/* Turtle
 * <Description>
 * Draws pentagrams
 * Draws all stars with N points for all odd N
 * <Usage>
 * javac Turtle.java StdDraw.java
 * <References>
 * StdLib StdDraw
 * UAB CIS201L-Summer 2014 Dr. Sloan
 * @author
 * Dan Latham
 * <l3li3l@torguard.tg>
 * @version 0.0.1
 *
 */
 
public class Turtle
{
	private double x, y;
	private double angle;

	public Turtle(double x0, double y0, double a0)
	{
		x = x0;
		y = y0;
		angle = a0;
	}
	public void turnLeft(double delta)
	{
		angle+= delta;
	}
	public void goForward(double step)
	{ //Compute new position, move and draw line to it.
		double oldx = x, oldy = y;
		x += step * Math.cos(Math.toRadians(angle));
		y += step * Math.sin(Math.toRadians(angle));
		StdDraw.line(oldx, oldy, x, y);
	}

	public static void main(String[] args)
	{ // Draw an N-gon
		int N = Integer.parseInt(args[0]);
		Turtle turtle = new Turtle(1/N+.2,1/N+.1, 360.0/N);
		for (int i = 0; i < N; i++)
		{
			double step = Math.sin(Math.toRadians(360.0/N));
			turtle.goForward(step);
			turtle.turnLeft(180.0-(180.0/N));
		}
	}
}