org.joml.sampling.UniformSampling Maven / Gradle / Ivy
/*
* (C) Copyright 2016-2017 JOML
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 org.joml.sampling;
/**
* Generates uniform samples.
*
* @author Kai Burjack
*/
public class UniformSampling {
/**
* Generates uniform samples on a unit disk.
*
* @author Kai Burjack
*/
public static class Disk {
private final Random rnd;
/**
* Create a new instance of {@link Disk}, initialize the random number generator with the given seed and generate numSamples number of sample
* positions on the unit disk, and call the given callback for each sample generate.
*
* @param seed
* the seed to initialize the random number generator with
* @param numSamples
* the number of samples to generate
* @param callback
* will be called for each sample generated
*/
public Disk(long seed, int numSamples, Callback2d callback) {
this.rnd = new Random(seed);
generate(numSamples, callback);
}
private void generate(int numSamples, Callback2d callback) {
for (int i = 0; i < numSamples; i++) {
float r = rnd.nextFloat();
float a = rnd.nextFloat() * 2.0f * (float) Math.PI;
float sqrtR = (float) Math.sqrt(r);
float x = sqrtR * (float) Math.sin_roquen_9(a + 0.5 * Math.PI);
float y = sqrtR * (float) Math.sin_roquen_9(a);
callback.onNewSample(x, y);
}
}
}
/**
* Generates uniform samples on a unit sphere.
*
* @author Kai Burjack
*/
public static class Sphere {
private final Random rnd;
/**
* Create a new instance of {@link Sphere}, initialize the random number generator with the given seed and generate numSamples number of sample
* positions on the unit sphere, and call the given callback for each sample generate.
*
* @param seed
* the seed to initialize the random number generator with
* @param numSamples
* the number of samples to generate
* @param callback
* will be called for each sample generated
*/
public Sphere(long seed, int numSamples, Callback3d callback) {
this.rnd = new Random(seed);
generate(numSamples, callback);
}
/**
* Create numSamples number of samples which are uniformly distributed on a unit sphere, and call the given callback for each sample generated.
*
* Reference: http://mathworld.wolfram.com/
*
* @param numSamples
* the number of samples to generate
* @param callback
* will be called for each sample generated
*/
public void generate(int numSamples, Callback3d callback) {
for (int i = 0; i < numSamples;) {
float x1 = rnd.nextFloat() * 2.0f - 1.0f;
float x2 = rnd.nextFloat() * 2.0f - 1.0f;
if (x1 * x1 + x2 * x2 >= 1.0f)
continue;
float sqrt = (float) Math.sqrt(1.0 - x1 * x1 - x2 * x2);
float x = 2 * x1 * sqrt;
float y = 2 * x2 * sqrt;
float z = 1.0f - 2.0f * (x1 * x1 + x2 * x2);
callback.onNewSample(x, y, z);
i++;
}
}
}
}