139 lines
3.8 KiB
C++
139 lines
3.8 KiB
C++
// sg_time.hxx -- data structures and routines for managing time related stuff.
|
|
//
|
|
// Written by Curtis Olson, started August 1997.
|
|
//
|
|
// Copyright (C) 1997 Curtis L. Olson - curt@flightgear.org
|
|
//
|
|
// This library is free software; you can redistribute it and/or
|
|
// modify it under the terms of the GNU Library General Public
|
|
// License as published by the Free Software Foundation; either
|
|
// version 2 of the License, or (at your option) any later version.
|
|
//
|
|
// This library 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
|
|
// Library General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Library General Public
|
|
// License along with this library; if not, write to the
|
|
// Free Software Foundation, Inc., 59 Temple Place - Suite 330,
|
|
// Boston, MA 02111-1307, USA.
|
|
//
|
|
// $Id$
|
|
|
|
|
|
#ifndef _SG_TIME_HXX
|
|
#define _SG_TIME_HXX
|
|
|
|
|
|
#ifndef __cplusplus
|
|
# error This library requires C++
|
|
#endif
|
|
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
# include <config.h>
|
|
#endif
|
|
|
|
#include <simgear/compiler.h>
|
|
|
|
#ifdef FG_HAVE_STD_INCLUDES
|
|
# include <ctime>
|
|
#else
|
|
# include <time.h>
|
|
#endif
|
|
|
|
#include <simgear/timing/timezone.h>
|
|
|
|
|
|
// Define a structure containing time parameters
|
|
class SGTime {
|
|
|
|
private:
|
|
// tzContainer stores all the current Timezone control points/
|
|
TimezoneContainer* tzContainer;
|
|
|
|
// Points to the current local timezone name;
|
|
char *zonename;
|
|
|
|
// Unix "calendar" time in seconds
|
|
time_t cur_time;
|
|
|
|
// Break down of equivalent GMT time
|
|
struct tm *gmt;
|
|
|
|
// offset of local time relative to GMT
|
|
time_t local_offset;
|
|
|
|
// Julian date
|
|
double jd;
|
|
|
|
// modified Julian date
|
|
double mjd;
|
|
|
|
// side real time at prime meridian
|
|
double gst;
|
|
|
|
// local sidereal time
|
|
double lst;
|
|
|
|
// the difference between the precise / expensive sidereal time
|
|
// algorithm result and the quick course result. course_gst +
|
|
// gst_diff has pretty good accuracy over the span of a couple hours
|
|
double gst_diff;
|
|
|
|
public:
|
|
|
|
SGTime( double lon, double lat, const string& root );
|
|
SGTime( const string& root );
|
|
SGTime();
|
|
~SGTime();
|
|
|
|
// Update the time related variables
|
|
void update( double lon, double lat, long int warp = 0 );
|
|
|
|
// Given lon/lat, update timezone information and local_offset
|
|
void updateLocal( double lon, double lat, const string& root );
|
|
|
|
inline time_t get_cur_time() const { return cur_time; };
|
|
inline char* get_zonename() const { return zonename; }
|
|
inline struct tm* getGmt()const { return gmt; };
|
|
inline double getJD() const { return jd; };
|
|
inline double getMjd() const { return mjd; };
|
|
inline double getLst() const { return lst; };
|
|
inline double getGst() const { return gst; };
|
|
};
|
|
|
|
|
|
// Some useful utility functions that don't make sense to be part of
|
|
// the SGTime class
|
|
|
|
// Return unix time in seconds for the given data (relative to GMT)
|
|
time_t sgTimeGetGMT(int year, int month, int day,
|
|
int hour, int minute, int second);
|
|
|
|
// this is just a wrapper
|
|
inline time_t sgTimeGetGMT(struct tm* the_time) {
|
|
// printf("Using: %24s as input\n", asctime(the_time));
|
|
return sgTimeGetGMT(the_time->tm_year,
|
|
the_time->tm_mon,
|
|
the_time->tm_mday,
|
|
the_time->tm_hour,
|
|
the_time->tm_min,
|
|
the_time->tm_sec);
|
|
}
|
|
|
|
// given a date in months, mn, days, dy, years, yr, return the
|
|
// modified Julian date (number of days elapsed since 1900 jan 0.5),
|
|
// mjd. Adapted from Xephem.
|
|
double sgTimeCalcMJD(int mn, double dy, int yr);
|
|
|
|
// given an mjd, calculate greenwich mean sidereal time, gst
|
|
double sgTimeCalcGST( double mjd );
|
|
|
|
// format time
|
|
char* sgTimeFormatTime( const struct tm* p, char* buf );
|
|
|
|
|
|
#endif // _SG_TIME_HXX
|