//
// Written by Curtis Olson, started August 1997.
//
-// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
+// Copyright (C) 1997 Curtis L. Olson - http://www.flightgear.org/~curt
//
-// 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.
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#ifdef HAVE_CONFIG_H
-# include <config.h>
+# include <simgear_config.h>
#endif
#include <simgear/compiler.h>
-#ifdef FG_HAVE_STD_INCLUDES
-# include <cmath>
-# include <cstdio>
-# include <cstdlib>
-# include <ctime>
-#else
-# include <math.h>
-# include <stdio.h>
-# include <stdlib.h>
-# include <time.h>
-#endif
+#include <errno.h> // for errno
+
+#include <cstdio>
+#include <cstdlib>
+#include <ctime>
+#include <cstring>
+#include <string>
+
+#ifdef HAVE_SYS_TIME_H
+# include <sys/time.h> // for get/setitimer, gettimeofday, struct timeval
+#endif
#ifdef HAVE_SYS_TIMEB_H
# include <sys/timeb.h> // for ftime() and struct timeb
#endif
#ifdef HAVE_UNISTD_H
# include <unistd.h> // for gettimeofday()
#endif
-#ifdef HAVE_SYS_TIME_H
-# include <sys/time.h> // for get/setitimer, gettimeofday, struct timeval
-#endif
+
+#include <math.h> // for NAN
#include <simgear/constants.h>
#include <simgear/debug/logstream.hxx>
-#include <simgear/misc/fgpath.hxx>
+#include <simgear/misc/sg_path.hxx>
#include "sg_time.hxx"
#include "timezone.h"
#include "lowleveltime.h"
-
#define DEGHR(x) ((x)/15.)
-#define RADHR(x) DEGHR(x*RAD_TO_DEG)
+#define RADHR(x) DEGHR(x*SGD_RADIANS_TO_DEGREES)
+using std::string;
-SGTime::SGTime( const string& root )
-{
- FGPath zone( root );
- zone.append( "Timezone" );
- zone.append( "zone.tab" );
+static const double MJD0 = 2415020.0;
+static const double J2000 = 2451545.0 - MJD0;
+static const double SIDRATE = 0.9972695677;
- FG_LOG( FG_EVENT, FG_DEBUG, "Reading timezone info from: " << zone.str() );
- tzContainer = new TimezoneContainer( zone.c_str() );
- zonename = NULL;
-}
+void SGTime::init( double lon_rad, double lat_rad,
+ const string& root, time_t init_time )
+{
+ SG_LOG( SG_EVENT, SG_INFO, "Initializing Time" );
+ gst_diff = -9999.0;
-SGTime::~SGTime()
-{
- delete tzContainer;
+ if ( init_time ) {
+ cur_time = init_time;
+ } else {
+ cur_time = time(NULL);
+ }
- if ( zonename != NULL ) {
- delete zonename;
+ SG_LOG( SG_EVENT, SG_INFO,
+ "Current greenwich mean time = " << asctime(gmtime(&cur_time)));
+ SG_LOG( SG_EVENT, SG_INFO,
+ "Current local time = " << asctime(localtime(&cur_time)));
+
+ if ( !root.empty()) {
+ SGPath zone( root );
+ zone.append( "zone.tab" );
+ SG_LOG( SG_EVENT, SG_INFO, "Reading timezone info from: "
+ << zone.str() );
+ tzContainer = new SGTimeZoneContainer( zone.c_str() );
+ SGGeod location(SGGeod::fromRad(lon_rad, lat_rad));
+ SGTimeZone* nearestTz = tzContainer->getNearest(location);
+
+ SGPath name( root );
+ name.append( nearestTz->getDescription() );
+ zonename = name.str();
+ SG_LOG( SG_EVENT, SG_INFO, "Using zonename = " << zonename );
+ } else {
+ SG_LOG( SG_EVENT, SG_INFO, "*** NO TIME ZONE NAME ***" );
+ tzContainer = NULL;
+ zonename.erase();
}
}
-
-// Initialize the time related variables
-void SGTime::init( double lon, double lat, const string& root )
+SGTime::SGTime( double lon_rad, double lat_rad, const string& root,
+ time_t init_time )
{
- FG_LOG( FG_EVENT, FG_INFO, "Initializing Time" );
- gst_diff = -9999.0;
-
- // time_t currGMT;
- // time_t systemLocalTime;
- // time_t aircraftLocalTime;
-
- // would it be better to put these sanity checks in the options
- // parsing code? (CLO)
-
- cur_time = time(NULL);
-
- // printf ("Current greenwich mean time = %24s", asctime(gmtime(&cur_time)));
- // printf ("Current local time = %24s", asctime(localtime(&cur_time)));
- // time_t tmp = cur_time;
- GeoCoord location( RAD_TO_DEG * lat, RAD_TO_DEG * lon );
-
- GeoCoord* nearestTz = tzContainer->getNearest(location);
-
- FGPath zone( root );
- zone.append( "Timezone" );
- zone.append( nearestTz->getDescription() );
