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
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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.
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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
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31 */
32package com.jme3.bullet.joints;
33
34import com.bulletphysics.dynamics.constraintsolver.HingeConstraint;
35import com.jme3.bullet.objects.PhysicsRigidBody;
36import com.jme3.bullet.util.Converter;
37import com.jme3.export.InputCapsule;
38import com.jme3.export.JmeExporter;
39import com.jme3.export.JmeImporter;
40import com.jme3.export.OutputCapsule;
41import com.jme3.math.Vector3f;
42import java.io.IOException;
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 */
52public 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        ((HingeConstraint) constraint).enableAngularMotor(enable, targetVelocity, maxMotorImpulse);
78    }
79
80    public void setLimit(float low, float high) {
81        ((HingeConstraint) constraint).setLimit(low, high);
82    }
83
84    public void setLimit(float low, float high, float _softness, float _biasFactor, float _relaxationFactor) {
85        biasFactor = _biasFactor;
86        relaxationFactor = _relaxationFactor;
87        limitSoftness = _softness;
88        ((HingeConstraint) constraint).setLimit(low, high, _softness, _biasFactor, _relaxationFactor);
89    }
90
91    public float getUpperLimit(){
92        return ((HingeConstraint) constraint).getUpperLimit();
93    }
94
95    public float getLowerLimit(){
96        return ((HingeConstraint) constraint).getLowerLimit();
97    }
98
99    public void setAngularOnly(boolean angularOnly) {
100        this.angularOnly = angularOnly;
101        ((HingeConstraint) constraint).setAngularOnly(angularOnly);
102    }
103
104    public float getHingeAngle() {
105        return ((HingeConstraint) constraint).getHingeAngle();
106    }
107
108    public void write(JmeExporter ex) throws IOException {
109        super.write(ex);
110        OutputCapsule capsule = ex.getCapsule(this);
111        capsule.write(axisA, "axisA", new Vector3f());
112        capsule.write(axisB, "axisB", new Vector3f());
113
114        capsule.write(angularOnly, "angularOnly", false);
115
116        capsule.write(((HingeConstraint) constraint).getLowerLimit(), "lowerLimit", 1e30f);
117        capsule.write(((HingeConstraint) constraint).getUpperLimit(), "upperLimit", -1e30f);
118
119        capsule.write(biasFactor, "biasFactor", 0.3f);
120        capsule.write(relaxationFactor, "relaxationFactor", 1f);
121        capsule.write(limitSoftness, "limitSoftness", 0.9f);
122
123        capsule.write(((HingeConstraint) constraint).getEnableAngularMotor(), "enableAngularMotor", false);
124        capsule.write(((HingeConstraint) constraint).getMotorTargetVelosity(), "targetVelocity", 0.0f);
125        capsule.write(((HingeConstraint) constraint).getMaxMotorImpulse(), "maxMotorImpulse", 0.0f);
126    }
127
128    public void read(JmeImporter im) throws IOException {
129        super.read(im);
130        InputCapsule capsule = im.getCapsule(this);
131        this.axisA = (Vector3f) capsule.readSavable("axisA", new Vector3f());
132        this.axisB = (Vector3f) capsule.readSavable("axisB", new Vector3f());
133
134        this.angularOnly = capsule.readBoolean("angularOnly", false);
135        float lowerLimit = capsule.readFloat("lowerLimit", 1e30f);
136        float upperLimit = capsule.readFloat("upperLimit", -1e30f);
137
138        this.biasFactor = capsule.readFloat("biasFactor", 0.3f);
139        this.relaxationFactor = capsule.readFloat("relaxationFactor", 1f);
140        this.limitSoftness = capsule.readFloat("limitSoftness", 0.9f);
141
142        boolean enableAngularMotor=capsule.readBoolean("enableAngularMotor", false);
143        float targetVelocity=capsule.readFloat("targetVelocity", 0.0f);
144        float maxMotorImpulse=capsule.readFloat("maxMotorImpulse", 0.0f);
145
146        createJoint();
147        enableMotor(enableAngularMotor, targetVelocity, maxMotorImpulse);
148        ((HingeConstraint) constraint).setLimit(lowerLimit, upperLimit, limitSoftness, biasFactor, relaxationFactor);
149    }
150
151    protected void createJoint() {
152        constraint = new HingeConstraint(nodeA.getObjectId(), nodeB.getObjectId(),
153                Converter.convert(pivotA), Converter.convert(pivotB),
154                Converter.convert(axisA), Converter.convert(axisB));
155    }
156}
157