/*
* Copyright (c) 2009-2012 jMonkeyEngine
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* * Neither the name of 'jMonkeyEngine' nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package com.jme3.math;
import com.jme3.export.*;
import java.io.IOException;
/**
* <code>Ring</code> defines a flat ring or disk within three dimensional
* space that is specified via the ring's center point, an up vector, an inner
* radius, and an outer radius.
*
* @author Andrzej Kapolka
* @author Joshua Slack
*/
public final class Ring implements Savable, Cloneable, java.io.Serializable {
static final long serialVersionUID = 1;
private Vector3f center, up;
private float innerRadius, outerRadius;
private transient static Vector3f b1 = new Vector3f(), b2 = new Vector3f();
/**
* Constructor creates a new <code>Ring</code> lying on the XZ plane,
* centered at the origin, with an inner radius of zero and an outer radius
* of one (a unit disk).
*/
public Ring() {
center = new Vector3f();
up = Vector3f.UNIT_Y.clone();
innerRadius = 0f;
outerRadius = 1f;
}
/**
* Constructor creates a new <code>Ring</code> with defined center point,
* up vector, and inner and outer radii.
*
* @param center
* the center of the ring.
* @param up
* the unit up vector defining the ring's orientation.
* @param innerRadius
* the ring's inner radius.
* @param outerRadius
* the ring's outer radius.
*/
public Ring(Vector3f center, Vector3f up, float innerRadius,
float outerRadius) {
this.center = center;
this.up = up;
this.innerRadius = innerRadius;
this.outerRadius = outerRadius;
}
/**
* <code>getCenter</code> returns the center of the ring.
*
* @return the center of the ring.
*/
public Vector3f getCenter() {
return center;
}
/**
* <code>setCenter</code> sets the center of the ring.
*
* @param center
* the center of the ring.
*/
public void setCenter(Vector3f center) {
this.center = center;
}
/**
* <code>getUp</code> returns the ring's up vector.
*
* @return the ring's up vector.
*/
public Vector3f getUp() {
return up;
}
/**
* <code>setUp</code> sets the ring's up vector.
*
* @param up
* the ring's up vector.
*/
public void setUp(Vector3f up) {
this.up = up;
}
/**
* <code>getInnerRadius</code> returns the ring's inner radius.
*
* @return the ring's inner radius.
*/
public float getInnerRadius() {
return innerRadius;
}
/**
* <code>setInnerRadius</code> sets the ring's inner radius.
*
* @param innerRadius
* the ring's inner radius.
*/
public void setInnerRadius(float innerRadius) {
this.innerRadius = innerRadius;
}
/**
* <code>getOuterRadius</code> returns the ring's outer radius.
*
* @return the ring's outer radius.
*/
public float getOuterRadius() {
return outerRadius;
}
/**
* <code>setOuterRadius</code> sets the ring's outer radius.
*
* @param outerRadius
* the ring's outer radius.
*/
public void setOuterRadius(float outerRadius) {
this.outerRadius = outerRadius;
}
/**
*
* <code>random</code> returns a random point within the ring.
*
* @return a random point within the ring.
*/
public Vector3f random() {
return random(null);
}
/**
*
* <code>random</code> returns a random point within the ring.
*
* @param result Vector to store result in
* @return a random point within the ring.
*/
public Vector3f random(Vector3f result) {
if (result == null) {
result = new Vector3f();
}
// compute a random radius according to the ring area distribution
float inner2 = innerRadius * innerRadius, outer2 = outerRadius
* outerRadius, r = FastMath.sqrt(inner2
+ FastMath.nextRandomFloat() * (outer2 - inner2)), theta = FastMath
.nextRandomFloat()
* FastMath.TWO_PI;
up.cross(Vector3f.UNIT_X, b1);
if (b1.lengthSquared() < FastMath.FLT_EPSILON) {
up.cross(Vector3f.UNIT_Y, b1);
}
b1.normalizeLocal();
up.cross(b1, b2);
result.set(b1).multLocal(r * FastMath.cos(theta)).addLocal(center);
result.scaleAdd(r * FastMath.sin(theta), b2, result);
return result;
}
public void write(JmeExporter e) throws IOException {
OutputCapsule capsule = e.getCapsule(this);
capsule.write(center, "center", Vector3f.ZERO);
capsule.write(up, "up", Vector3f.UNIT_Z);
capsule.write(innerRadius, "innerRadius", 0f);
capsule.write(outerRadius, "outerRadius", 1f);
}
public void read(JmeImporter e) throws IOException {
InputCapsule capsule = e.getCapsule(this);
center = (Vector3f) capsule.readSavable("center",
Vector3f.ZERO.clone());
up = (Vector3f) capsule
.readSavable("up", Vector3f.UNIT_Z.clone());
innerRadius = capsule.readFloat("innerRadius", 0f);
outerRadius = capsule.readFloat("outerRadius", 1f);
}
@Override
public Ring clone() {
try {
Ring r = (Ring) super.clone();
r.center = center.clone();
r.up = up.clone();
return r;
} catch (CloneNotSupportedException e) {
throw new AssertionError();
}
}
}