Question

(In Java) Create an applet which draws two sets of concentric circles. Each set will use recursion:

• Start with a diameter of 255 for the outermost circle
• As each circle is drawn, use a color created via a constructor in the Color class:

Color circleColor = new Color(diameter, diameter, diameter) ;

• Use recursion to draw the next inner circle:
  • for one set of circles, decrease the diameter of each circle by 20 pixels
  • for the other set of circles, decrease the diameter of each circle by 10%
• The base case: stop when the diameter of the circle is less than to 20 pixels.

Include a program file of your code and a PrintScreen of the output of your program.

Below is a sample output. Notice how the circles on the left form a figure that appears flat, while the circles on the right appear to have some depth.

Answer 1

import java.applet.Applet;
import java.awt.Color;
import java.awt.Graphics;

public class Circle extends Applet
{

public void drawCircle(Graphics g,int diameter)
{
//condition to check if diameter is less than 20 pixels
if(diameter<20)
return;
//constructor for Color class
Color circleColor= new Color(diameter,diameter,diameter);
g.setColor(circleColor);
//decrease the diameter of each circle by 20
int i=20+(255-diameter);
//Method to create a circle
g.drawOval(i,i,255-(255-diameter-diameter),255-(255-diameter-diameter));
drawCircle(g,diameter-20);

}

//Method for drawing concentric circle diameter decreses by 10%
public void drawCircle2(Graphics g,int diameter)
{
if(diameter<20)
return;
Color circleColor= new Color(diameter,diameter,diameter);
g.setColor(circleColor);
//x- coordinate
int x=540+(255-diameter);
//y-Coordinate
int y=20+(255-diameter);
g.drawOval(x,y,255-(255-diameter-diameter),255-(255-diameter-diameter));
//reduce diameter by 10%
drawCircle2(g,diameter-(int)(0.1*diameter));

}
public void paint(Graphics g)
{
  
//Method to decrease the diameter of each circle by 20 pixels
drawCircle(g,255);
//Method to decrease the diameter of each circle by 10%
drawCircle2(g,255);
}

}

let Viewer: Circle.class Applet