public class RevoluteJointDef
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:
you might not know where the center of mass will be.
if you add/remove shapes from a body and recompute the mass, the joints will be broken.
Fields
public Vec2 localAnchorA | The local anchor point relative to body1’s origin. |
public Vec2 localAnchorB | The local anchor point relative to body2’s origin. |
public float referenceAngle | The body2 angle minus body1 angle in the reference state (radians). |
public boolean enableLimit | A flag to enable joint limits. |
public float lowerAngle | The lower angle for the joint limit (radians). |
public float upperAngle | The upper angle for the joint limit (radians). |
public boolean enableMotor | A flag to enable the joint motor. |
public float motorSpeed | The desired motor speed. |
public float maxMotorTorque | The maximum motor torque used to achieve the desired motor speed. |
Constructors
public RevoluteJointDef() |
Methods
public void initialize(Body b1, Body b2, Vec2 anchor) | Initialize the bodies, anchors, and reference angle using the world anchor. |
Inherited fields
Inherited methods
Field details
localAnchorA
public Vec2 localAnchorAThe local anchor point relative to body1’s origin.
localAnchorB
public Vec2 localAnchorBThe local anchor point relative to body2’s origin.
referenceAngle
public float referenceAngleThe body2 angle minus body1 angle in the reference state (radians).
enableLimit
public boolean enableLimitA flag to enable joint limits.
lowerAngle
public float lowerAngleThe lower angle for the joint limit (radians).
upperAngle
public float upperAngleThe upper angle for the joint limit (radians).
enableMotor
public boolean enableMotorA flag to enable the joint motor.
motorSpeed
public float motorSpeedThe desired motor speed. Usually in radians per second.
maxMotorTorque
public float maxMotorTorqueThe maximum motor torque used to achieve the desired motor speed.
Usually in N-m.
Constructor details
RevoluteJointDef
public RevoluteJointDef()Method details
initialize
public void initialize(Body b1, Body b2, Vec2 anchor)Initialize the bodies, anchors, and reference angle using the world
anchor.