/****************************************************************************
** COPYRIGHT (C):    1997 Cay S. Horstmann. All Rights Reserved.
** PROJECT:          Practical OO Development with C++ and Java
** FILE:             Polygon.java
** PURPOSE:          shape class
** VERSION           1.0
** PROGRAMMERS:      Cay Horstmann (CSH)
** RELEASE DATE:     3-15-97 (CSH)
** UPDATE HISTORY:
****************************************************************************/

package practicaloo;

import java.awt.Graphics;
import java.io.PrintStream;

public class Polygon
{   public Polygon(int n)
    {   _corners = new Point[n];
    }


    public void set_vertex(int i, Point p)
    {   if(0 <= i && i < _corners.length);
        _corners[i] = p;
    }


    public void move(int dx, int dy)
    {   for(int i = 0; i < _corners.length; i++)
            _corners[i].move(dx, dy);
    }

    public void scale(Point center, double s)
    {   for(int i = 0; i < _corners.length; i++)
            _corners[i].scale(center, s);
    }

    public void plot(Graphics g)
    {   for(int i = 0; i < _corners.length; i++)
        {   int j = (i + 1) % _corners.length;
            g.drawLine(_corners[i].get_x(), _corners[i].get_y(),
                _corners[j].get_x(), _corners[j].get_y());
        }
    }

    public void print(PrintStream p)
    {   p.print(System.out);
    }

    public Point vertex(int i)
    {   return _corners[i];
    }


    private Point[] _corners;

}