Moire.java

import java.awt.Canvas;
import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;

public class Moire extends Canvas {

    public static void main(String[] args) {
        JFrame frame = new JFrame("Moire Pattern");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Canvas canvas = new Moire();
        canvas.setSize(400, 400);
        canvas.setBackground(Color.WHITE);
        frame.add(canvas);
        frame.pack();
        frame.setVisible(true);
    }

    public void paint(Graphics g) {
        int i = 90;
        while (i < getWidth()) {
            g.drawOval(0, 0, i, i);
            i = i + 3;
        }
    }

}