/**
* Minimal constructor.
*
* <p>Creates a fixed distance {@link Joint} where the joined {@link Body}s do not participate in
* collision detection and resolution.
*
* @param body1 the first {@link Body}
* @param body2 the second {@link Body}
* @param anchor1 in world coordinates
* @param anchor2 in world coordinates
* @throws NullPointerException if body1, body2, anchor1, or anchor2 is null
* @throws IllegalArgumentException if body1 == body2
*/
public DistanceJoint(Body body1, Body body2, Vector2 anchor1, Vector2 anchor2) {
super(body1, body2, false);
// verify the bodies are not the same instance
if (body1 == body2)
throw new IllegalArgumentException(Messages.getString("dynamics.joint.sameBody"));
// verify the anchor points are not null
if (anchor1 == null)
throw new NullPointerException(Messages.getString("dynamics.joint.nullAnchor1"));
if (anchor2 == null)
throw new NullPointerException(Messages.getString("dynamics.joint.nullAnchor2"));
// get the local anchor points
this.localAnchor1 = body1.getLocalPoint(anchor1);
this.localAnchor2 = body2.getLocalPoint(anchor2);
// compute the initial distance
this.distance = anchor1.distance(anchor2);
}
/**
* Minimal constructor.
*
* @param body1 the first {@link Body}
* @param body2 the second {@link Body}
* @throws NullPointerException if body1 or body2 is null
* @throws IllegalArgumentException if body1 == body2
*/
public AngleJoint(Body body1, Body body2) {
// default no collision allowed
super(body1, body2, false);
// verify the bodies are not the same instance
if (body1 == body2)
throw new IllegalArgumentException(Messages.getString("dynamics.joint.sameBody"));
// initialize
this.ratio = 1.0;
this.impulse = 0.0;
// compute the reference angle
this.referenceAngle = body1.getTransform().getRotation() - body2.getTransform().getRotation();
// set both limits
this.upperLimit = this.referenceAngle;
this.lowerLimit = this.referenceAngle;
// set enabled
this.limitEnabled = true;
// default the limit state
this.limitState = LimitState.EQUAL;
}
