// TwoSpacePoint.h

#ifndef TwoSpacePoint_H
#define TwoSpacePoint_H

// Describes a point in 2-space. The default Space point is at the origin.
// Derived classes can be used to set values in cartesian or cylindrical
// coordinates.  Point is set in the constructor and cannot be changed.
// The methods simply return different coordinates.
//
// Transformations (translations, rotations, etc) are carried out by
// external functions which return new TwoSpacePoints.

#include <iostream>

#ifdef DEFECT_NO_BOOL
#include <bool.h>
#endif

class TwoSpacePoint {

protected:  // data
  double _x;
  double _y;
  double _xy;
  double _phi;

public:  // static methods

  // Return if two doubles are close enough to be considered equal.
  // This is used to compare components for operator==.
  static bool equal(double x1, double x2);

public:  // methods

  // Default constructor.
  // Sets point to be the origin.
  TwoSpacePoint( );

  // Destructor.
  virtual ~TwoSpacePoint( );

  // Cartesian x.
  double x( ) const { return _x; };

  // Cartesian y.
  double y( ) const { return _y; };

  // Cylindrical r.
  double rxy( ) const { return _xy; };

  // Cylindrical phi.
  double phi( ) const { return _phi; };

  // cos(phi)
  double cos_phi( ) const;

  // sin(phi)
  double sin_phi( ) const;

};

std::ostream& operator<<(std::ostream & stream, const TwoSpacePoint& spt);

//**********************************************************************

class CartesianTwoPoint : public TwoSpacePoint {

public:

  // Constructor.
  CartesianTwoPoint(double x, double y);

};
  
//**********************************************************************

class CylindricalTwoPoint : public TwoSpacePoint {

public:

  // Constructor.
  CylindricalTwoPoint(double r, double phi);

};
  
//**********************************************************************
// Free functions.
//**********************************************************************

// Equality.

bool operator==(const TwoSpacePoint& lhs, const TwoSpacePoint& rhs);

//**********************************************************************

// Inequality.

bool operator!=(const TwoSpacePoint& lhs, const TwoSpacePoint& rhs);

//**********************************************************************

// Return the distance between two space points.
double distance(const TwoSpacePoint spt1, const TwoSpacePoint spt2);

//**********************************************************************

#endif