/****************************************************************************
** Point2d.java - model a 2d point or vector
** Copyright (C) 1996  Ray L. Ewbank
**     
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
** 
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU General Public License for more details.
**   
** You should have received a copy of the GNU General Public License
** along with this program; if not, write to the Free Software
** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
**
** Direct any questions concerning this piece of Software to:
**
**   Ray L. Ewbank
**   29-02 Arlington Road
**   Woburn, MA  01801
**
**   (617) 938-7137
**
**   ewbank@gis.net
****************************************************************************
*/
class Point2d {
  public double x;
  public double y;
  public Point2d() {x=y=0.0;}
  public Point2d(double inx, double iny) {x=inx;y=iny;}
  public void normalize() {
    double r = x*x+y*y;
    if (r > 0.0) {
      r = Math.sqrt(r);
      x/=r; y/=r;
    }
  }
  public double dot(Point2d p) {
    return x*p.x+y*p.y;
  }
  public Point2d subtract(Point2d p) {
    Point2d t = new Point2d();
    t.x = x-p.x;
    t.y = y-p.y;
    return t;
  }
  public int hashCode() {
    return (int)(x*27) ^ (int)(y*31);
  }
  public boolean equals(Object obj) {
    if (obj instanceof Point3d) {
      Point3d p = (Point3d)obj;
      return (x==p.x) && (y==p.y);
    }
    return false;
  }
  public String toString() {
    return getClass().getName()+ "[x=" + x + ",y=" + y + "]";
  }
}