-
- // cout << "Using " << zone.str() << " for timezone information" << endl;
- zonename = strdup( zone.c_str() );
- // cout << "zonename = " << zonename << endl;
- //show( buffer.c_str(), cur_time, 1);
- //printf ("Current greenwich mean time = %24s", asctime(gmtime(&cur_time)));
- //printf ("Current local time = %24s", asctime(localtime(&cur_time)));
- // currGMT = get_gmt( gmtime(&cur_time) );
- // cout << "currGMT = " << currGMT << endl;
-
- // systemLocalTime = get_gmt( localtime(&cur_time) );
- // cout << "systemLocalTime = " << systemLocalTime << endl;
-
- // aircraftLocalTime = get_gmt( fgLocaltime(&cur_time, zone.c_str()) );
- //printf ("Current greenwich mean time = %24s", asctime(gmtime(&cur_time)));
- //printf ("Current local time = %24s", asctime(localtime(&cur_time)));
+ init( lon_rad, lat_rad, root, init_time );
}
-// Update the time related variables
-void SGTime::update( double lon, double lat, double alt_m, long int warp ) {
- double gst_precise, gst_course;
-
- FG_LOG( FG_EVENT, FG_DEBUG, "Updating time" );
-
- // get current Unix calendar time (in seconds)
- // warp += warp_delta;
- cur_time = time(NULL) + warp;
- FG_LOG( FG_EVENT, FG_DEBUG,
- " Current Unix calendar time = " << cur_time
- << " warp = " << warp );
-
- // get GMT break down for current time
- gmt = gmtime(&cur_time);
- FG_LOG( FG_EVENT, FG_DEBUG,
- " Current GMT = " << gmt->tm_mon+1 << "/"
- << gmt->tm_mday << "/" << gmt->tm_year << " "
- << gmt->tm_hour << ":" << gmt->tm_min << ":"
- << gmt->tm_sec );
-
- // calculate modified Julian date
- // t->mjd = cal_mjd ((int)(t->gmt->tm_mon+1), (double)t->gmt->tm_mday,
- // (int)(t->gmt->tm_year + 1900));
- mjd = sgTimeCalcMJD( (int)(gmt->tm_mon+1), (double)gmt->tm_mday,
- (int)(gmt->tm_year + 1900) );
-
- // add in partial day
- mjd += (gmt->tm_hour / 24.0) + (gmt->tm_min / (24.0 * 60.0)) +
- (gmt->tm_sec / (24.0 * 60.0 * 60.0));
-
- // convert "back" to Julian date + partial day (as a fraction of one)
- jd = mjd + MJD0;
- FG_LOG( FG_EVENT, FG_DEBUG, " Current Julian Date = " << jd );
-
- // printf(" Current Longitude = %.3f\n", FG_Longitude * RAD_TO_DEG);
-
- // Calculate local side real time
- if ( gst_diff < -100.0 ) {
- // first time through do the expensive calculation & cheap
- // calculation to get the difference.
- FG_LOG( FG_EVENT, FG_INFO, " First time, doing precise gst" );
- gst_precise = gst = sidereal_precise(0.00);
- gst_course = sidereal_course(0.00);
-
- gst_diff = gst_precise - gst_course;
+SGTime::SGTime( const string& root ) {
+ init( 0.0, 0.0, root, 0 );
+}
- lst = sidereal_course(-(lon * RAD_TO_DEG)) + gst_diff;
- } else {
- // course + difference should drift off very slowly
- gst = sidereal_course( 0.00 ) + gst_diff;
- lst = sidereal_course( -(lon * RAD_TO_DEG)) + gst_diff;
- }
- FG_LOG( FG_EVENT, FG_DEBUG,
- " Current lon=0.00 Sidereal Time = " << gst );
- FG_LOG( FG_EVENT, FG_DEBUG,
- " Current LOCAL Sidereal Time = " << lst << " ("
- << sidereal_precise(-(lon * RAD_TO_DEG))
- << ") (diff = " << gst_diff << ")" );
+SGTime::SGTime() {
+ init( 0.0, 0.0, "", 0 );
}
-// Given lon/lat, update timezone information and local_offset
-void SGTime::updateLocal( double lon, double lat, const string& root )
+SGTime::~SGTime()
{
- time_t currGMT;
- time_t aircraftLocalTime;
- GeoCoord location( RAD_TO_DEG * lat, RAD_TO_DEG * lon );
- GeoCoord* nearestTz = tzContainer->getNearest(location);
- FGPath zone( root );
- zone.append ("Timezone" );
- zone.append ( nearestTz->getDescription() );
- if ( zonename ) {
- delete zonename;
- }
- zonename = strdup( zone.c_str() );
- currGMT = get_gmt( gmtime(&cur_time) );
- aircraftLocalTime = get_gmt( (fgLocaltime(&cur_time, zone.c_str())) );
- local_offset = aircraftLocalTime - currGMT;
- // cout << "Using " << local_offset << " as local time offset Timezone is "
- // << zonename << endl;
+ delete tzContainer;
}
// Local Sidereal Time, in decimal hours.
