com.badlogic.gdx.physics.box2d.joints.RevoluteJointDef Maven / Gradle / Ivy
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* Copyright 2011 See AUTHORS file.
*
* 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.
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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;
}