org.jbox2d.dynamics.joints

Class Joint

java.lang.Object

org.jbox2d.dynamics.joints.Joint

Direct Known Subclasses:

ConstantVolumeJoint, DistanceJoint, FrictionJoint, GearJoint, MouseJoint, PrismaticJoint, PulleyJoint, RevoluteJoint, RopeJoint, WeldJoint, WheelJoint

public abstract class Joint
extends java.lang.Object

The base joint class. Joints are used to constrain two bodies together in various fashions. Some joints also feature limits and motors.

Author:

Daniel Murphy

Field Summary

Fields

Modifier and Type	Field and Description
protected Body	m_bodyA
protected Body	m_bodyB
JointEdge	m_edgeA
JointEdge	m_edgeB
boolean	m_islandFlag
Joint	m_next
Joint	m_prev
java.lang.Object	m_userData
protected IWorldPool	pool

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Joint(IWorldPool worldPool, JointDef def)

Method Summary

Modifier and Type	Method and Description
static Joint	create(World world, JointDef def)
static void	destroy(Joint joint)
void	destructor() Override to handle destruction of joint
abstract void	getAnchorA(Vec2 out) get the anchor point on bodyA in world coordinates.
abstract void	getAnchorB(Vec2 out) get the anchor point on bodyB in world coordinates.
Body	getBodyA() get the first body attached to this joint.
Body	getBodyB() get the second body attached to this joint.
boolean	getCollideConnected()
Joint	getNext() get the next joint the world joint list.
abstract void	getReactionForce(float inv_dt, Vec2 out) get the reaction force on body2 at the joint anchor in Newtons.
abstract float	getReactionTorque(float inv_dt) get the reaction torque on body2 in N*m.
JointType	getType() get the type of the concrete joint.
java.lang.Object	getUserData() get the user data pointer.
abstract void	initVelocityConstraints(SolverData data)
boolean	isActive() Short-cut function to determine if either body is inactive.
void	setUserData(java.lang.Object data) Set the user data pointer.
abstract boolean	solvePositionConstraints(SolverData data) This returns true if the position errors are within tolerance.
abstract void	solveVelocityConstraints(SolverData data)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

m_prev

public Joint m_prev

m_next

public Joint m_next

m_edgeA

public JointEdge m_edgeA

m_edgeB

public JointEdge m_edgeB

m_bodyA

protected Body m_bodyA

m_bodyB

protected Body m_bodyB

m_islandFlag

public boolean m_islandFlag

m_userData

public java.lang.Object m_userData

pool

protected IWorldPool pool

Constructor Detail

Joint

protected Joint(IWorldPool worldPool,
                JointDef def)

Method Detail

create

public static Joint create(World world,
                           JointDef def)

destroy

public static void destroy(Joint joint)

getType

public JointType getType()

get the type of the concrete joint.

Returns:

getBodyA

public final Body getBodyA()

get the first body attached to this joint.

getBodyB

public final Body getBodyB()

get the second body attached to this joint.

Returns:

getAnchorA

public abstract void getAnchorA(Vec2 out)

get the anchor point on bodyA in world coordinates.

getAnchorB

public abstract void getAnchorB(Vec2 out)

get the anchor point on bodyB in world coordinates.

getReactionForce

public abstract void getReactionForce(float inv_dt,
                                      Vec2 out)

get the reaction force on body2 at the joint anchor in Newtons.

Parameters:

inv_dt -

getReactionTorque

public abstract float getReactionTorque(float inv_dt)

get the reaction torque on body2 in N*m.

Parameters:

inv_dt -

Returns:

getNext

public Joint getNext()

get the next joint the world joint list.

getUserData

public java.lang.Object getUserData()

get the user data pointer.

setUserData

public void setUserData(java.lang.Object data)

Set the user data pointer.

getCollideConnected

public final boolean getCollideConnected()

isActive

public boolean isActive()

Short-cut function to determine if either body is inactive.

Returns:

initVelocityConstraints

public abstract void initVelocityConstraints(SolverData data)

solveVelocityConstraints

public abstract void solveVelocityConstraints(SolverData data)

solvePositionConstraints

public abstract boolean solvePositionConstraints(SolverData data)

This returns true if the position errors are within tolerance.

Parameters:

baumgarte -

Returns:

destructor

public void destructor()

Override to handle destruction of joint