Koch snowflake fractles

KochSnowflake.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class KochSnowflake extends JFrame {
    private KochFrame koch = new KochFrame();
    private JTextField tf = new JTextField("0", 5);
    
    public KochSnowflake() {
        JPanel panel = new JPanel();
        panel.add(new JLabel("Enter an order: "));
        panel.add(tf);
        
        add(panel);
        
        koch.setSize(400, 474);
        koch.setLocation(200, 75);
        koch.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        koch.setVisible(true);
        
        tf.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                koch.setOrder(Integer.parseInt(tf.getText()));
                koch.setVisible(true);
            }
        });
    }

    public static void main(String[] args) {
        JFrame frame = new KochSnowflake();
        frame.setSize(200, 100);
        frame.setLocationRelativeTo(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
    }
}

class KochFrame extends JFrame {
    private int order = 1;
    
    public void setOrder(int order) {
        this.order = order;
        repaint();
    }
    
    @Override
    public void paint(Graphics g) {
        super.paint(g);
        Point p1 = new Point(10, getHeight() - 120);
        Point p2 = new Point(getWidth() - 10, getHeight() - 120);
        Point p3 = new Point(getWidth() / 2, 40);
        
        g.setColor(Color.red);
        
        drawLineSegment(g, order, p1, p2);
        drawLineSegment(g, order, p2, p3);
        drawLineSegment(g, order, p3, p1);
    }
    
    
    private void drawLineSegment(Graphics g, int order, 
            Point startPoint, Point endPoint) {
        
        if (order == 0) {
            g.drawLine(startPoint.x, startPoint.y, endPoint.x, endPoint.y);
        } else {
            Point distance = new Point((endPoint.x - startPoint.x) / 3, 
                    (endPoint.y - startPoint.y) / 3);
            
            Point p1 = new Point(startPoint.x + distance.x, 
                    startPoint.y + distance.y);
                        
            Point p2 = new Point(p1.x + (int) (distance.x * 0.5 + 
                    distance.y * Math.sin(Math.toRadians(-60))), 
                    p1.y + (int) (distance.y * 0.5 - 
                    distance.x * Math.sin(Math.toRadians(-60))));
            
            Point p3 = new Point(endPoint.x - distance.x, endPoint.y - distance.y);
            
            drawLineSegment(g, order - 1, startPoint, p1);
            drawLineSegment(g, order - 1, p1, p2);
            drawLineSegment(g, order - 1, p2, p3);
            drawLineSegment(g, order - 1, p3, endPoint);
        }
    }
    
}