#ifndef _OWLPS_POSITIONING_POINT3D_HH_
#define _OWLPS_POSITIONING_POINT3D_HH_

#include <ostream>
#include <cmath>

/// Represents a point of the 3-D space
class Point3D
{
protected:
  float x ; ///< X horizontal coordinate (abscissa)
  float y ; ///< Y horizontal coordinate (ordinate)
  float z ; ///< Vertical coordinate

public:
  /// 3 float constructor or default constructor
  Point3D(const float &_x = 0, const float &_y = 0, const float &_z = 0) ;
  /// Copy constructor
  Point3D(const Point3D &p) ;
  /// 3-float array constructor
  Point3D(const float c[3]) ;

  virtual ~Point3D(void) {} ///< Destructor (do nothing)

  /** @name Read accessors */
  //@{
  float get_x(void) const ; ///< #x read accessor
  float get_y(void) const ; ///< #y read accessor
  float get_z(void) const ; ///< #z read accessor
  //@}

  /** @name Write accessors */
  //@{
  void set_x(const float &_x) ; ///< #x write accessor
  void set_y(const float &_y) ; ///< #y write accessor
  void set_z(const float &_z) ; ///< #z write accessor
  void set_coordinates(const Point3D &p) ; ///< Sets all coordinates
  //@}

  /** @name Distance operations */
  //@{
  /// Square euclidean distance to a Point3D
  float square_distance(const Point3D &p) const ;
  /// Euclidean distance to a Point3D
  float distance(const Point3D &p) const ;
  /// Square euclidean distance to a 3-float defined point
  float square_distance(const float &mx,
                        const float &my,
                        const float &mz) const ;
  /// Euclidean distance to a 3-float defined point
  float distance(const float &mx,
                 const float &my,
                 const float &mz) const ;
  //@}

  /** @name Operators */
  //@{
  const Point3D& operator=(const Point3D &p) ;
  bool operator==(const Point3D &p) const ;
  bool operator!=(const Point3D &p) const ;
  bool operator<(const Point3D &p) const ;
  bool operator>(const Point3D &p) const ;
  bool operator<=(const Point3D &p) const ;
  bool operator>=(const Point3D &p) const ;
  //@}

  /// Displays a Point3D
  friend std::ostream& operator<<(std::ostream &os, const Point3D &p) ;
} ;



/* *** Read accessors *** */


inline float Point3D::get_x() const
{
  return x ;
}


inline float Point3D::get_y() const
{
  return y ;
}


inline float Point3D::get_z() const
{
  return z ;
}



/* *** Write accessors *** */


inline void Point3D::set_x(const float &_x)
{
  x = _x ;
}


inline void Point3D::set_y(const float &_y)
{
  y = _y ;
}


inline void Point3D::set_z(const float &_z)
{
  z = _z ;
}


/**
 * Updates x, y, z by passing a Point3D.
 * This is useful for derivated classes, and different than a direct
 * call to operator=().
 */
inline void Point3D::set_coordinates(const Point3D &p)
{
  this->operator=(p) ;
}



/* *** Distance operations *** */


/**
 * Note: to compare distances, use preferably square_distance(),
 * which is more efficient.
 */
inline float Point3D::distance(const Point3D &p) const
{
  return sqrt(square_distance(p)) ;
}


/**
 * Note: to compare distances, use preferably square_distance(),
 * which is more efficient.
 */
inline float Point3D::distance(const float &_x,
                               const float &_y,
                               const float &_z) const
{
  return sqrt(square_distance(_x, _y, _z)) ;
}



/* *** Operators *** */


inline bool Point3D::operator!=(const Point3D &p) const
{
  return !(*this == p) ;
}


inline bool Point3D::operator>(const Point3D &p) const
{
  return (p < *this) ;
}


inline bool Point3D::operator<=(const Point3D &p) const
{
  return (*this < p || *this == p) ;
}


inline bool Point3D::operator>=(const Point3D &p) const
{
  return (p <= *this) ;
}



#endif // _OWLPS_POSITIONING_POINT3D_HH_