#include <CUJoint.h>

Inheritance diagram for cugl::physics2::Joint:

Public Member Functions
	Joint ()

virtual	~Joint ()

bool	init ()

virtual bool	initWithObstacles (const std::shared_ptr< Obstacle > &obsA, const std::shared_ptr< Obstacle > &obsB)

b2JointType	getType () const

void	setObstacleA (const std::shared_ptr< Obstacle > &obs)

std::shared_ptr< Obstacle > &	getObstacleA ()

void	setObstacleB (const std::shared_ptr< Obstacle > &obs)

std::shared_ptr< Obstacle > &	getObstacleB ()

bool	getCollideConnected ()

void	setCollideConnected (bool flag)

void	release ()

bool	isRemoved () const

void	markRemoved (bool value)

bool	isDirty () const

void	markDirty (bool value)

b2Joint *	getJoint ()

virtual bool	activatePhysics (b2World &world)

void	deactivatePhysics (b2World &world)

Protected Attributes
b2Joint *	_joint

b2JointType	_type

std::shared_ptr< Obstacle >	_bodyA

std::shared_ptr< Obstacle >	_bodyB

bool	_collideConnected

bool	_remove
	Track garbage collection status.

bool	_dirty

Detailed Description

The base joint class.

This is an extension of the Box2d b2Joint class to make it easier to use with the Obstacle. Like that class, we combine the definition and the joint itself into a single class.

This class stores the base attributes for a joint, as well as the methods for managing physics and garbage collection. However, there is type information, and you should never instantiate objects of the class. Use one of the subclasses instead.

Many of the method comments in this class are taken from the Box2d manual by Erin Catto (2011).

Constructor & Destructor Documentation

◆ Joint()

cugl::physics2::Joint::Joint ( )

Creates a new physics joint with no obstacles

NEVER USE A CONSTRUCTOR WITH NEW. If you want to allocate an object on the heap, use one of the static constructors instead (in this case, in one of the subclasses).

◆ ~Joint()

virtual cugl::physics2::Joint::~Joint ( )

virtual

Deletes this physics joint and all of its resources.

We have to make the destructor public so that we can polymorphically delete physics objects. Note that we do not allow an joint to be deleted while physics is still active. Doing so will result in an error.

Member Function Documentation

◆ activatePhysics()

virtual bool cugl::physics2::Joint::activatePhysics ( b2World & world )

inlinevirtual

Creates the Box2d joint, adding it to the world.

Calling this method activates the physics of the associated obstacles, if necessary.

Implementations of this method should NOT retain ownership of the Box2D world. That is a tight coupling that we should avoid.

Parameters

world Box2D world to store the joint

Returns: true if object allocation succeeded

Reimplemented in cugl::physics2::DistanceJoint, cugl::physics2::FrictionJoint, cugl::physics2::GearJoint, cugl::physics2::MotorJoint, cugl::physics2::MouseJoint, cugl::physics2::PrismaticJoint, cugl::physics2::PulleyJoint, cugl::physics2::RevoluteJoint, cugl::physics2::WeldJoint, and cugl::physics2::WheelJoint.

◆ deactivatePhysics()

void cugl::physics2::Joint::deactivatePhysics ( b2World & world )

inline

Destroys the Box2D joint if applicable.

This removes the joint from the Box2D world.

Parameters

world Box2D world that stores the joint

◆ getCollideConnected()

bool cugl::physics2::Joint::getCollideConnected ( )

inline

Returns true if the attached bodies should collide.

Returns: true if the attached bodies should collide.

◆ getJoint()

b2Joint * cugl::physics2::Joint::getJoint ( )

inline

Returns a (weak) reference to the Box2D joint

You use this joint to access Box2D primitives. As a weak reference, this physics obstacle does not transfer ownership of this body. In addition, the value may be a nullptr.

Returns: a (weak) reference to the Box2D joint

◆ getObstacleA()

std::shared_ptr< Obstacle > & cugl::physics2::Joint::getObstacleA ( )

inline

Returns the first obstacle attached to this joint.

Returns: the first obstacle attached to this joint.

◆ getObstacleB()

std::shared_ptr< Obstacle > & cugl::physics2::Joint::getObstacleB ( )

inline

Returns the second obstacle attached to this joint.

Returns: the second obstacle attached to this joint.

◆ getType()

b2JointType cugl::physics2::Joint::getType ( ) const

inline

Returns the type of this joint

Returns: the type of this joint

◆ init()

bool cugl::physics2::Joint::init ( )

inline

Initializes a new physics joint with no obstacles.

You should set the obstacles (and other attributes) before activating this joint.

Returns: true if the obstacle is initialized properly, false otherwise.

