//Angle class   --   copyright 2001, Information Disciplines, Inc.
//  This class supports operations on plane angles.  
 
#ifndef ANGLE
#define ANGLE const Angle
#include <math.h>             /*  For trig functions              */


class Angle{
  double  value;                 //  normalized radians
 

//  For compatibility with the standard C-library and other software, range is
//  (-pi,pi] not [0,2pi), enforced by the following function:  

  void normalize();


//  Constructors
//  ------------

public:   
  Angle(DOUBLE rad = 0.0)  : value(rad) {normalize();}
  Angle(INT deg, INT min, INT sec=0); 

//  The compiler will supply an acceptable copy constructor, destructor
//  and assignment operator.


//  Accessors
//  ---------
 
 double toDegrees() const {return  180.0 * (value / PI);}
 double toRadians() const {return  value;}
 short  degrees()   const {return  short(toDegrees());}
 short  minutes()   const;
 short  seconds()   const;                  



//  Operators follow the standard additive pattern
//  ---------

#define Class Angle
  #include "Additive.hpp" 
#undef  Class


//  Trigonometric functions (for notational consistency and to hide internal 
//  -----------------------  representation.  User can use other old functions
//                           by extracting value with  toRadians() accessor)

  double cos()          const {return ::cos (value);}
  double sin()          const {return ::sin (value);}
  double tan()          const {return ::tan (value);}

};                 //  *************** End of class definition




//  Non-member operators
//  --------------------
    ostream& operator<< (ostream& ls, ANGLE rs); 
 
//  WARNING:  Floating point equality test is undependable

 inline bool   operator==(ANGLE  ls, ANGLE rs)
                         {return ls.toRadians() == rs.toRadians();}

//  NOTE:  Ordering is ambiguous and not transitive, due to normalization.
 inline bool   operator<  (ANGLE  ls, ANGLE rs)  
                         {return ls.toRadians() < rs.toRadians();}


//  Inverse trigonometric functions (forward to C library versions)
//  ------------------------------- 

 inline Angle  arccos(DOUBLE x)         {return ::acos(x);}
 inline Angle  arcsin(DOUBLE x)         {return ::asin(x);}
 inline Angle  arctan(DOUBLE y, 
                      DOUBLE x = 1.0)   {return ::atan2(y,x);}
#endif