CODEWITHSUNDEEP
javaformswindowdrawing
user3065721
user3065721

Reputation: 1

Java: How can I draw a Star in a window form application using Math.PI and triangles?

I want to modify my code so it will ask me how much arms I want my Star to have and then draw me the Star with the given number of arms. I don't know how to do it with Math.PI using triangles for example. Can you please help me?

This is what I have so far. Just a program drawing a Star without user input.

import java.awt.BasicStroke;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.geom.Path2D;
import java.util.Scanner;

public class App extends Frame
{
        public static void main(String[] args)
        {
                Scanner czytnik = new Scanner(System.in);
                System.out.println("Ile ramion ma mieć gwiazda?");
                new App();
                czytnik.close();
        }

        public App()
        {
                setSize(540, 380);
                setVisible(true);
        }

        public void paint(Graphics g)
        {
                Graphics2D g2 = (Graphics2D) g; 
                g2.setStroke (new BasicStroke (15.0f)); 

                Rectangle r = getBounds(); 
                float width = 166; 
                float height = 166; 

                g2.translate( r.getWidth() / 2 - width/2, r.getHeight() / 2 - height/2); 

                Path2D star = new Path2D.Float (); 
                star.moveTo (width/5F, height-1); 
                star.lineTo (width/2F, 0); 
                star.lineTo (4*width/5F, height-1); 
                star.lineTo (0, 2*height/5F); 
                star.lineTo (width-1, 2*height/5F); 
                star.closePath (); 
                g2.draw (star); 
                g2.fill (star);
        }
}

Upvotes: 0

Views: 537

Answers (1)

DoubleDouble
DoubleDouble

Reputation: 1493

Imagine you have two circles, they have the same center point and one is larger than the other.

Actually I made a quick picture:

example

You could imagine the inner circle has a radius of 1, the outer circle has a radius of two. Those numbers could both be changeable in your code.

The star has 5 points, so both circles are divided into 5 sections by equally placing 5 points on the circle.

The inner circle is rotated half the distance of one of the divided sections.

Then lines are drawn connecting the points.

This is how I would start trying to make a star-creator class, but it is just a concept so you'll have to find the details for yourself.

Upvotes: 1

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