How do I make an arc using g.drawArc() go counter clockwise?

user12447991 :

Whenever I use g.drawArc when g is a Graphics object, it always starts at start point and finished at the end point, but always clockwise. I want to have an arc that starts from 90 degrees, and goes counter clockwise to 270 degrees, but it always went clockwise. I tried putting 90 degrees to -90 degrees, but it treats negative numbers as 0. How do I approach this?

MadProgrammer :

Ok, so, not having any issues on my end

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;

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

    public Test() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                JFrame frame = new JFrame();
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        @Override
        protected void paintComponent(Graphics g) {
            super.paintComponent(g);

            Graphics2D g2d = (Graphics2D) g.create();

            g2d.setColor(Color.RED);
            g2d.drawArc(10, 10, 80, 80, 0, -270);
            g2d.setColor(Color.BLUE);
            g2d.drawArc(100, 10, 80, 80, 0, 270);

            g2d.dispose();            
        }

    }
}

Some notes:

• 0 is always points to the right (both images start at 0)
• The arcAngle is the number of degrees from the startAngle to draw (ie "extent"), which is why the images look inverted.

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