Box2D: b2RevoluteJointDef Struct Reference

Box2D

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b2RevoluteJointDef Struct Reference

Revolute joint definition. More...

Inheritance diagram for b2RevoluteJointDef:

b2JointDef

List of all members.

Public Member Functions

void Initialize (b2Body *body1, b2Body *body2, const b2Vec2 &anchor)
 Initialize the bodies, anchors, and reference angle using the world anchor.

Public Attributes

b2Vec2 localAnchor1
 The local anchor point relative to body1's origin.
b2Vec2 localAnchor2
 The local anchor point relative to body2's origin.
float32 referenceAngle
 The body2 angle minus body1 angle in the reference state (radians).
bool enableLimit
 A flag to enable joint limits.
float32 lowerAngle
 The lower angle for the joint limit (radians).
float32 upperAngle
 The upper angle for the joint limit (radians).
bool enableMotor
 A flag to enable the joint motor.
float32 motorSpeed
 The desired motor speed. Usually in radians per second.
float32 maxMotorTorque
 The maximum motor torque used to achieve the desired motor speed.

Detailed Description

Revolute joint definition.

This requires defining an anchor point where the bodies are joined. The definition uses local anchor points so that the initial configuration can violate the constraint slightly. You also need to specify the initial relative angle for joint limits. This helps when saving and loading a game. The local anchor points are measured from the body's origin rather than the center of mass because: 1. you might not know where the center of mass will be. 2. if you add/remove shapes from a body and recompute the mass, the joints will be broken.

Member Function Documentation

void b2RevoluteJointDef::Initialize ( b2Body *  body1,
b2Body *  body2,
const b2Vec2 &  anchor 
)

Initialize the bodies, anchors, and reference angle using the world anchor.

Member Data Documentation

float32 b2RevoluteJointDef::maxMotorTorque

The maximum motor torque used to achieve the desired motor speed.

Usually in N-m.

The documentation for this struct was generated from the following files:
  • b2RevoluteJoint.h
  • b2RevoluteJoint.cpp
Generated on Sun Apr 13 15:21:27 2008 for Box2D by  doxygen 1.5.4

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