org.jbox2d.dynamics.joints

Class DistanceJoint

java.lang.Object

org.jbox2d.dynamics.joints.Joint

org.jbox2d.dynamics.joints.DistanceJoint

public class DistanceJoint
extends Joint

A distance joint constrains two points on two bodies to remain at a fixed distance from each other. You can view this as a massless, rigid rod.

Field Summary

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	DistanceJoint(IWorldPool argWorld, DistanceJointDef def)

Method Summary

Modifier and Type	Method and 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.
float	getDampingRatio()
float	getFrequency()
float	getLength()
Vec2	getLocalAnchorA()
Vec2	getLocalAnchorB()
void	getReactionForce(float inv_dt, Vec2 argOut) Get the reaction force given the inverse time step.
float	getReactionTorque(float inv_dt) Get the reaction torque given the inverse time step.
void	initVelocityConstraints(SolverData data)
void	setDampingRatio(float damp)
void	setFrequency(float hz)
void	setLength(float argLength)
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

Constructor Detail

DistanceJoint

protected DistanceJoint(IWorldPool argWorld,
                        DistanceJointDef def)

Method Detail

setFrequency

public void setFrequency(float hz)

getFrequency

public float getFrequency()

getLength

public float getLength()

setLength

public void setLength(float argLength)

setDampingRatio

public void setDampingRatio(float damp)

getDampingRatio

public float getDampingRatio()

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

getLocalAnchorA

public Vec2 getLocalAnchorA()

getLocalAnchorB

public Vec2 getLocalAnchorB()

getReactionForce

public void getReactionForce(float inv_dt,
                             Vec2 argOut)

Get the reaction force given the inverse time step. Unit is N.

Specified by:

getReactionForce in class Joint

getReactionTorque

public float getReactionTorque(float inv_dt)

Get the reaction torque given the inverse time step. Unit is N*m. This is always zero for a distance joint.

Specified by:

getReactionTorque in class Joint

Returns:

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: