RosettaCodeData/Task/Sierpinski-triangle-Graphical/Java/sierpinski-triangle-graphic...

59 lines
1.4 KiB
Java

import javax.swing.*;
import java.awt.*;
/**
* SierpinskyTriangle.java
* Draws a SierpinskyTriangle in a JFrame
* The order of complexity is given from command line, but
* defaults to 3
*
* @author Istarnion
*/
class SierpinskyTriangle {
public static void main(String[] args) {
int i = 3; // Default to 3
if(args.length >= 1) {
try {
i = Integer.parseInt(args[0]);
}
catch(NumberFormatException e) {
System.out.println("Usage: 'java SierpinskyTriangle [level]'\nNow setting level to "+i);
}
}
final int level = i;
JFrame frame = new JFrame("Sierpinsky Triangle - Java");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JPanel panel = new JPanel() {
@Override
public void paintComponent(Graphics g) {
g.setColor(Color.BLACK);
drawSierpinskyTriangle(level, 20, 20, 360, (Graphics2D)g);
}
};
panel.setPreferredSize(new Dimension(400, 400));
frame.add(panel);
frame.pack();
frame.setResizable(false);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
private static void drawSierpinskyTriangle(int level, int x, int y, int size, Graphics2D g) {
if(level <= 0) return;
g.drawLine(x, y, x+size, y);
g.drawLine(x, y, x, y+size);
g.drawLine(x+size, y, x, y+size);
drawSierpinskyTriangle(level-1, x, y, size/2, g);
drawSierpinskyTriangle(level-1, x+size/2, y, size/2, g);
drawSierpinskyTriangle(level-1, x, y+size/2, size/2, g);
}
}