b2Joint Class Reference

#include <b2Joint.h>

Inheritance diagram for b2Joint:

List of all members.

Public Member Functions
b2JointType	GetType () const
	Get the type of the concrete joint.
b2Body *	GetBodyA ()
	Get the first body attached to this joint.
b2Body *	GetBodyB ()
	Get the second body attached to this joint.
virtual b2Vec2	GetAnchorA () const =0
	Get the anchor point on bodyA in world coordinates.
virtual b2Vec2	GetAnchorB () const =0
	Get the anchor point on bodyB in world coordinates.
virtual b2Vec2	GetReactionForce (float32 inv_dt) const =0
	Get the reaction force on body2 at the joint anchor in Newtons.
virtual float32	GetReactionTorque (float32 inv_dt) const =0
	Get the reaction torque on body2 in N*m.
b2Joint *	GetNext ()
	Get the next joint the world joint list.
void *	GetUserData () const
	Get the user data pointer.
void	SetUserData (void *data)
	Set the user data pointer.
bool	IsActive () const
	Short-cut function to determine if either body is inactive.
Protected Member Functions
	b2Joint (const b2JointDef *def)
virtual	~b2Joint ()
virtual void	InitVelocityConstraints (const b2TimeStep &step)=0
virtual void	SolveVelocityConstraints (const b2TimeStep &step)=0
virtual bool	SolvePositionConstraints (float32 baumgarte)=0
Static Protected Member Functions
static b2Joint *	Create (const b2JointDef *def, b2BlockAllocator *allocator)
static void	Destroy (b2Joint *joint, b2BlockAllocator *allocator)
Protected Attributes
b2JointType	m_type
b2Joint *	m_prev
b2Joint *	m_next
b2JointEdge	m_edgeA
b2JointEdge	m_edgeB
b2Body *	m_bodyA
b2Body *	m_bodyB
bool	m_islandFlag
bool	m_collideConnected
void *	m_userData
b2Vec2	m_localCenterA
b2Vec2	m_localCenterB
float32	m_invMassA
float32	m_invIA
float32	m_invMassB
float32	m_invIB
Friends
class	b2World
class	b2Body
class	b2Island

---

Detailed Description

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

---

Constructor & Destructor Documentation

b2Joint::b2Joint

(

const b2JointDef *

def

)

[protected]

virtual b2Joint::~b2Joint

(

)

[inline, protected, virtual]

---

Member Function Documentation

b2Joint * b2Joint::Create	(	const b2JointDef *	def,
		b2BlockAllocator *	allocator
	)			[static, protected]

void b2Joint::Destroy	(	b2Joint *	joint,
		b2BlockAllocator *	allocator
	)			[static, protected]

virtual b2Vec2 b2Joint::GetAnchorA

(

)

const [pure virtual]

Get the anchor point on bodyA in world coordinates.

Implemented in b2DistanceJoint, b2FrictionJoint, b2GearJoint, b2LineJoint, b2MouseJoint, b2PrismaticJoint, b2PulleyJoint, b2RevoluteJoint, and b2WeldJoint.

virtual b2Vec2 b2Joint::GetAnchorB

(

)

const [pure virtual]

Get the anchor point on bodyB in world coordinates.

Implemented in b2DistanceJoint, b2FrictionJoint, b2GearJoint, b2LineJoint, b2MouseJoint, b2PrismaticJoint, b2PulleyJoint, b2RevoluteJoint, and b2WeldJoint.

b2Body * b2Joint::GetBodyA

(

)

[inline]

Get the first body attached to this joint.

b2Body * b2Joint::GetBodyB

(

)

[inline]

Get the second body attached to this joint.

b2Joint * b2Joint::GetNext

(

)

[inline]

Get the next joint the world joint list.

virtual b2Vec2 b2Joint::GetReactionForce

(

float32

inv_dt

)

const [pure virtual]

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

Implemented in b2DistanceJoint, b2FrictionJoint, b2GearJoint, b2LineJoint, b2MouseJoint, b2PrismaticJoint, b2PulleyJoint, b2RevoluteJoint, and b2WeldJoint.

virtual float32 b2Joint::GetReactionTorque

(

float32

inv_dt

)

const [pure virtual]

Get the reaction torque on body2 in N*m.

Implemented in b2DistanceJoint, b2FrictionJoint, b2GearJoint, b2LineJoint, b2MouseJoint, b2PrismaticJoint, b2PulleyJoint, b2RevoluteJoint, and b2WeldJoint.

b2JointType b2Joint::GetType

(

)

const [inline]

Get the type of the concrete joint.

void * b2Joint::GetUserData

(

)

const [inline]

Get the user data pointer.

virtual void b2Joint::InitVelocityConstraints

(

const b2TimeStep &

step

)

[protected, pure virtual]

Implemented in b2DistanceJoint, b2FrictionJoint, b2GearJoint, b2LineJoint, b2MouseJoint, b2PrismaticJoint, b2PulleyJoint, b2RevoluteJoint, and b2WeldJoint.

bool b2Joint::IsActive

(

)

const

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

void b2Joint::SetUserData

(

void *

data

)

[inline]

Set the user data pointer.

virtual bool b2Joint::SolvePositionConstraints

(

float32

baumgarte

)

[protected, pure virtual]

Implemented in b2DistanceJoint, b2FrictionJoint, b2GearJoint, b2LineJoint, b2MouseJoint, b2PrismaticJoint, b2PulleyJoint, b2RevoluteJoint, and b2WeldJoint.

virtual void b2Joint::SolveVelocityConstraints

(

const b2TimeStep &

step

)

[protected, pure virtual]

Implemented in b2DistanceJoint, b2FrictionJoint, b2GearJoint, b2LineJoint, b2MouseJoint, b2PrismaticJoint, b2PulleyJoint, b2RevoluteJoint, and b2WeldJoint.

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Friends And Related Function Documentation

friend class b2Body [friend]

friend class b2Island [friend]

friend class b2World [friend]

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Member Data Documentation

b2Body* b2Joint::m_bodyA [protected]

b2Body* b2Joint::m_bodyB [protected]

bool b2Joint::m_collideConnected [protected]

b2JointEdge b2Joint::m_edgeA [protected]

b2JointEdge b2Joint::m_edgeB [protected]

float32 b2Joint::m_invIA [protected]

float32 b2Joint::m_invIB [protected]

float32 b2Joint::m_invMassA [protected]

float32 b2Joint::m_invMassB [protected]

bool b2Joint::m_islandFlag [protected]

b2Vec2 b2Joint::m_localCenterA [protected]

b2Vec2 b2Joint::m_localCenterB [protected]

b2Joint* b2Joint::m_next [protected]

b2Joint* b2Joint::m_prev [protected]

b2JointType b2Joint::m_type [protected]

void* b2Joint::m_userData [protected]

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

• Box2D/Box2D/Dynamics/Joints/b2Joint.h
• Box2D/Box2D/Dynamics/Joints/b2Joint.cpp