import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Sym extends Applet implements MouseMotionListener {
 int r[][]=new int[200][6],m[]=new int[6],W;
 public void init(){
  W=getSize().width;
  addMouseMotionListener(this);
 }
 public void mouseDragged(MouseEvent e){
  Point p=e.getPoint();
  int[]t=r[199];
  t[0]=p.x;t[1]=p.y;
  System.arraycopy(r,0,r,1,200-1);
  r[0]=t;
 }
 public void mouseMoved(MouseEvent e){}
 public void update (Graphics h) {paint(h);}
 public void paint(Graphics g){
  Image I=createImage(W,W);
  Graphics G=I.getGraphics();
  for(int i=200;--i>=0;)
  {
   int[]l=r[i];
   G.setColor(new Color(l[3],l[4],l[5]));
   int x=l[0],y=l[1],D=W/8,R=D/2;
   G.fillOval(x-R,y-R,D,D);
   G.fillOval(W-x-R,W-y-R,D,D);
   // mirror symmetry
   G.fillOval(W-x-R,y-R,D,D);
   G.fillOval(x-R,W-y-R,D,D);
   // If you prefer rotational symmetry, disable
   // the previous two lines and use these instead:
//    G.fillOval(y-R,W-x-R,D,D);
//    G.fillOval(W-y-R,x-R,D,D);
  }
  g.drawImage(I,0,0,this);
  for (int i=200;--i>0;)
   System.arraycopy(r[i-1],3,r[i],3,3);
  int l[]=r[0],t;
  for (int i=3;i<6;++i){
   t=l[i];
   double f=(Math.random()*256)-t;
   int d=(m[i]+=(f>0)?1:-1);
   t+=(d>0?5:-5);
   l[i]=(t<0)?0:(t>255)?255:t;
  }
  repaint();
 }
}