Box2D  2.4.0
A 2D physics engine for games
b2DistanceJoint Class Reference

#include <b2_distance_joint.h>

Inheritance diagram for b2DistanceJoint:
b2Joint

Public Member Functions

b2Vec2 GetAnchorA () const override
 Get the anchor point on bodyA in world coordinates.
 
b2Vec2 GetAnchorB () const override
 Get the anchor point on bodyB in world coordinates.
 
b2Vec2 GetReactionForce (float inv_dt) const override
 
float GetReactionTorque (float inv_dt) const override
 
const b2Vec2GetLocalAnchorA () const
 The local anchor point relative to bodyA's origin.
 
const b2Vec2GetLocalAnchorB () const
 The local anchor point relative to bodyB's origin.
 
void SetLength (float length)
 
float GetLength () const
 
void SetStiffness (float stiffness)
 Set/get the linear stiffness in N/m.
 
float GetStiffness () const
 
void SetDamping (float damping)
 Set/get linear damping in N*s/m.
 
float GetDamping () const
 
void Dump () override
 Dump joint to dmLog.
 
- Public Member Functions inherited from b2Joint
b2JointType GetType () const
 Get the type of the concrete joint.
 
b2BodyGetBodyA ()
 Get the first body attached to this joint.
 
b2BodyGetBodyB ()
 Get the second body attached to this joint.
 
b2JointGetNext ()
 Get the next joint the world joint list.
 
const b2JointGetNext () const
 
void * GetUserData () const
 Get the user data pointer.
 
void SetUserData (void *data)
 Set the user data pointer.
 
bool IsEnabled () const
 Short-cut function to determine if either body is enabled.
 
bool GetCollideConnected () const
 
virtual void ShiftOrigin (const b2Vec2 &newOrigin)
 Shift the origin for any points stored in world coordinates.
 
virtual void Draw (b2Draw *draw) const
 Debug draw this joint.
 

Protected Member Functions

 b2DistanceJoint (const b2DistanceJointDef *data)
 
void InitVelocityConstraints (const b2SolverData &data) override
 
void SolveVelocityConstraints (const b2SolverData &data) override
 
bool SolvePositionConstraints (const b2SolverData &data) override
 
- Protected Member Functions inherited from b2Joint
 b2Joint (const b2JointDef *def)
 

Protected Attributes

float m_stiffness
 
float m_damping
 
float m_bias
 
b2Vec2 m_localAnchorA
 
b2Vec2 m_localAnchorB
 
float m_gamma
 
float m_impulse
 
float m_length
 
int32 m_indexA
 
int32 m_indexB
 
b2Vec2 m_u
 
b2Vec2 m_rA
 
b2Vec2 m_rB
 
b2Vec2 m_localCenterA
 
b2Vec2 m_localCenterB
 
float m_invMassA
 
float m_invMassB
 
float m_invIA
 
float m_invIB
 
float m_mass
 
- Protected Attributes inherited from b2Joint
b2JointType m_type
 
b2Jointm_prev
 
b2Jointm_next
 
b2JointEdge m_edgeA
 
b2JointEdge m_edgeB
 
b2Bodym_bodyA
 
b2Bodym_bodyB
 
int32 m_index
 
bool m_islandFlag
 
bool m_collideConnected
 
void * m_userData
 

Friends

class b2Joint
 

Additional Inherited Members

- Static Protected Member Functions inherited from b2Joint
static b2JointCreate (const b2JointDef *def, b2BlockAllocator *allocator)
 
static void Destroy (b2Joint *joint, b2BlockAllocator *allocator)
 

Detailed Description

A distance joint constrains two points on two bodies to remain at a fixed distance from each other. You can view this as a massless, rigid rod.

Member Function Documentation

◆ GetReactionForce()

b2Vec2 b2DistanceJoint::GetReactionForce ( float  inv_dt) const
overridevirtual

Get the reaction force given the inverse time step. Unit is N.

Implements b2Joint.

◆ GetReactionTorque()

float b2DistanceJoint::GetReactionTorque ( float  inv_dt) const
overridevirtual

Get the reaction torque given the inverse time step. Unit is N*m. This is always zero for a distance joint.

Implements b2Joint.

◆ SetLength()

void b2DistanceJoint::SetLength ( float  length)
inline

Set/get the natural length. Manipulating the length can lead to non-physical behavior when the frequency is zero.


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