/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.math4.userguide.genetics;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.geom.GeneralPath;
import org.apache.commons.rng.UniformRandomProvider;
import org.apache.commons.rng.simple.RandomSource;
import org.apache.commons.math4.genetics.GeneticAlgorithm;
import org.apache.commons.math4.util.FastMath;
/**
* Represents a fixed size polgon with its fill color.
*/
public class Polygon {
// the polygon in packed representation:
// index | data
// 0 | red component
// 1 | green component
// 2 | blue component
// 3 | alpha channel
// 4 | first x coordinate
// 5 | first y coordinate
// 6 | second x coordinate
// ...
// N | last y coordinate
// ---------------------------
/// size = 4 + 2*polygonlength
private float[] data;
/**
* Creates a new random Polygon of the given length.
*/
public static Polygon randomPolygon(int length) {
final int polygonSize = 4 + 2 * length;
final UniformRandomProvider random = GeneticAlgorithm.getRandomGenerator();
Polygon p = new Polygon();
p.data = new float[polygonSize];
p.data[0] = random.nextFloat(); // r
p.data[1] = random.nextFloat(); // g
p.data[2] = random.nextFloat(); // b
p.data[3] = FastMath.max(0.2f, random.nextFloat() * random.nextFloat()); // a
float px = random.nextFloat();
float py = random.nextFloat();
for (int k = 0; k < length; k++) {
p.data[4 + 2*k] = px + (random.nextFloat() - 0.5f);
p.data[5 + 2*k] = py + (random.nextFloat() - 0.5f);
}
return p;
}
/**
* Return a new Polygon, mutated with the given rate and amount.
* <p>
* Each component of the Polygon may be mutated according to the specified mutation rate.
* In case a component is going to be mutated, its value will be randomly modified in the
* uniform range of [-mutationAmount, +mutationAmount].
*
* @param mutationRate the mutation rate
* @param mutationAmount the mutation amount
* @return a new Polygon
*/
public Polygon mutate(float mutationRate, float mutationAmount) {
Polygon mutated = new Polygon();
int size = data.length;
mutated.data = new float[size];
for (int i = 0; i < size; i++) {
float val = this.data[i];
if (GeneticAlgorithm.getRandomGenerator().nextFloat() < mutationRate) {
val += GeneticAlgorithm.getRandomGenerator().nextFloat() * mutationAmount * 2 - mutationAmount;
if (val < 0f) {
val = 0f;
} else if (val > 1f) {
val = 1f;
}
}
mutated.data[i] = val;
}
return mutated;
}
/**
* Draw the Polygon to the buffer of the given size.
*/
public void draw(Graphics2D g, int width, int height) {
g.setColor(new Color(data[0], data[1], data[2], data[3]));
GeneralPath path = new GeneralPath();
path.moveTo(data[4] * width, data[5] * height);
int polygonLength = (data.length - 4) / 2;
for (int j = 1; j < polygonLength; j++) {
path.lineTo(data[4 + j * 2] * width, data[5 + j * 2] * height);
}
path.closePath();
g.fill(path);
}
}