//
// Copyright (C) 1997 Curtis L. Olson - curt@flightgear.org
//
-// This program is free software; you can redistribute it and/or
-// modify it under the terms of the GNU 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 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 program is distributed in the hope that it will be useful, but
-// WITHOUT ANY WARRANTY; without even the implied warranty of
+// 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
-// General Public License for more details.
+// Library General Public License for more details.
//
-// You should have received a copy of the GNU General Public License
-// along with this program; if not, write to the Free Software
-// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+// 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.
//
// $Id$
# include <config.h>
#endif
-#ifdef HAVE_WINDOWS_H
-# include <windows.h>
-#endif
-
-#include <GL/glut.h>
-
#include <simgear/compiler.h>
#ifdef FG_HAVE_STD_INCLUDES
# include <time.h>
#endif
-// #include <FDM/flight.hxx>
-
-#include "timezone.h"
-// #include "lowleveltime.h"
-
-
-enum sgTimingOffsetType {
- SG_TIME_SYS_OFFSET = 0,
- SG_TIME_GMT_OFFSET = 1,
- SG_TIME_LAT_OFFSET = 2,
- SG_TIME_SYS_ABSOLUTE = 3,
- SG_TIME_GMT_ABSOLUTE = 4,
- SG_TIME_LAT_ABSOLUTE = 5
-};
+#include <simgear/timing/timezone.h>
// Define a structure containing time parameters
// tzContainer stores all the current Timezone control points/
TimezoneContainer* tzContainer;
- //Store the current local timezone name;
+ // Points to the current local timezone name;
char *zonename;
// Unix "calendar" time in seconds
time_t cur_time;
- // Break down of GMT 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;
- double last_mjd, last_dy;
- int last_mn, last_yr;
-
// side real time at prime meridian
double gst;
// local sidereal time
double lst;
- // local offset to GMT
- time_t localOffset;
-
- // the difference between the precise sidereal time algorithm
- // result and the course result. course + diff has good accuracy
- // for the short term
+ // 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;
- // An offset in seconds from the true time. Allows us to adjust
- // the effective time of day.
- long int warp;
-
- // How much to change the value of warp each iteration. Allows us
- // to make time progress faster than normal.
- long int warp_delta;
-
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; };
- inline time_t get_cur_time() const { return cur_time; };
- inline struct tm* getGmt()const { return gmt; };
-
- void adjust_warp(int val) { warp += val; };
- void adjust_warp_delta(int val) { warp_delta += val; };
-
- // Initialize the time dependent variables
- void init( double lon, double lat, const string& root,
- time_t timeOffset, sgTimingOffsetType offsetType );
+};
- // Update the time dependent variables
- void update( double lon, double lat, double alt_m );
- void updateLocal( double lon, double lat, const string& root );
- void cal_mjd (int mn, double dy, int yr);
- void utc_gst();
- double sidereal_precise (double lng);
- double sidereal_course(double lng);
- static SGTime *cur_time_params;
-
- // Some other stuff which were changed to SGTime members on
- // questionable grounds -:)
- // time_t get_start_gmt(int year);
- time_t get_gmt(int year, int month, int day,
- int hour, int minute, int second);
- time_t get_gmt(struct tm* the_time);
-
- char* format_time( const struct tm* p, char* buf );
- long int fix_up_timezone( long int timezone_orig );
-
- inline int get_warp_delta() const { return warp_delta; }
-};
+// 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);
-inline time_t SGTime::get_gmt(struct tm* the_time) // this is just a wrapper
-{
- //printf("Using: %24s as input\n", asctime(the_time));
- return get_gmt(the_time->tm_year,
- the_time->tm_mon,
- the_time->tm_mday,
- the_time->tm_hour,
- the_time->tm_min,
- the_time->tm_sec);
+// 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
projects / simgear.git / blobdiff