org.jbox2d.dynamics.joints

Class PrismaticJoint

java.lang.Object

org.jbox2d.dynamics.joints.Joint

org.jbox2d.dynamics.joints.PrismaticJoint

public class PrismaticJoint
extends Joint

A prismatic joint. This joint provides one degree of freedom: translation along an axis fixed in bodyA. Relative rotation is prevented. You can use a joint limit to restrict the range of motion and a joint motor to drive the motion or to model joint friction.

Author:

Daniel

Field Summary

Fields

Modifier and Type	Field and Description
protected Vec2	m_localAnchorA
protected Vec2	m_localAnchorB
protected Vec2	m_localXAxisA
protected Vec2	m_localYAxisA
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	PrismaticJoint(IWorldPool argWorld, PrismaticJointDef def)

Method Summary

Modifier and Type	Method and Description
void	enableLimit(boolean flag) Enable/disable the joint limit.
void	enableMotor(boolean flag) Enable/disable the joint motor.
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	getJointSpeed() Get the current joint translation, usually in meters.
float	getJointTranslation()
Vec2	getLocalAnchorA()
Vec2	getLocalAnchorB()
Vec2	getLocalAxisA()
float	getLowerLimit() Get the lower joint limit, usually in meters.
float	getMaxMotorForce()
float	getMotorForce(float inv_dt) Get the current motor force, usually in N.
float	getMotorSpeed() Get the motor speed, usually in meters per second.
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() Get the upper joint limit, usually in meters.
void	initVelocityConstraints(SolverData data)
boolean	isLimitEnabled() Is the joint limit enabled?
boolean	isMotorEnabled() Is the joint motor enabled?
void	setLimits(float lower, float upper) Set the joint limits, usually in meters.
void	setMaxMotorForce(float force) Set the maximum motor force, usually in N.
void	setMotorSpeed(float speed) Set the motor speed, usually in meters per second.
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_localXAxisA

protected final Vec2 m_localXAxisA

m_localYAxisA

protected final Vec2 m_localYAxisA

m_referenceAngle

protected float m_referenceAngle

Constructor Detail

PrismaticJoint

protected PrismaticJoint(IWorldPool argWorld,
                         PrismaticJointDef def)

Method Detail

getLocalAnchorA

public Vec2 getLocalAnchorA()

getLocalAnchorB

public Vec2 getLocalAnchorB()

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:

getJointSpeed

public float getJointSpeed()

Get the current joint translation, usually in meters.

getJointTranslation

public float getJointTranslation()

isLimitEnabled

public boolean isLimitEnabled()

Is the joint limit enabled?

Returns:

enableLimit

public void enableLimit(boolean flag)

Enable/disable the joint limit.

Parameters:

flag -

getLowerLimit

public float getLowerLimit()

Get the lower joint limit, usually in meters.

Returns:

getUpperLimit

public float getUpperLimit()

Get the upper joint limit, usually in meters.

Returns:

setLimits

public void setLimits(float lower,
                      float upper)

Set the joint limits, usually in meters.

Parameters:

lower -

upper -

isMotorEnabled

public boolean isMotorEnabled()

Is the joint motor enabled?

Returns:

enableMotor

public void enableMotor(boolean flag)

Enable/disable the joint motor.

Parameters:

flag -

setMotorSpeed

public void setMotorSpeed(float speed)

Set the motor speed, usually in meters per second.

Parameters:

speed -

getMotorSpeed

public float getMotorSpeed()

Get the motor speed, usually in meters per second.

Returns:

setMaxMotorForce

public void setMaxMotorForce(float force)

Set the maximum motor force, usually in N.

Parameters:

force -

getMotorForce

public float getMotorForce(float inv_dt)

Get the current motor force, usually in N.

Parameters:

inv_dt -

Returns:

getMaxMotorForce

public float getMaxMotorForce()

getReferenceAngle

public float getReferenceAngle()

getLocalAxisA

public Vec2 getLocalAxisA()

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: