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Scarsz/GenerateUndirectedGraphWithRoutesMaxLength.java

Last active April 21, 2018 01:21
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Join a list of points with routes of a maximum length
Raw
GenerateUndirectedGraphWithRoutesMaxLength.java
import javafx.geometry.Point3D;
import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import java.util.HashSet;
import java.util.Random;
import java.util.Set;
/**
* Note: Point3D's are used though this is a 2D graph.<br>
* This is because this gist was originally made with the intent to route points in 3D.
* The resulting picture is 2D just to show the concept.
*/
public class GenerateUndirectedGraphWithRoutesMaxLength {
public static final File OUTPUT = new File("output.png");
public static final Random RANDOM = new Random();
public static void main(String[] args) {
int pointsToGenerate = 25;
int maxDistanceBetweenPoints = 100;
int connectionWidth = 3;
int pointSize = 20;
int pictureSize = 1000;
int borderSize = 100;
Set<Point3D> points = new HashSet<>();
for (int i = 0; i < pointsToGenerate; i++) points.add(new Point3D(RANDOM.nextInt(pictureSize - (borderSize * 2)) + borderSize, RANDOM.nextInt(pictureSize - (borderSize * 2)) + borderSize, 0));
Set<Route> routes = Route.computeAllRoutes(points, maxDistanceBetweenPoints);
try {
BufferedImage image = new BufferedImage(pictureSize, pictureSize, BufferedImage.TYPE_INT_ARGB);
Graphics2D graphics = image.createGraphics();
graphics.setPaint(Color.white);
graphics.fillRect(0, 0, pictureSize, pictureSize);
// radii
graphics.setPaint(new Color(255, 21, 24, 150));
for (Point3D point : points) {
graphics.fillOval(
(int) point.getX() - maxDistanceBetweenPoints,
(int) point.getY() - maxDistanceBetweenPoints,
maxDistanceBetweenPoints * 2,
maxDistanceBetweenPoints * 2
);
}
// points
graphics.setPaint(Color.black);
for (Point3D point : points) {
graphics.fillOval(
(int) point.getX() - (pointSize / 2),
(int) point.getY() - (pointSize / 2),
pointSize,
pointSize
);
}
// connections
graphics.setPaint(Color.green);
graphics.setStroke(new BasicStroke(connectionWidth));
for (Route route : routes) {
graphics.drawLine(
(int) route.getPoint1().getX(),
(int) route.getPoint1().getY(),
(int) route.getPoint2().getX(),
(int) route.getPoint2().getY()
);
}
ImageIO.write(image, "PNG", OUTPUT);
} catch (IOException ie) {
ie.printStackTrace();
}
}
}
Raw
Route.java
import javafx.geometry.Point3D;
import java.util.HashSet;
import java.util.Set;
public class Route {
public static Set<Route> computeAllRoutes(Set<Point3D> points, int maxDistance) {
Set<Route> routes = new HashSet<>();
for (Point3D point1 : points) {
for (Point3D point2 : points) {
if (point1.equals(point2)) continue;
boolean routeExists = routes.stream()
.anyMatch(route ->
(point1.equals(route.getPoint1()) || point1.equals(route.getPoint2())) &&
(point2.equals(route.getPoint1()) || point2.equals(route.getPoint2()))
);
if (!routeExists) routes.add(new Route(point1, point2));
}
}
// invalidate the route if the points are too far apart
routes.removeIf(route -> route.getDistance() > maxDistance);
return routes;
}
private final Point3D[] points;
public Route(Point3D point1, Point3D point2) {
this.points = new Point3D[] { point1, point2 };
}
public double getDistance() {
return getPoint1().distance(getPoint2());
}
public Point3D getPoint1() {
return points[0];
}
public Point3D getPoint2() {
return points[1];
}
}
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