Module org.dyn4j

Package org.dyn4j.dynamics.joint

Interface Joint<T extends PhysicsBody>

Type Parameters:

T - the PhysicsBody type

All Superinterfaces:

DataContainer, Ownable, Shiftable

All Known Subinterfaces:

PairedBodyJoint<T>, SingleBodyJoint<T>

All Known Implementing Classes:

AbstractJoint, AbstractPairedBodyJoint, AbstractSingleBodyJoint, AngleJoint, DistanceJoint, FrictionJoint, MotorJoint, PinJoint, PrismaticJoint, PulleyJoint, RevoluteJoint, WeldJoint, WheelJoint

public interface Joint<T extends PhysicsBody>
extends Shiftable, DataContainer, Ownable

Represents constrained motion between PhysicsBodys.

Since:

5.0.0

Version:

5.0.0

Author:

William Bittle

Field Summary

Fields

Modifier and Type	Field	Description
static int	SPRING_MODE_FREQUENCY	Mode indicating that the current frequency should be used to calculate the spring stiffness
static int	SPRING_MODE_STIFFNESS	Mode indicating that the current stiffness should be used to calculate the spring frequency

Method Summary

Modifier and Type	Method	Description
List<T>	getBodies()	Returns an unmodifiable list of bodies involved in this joint.
T	getBody(int index)	Returns the body at the given index.
int	getBodyCount()	Returns the number of bodies involved in this joint.
Iterator<T>	getBodyIterator()	Returns an iterator for the bodies involved in this joint.
Vector2	getReactionForce(double invdt)	Returns the force applied to the PhysicsBodys in order to satisfy the constraint in newtons.
double	getReactionTorque(double invdt)	Returns the torque applied to the PhysicsBodys in order to satisfy the constraint in newton-meters.
void	initializeConstraints(TimeStep step, Settings settings)	Performs any initialization of the velocity and position constraints.
boolean	isCollisionAllowed()	Returns true if collision between the joined PhysicsBodys is allowed.
boolean	isEnabled()	Returns true if this Joint is enabled.
boolean	isMember(CollisionBody<?> body)	Returns true if the given body is a member of this joint.
void	setCollisionAllowed(boolean flag)	Sets whether collision is allowed between the joined PhysicsBodys.
boolean	solvePositionConstraints(TimeStep step, Settings settings)	Solves the position constraints.
void	solveVelocityConstraints(TimeStep step, Settings settings)	Solves the velocity constraints.

Methods inherited from interface DataContainer

getUserData, setUserData

Methods inherited from interface Ownable

getOwner, setOwner

Methods inherited from interface Shiftable

shift

Field Detail

SPRING_MODE_FREQUENCY

static final int SPRING_MODE_FREQUENCY

Mode indicating that the current frequency should be used to calculate the spring stiffness

See Also:

Constant Field Values

SPRING_MODE_STIFFNESS

static final int SPRING_MODE_STIFFNESS

Mode indicating that the current stiffness should be used to calculate the spring frequency

See Also:

Constant Field Values

Method Detail

getBodies

List<T> getBodies()

Returns an unmodifiable list of bodies involved in this joint.

Returns:

List<T>

getBodyCount

int getBodyCount()

Returns the number of bodies involved in this joint.

Returns:

int

getBody

T getBody(int index)

Returns the body at the given index.

Parameters:

index - the index

Returns:

T

Throws:

IndexOutOfBoundsException - when index is greater than or equal to getBodyCount()

getBodyIterator

Iterator<T> getBodyIterator()

Returns an iterator for the bodies involved in this joint.

NOTE: The iterator is read-only and will throw if methods like remove are used.

Returns:

Iterator<T>

isMember

boolean isMember(CollisionBody<?> body)

Returns true if the given body is a member of this joint.

Parameters:

body - the body

Returns:

boolean

initializeConstraints

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

void solveVelocityConstraints(TimeStep step,
                              Settings settings)

Solves the velocity constraints.

Parameters:

step - the time step information

settings - the current world settings

solvePositionConstraints

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

getReactionForce

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

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

isEnabled

boolean isEnabled()

Returns true if this Joint is enabled.

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

Returns:

boolean

isCollisionAllowed

boolean isCollisionAllowed()

Returns true if collision between the joined PhysicsBodys is allowed.

Returns:

boolean

setCollisionAllowed

void setCollisionAllowed(boolean flag)

Sets whether collision is allowed between the joined PhysicsBodys.

Parameters:

flag - true if collisions are allowed