Android Open Source - gameengine Pulley Joint

• Back to Game/engine  ↑

From Project

Back to project page gameengine.

License

The source code is released under:

Apache License

Java Source Code

/*******************************************************************************
 * Copyright 2011 See AUTHORS file./* w  ww.java  2  s . 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.Joint;
import com.badlogic.gdx.physics.box2d.World;

/**
 * The pulley joint is connected to two bodies and two fixed ground points. The
 * pulley supports a ratio such that: length1 + ratio * length2 <= constant Yes,
 * the force transmitted is scaled by the ratio. The pulley also enforces a
 * maximum length limit on both sides. This is useful to prevent one side of the
 * pulley hitting the top.
 */
public class PulleyJoint extends Joint {
    /*
     * JNI #include <Box2D/Box2D.h>
     */

    public PulleyJoint(World world, long addr) {
        super(world, addr);
    }

    /** Get the first ground anchor. */
    private final float[] tmp = new float[2];
    private final Vector2 groundAnchorA = new Vector2();

    public Vector2 getGroundAnchorA() {
        jniGetGroundAnchorA(addr, tmp);
        groundAnchorA.set(tmp[0], tmp[1]);
        return groundAnchorA;
    }

    private native void jniGetGroundAnchorA(long addr, float[] anchor); /*
                                                                         * b2PulleyJoint
                                                                         * *
                                                                         * joint
                                                                         * = (
                                                                         * b2PulleyJoint
                                                                         * *
                                                                         * )addr
                                                                         * ;
                                                                         * anchor
                                                                         * [0] =
                                                                         * joint
                                                                         * ->
                                                                         * GetGroundAnchorA
                                                                         * ().x;
                                                                         * anchor
                                                                         * [1] =
                                                                         * joint
                                                                         * ->
                                                                         * GetGroundAnchorA
                                                                         * ().y;
                                                                         */

    /** Get the second ground anchor. */
    private final Vector2 groundAnchorB = new Vector2();

    public Vector2 getGroundAnchorB() {
        jniGetGroundAnchorB(addr, tmp);
        groundAnchorB.set(tmp[0], tmp[1]);
        return groundAnchorB;
    }

    private native void jniGetGroundAnchorB(long addr, float[] anchor); /*
                                                                         * b2PulleyJoint
                                                                         * *
                                                                         * joint
                                                                         * = (
                                                                         * b2PulleyJoint
                                                                         * *
                                                                         * )addr
                                                                         * ;
                                                                         * anchor
                                                                         * [0] =
                                                                         * joint
                                                                         * ->
                                                                         * GetGroundAnchorB
                                                                         * ().x;
                                                                         * anchor
                                                                         * [1] =
                                                                         * joint
                                                                         * ->
                                                                         * GetGroundAnchorB
                                                                         * ().y;
                                                                         */

    /** Get the current length of the segment attached to body1. */
    public float getLength1() {
        return jniGetLength1(addr);
    }

    private native float jniGetLength1(long addr); /*
                                                    * b2PulleyJoint* joint =
                                                    * (b2PulleyJoint*)addr;
                                                    * return
                                                    * joint->GetLengthA();
                                                    */

    /** Get the current length of the segment attached to body2. */
    public float getLength2() {
        return jniGetLength2(addr);
    }

    private native float jniGetLength2(long addr); /*
                                                    * b2PulleyJoint* joint =
                                                    * (b2PulleyJoint*)addr;
                                                    * return
                                                    * joint->GetLengthB();
                                                    */

    /** Get the pulley ratio. */
    public float getRatio() {
        return jniGetRatio(addr);
    }

    private native float jniGetRatio(long addr); /*
                                                  * b2PulleyJoint* joint =
                                                  * (b2PulleyJoint*)addr; return
                                                  * joint->GetRatio();
                                                  */
}

Java Source Code List

• Back to Game/engine  ↑