/**
* Java Modular Image Synthesis Toolkit (JMIST)
* Copyright (C) 2008-2013 Bradley W. Kimmel
*
* Permission is hereby granted, free of charge, to any person
* obtaining a copy of this software and associated documentation
* files (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use,
* copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following
* conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
* OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
* WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
package ca.eandb.jmist.framework.accel;
import ca.eandb.jmist.framework.IntersectionRecorder;
import ca.eandb.jmist.framework.NearestIntersectionRecorder;
import ca.eandb.jmist.framework.SceneElement;
import ca.eandb.jmist.framework.Visitor;
import ca.eandb.jmist.framework.scene.SceneElementDecorator;
import ca.eandb.jmist.math.Interval;
import ca.eandb.jmist.math.Ray3;
/**
* A decorator <code>SceneElement</code> that applies a bounding box hierarchy
* to the decorated <code>SceneElement</code> to accelerate ray-intersection
* tests.
*
* @author Brad Kimmel
*/
public final class BBHSceneElement extends SceneElementDecorator {
/** Serialization version ID. */
private static final long serialVersionUID = -3334720789877135936L;
/**
* The <code>BoundingBoxHierarchy3</code> to use for accelerating
* ray-intersection tests.
*/
private transient BoundingBoxHierarchy3 bbh = null;
/**
* @param inner
*/
public BBHSceneElement(SceneElement inner) {
super(inner);
}
/** Called to build the BBH on demand. */
private void ensureReady() {
if (bbh == null) {
build();
}
}
/** Builds the BBH. */
private synchronized void build() {
if (bbh != null) { // double check inside synchronized method
return;
}
bbh = new BoundingBoxHierarchy3();
for (int i = 0, n = getNumPrimitives(); i < n; i++) {
bbh.addItem(i, getBoundingBox(i));
}
}
/**
* The <code>Visitor</code> used by the BBH.
* @author Brad Kimmel
*/
private final class BBHVisitor implements Visitor {
/** The <code>Ray3</code> to perform intersection tests with. */
private final Ray3 ray;
/** The <code>IntersectionRecorder</code> to record intersections to. */
private final IntersectionRecorder recorder;
/**
* Creates a new <code>BBHVisitor</code>.
* @param ray The <code>Ray3</code> to perform intersection tests with.
* @param recorder The <code>IntersectionRecorder</code> to record
* intersections to.
*/
public BBHVisitor(Ray3 ray, IntersectionRecorder recorder) {
this.ray = ray;
this.recorder = recorder;
}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.Visitor#visit(java.lang.Object)
*/
@Override
public boolean visit(Object object) {
int index = (Integer) object;
intersect(index, ray, recorder);
return true;
}
}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.scene.SceneElementDecorator#intersect(ca.eandb.jmist.math.Ray3, ca.eandb.jmist.framework.IntersectionRecorder)
*/
@Override
public void intersect(Ray3 ray, IntersectionRecorder recorder) {
ensureReady();
bbh.intersect(ray, recorder.interval(), new BBHVisitor(ray, recorder));
}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.scene.SceneElementDecorator#visibility(ca.eandb.jmist.math.Ray3)
*/
@Override
public boolean visibility(Ray3 ray) {
NearestIntersectionRecorder recorder = new NearestIntersectionRecorder(new Interval(0.0, ray.limit()));
intersect(ray, recorder);
return recorder.isEmpty();
}
}