/**
* 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.light;
import java.util.Collection;
import ca.eandb.jmist.framework.Illuminable;
import ca.eandb.jmist.framework.Light;
import ca.eandb.jmist.framework.LightSample;
import ca.eandb.jmist.framework.Random;
import ca.eandb.jmist.framework.SurfacePoint;
import ca.eandb.jmist.framework.color.WavelengthPacket;
import ca.eandb.jmist.framework.path.LightNode;
import ca.eandb.jmist.framework.path.PathInfo;
import ca.eandb.jmist.framework.path.ScaledLightNode;
import ca.eandb.jmist.framework.random.RandomUtil;
import ca.eandb.jmist.framework.random.SeedReference;
/**
* @author Brad Kimmel
*
*/
public final class RandomCompositeLight extends CompositeLight {
/**
* Serialization version ID.
*/
private static final long serialVersionUID = 6951460238617706023L;
public RandomCompositeLight() {
super();
}
public RandomCompositeLight(Collection<? extends Light> children) {
super(children);
}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.Light#illuminate(ca.eandb.jmist.framework.SurfacePoint, ca.eandb.jmist.framework.color.WavelengthPacket, ca.eandb.jmist.framework.Random, ca.eandb.jmist.framework.Illuminable)
*/
public void illuminate(SurfacePoint x, WavelengthPacket lambda, Random rng, final Illuminable target) {
int index = RandomUtil.discrete(0, children().size() - 1, rng);
children().get(index).illuminate(x, lambda, rng, new Illuminable() {
public void addLightSample(LightSample sample) {
target.addLightSample(ScaledLightSample.create(children().size(), sample));
}
});
}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.Light#sample(ca.eandb.jmist.framework.path.PathInfo, ca.eandb.jmist.framework.Random)
*/
public LightNode sample(PathInfo pathInfo, double ru, double rv, double rj) {
SeedReference ref = new SeedReference(rj);
int index = RandomUtil.discrete(0, children().size() - 1, ref);
return ScaledLightNode.create(1.0 / children().size(),
children().get(index).sample(pathInfo, ru, rv, ref.seed), rj);
}
/* (non-Javadoc)
* @see ca.eandb.jmist.framework.Light#getSamplePDF(ca.eandb.jmist.framework.SurfacePoint, ca.eandb.jmist.framework.path.PathInfo)
*/
public double getSamplePDF(SurfacePoint x, PathInfo pathInfo) {
double pdf = 0.0;
for (Light light : children()) {
pdf += light.getSamplePDF(x, pathInfo);
}
return pdf / (double) children().size();
}
}