import java.awt.*;       // Import Abstract Window Toolkit
import java.applet.*;    // Import Applet stuff

// Drawing snowflakes (Koch curves) with turtles.

public class SnowflakeWorld extends TurtleWorld 
{
     String parameterNames [] = {"Levels", "Length"};
     String parameterFields [] = {"1", "200"};
     ParameterFrame params;
     
     //------------------------------------------------------------------------------
     // The following main method is needed to run the applet as an application
     public static void main (String[] args) {
       runAsApplication(new SnowflakeWorld(), "SnowflakeWorld"); 
     }
     //------------------------------------------------------------------------------
     
     public void setup() 
     {
          params = new ParameterFrame("Snowflake Parameters",
                                      TurtleWorld.frameSize,0,
                                      140, 110,
                                      parameterNames, parameterFields);
     }
     
     public void run() 
     {
          SnowflakeMaker snowy = new SnowflakeMaker();
          // Use a little geometry to start of in nice spot
          double radius = 0.75 * (params.getIntParam("Length") / Math.sqrt(3));
          snowy.pu();
          snowy.lt(90);
          snowy.fd(radius/4);
          snowy.rt(120);
          snowy.bd(radius);
          snowy.lt(30);
          snowy.pd();
          snowy.snowflake(params.getIntParam("Levels"), 
                          (double) params.getIntParam("Length"));
     }
}

class SnowflakeMaker extends Turtle 
{
     public void snowflake (int levels, double length) 
     {
          snowside(levels, length);
          rt(120);
          snowside(levels, length);
          rt(120);
          snowside(levels, length);
          rt(120);
     }
     
     public void snowside (int levels, double length) 
     {
          if (levels == 0) {
               fd(length);
          } else {
               snowside(levels - 1, length/3);
               lt(60);
               snowside(levels - 1, length/3);
               rt(120);
               snowside(levels - 1, length/3);
               lt(60);
               snowside(levels - 1, length/3);
          }
     }
}