//
// IMPORTANT NOTE:
// This code is not meant to serve as an example of good coding style.
// In fact, it is an ugly hack of some very old code written for DOS
// and ported to Java.
//

import java.applet.Applet;
import java.awt.*;  // for Graphics, Color, Image, Point, ...
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.lang.Math;

public class SnowflakeCurve extends Applet implements MouseListener {

   int width, height;
   Color fgcolor = Color.black, bgcolor = Color.white;
   int maxGeneration = 6;
   int generation = 1;
   double x, y; // current plotting position
   double s; // segment length
   Graphics global_g;

   static final double s0 = 0.8;

   public void init() {
      width = getSize().width;
      height = getSize().height;
      s = s0 * width;

      try {
         maxGeneration = Integer.parseInt( getParameter("max_generation") );
      } catch (Exception E) { }
      try {
         fgcolor = new Color(Integer.parseInt( getParameter("fgcolor"), 16 ));
      } catch (Exception E) { }
      try {
         bgcolor = new Color(Integer.parseInt( getParameter("bgcolor"), 16 ));
      } catch (Exception E) { }

      setBackground( bgcolor );
      setForeground( fgcolor );

      addMouseListener( this );
   }

   public void mouseEntered( MouseEvent e ) { }
   public void mouseExited( MouseEvent e ) { }
   public void mouseClicked( MouseEvent e ) {
      ++ generation;
      if ( generation > maxGeneration ) {
         generation = 1;
         s = s0 * width;
      }
      else s /= 3;

      repaint();
      e.consume();
   }
   public void mousePressed( MouseEvent e ) { }
   public void mouseReleased( MouseEvent e ) { }

   void plot( double x_new, double y_new ) {
      global_g.drawLine(
         (int)Math.round( x ), (int)Math.round( y ),
         (int)Math.round( x_new ), (int)Math.round( y_new )
      );
      x = x_new;
      y = y_new;
   }

   void A( int generation ) {
      if ( generation > 1 ) {
         A( generation-1 );
         B2( generation-1 );
         C2( generation-1 );
         A( generation-1 );
      }
      else plot(x+(s*Math.cos(60*Math.PI/180)),y+(s*Math.sin(60*Math.PI/180)));
   }

   void B( int generation ) {
      if (generation > 1) {
         B( generation-1 );
         C2( generation-1 );
         A2( generation-1 );
         B( generation-1 );
      }
      else plot(x+(s*Math.cos(180*Math.PI/180)),y+(s*Math.sin(180*Math.PI/180)));
   }

   void C( int generation ) {
      if (generation > 1) {
         C( generation-1 );
         A2( generation-1 );
         B2( generation-1 );
         C( generation-1 );
      }
      else plot(x+(s*Math.cos(300*Math.PI/180)),y+(s*Math.sin(300*Math.PI/180)));
   }

   void A2( int generation ) {
      if (generation > 1) {
         A2( generation-1 );
         B( generation-1 );
         C( generation-1 );
         A2( generation-1 );
      }
      else plot(x+(s*Math.cos(240*Math.PI/180)),y+(s*Math.sin(240*Math.PI/180)));
   }

   void B2( int generation ) {
      if (generation > 1) {
         B2( generation-1 );
         C( generation-1 );
         A( generation-1 );
         B2( generation-1 );
      }
      else plot(x+(s*Math.cos(0*Math.PI/180)),y+(s*Math.sin(0*Math.PI/180)));
   }

   void C2( int generation ) {
      if (generation > 1) {
         C2( generation-1 );
         A( generation-1 );
         B( generation-1 );
         C2( generation-1 );
      }
      else plot(x+(s*Math.cos(120*Math.PI/180)),y+(s*Math.sin(120*Math.PI/180)));
   }

   public void paint( Graphics g ) {
      global_g = g; // this is a hack to avoid having to pass g around
      x = width / 2;
      y = (height - (s0*width) * Math.sin(60*Math.PI/180) * 4/3) / 2;

      A( generation );
      B( generation );
      C( generation );
   }

   public String getAppletInfo() {
      return "Written by Michael McGuffin";
   }
}