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      1 /*
      2  * Copyright (c) 2009-2010 jMonkeyEngine
      3  * All rights reserved.
      4  *
      5  * Redistribution and use in source and binary forms, with or without
      6  * modification, are permitted provided that the following conditions are
      7  * met:
      8  *
      9  * * Redistributions of source code must retain the above copyright
     10  *   notice, this list of conditions and the following disclaimer.
     11  *
     12  * * Redistributions in binary form must reproduce the above copyright
     13  *   notice, this list of conditions and the following disclaimer in the
     14  *   documentation and/or other materials provided with the distribution.
     15  *
     16  * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
     17  *   may be used to endorse or promote products derived from this software
     18  *   without specific prior written permission.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
     24  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     25  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     26  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     27  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
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     29  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
     30  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 package com.jme3.bullet.joints;
     33 
     34 import com.jme3.bullet.objects.PhysicsRigidBody;
     35 import com.jme3.export.InputCapsule;
     36 import com.jme3.export.JmeExporter;
     37 import com.jme3.export.JmeImporter;
     38 import com.jme3.export.OutputCapsule;
     39 import com.jme3.math.Vector3f;
     40 import java.io.IOException;
     41 import java.util.logging.Level;
     42 import java.util.logging.Logger;
     43 
     44 /**
     45  * <i>From bullet manual:</i><br>
     46  * Hinge constraint, or revolute joint restricts two additional angular degrees of freedom,
     47  * so the body can only rotate around one axis, the hinge axis.
     48  * This can be useful to represent doors or wheels rotating around one axis.
     49  * The user can specify limits and motor for the hinge.
     50  * @author normenhansen
     51  */
     52 public class HingeJoint extends PhysicsJoint {
     53 
     54     protected Vector3f axisA;
     55     protected Vector3f axisB;
     56     protected boolean angularOnly = false;
     57     protected float biasFactor = 0.3f;
     58     protected float relaxationFactor = 1.0f;
     59     protected float limitSoftness = 0.9f;
     60 
     61     public HingeJoint() {
     62     }
     63 
     64     /**
     65      * Creates a new HingeJoint
     66      * @param pivotA local translation of the joint connection point in node A
     67      * @param pivotB local translation of the joint connection point in node B
     68      */
     69     public HingeJoint(PhysicsRigidBody nodeA, PhysicsRigidBody nodeB, Vector3f pivotA, Vector3f pivotB, Vector3f axisA, Vector3f axisB) {
     70         super(nodeA, nodeB, pivotA, pivotB);
     71         this.axisA = axisA;
     72         this.axisB = axisB;
     73         createJoint();
     74     }
     75 
     76     public void enableMotor(boolean enable, float targetVelocity, float maxMotorImpulse) {
     77         enableMotor(objectId, enable, targetVelocity, maxMotorImpulse);
     78     }
     79 
     80     private native void enableMotor(long objectId, boolean enable, float targetVelocity, float maxMotorImpulse);
     81 
     82     public boolean getEnableMotor() {
     83         return getEnableAngularMotor(objectId);
     84     }
     85 
     86     private native boolean getEnableAngularMotor(long objectId);
     87 
     88     public float getMotorTargetVelocity() {
     89         return getMotorTargetVelocity(objectId);
     90     }
     91 
     92     private native float getMotorTargetVelocity(long objectId);
     93 
     94     public float getMaxMotorImpulse() {
     95         return getMaxMotorImpulse(objectId);
     96     }
     97 
     98     private native float getMaxMotorImpulse(long objectId);
     99 
    100     public void setLimit(float low, float high) {
