MID POINT ELLIPSE ALGORITHM USING JAVA

import java.awt.*;
import java.util.*;
import javax.swing.*;

class myellipse extends JPanel{


public void paint(Graphics g){
int a=200;
int b=100;
int x=0;
int y=b;
int d=b*b+(a*a/4)-b*a*a;

while(2*a*a*y> 2*b*b*x){

g.drawOval(400+x,400+y,2,2);
g.drawOval(400-x,400+y,2,2);
g.drawOval(400+x,400-y,2,2);
g.drawOval(400-x,400-y,2,2);
x+=1;
if(d<0)
d=d+b*b*(3+2*x);


else{
y-=1;
d=d+b*b*(3+2*x)-2*a*a*(y-1);
}

}
while(y>0){
g.drawOval(400+x,400+y,2,2);
g.drawOval(400-x,400+y,2,2);
g.drawOval(400+x,400-y,2,2);
   g.drawOval(400-x,400-y,2,2);
y-=1;
if(d>0){
d=d+a*a*(3-2*y);


}
else{
x+=1;
d=d+2*b*b*(x+1)+a*a*(3-2*y);


}

}
}
public static void main(String arg[]){

JFrame j=new JFrame("ellipse");
j.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
myellipse e=new myellipse();
j.setSize(800,800);
j.add(e);
j.setVisible(true);


}

}