Module org.dyn4j

Package org.dyn4j.dynamics.joint

Class Joint<T extends PhysicsBody>

Object

Joint<T>

Type Parameters:

T - the PhysicsBody type

All Implemented Interfaces:

DataContainer, Shiftable, Ownable

Direct Known Subclasses:

AngleJoint, DistanceJoint, FrictionJoint, MotorJoint, PinJoint, PrismaticJoint, PulleyJoint, RevoluteJoint, RopeJoint, WeldJoint, WheelJoint

public abstract class Joint<T extends PhysicsBody>
extends Object
implements Shiftable, DataContainer, Ownable

Represents constrained motion between two PhysicsBodys.

Since:

1.0.0

Version:

4.0.0

Author:

William Bittle

Constructor Summary

Constructors

Constructor	Description
Joint(T body1, T body2)	Optional constructor.
Joint(T body1, T body2, boolean collisionAllowed)	Full constructor.

Method Summary

Modifier and Type	Method	Description
abstract Vector2	getAnchor1()	Returns the anchor point on the first PhysicsBody in world coordinates.
abstract Vector2	getAnchor2()	Returns the anchor point on the second PhysicsBody in world coordinates.
T	getBody1()	Returns the first body.
T	getBody2()	Returns the second body.
T	getOtherBody(CollisionBody<?> body)	Returns the body that does not match the given body.
Object	getOwner()	Returns the owner for this body.
abstract Vector2	getReactionForce(double invdt)	Returns the force applied to the PhysicsBodys in order to satisfy the constraint in newtons.
abstract double	getReactionTorque(double invdt)	Returns the torque applied to the PhysicsBodys in order to satisfy the constraint in newton-meters.
Object	getUserData()	Gets the custom user data.
abstract void	initializeConstraints(TimeStep step, Settings settings)	Performs any initialization of the velocity and position constraints.
boolean	isActive()	Deprecated. Deprecated in 4.0.0.
boolean	isCollisionAllowed()	Returns true if collision between the joined PhysicsBodys is allowed.
boolean	isEnabled()	Returns true if this Joint is enabled.
boolean	isOnIsland()	Deprecated. Deprecated in 4.0.0.
void	setCollisionAllowed(boolean flag)	Sets whether collision is allowed between the joined PhysicsBodys.
void	setOnIsland(boolean flag)	Deprecated. Deprecated in 4.0.0.
void	setOwner(Object owner)	Sets the owner of this body.
void	setUserData(Object userData)	Sets the custom user data to the given data.
abstract boolean	solvePositionConstraints(TimeStep step, Settings settings)	Solves the position constraints.
abstract void	solveVelocityConstraints(TimeStep step, Settings settings)	Solves the velocity constraints.
String	toString()

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface Shiftable

shift

Constructor Detail

Joint

public Joint(T body1,
             T body2)

Optional constructor.

Assumes that the joined bodies do not participate in collision detection and resolution.

Parameters:

body1 - the first PhysicsBody

body2 - the second PhysicsBody

Throws:

NullPointerException - if body1 or body2 is null

Joint

public Joint(T body1,
             T body2,
             boolean collisionAllowed)

Full constructor.

Parameters:

body1 - the first PhysicsBody

body2 - the second PhysicsBody

collisionAllowed - true if the joined PhysicsBodys can take part in collision detection

Throws:

NullPointerException - if body1 or body2 is null

Method Detail

toString

public String toString()

Overrides:

toString in class Object

initializeConstraints

public abstract void initializeConstraints(TimeStep step,
                                           Settings settings)

Performs any initialization of the velocity and position constraints.

Parameters:

step - the time step information

settings - the current world settings

solveVelocityConstraints

public abstract void solveVelocityConstraints(TimeStep step,
                                              Settings settings)

Solves the velocity constraints.

Parameters:

step - the time step information

settings - the current world settings

solvePositionConstraints

public abstract boolean solvePositionConstraints(TimeStep step,
                                                 Settings settings)

Solves the position constraints.

Parameters:

step - the time step information

settings - the current world settings

Returns:

boolean true if the position constraints were solved

getBody1

public T getBody1()

Returns the first body.

Returns:

T

getBody2

public T getBody2()

Returns the second body.

Returns:

T

getOtherBody

public T getOtherBody(CollisionBody<?> body)

Returns the body that does not match the given body.

If the given body is neither body1 or body2, null is returned.

Parameters:

body - the body

Returns:

T

getAnchor1

public abstract Vector2 getAnchor1()

Returns the anchor point on the first PhysicsBody in world coordinates.

Returns:

Vector2

getAnchor2

public abstract Vector2 getAnchor2()

Returns the anchor point on the second PhysicsBody in world coordinates.

Returns:

Vector2

getReactionForce

public abstract Vector2 getReactionForce(double invdt)

Returns the force applied to the PhysicsBodys in order to satisfy the constraint in newtons.

Parameters:

invdt - the inverse delta time

Returns:

Vector2

getReactionTorque

public abstract double getReactionTorque(double invdt)

Returns the torque applied to the PhysicsBodys in order to satisfy the constraint in newton-meters.

Parameters:

invdt - the inverse delta time

Returns:

double

isActive

@Deprecated
public boolean isActive()

Deprecated.

Deprecated in 4.0.0. Use the isEnabled method instead

Returns true if this Joint is active.

A joint is only active if both joined PhysicsBodys are active.

Returns:

boolean

isEnabled

public boolean isEnabled()

Returns true if this Joint is enabled.

A joint is only enabled if both joined PhysicsBodys are enabled.

Returns:

boolean

isCollisionAllowed

public boolean isCollisionAllowed()

Returns true if collision between the joined PhysicsBodys is allowed.

Returns:

boolean

setCollisionAllowed

public void setCollisionAllowed(boolean flag)

Sets whether collision is allowed between the joined PhysicsBodys.

Parameters:

flag - true if collisions are allowed

getUserData

public Object getUserData()

Description copied from interface: DataContainer

Gets the custom user data.

Specified by:

getUserData in interface DataContainer

Returns:

Object will return null if not set

setUserData

public void setUserData(Object userData)

Description copied from interface: DataContainer

Sets the custom user data to the given data.

Specified by:

setUserData in interface DataContainer

Parameters:

userData - the user data

isOnIsland

@Deprecated
public boolean isOnIsland()

Deprecated.

Deprecated in 4.0.0. No replacement needed.

Returns true if this joint is on an island.

Returns:

boolean

setOnIsland

@Deprecated
public void setOnIsland(boolean flag)

Deprecated.

Deprecated in 4.0.0. No replacement needed.

Flags this joint as being on an island.

Parameters:

flag - true if this joint is on an island

getOwner

public Object getOwner()

Description copied from interface: Ownable

Returns the owner for this body.

Specified by:

getOwner in interface Ownable

Returns:

Object

setOwner

public void setOwner(Object owner)

Description copied from interface: Ownable

Sets the owner of this body.

Specified by:

setOwner in interface Ownable

Parameters:

owner - the owner