/*
* Copyright 2010 Mario Zechner (contact@badlogicgames.com), Nathan Sweet (admin@esotericsoftware.com)
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS"
* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language
* governing permissions and limitations under the License.
*/
package com.badlogic.gdx.physics.box2d.joints;
import com.badlogic.gdx.math.Vector2;
import com.badlogic.gdx.physics.box2d.Body;
import com.badlogic.gdx.physics.box2d.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: 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.
*/
public class RevoluteJointDef extends JointDef {
public RevoluteJointDef () {
type = JointType.RevoluteJoint;
}
/**
* Initialize the bodies, anchors, and reference angle using a world anchor point.
*/
public void initialize (Body bodyA, Body bodyB, Vector2 anchor) {
this.bodyA = bodyA;
this.bodyB = bodyB;
localAnchorA.set(bodyA.getLocalPoint(anchor));
localAnchorB.set(bodyB.getLocalPoint(anchor));
referenceAngle = bodyB.getAngle() - bodyA.getAngle();
}
/**
* The local anchor point relative to body1's origin.
*/
public final Vector2 localAnchorA = new Vector2();
/**
* The local anchor point relative to body2's origin.
*/
public final Vector2 localAnchorB = new Vector2();;
/**
* The body2 angle minus body1 angle in the reference state (radians).
*/
public float referenceAngle = 0;
/**
* A flag to enable joint limits.
*/
public boolean enableLimit = false;
/**
* The lower angle for the joint limit (radians).
*/
public float lowerAngle = 0;
/**
* The upper angle for the joint limit (radians).
*/
public float upperAngle = 0;
/**
* A flag to enable the joint motor.
*/
public boolean enableMotor = false;
/**
* The desired motor speed. Usually in radians per second.
*/
public float motorSpeed = 0;
/**
* The maximum motor torque used to achieve the desired motor speed. Usually in N-m.
*/
public float maxMotorTorque = 0;
}
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