| Box2D 2.2.1 A 2D Physics Engine for Games

- Main Page
- Classes
- Files

- Class List
- Class Index
- Class Hierarchy
- Class Members

Public Member Functions | Protected Member Functions | Protected Attributes | Friends
b2DistanceJoint Class Reference

`#include <b2DistanceJoint.h>`

Inheritance diagram for b2DistanceJoint:

List of all members.

## Public Member Functions

b2Vec2 | GetAnchorA () const
| Get the anchor point on bodyA in world coordinates.
b2Vec2 | GetAnchorB () const
| Get the anchor point on bodyB in world coordinates.
b2Vec2 | GetReactionForce (float32 inv_dt) const
float32 | GetReactionTorque (float32 inv_dt) const
const b2Vec2 & | GetLocalAnchorA () const
| The local anchor point relative to bodyA's origin.
const b2Vec2 & | GetLocalAnchorB () const
| The local anchor point relative to bodyB's origin.
void | SetLength (float32 length)
float32 | GetLength () const
void | SetFrequency (float32 hz)
| Set/get frequency in Hz.
float32 | GetFrequency () const
void | SetDampingRatio (float32 ratio)
| Set/get damping ratio.
float32 | GetDampingRatio () const
void | Dump ()
| Dump joint to dmLog.

## Protected Member Functions

| b2DistanceJoint (const b2DistanceJointDef *data)
void | InitVelocityConstraints (const b2SolverData &data)
void | SolveVelocityConstraints (const b2SolverData &data)
bool | SolvePositionConstraints (const b2SolverData &data)

## Protected Attributes

float32 | m_frequencyHz
float32 | m_dampingRatio
float32 | m_bias
b2Vec2 | m_localAnchorA
b2Vec2 | m_localAnchorB
float32 | m_gamma
float32 | m_impulse
float32 | m_length
int32 | m_indexA
int32 | m_indexB
b2Vec2 | m_u
b2Vec2 | m_rA
b2Vec2 | m_rB
b2Vec2 | m_localCenterA
b2Vec2 | m_localCenterB
float32 | m_invMassA
float32 | m_invMassB
float32 | m_invIA
float32 | m_invIB
float32 | m_mass

## Friends

class | b2Joint

## 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

b2Vec2 b2DistanceJoint::GetReactionForce | ( | float32 | inv_dt | ) | const`[virtual]`

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

Implements b2Joint.

float32 b2DistanceJoint::GetReactionTorque | ( | float32 | inv_dt | ) | const`[virtual]`

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

Implements b2Joint.

void b2DistanceJoint::SetLength | ( | float32 | 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 files:

- b2DistanceJoint.h
- b2DistanceJoint.cpp

All Classes Files Functions Variables Enumerations Enumerator Defines