SolTrack.h

/*
  SolTrack: a simple, free, fast and accurate C routine to compute the position of the Sun
  
  
  Copyright (c) 2014-2017  Marc van der Sluys, Paul van Kan and Jurgen Reintjes,
  Lectorate of Sustainable Energy, HAN University of applied sciences, Arnhem, The Netherlands
  
   
  This file is part of the SolTrack package, see: http://soltrack.sourceforge.net
  SolTrack is derived from libTheSky (http://libthesky.sourceforge.net) under the terms of the GPL v.3
  
  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, either version 3 of the License, or (at your option) any later version.
  
  This software is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
  
  You should have received a copy of the GNU Lesser General Public License along with this code.  If not, see 
  <http://www.gnu.org/licenses/>.
*/


#ifndef __SOLTRACK_H
#define __SOLTRACK_H


#include "stdio.h"
#include "math.h"


// Constants:
#define PI             3.14159265358979323846    // Pi
#define TWO_PI         6.28318530717958647693    // 2 pi
#define MPI            3.14159265358979323846e6  // One Megapi...
#define R2D            57.2957795130823208768    // Radians to degrees conversion factor
#define R2H            3.81971863420548805845    // Radians to hours conversion factor




// Structs:

/// @brief Date and time to compute the Sun's position for, in UT
struct Time {
  int year,month,day,  hour,minute;
  double second;
};


/// @brief Location to compute the Sun's position for
struct Location {
  double longitude, latitude;
  double sinLat, cosLat;
  double pressure, temperature;
};


/// @brief Position of the Sun
struct Position {
  double julianDay, tJD, tJC,tJC2;
  double longitude, distance;
  double obliquity,cosObliquity, nutationLon;
  double rightAscension,declination, hourAngle,agst;
  double altitude, altitudeRefract,azimuthRefract;
  double hourAngleRefract, declinationRefract;
};


/// @brief Rise and set data for the Sun
struct RiseSet {
  double riseTime, transitTime, setTime;
  double riseAzimuth, transitAltitude, setAzimuth;
};


// Function prototypes:
void SolTrack(struct Time time, struct Location location, struct Position *position,  int useDegrees, int useNorthEqualsZero, int computeRefrEquatorial, int computeDistance);
double computeJulianDay(int year, int month, int day,  int hour, int minute, double second);
void computeLongitude(int computeDistance, struct Position *position);
void convertEclipticToEquatorial(double longitude, double cosObliquity,  double *rightAscension, double *declination);
void convertEquatorialToHorizontal(struct Location location, struct Position *position);
void eq2horiz(double sinLat, double cosLat, double longitude,  double rightAscension, double declination,   double agst, double *azimuth, double *sinAlt);
void convertHorizontalToEquatorial(double sinLat, double cosLat, double azimuth, double altitude, double *hourAngle, double *declination);
void setNorthToZero(double *azimuth, double *hourAngle, int computeRefrEquatorial);
void convertRadiansToDegrees(double *longitude,  double *rightAscension, double *declination,  \
			     double *altitude, double *azimuthRefract, double *altitudeRefract,  \
			     double *hourAngle, double *declinationRefract, int computeRefrEquatorial);
double STatan2(double y, double x);

void SolTrack_RiseSet(struct Time time,  struct Location location, struct Position *position, struct RiseSet *riseSet, double sa0, int useDegrees, int useNorthEqualsZero);
double rev(double angle);
double rev2(double angle);
#endif