/*   []----------------------------------------[]
      |                Vector.h                |
     []----------------------------------------[]
      |                                        |
      |   AUTHOR:    MFSomers 2005.            |
      |   USE:       Vector type def...        |
      |                                        |
     []----------------------------------------[]
*/

// Copyright (C) 2005 M.F. Somers, Theoretical Chemistry Department, Leiden University
//
// This is free software; you can redistribute it and/or modify it under the terms of
// the GNU Lesser General Public License as published by the Free Software Foundation.
//
// http://www.gnu.org/licenses/lgpl.txt

#if !defined(__VECTOR_INCLUDED__)

#define __VECTOR_INCLUDED__

#include "Constants.h"
#include "Global.h"
#include "Rand.h"

/* ----------------------------------------------------------------------- */
/* the type definion of a vector */

typedef struct { 
                 double X,
                        Y,
                        Z;
               } Vector;

/* ----------------------------------------------------------------------- */
/* Some basic vector operators */

inline Vector operator+( const Vector& A, const Vector& B )
              {
	       Vector C;
	       
	       C.X = A.X + B.X;
	       C.Y = A.Y + B.Y;
	       C.Z = A.Z + B.Z;

	       return( C );
	      };
	      
/* ----------------------------------------------------------------------- */

inline Vector operator-( const Vector& A, const Vector& B )
              {
	       Vector C;
	       
	       C.X = A.X - B.X;
	       C.Y = A.Y - B.Y;
	       C.Z = A.Z - B.Z;

	       return( C );
	      };
	      
/* ----------------------------------------------------------------------- */
	      
inline Vector& operator+=( Vector& A,  const Vector& B )
        {
	 A.X += B.X;
	 A.Y += B.Y;
	 A.Z += B.Z;
         return( A );
	}
	 
/* ----------------------------------------------------------------------- */
	      
inline Vector& operator-=( Vector& A, const Vector& B )
        {
	 A.X -= B.X;
	 A.Y -= B.Y;
	 A.Z -= B.Z;
         return( A );
	}
	
/* ----------------------------------------------------------------------- */	

inline Vector operator*( const Vector& A, double B )
              {
	       Vector C;
	       
	       C.X = A.X * B;
	       C.Y = A.Y * B;
	       C.Z = A.Z * B;

	       return( C );
	      }
	      
/* ----------------------------------------------------------------------- */

inline Vector operator*( double A, const Vector& B )
              {
	       return( B * A );
	      }

/* ----------------------------------------------------------------------- */

inline Vector& operator*=( Vector& A, double B )
               {
	        A.X *= B;
		A.Y *= B;
		A.Z *= B;
		return( A );
	       }
	       
/* ----------------------------------------------------------------------- */

inline Vector operator/( const Vector& A, double B )
              {
               Vector C;
	       
	       C.X = A.X / B;
	       C.Y = A.Y / B;
	       C.Z = A.Z / B;
	       
	       return( C );
              }

/* ----------------------------------------------------------------------- */

inline Vector& operator/=( Vector& A, double B )
               {
	        A.X /= B;
		A.Y /= B;
		A.Z /= B;
		return( A );
	       }
      
/* ----------------------------------------------------------------------- */	       	

inline double Abs( const Vector& A )
              {
	       return( sqrt( A.X*A.X + A.Y*A.Y + A.Z*A.Z ) );
	      }
	      
/* ----------------------------------------------------------------------- */	       	

inline double AbsSqr( const Vector& A )
              {
	       return( A.X*A.X + A.Y*A.Y + A.Z*A.Z );
	      }
	      	      
/* ----------------------------------------------------------------------- */

inline double Dot( const Vector& A, const Vector& B )
              {
	       return( A.X*B.X + A.Y*B.Y + A.Z*B.Z );
	      } 	      

/* ----------------------------------------------------------------------- */	      
/* Now the more complicated (non-inlined) Vector functions... */

double Angle( const Vector& A, const Vector& B );
Vector Cross( const Vector& A, const Vector& B );
Vector SphericalToCartesian( double r, double theta, double phi );
void   CartesianToSpherical( const Vector& V, double& r, double& theta, double& phi );
void   RotateVectorAroundAxis( Vector& V, Vector RotationAxis, double Angle );
Vector MimimumSystemImageConventionVector( const Vector& V, const Vector& TheBox );
Vector ARandomNormalizedVector( void );

ostream& operator<<( ostream& out, const Vector& A );
istream& operator>>( istream& in, Vector& A );

/* ----------------------------------------------------------------------- */
      
#endif