/*****************************************************************
 * File: Point2d.java
 * Synopsis:
 *      Basic Point Class for 2-dimensional geometry
 *
 * Visualization Class, Spring 2003
 * Author: Chee Yap (yap@cs.nyu.edu)
 *
 * $Id: Point2d.java,v 1.2 2003/02/20 16:59:57 yap Exp yap $
 *****************************************************************/

class Point2d
	extends Vector2d
{
  // already in Vector2d
  // 	public double x, y;
 
  public static Point2d origin = new Point2d(0.0, 0.0);

  //Constructors
  public Point2d(double a, double b) {
	super(POINT_TYPE, 0);
	x=a; y=b;
  };
  public Point2d() {
	super(POINT_TYPE, 0);
	x=0.0; y=0.0;
  };  
  public Point2d( Point2d p) {
	super(POINT_TYPE, 0);
	x = p.x; y = p.y;
  };

  //Methods
  public boolean isEqual( Point2d p) {
	return ((x == p.x) && (y == p.y));
  }
  public boolean isOrigin() {
	return ((x == 0.0) && (y == 0.0));
  }
  
  // There is a set in Vector2d already
  // public Point2d set(double a, double b) {
  // 	x = a; y = b;
  // 	return this;
  //  }

  public Point2d set( Point2d p) {
	x = p.x; y = p.y;
	return this;
  }

  // returns the Euclidean distance between p and this
  double distance(Point2d p) {
	double xdiff = p.x - x;
	double ydiff = p.y - y;
	return Math.sqrt(xdiff * xdiff + ydiff * ydiff);
  }

  // returns distance between this and origin
  double distance()  {
	return distance(new Point2d());
  }

  Point2d add( Point2d p) {
	return new Point2d(x + p.x,   y + p.y);
  };
  Point2d add( double a, double b) {
	return new Point2d(x + a,   y + b);
  };
  Point2d sub( Point2d p) {
	return new Point2d(x - p.x,   y - p.y);
  };
  Point2d sub( double a, double b) {
	return new Point2d(x - a,   y - b);
  };

  // rotate q by angle of 90 degrees
  void rotate90(  Point2d q) {
	x = -q.y; y = q.x;
  };

/*
  bool operator==( Point2d) ;
  bool operator!=( Point2d p)  {return !operator==(p); }
  void read();
  // reads the x and y coordinates of point p from standard input 
*/

  // write point p to output stream, printing message m
  public int dump(String pre, String post) {
	System.out.print(pre);
	System.out.print("(" + x + ", " + y + ")");
	System.out.print(post);
	return(0);
  };
  public int dump(String pre){
	return dump(pre, "\n");
  };
  // dump without message
  public int dump(){
	return dump("", "\n");
  };


  public static void main (String[] args){

	Point2d p = new Point2d();
	p.add(4.0, 3.0);
	p.dump("dumping p(4, 3) :: ");

	p.sub(1.5, 0.5);
	p.dump("dumping p(2.5, 2.5) :: ");
	
  }
};

/*
// OTHER:
Point2d center(Point2d a, Point2d b); 
int orientation2d( Point2d a,  Point2d b,  Point2d c);
double area( Point2d a,  Point2d b,  Point2d c);
bool collinear( Point2d a,  Point2d b,  Point2d c);
*/