polygon.java

一个用于排队系统仿真的开源软件,有非常形象的图象仿真过程!

// Copyright (C) Chris Pudney, The University of Western Australia, 1998.
// All rights reserved.
//  
// Permission to use, copy, modify and distribute this software and its
// documentation only for the purposes of teaching and research is hereby
// granted without fee, provided that the above copyright notice and this
// permission notice appear in all copies of this software/documentation
// and that you do not sell the software.  No commercial use or
// distribution of the software is permitted without the consent of the
// copyright owners.  Commercial licensing is available by contacting the
// author(s).
// 
// THIS SOFTWARE/DOCUMENTATION IS PROVIDED WITH NO WARRANTY, EXPRESS OR
// IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTY OF MERCHANTABILITY OR
// FITNESS FOR A PARTICULAR PURPOSE.
package jmt.engine.jaba.Hull;
import java.util.Enumeration;
import java.util.Vector;


/**
 * A class representing a polygon
 *
 * @author  Chris Pudney <[e-mail]>
 * @version 1.1
 */
public class Polygon
{
  /** 
   * The set of vertices representing the polygon.  The vertices must
   * be stored in the vector in the order in which they define polygon
   * perimeter.  For planar polygons this should be clockwise with
   * respect to the outwards pointing normal.
   */
  private Vector vertices;	// Polygon vertices


  /**
   * Construct a polygon with no vertices.
   */
  public Polygon()
    {
      vertices = new Vector();
    }


  /**
   * Construct a polygon given a list of vertices.
   *
   * @param v  the list of vertices
   */
  public Polygon(Vector v)
    {
      vertices = v;
    }

  /**
   * Reverse the order of the vertices that define a contour
   */
  public void reverse()
    {
      /* Add vertices in reverse order */
      Vector vertices = getVertices();
      int size = vertices.size();
      for (int i = 1;
	   i < size;
	   i++)
	{
	  vertices.insertElementAt(vertices.elementAt(i), 0);
	  vertices.removeElementAt(i + 1);
	}
    }
  
  /**
   * Get the vertices of a polygon.
   *
   * @return Returns a vector p
   */
  public Vector getVertices()
    {
      return vertices;
    }


  /**
    * Returns the next vertex of a polygon
    *
    * @param v  the vertex
    * @return   the vertex following v, or null if v is not a vertex of the
    *           polygon
    */
  public Vertex nextVertex(Vertex v)
    {
      int ind = vertices.indexOf(v);
      return (Vertex)(ind == -1 ?
	null : vertices.elementAt((ind + 1) % vertices.size()));
    }


  /**
   * Returns a string describing a polygon.
   */
  public String toString()
    { 
      String s = new String();

      for (Enumeration e = getVertices().elements();
	   e.hasMoreElements();)
	{
	  s += e.nextElement();
	}
      return s;
    }
}