/* FILE NAME: BoomerangWorld.java
 * AUTHOR:  Stella
 * DATE: Oct 10 2007
 * COMMENTS: Defines a recursive methods
 * on Turtle World, to be used in lab to draw Boomerangs.
 * 
 * MODIFICATION HISTORY: Based on an older version.
 * Now it can run as an application and an applet.
 * 
 */

import java.awt.*;  

public class BoomerangWorld extends TurtleWorld {
  
  String parameterNames [] = {"size", "number", "offset"};
  ParameterFrame params;
  
  public void setup() {
    params = new ParameterFrame("Boomerang Parameters",200, 100, parameterNames);
  }
  
  public void run() {
    BoomerangThrower barb = new BoomerangThrower();
    //Add code to move the turtle to good initial position, 
    //but only if you want to!
    
    
    barb.throwBoomerangs(params.getDoubleParam("size"),
                         params.getIntParam("number"), 
                         params.getDoubleParam("offset")); 
  }
  
  //------------------------------------------------------------------------------
  // The following main method is needed to run the applet as an application
  
  public static void main (String[] args) {
    runAsApplication(new BoomerangWorld(), "BoomerangWorld"); 
  }
  
}

class BoomerangThrower extends Turtle {
  
  //It draws "number" of boomerangs. Each one is "size" long on each side.
  //Boomerangs are spaced "offset" distance apart.
  public void throwBoomerangs (double size, int number, double offset) {
    System.out.println("throwBoomerangs("+size+", "+number+", "+offset+");");
    if (number == 0) return;  //base case: do nothing
    
    drawOneBoomerang(size);    //draw the current boomerang
    moveForNextBoomerang(offset); //move in position to draw next pattern
    throwBoomerangs(size, number-1, offset);  //draw the rest of the pattern
    returnToStart(offset);   // meet invariant: start and end in same place
  }
  
  // add additional methods here
  
//It draws a boomerang of specified size with inner angle 120 degrees.
//Assumes the starting point to be the top point of the upper leg of the shape. 
//After it is done drawing, the position and facing of the turtle 
//is the same as the starting ones.
  public void drawOneBoomerang (double size) {
    System.out.println("Inside drawOneBoomerang()");
    //System.out.println("Position before starting: " + getPosition());
    
    rt(60); //turn to start the upper leg of the V-shape
    fd(size);  //draw the upper leg of the V-shape
    
    rt(60);  //get in position to start the lower leg of the V-shape
    fd(size);  //draw the lower leg of the V-shape
    
    //Now the turtle is positioned on the far tip of the lower leg,
    //facing douth-west.
    //System.out.println("Position after just drawing: " + getPosition());
    
    //Get it back to starting position and facing.
    //One way of doing this is by back-tracking your steps:
    bd(size);
    lt(60);
    bd(size);
    lt(60);
  }
  
  //It moves the turtle "offset" ahead, in preparation of
  //starting the next shape. No trace is left behind.
  public void moveForNextBoomerang (double offset) {
    System.out.println("Inside moveToNextBoomerang()");
    pu();
    fd(offset);
    pd();
  }
  
  //It moves the turtle "offset" backwards.
  //No trace is left behind.
  public void returnToStart (double offset) {
    System.out.println("Inside returnToStart()");
    pu();
    bd(offset);
    pd();
  }
  
  
}