private float`	`m_referenceAngleB`
`private JointType`	`m_typeA`
`private JointType`	`m_typeB`

Fields inherited from class org.jbox2d.dynamics.joints.Joint
m_bodyA, m_bodyB, m_edgeA, m_edgeB, m_islandFlag, m_next, m_prev, m_userData, pool

Constructor Summary

Constructors
Modifier Constructor Description

protected GearJoint(IWorldPool argWorldPool, GearJointDef def)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`getAnchorA(Vec2 argOut)`	get the anchor point on bodyA in world coordinates.
`void`	`getAnchorB(Vec2 argOut)`	get the anchor point on bodyB in world coordinates.
`Joint`	`getJoint1()`
`Joint`	`getJoint2()`
`float`	`getRatio()`
`void`	`getReactionForce(float inv_dt, Vec2 argOut)`	get the reaction force on body2 at the joint anchor in Newtons.
`float`	`getReactionTorque(float inv_dt)`	get the reaction torque on body2 in N*m.
`void`	`initVelocityConstraints(SolverData data)`
`void`	`setRatio(float argRatio)`
`boolean`	`solvePositionConstraints(SolverData data)`	This returns true if the position errors are within tolerance.
`void`	`solveVelocityConstraints(SolverData data)`

Methods inherited from class org.jbox2d.dynamics.joints.Joint
create, destroy, destructor, getBodyA, getBodyB, getCollideConnected, getNext, getType, getUserData, isActive, setUserData

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_joint1
```
private final Joint m_joint1
```

m_joint2
```
private final Joint m_joint2
```

m_typeA
```
private final JointType m_typeA
```

m_typeB
```
private final JointType m_typeB
```

m_bodyC
```
private final Body m_bodyC
```

m_bodyD
```
private final Body m_bodyD
```

m_localAnchorA
```
private final Vec2 m_localAnchorA
```

m_localAnchorB
```
private final Vec2 m_localAnchorB
```

m_localAnchorC
```
private final Vec2 m_localAnchorC
```

m_localAnchorD
```
private final Vec2 m_localAnchorD
```

m_localAxisC
```
private final Vec2 m_localAxisC
```

m_localAxisD
```
private final Vec2 m_localAxisD
```

m_referenceAngleA
```
private float m_referenceAngleA
```

m_referenceAngleB
```
private float m_referenceAngleB
```

m_constant
```
private float m_constant
```

m_ratio
```
private float m_ratio
```

m_impulse
```
private float m_impulse
```

m_indexA
```
private int m_indexA
```

m_indexB
```
private int m_indexB
```

m_indexC
```
private int m_indexC
```

m_indexD
```
private int m_indexD
```

m_lcA
```
private final Vec2 m_lcA
```

m_lcB
```
private final Vec2 m_lcB
```

m_lcC
```
private final Vec2 m_lcC
```

m_lcD
```
private final Vec2 m_lcD
```

m_mA
```
private float m_mA
```

m_mB
```
private float m_mB
```

m_mC
```
private float m_mC
```

m_mD
```
private float m_mD
```

m_iA
```
private float m_iA
```

m_iB
```
private float m_iB
```

m_iC
```
private float m_iC
```

m_iD
```
private float m_iD
```

m_JvAC
```
private final Vec2 m_JvAC
```

m_JvBD
```
private final Vec2 m_JvBD
```

m_JwA
```
private float m_JwA
```

m_JwB
```
private float m_JwB
```

m_JwC
```
private float m_JwC
```

m_JwD
```
private float m_JwD
```

m_mass
```
private float m_mass
```

Constructor Detail

GearJoint

protected GearJoint(IWorldPool argWorldPool,
                    GearJointDef def)

Method Detail
- getAnchorA
```
public void getAnchorA(Vec2 argOut)
```
  Description copied from class: Joint
  
  get the anchor point on bodyA in world coordinates.
  
  Specified by:
  
  getAnchorA in class Joint
- getAnchorB
```
public void getAnchorB(Vec2 argOut)
```
  Description copied from class: Joint
  
  get the anchor point on bodyB in world coordinates.
  
  Specified by:
  
  getAnchorB in class Joint
- getReactionForce
```
public void getReactionForce(float inv_dt,
                             Vec2 argOut)
```
  Description copied from class: Joint
  
  get the reaction force on body2 at the joint anchor in Newtons.
  
  Specified by:
  
  getReactionForce in class Joint
- getReactionTorque
```
public float getReactionTorque(float inv_dt)
```
  Description copied from class: Joint
  
  get the reaction torque on body2 in N*m.
  
  Specified by:
  
  getReactionTorque in class Joint
  
  Returns:
- setRatio
```
public void setRatio(float argRatio)
```
- getRatio
```
public float getRatio()
```
- initVelocityConstraints
```
public void initVelocityConstraints(SolverData data)
```
  Specified by:
  
  initVelocityConstraints in class Joint
- solveVelocityConstraints
```
public void solveVelocityConstraints(SolverData data)
```
  Specified by:
  
  solveVelocityConstraints in class Joint
- getJoint1
```
public Joint getJoint1()
```
- getJoint2
```
public Joint getJoint2()
```
- solvePositionConstraints
```
public boolean solvePositionConstraints(SolverData data)
```
  Description copied from class: Joint
  
  This returns true if the position errors are within tolerance.
  
  Specified by:
  
  solvePositionConstraints in class Joint
  
  Returns:

Class GearJoint

Field Summary

Fields inherited from class org.jbox2d.dynamics.joints.Joint

Constructor Summary

Method Summary

Methods inherited from class org.jbox2d.dynamics.joints.Joint

Methods inherited from class java.lang.Object

Field Detail

m_joint1

m_joint2

m_typeA

m_typeB

m_bodyC

m_bodyD

m_localAnchorA

m_localAnchorB

m_localAnchorC

m_localAnchorD

m_localAxisC

m_localAxisD

m_referenceAngleA

m_referenceAngleB

m_constant

m_ratio

m_impulse

m_indexA

m_indexB

m_indexC

m_indexD

m_lcA

m_lcB

m_lcC

m_lcD

m_mA

m_mB

m_mC

m_mD

m_iA

m_iB

m_iC

m_iD

m_JvAC

m_JvBD

m_JwA

m_JwB

m_JwC

m_JwD

m_mass

Constructor Detail

GearJoint

Method Detail

getAnchorA

getAnchorB

getReactionForce

getReactionTorque

setRatio

getRatio

initVelocityConstraints

solveVelocityConstraints

getJoint1

getJoint2

solvePositionConstraints