org.jbox2d.dynamics.joints

Class RevoluteJoint

java.lang.Object

org.jbox2d.dynamics.joints.Joint

org.jbox2d.dynamics.joints.RevoluteJoint

public class RevoluteJoint
extends Joint

A revolute joint constrains two bodies to share a common point while they are free to rotate about the point. The relative rotation about the shared point is the joint angle. You can limit the relative rotation with a joint limit that specifies a lower and upper angle. You can use a motor to drive the relative rotation about the shared point. A maximum motor torque is provided so that infinite forces are not generated.

Author:

Daniel Murphy

Field Summary

Fields

Modifier and Type	Field and Description
protected Vec2	m_localAnchorA
protected Vec2	m_localAnchorB
protected float	m_referenceAngle

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 and Description
protected	RevoluteJoint(IWorldPool argWorld, RevoluteJointDef def)

Method Summary

Modifier and Type	Method and Description
void	enableLimit(boolean flag)
void	enableMotor(boolean flag)
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.
float	getJointAngle()
float	getJointSpeed()
Vec2	getLocalAnchorA()
Vec2	getLocalAnchorB()
float	getLowerLimit()
float	getMaxMotorTorque()
float	getMotorSpeed()
float	getMotorTorque(float inv_dt)
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.
float	getReferenceAngle()
float	getUpperLimit()
void	initVelocityConstraints(SolverData data)
boolean	isLimitEnabled()
boolean	isMotorEnabled()
void	setLimits(float lower, float upper)
void	setMaxMotorTorque(float torque)
void	setMotorSpeed(float speed)
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_localAnchorA

protected final Vec2 m_localAnchorA

m_localAnchorB

protected final Vec2 m_localAnchorB

m_referenceAngle

protected float m_referenceAngle

Constructor Detail

RevoluteJoint

protected RevoluteJoint(IWorldPool argWorld,
                        RevoluteJointDef def)

Method Detail

initVelocityConstraints

public void initVelocityConstraints(SolverData data)

Specified by:

initVelocityConstraints in class Joint

solveVelocityConstraints

public void solveVelocityConstraints(SolverData data)

Specified by:

solveVelocityConstraints in class Joint

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:

getLocalAnchorA

public Vec2 getLocalAnchorA()

getLocalAnchorB

public Vec2 getLocalAnchorB()

getReferenceAngle

public float getReferenceAngle()

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:

getJointAngle

public float getJointAngle()

getJointSpeed

public float getJointSpeed()

isMotorEnabled

public boolean isMotorEnabled()

enableMotor

public void enableMotor(boolean flag)

getMotorTorque

public float getMotorTorque(float inv_dt)

setMotorSpeed

public void setMotorSpeed(float speed)

setMaxMotorTorque

public void setMaxMotorTorque(float torque)

getMotorSpeed

public float getMotorSpeed()

getMaxMotorTorque

public float getMaxMotorTorque()

isLimitEnabled

public boolean isLimitEnabled()

enableLimit

public void enableLimit(boolean flag)

getLowerLimit

public float getLowerLimit()

getUpperLimit

public float getUpperLimit()

setLimits

public void setLimits(float lower,
                      float upper)