/* FILE NAME: InvertedTrianglesWorld.java
 * AUTHOR: Stella
 * DATE: Oct 15 2007
 * COMMENTS: Defines a recursive methods
 * on Turtle World, to be used in lab to draw Inverted nested triangles.
 * 
 * MODIFICATION HISTORY: 
 * 
 */

import java.awt.*;

public class InvertedTrianglesWorld extends TurtleWorld {
  
  String parameterNames [] = {"size", "number"};
  ParameterFrame params;
  
  public void setup() {
    params = new ParameterFrame(" Parameters",200, 50, parameterNames);
  }
  
  public void run() {
    InvertedTriangleTurtle tina = new InvertedTriangleTurtle();
    // add code to move to good initial position, if you want.
   
    
    tina.invertTriangles(params.getDoubleParam("size"),
                         params.getIntParam("number")); 
  }
  
  //------------------------------------------------------------------------------
  // The following main method is needed to run the applet as an application
  public static void main (String[] args) {
    runAsApplication(new InvertedTrianglesWorld(), "InvertedTrianglesWorld"); 
  }
  
}


class InvertedTriangleTurtle extends Turtle {
  
  //It draws "number" nested, inverted equilateral triangles.
  //The outer-most triangle has side of length "size".
  //Assumes the drawing starts at the lower-left corner.
  public void  invertTriangles(double size, int number) {
    System.out.println("invertTriangles("+size+", "+number+");");
    // add your code here
    if (number == 0) return; //base case: do nothing
    
    //draw one triangle (the outr-most)
    fd(size);  //draw the base of triangle
    lt(120); fd(size); //draw one more side
    lt(120); fd(size);  //draw the third side
    
    //positin for next triangle
    lt(120);
    fd(size/2);
    lt(60);
    
    //call the method recursively, to draw the rest of the pattern
    invertTriangles(size/2, number-1);
  }
  
  // add additional methods here 
}