Class RevoluteJointDef


  • public class RevoluteJointDef
    extends JointDef
    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.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      void initialize​(Body b1, Body b2, Vec2 anchor)
      Initialize the bodies, anchors, and reference angle using the world anchor.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Field Detail

      • localAnchorA

        public Vec2 localAnchorA
        The local anchor point relative to body1's origin.
      • localAnchorB

        public Vec2 localAnchorB
        The local anchor point relative to body2's origin.
      • referenceAngle

        public float referenceAngle
        The body2 angle minus body1 angle in the reference state (radians).
      • enableLimit

        public boolean enableLimit
        A flag to enable joint limits.
      • lowerAngle

        public float lowerAngle
        The lower angle for the joint limit (radians).
      • upperAngle

        public float upperAngle
        The upper angle for the joint limit (radians).
      • enableMotor

        public boolean enableMotor
        A flag to enable the joint motor.
      • motorSpeed

        public float motorSpeed
        The desired motor speed. Usually in radians per second.
      • maxMotorTorque

        public float maxMotorTorque
        The maximum motor torque used to achieve the desired motor speed. Usually in N-m.
    • Constructor Detail

      • RevoluteJointDef

        public RevoluteJointDef()
    • Method Detail

      • initialize

        public void initialize​(Body b1,
                               Body b2,
                               Vec2 anchor)
        Initialize the bodies, anchors, and reference angle using the world anchor.
        Parameters:
        b1 -
        b2 -
        anchor -