| 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
b2PulleyJoint Class Reference

`#include <b2PulleyJoint.h>`

Inheritance diagram for b2PulleyJoint:

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
| Get the reaction force on bodyB at the joint anchor in Newtons.
float32 | GetReactionTorque (float32 inv_dt) const
| Get the reaction torque on bodyB in N*m.
b2Vec2 | GetGroundAnchorA () const
| Get the first ground anchor.
b2Vec2 | GetGroundAnchorB () const
| Get the second ground anchor.
float32 | GetLengthA () const
| Get the current length of the segment attached to bodyA.
float32 | GetLengthB () const
| Get the current length of the segment attached to bodyB.
float32 | GetRatio () const
| Get the pulley ratio.
void | Dump ()
| Dump joint to dmLog.

## Protected Member Functions

| b2PulleyJoint (const b2PulleyJointDef *data)
void | InitVelocityConstraints (const b2SolverData &data)
void | SolveVelocityConstraints (const b2SolverData &data)
bool | SolvePositionConstraints (const b2SolverData &data)

## Protected Attributes

b2Vec2 | m_groundAnchorA
b2Vec2 | m_groundAnchorB
float32 | m_lengthA
float32 | m_lengthB
b2Vec2 | m_localAnchorA
b2Vec2 | m_localAnchorB
float32 | m_constant
float32 | m_ratio
float32 | m_impulse
int32 | m_indexA
int32 | m_indexB
b2Vec2 | m_uA
b2Vec2 | m_uB
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

The pulley joint is connected to two bodies and two fixed ground points. The pulley supports a ratio such that: length1 + ratio * length2 <= constant Yes, the force transmitted is scaled by the ratio. Warning: the pulley joint can get a bit squirrelly by itself. They often work better when combined with prismatic joints. You should also cover the the anchor points with static shapes to prevent one side from going to zero length.

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

- b2PulleyJoint.h
- b2PulleyJoint.cpp

All Classes Files Functions Variables Enumerations Enumerator Defines