Draw a beautiful circle in Java

I'm using java graphics and I've been getting ugly

This is what my java program does

This is the same thing done in MATLAB

I think Java is obviously not as "nice" as MATLAB, especially at the edge of the circle Note that this is independent of resolution... These images are almost the same size Also note that I have set the rendering prompt

This is an independent main function that you can run to test this

package test;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.geom.AffineTransform;
import java.awt.geom.Ellipse2D;
import java.awt.image.BufferedImage;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.UIManager;

public class SimplePaint02 {

    private static final int LINE_THICKNESS = 4;
    private static final int LINE_GAP = 10;
    private Color lineColor = Color.red;

    public static void main(String[] args) {
        new SimplePaint02();
    }

    public SimplePaint02() {
        EventQueue.invokelater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception ex) {
                }

                JFrame frame = new JFrame();
                frame.setDefaultCloSEOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(100,100);
        }

        @Override
        public void paintComponent(Graphics g) {

            int radius = 50;
            BufferedImage buffer = new BufferedImage(radius,radius,BufferedImage.TYPE_INT_ARGB);
            Graphics2D g2d = buffer.createGraphics();
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION,RenderingHints.VALUE_INTERPOLATION_BILINEAR);

            Ellipse2D circle = new Ellipse2D.Float(0,radius);
            Shape clip = g2d.getClip();
            g2d.setClip(circle);
            AffineTransform at = g2d.getTransform();

            g2d.setTransform(AffineTransform.getRotateInstance(Math.toradians(45),radius / 2,radius / 2));

            int gap = LINE_GAP;

            g2d.setColor(Color.WHITE);
            g2d.fill(circle);

            g2d.setColor(lineColor);
            //g2d.setstroke(new Basicstroke(LINE_THICKNESS));
            for (int index = 0; index < 10; index++) {
                int x1 = index*gap-(LINE_THICKNESS/2);
                int y1 = 0;
                int x2 = index*gap+(LINE_THICKNESS/2);
                int y2 = radius;
                int width = x2 - x1;
                int height = y2 - y1;

                g2d.fillRect(x1,y1,width,height);
                //g2d.drawLine(index * gap,index * gap,geTradius());
            }

            g2d.setTransform(at);
            g2d.setClip(clip);
            g2d.dispose();
            g.drawImage(buffer,this);
        }

    }

}

Solution

Edit: please refer to the answer of code guy for a solution That's right, because Joey Rohan first thought it out!

When I try the same thing, I get a smooth advantage:

g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);

import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import javax.imageio.ImageIO;

public class DrawSmoothCircle {
    public static void main(String[] argv) throws Exception {
        BufferedImage bufferedImage = new BufferedImage(100,100,BufferedImage.TYPE_INT_RGB);
        Graphics2D g2d = bufferedImage.createGraphics();

        g2d.setRenderingHint (RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
        g2d.setPaint(Color.green);
        g2d.fillOval(10,10,50,50);
        g2d.dispose();

        ImageIO.write(bufferedImage,"png",new File("e:\\newimage.png"));
    }
}

to update:

Searched a lot:

There's nothing wrong with the code, but,

Well, unfortunately, Java 2D (or at least sun's current implementation) does not support "soft editing"

But there is also a trick clip: according to this link, you can achieve your requirements

(also, I have a smooth edge because I won't use clips of things in the image above me)