    101         setLimit(objectId, low, high);
    102     }
    103 
    104     private native void setLimit(long objectId, float low, float high);
    105 
    106     public void setLimit(float low, float high, float _softness, float _biasFactor, float _relaxationFactor) {
    107         biasFactor = _biasFactor;
    108         relaxationFactor = _relaxationFactor;
    109         limitSoftness = _softness;
    110         setLimit(objectId, low, high, _softness, _biasFactor, _relaxationFactor);
    111     }
    112 
    113     private native void setLimit(long objectId, float low, float high, float _softness, float _biasFactor, float _relaxationFactor);
    114 
    115     public float getUpperLimit() {
    116         return getUpperLimit(objectId);
    117     }
    118 
    119     private native float getUpperLimit(long objectId);
    120 
    121     public float getLowerLimit() {
    122         return getLowerLimit(objectId);
    123     }
    124 
    125     private native float getLowerLimit(long objectId);
    126 
    127     public void setAngularOnly(boolean angularOnly) {
    128         this.angularOnly = angularOnly;
    129         setAngularOnly(objectId, angularOnly);
    130     }
    131 
    132     private native void setAngularOnly(long objectId, boolean angularOnly);
    133 
    134     public float getHingeAngle() {
    135         return getHingeAngle(objectId);
    136     }
    137 
    138     private native float getHingeAngle(long objectId);
    139 
    140     public void write(JmeExporter ex) throws IOException {
    141         super.write(ex);
    142         OutputCapsule capsule = ex.getCapsule(this);
    143         capsule.write(axisA, "axisA", new Vector3f());
    144         capsule.write(axisB, "axisB", new Vector3f());
    145 
    146         capsule.write(angularOnly, "angularOnly", false);
    147 
    148         capsule.write(getLowerLimit(), "lowerLimit", 1e30f);
    149         capsule.write(getUpperLimit(), "upperLimit", -1e30f);
    150 
    151         capsule.write(biasFactor, "biasFactor", 0.3f);
    152         capsule.write(relaxationFactor, "relaxationFactor", 1f);
    153         capsule.write(limitSoftness, "limitSoftness", 0.9f);
    154 
    155         capsule.write(getEnableMotor(), "enableAngularMotor", false);
    156         capsule.write(getMotorTargetVelocity(), "targetVelocity", 0.0f);
    157         capsule.write(getMaxMotorImpulse(), "maxMotorImpulse", 0.0f);
    158     }
    159 
    160     public void read(JmeImporter im) throws IOException {
    161         super.read(im);
    162         InputCapsule capsule = im.getCapsule(this);
    163         this.axisA = (Vector3f) capsule.readSavable("axisA", new Vector3f());
    164         this.axisB = (Vector3f) capsule.readSavable("axisB", new Vector3f());
    165 
    166         this.angularOnly = capsule.readBoolean("angularOnly", false);
    167         float lowerLimit = capsule.readFloat("lowerLimit", 1e30f);
    168         float upperLimit = capsule.readFloat("upperLimit", -1e30f);
    169 
    170         this.biasFactor = capsule.readFloat("biasFactor", 0.3f);
    171         this.relaxationFactor = capsule.readFloat("relaxationFactor", 1f);
    172         this.limitSoftness = capsule.readFloat("limitSoftness", 0.9f);
    173 
    174         boolean enableAngularMotor = capsule.readBoolean("enableAngularMotor", false);
    175         float targetVelocity = capsule.readFloat("targetVelocity", 0.0f);
    176         float maxMotorImpulse = capsule.readFloat("maxMotorImpulse", 0.0f);
    177 
    178         createJoint();
    179         enableMotor(enableAngularMotor, targetVelocity, maxMotorImpulse);
    180         setLimit(lowerLimit, upperLimit, limitSoftness, biasFactor, relaxationFactor);
    181     }
    182 
    183     protected void createJoint() {
    184         objectId = createJoint(nodeA.getObjectId(), nodeB.getObjectId(), pivotA, axisA, pivotB, axisB);
    185         Logger.getLogger(this.getClass().getName()).log(Level.INFO, "Created Joint {0}", Long.toHexString(objectId));
    186     }
    187 
    188     private native long createJoint(long objectIdA, long objectIdB, Vector3f pivotA, Vector3f axisA, Vector3f pivotB, Vector3f axisB);
    189 }
    190