◆ initWithObstacles()

virtual bool cugl::physics2::Joint::initWithObstacles	(	const std::shared_ptr< Obstacle > &	obsA,
		const std::shared_ptr< Obstacle > &	obsB
	)

virtual

Initializes a new physics joint with the given obstacles.

All other attributes will be at their default values.

Parameters

obsA	The first obstacle to join
obsB	The second obstacle to join

Returns: true if the obstacle is initialized properly, false otherwise.

Reimplemented in cugl::physics2::DistanceJoint, cugl::physics2::FrictionJoint, cugl::physics2::PrismaticJoint, cugl::physics2::PulleyJoint, cugl::physics2::RevoluteJoint, cugl::physics2::WeldJoint, and cugl::physics2::WheelJoint.

◆ isDirty()

bool cugl::physics2::Joint::isDirty ( ) const

inline

Returns true if the shape information must be updated.

The joint must wait for collisions to complete before it can be reset. Reseting the joint is managed by ObstacleWorld.

Returns: true if the shape information must be updated.

◆ isRemoved()

bool cugl::physics2::Joint::isRemoved ( ) const

inline

Returns true if our object has been flagged for garbage collection

A garbage collected object will be removed from the physics world at the next time step.

Returns: true if our object has been flagged for garbage collection

◆ markDirty()

void cugl::physics2::Joint::markDirty ( bool value )

inline

Sets whether the shape information must be updated.

The joint must wait for collisions to complete before it can be reset. Reseting the joint is managed by ObstacleWorld.

Parameters

value whether the shape information must be updated.

◆ markRemoved()

void cugl::physics2::Joint::markRemoved ( bool value )

inline

Sets whether our object has been flagged for garbage collection

A garbage collected object will be removed from the physics world at the next time step.

Parameters

value whether our object has been flagged for garbage collection

◆ release()

void cugl::physics2::Joint::release ( )

Instructs the object to release its Box2d joint.

This method is required when a joint is deleted in response to a deletion of one of its bodies.

◆ setCollideConnected()

void cugl::physics2::Joint::setCollideConnected ( bool flag )

inline

Sets the flag for whether the attached bodies should collide.

If this method is called while the joint is active, then the joint will be marked as dirty. It will need to be deactivated and reactivated to work properly.

Parameters

flag	Whether the attached bodies should collide.

◆ setObstacleA()

void cugl::physics2::Joint::setObstacleA ( const std::shared_ptr< Obstacle > & obs )

inline

Sets the first obstacle attached to this joint.

If this method is called while the joint is active, then the joint will be marked as dirty. It will need to be deactivated and reactivated to work properly.

Parameters

obs	the first body attached to this joint.

◆ setObstacleB()

void cugl::physics2::Joint::setObstacleB ( const std::shared_ptr< Obstacle > & obs )

inline

Sets the second obstacle attached to this joint.

If this method is called while the joint is active, then the joint will be marked as dirty. It will need to be deactivated and reactivated to work properly.

Parameters

obs	the second obstacle attached to this joint.

Member Data Documentation

◆ _bodyA

std::shared_ptr<Obstacle> cugl::physics2::Joint::_bodyA

protected

The first attached obstacle.

◆ _bodyB

std::shared_ptr<Obstacle> cugl::physics2::Joint::_bodyB

protected

The second attached obstacle.

◆ _collideConnected

bool cugl::physics2::Joint::_collideConnected

protected

Set this flag to true if the attached bodies should collide.

◆ _dirty

bool cugl::physics2::Joint::_dirty

protected

Whether the joint has changed properties and needs to be rebuilt

◆ _joint

b2Joint* cugl::physics2::Joint::_joint

protected

A reference to the joint (nullptr if it is not active)

◆ _remove

bool cugl::physics2::Joint::_remove

protected

Track garbage collection status.

Whether the joint should be removed from the world on next pass

◆ _type

b2JointType cugl::physics2::Joint::_type

protected

The underlying joint type (set automatically for concrete joint types)

The documentation for this class was generated from the following file:

/Users/wmwhite/Developer/CUGL/include/cugl/physics2/CUJoint.h

Public Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ Joint()

◆ ~Joint()

Member Function Documentation

◆ activatePhysics()

◆ deactivatePhysics()

◆ getCollideConnected()

◆ getJoint()

◆ getObstacleA()

◆ getObstacleB()

◆ getType()

◆ init()

◆ initWithObstacles()

◆ isDirty()

◆ isRemoved()

◆ markDirty()

◆ markRemoved()

◆ release()

◆ setCollideConnected()

◆ setObstacleA()

◆ setObstacleB()

Member Data Documentation

◆ _bodyA

◆ _bodyB

◆ _collideConnected

◆ _dirty

◆ _joint

◆ _remove

◆ _type