//
// Provided courtesy of ecdowney@noao.edu (Elwood Downey)
-double SGTime::sidereal_precise( double lng )
+static double sidereal_precise( double mjd, double lng )
{
- double lstTmp;
-
/* printf ("Current Lst on JD %13.5f at %8.4f degrees West: ",
mjd + MJD0, lng); */
// convert to required internal units
- lng *= DEG_TO_RAD;
+ lng *= SGD_DEGREES_TO_RADIANS;
// compute LST and print
- gst = sgTimeCalcGST( mjd );
- lstTmp = gst - RADHR (lng);
- lstTmp -= 24.0*floor(lstTmp/24.0);
+ double gst = sgTimeCalcGST( mjd );
+ double lst = gst - RADHR( lng );
+ lst -= 24.0 * floor( lst / 24.0 );
// printf ("%7.4f\n", lstTmp);
- // that's all
- return (lstTmp);
+ return lst;
}
// return a courser but cheaper estimate of sidereal time
-double SGTime::sidereal_course( double lng )
+static double sidereal_course( time_t cur_time, const struct tm *gmt, double lng )
{
time_t start_gmt, now;
double diff, part, days, hours, lstTmp;
char tbuf[64];
now = cur_time;
- start_gmt = get_gmt(gmt->tm_year, 2, 21, 12, 0, 0);
+ start_gmt = sgTimeGetGMT(gmt->tm_year, 2, 21, 12, 0, 0);
- FG_LOG( FG_EVENT, FG_DEBUG, " COURSE: GMT = "
+ SG_LOG( SG_EVENT, SG_DEBUG, " COURSE: GMT = "
<< sgTimeFormatTime(gmt, tbuf) );
- FG_LOG( FG_EVENT, FG_DEBUG, " March 21 noon (GMT) = " << start_gmt );
+ SG_LOG( SG_EVENT, SG_DEBUG, " March 21 noon (GMT) = " << start_gmt );
diff = (now - start_gmt) / (3600.0 * 24.0);
- FG_LOG( FG_EVENT, FG_DEBUG,
+ SG_LOG( SG_EVENT, SG_DEBUG,
" Time since 3/21/" << gmt->tm_year << " GMT = " << diff );
part = fmod(diff, 1.0);
lstTmp += 24.0;
}
- FG_LOG( FG_EVENT, FG_DEBUG,
+ SG_LOG( SG_EVENT, SG_DEBUG,
" days = " << days << " hours = " << hours << " lon = "
<< lng << " lst = " << lstTmp );
- return(lstTmp);
+ return lstTmp;
+}
+
+
+// Update the time related variables
+void SGTime::update( double lon_rad, double lat_rad,
+ time_t ct, long int warp )
+{
+ double gst_precise, gst_course;
+
+
+ tm * gmt = &m_gmt;
+
+
+ SG_LOG( SG_EVENT, SG_DEBUG, "Updating time" );
+
+ // get current Unix calendar time (in seconds)
+ // warp += warp_delta;
+ if ( ct ) {
+ cur_time = ct + warp;
+ } else {
+ cur_time = time(NULL) + warp;
+ }
+ SG_LOG( SG_EVENT, SG_DEBUG,
+ " Current Unix calendar time = " << cur_time
+ << " warp = " << warp );
+
+ // get GMT break down for current time
+
+ memcpy( gmt, gmtime(&cur_time), sizeof(tm) );
+ SG_LOG( SG_EVENT, SG_DEBUG,
+ " Current GMT = " << gmt->tm_mon+1 << "/"
+ << gmt->tm_mday << "/" << (1900 + gmt->tm_year) << " "
+ << gmt->tm_hour << ":" << gmt->tm_min << ":"
+ << gmt->tm_sec );
+
+ // calculate modified Julian date starting with current
+ mjd = sgTimeCurrentMJD( ct, warp );
+
+ // add in partial day
+ mjd += (gmt->tm_hour / 24.0) + (gmt->tm_min / (24.0 * 60.0)) +
+ (gmt->tm_sec / (24.0 * 60.0 * 60.0));
+
+ // convert "back" to Julian date + partial day (as a fraction of one)
+ jd = mjd + MJD0;
+ SG_LOG( SG_EVENT, SG_DEBUG, " Current Julian Date = " << jd );
+
+ // printf(" Current Longitude = %.3f\n", FG_Longitude * SGD_RADIANS_TO_DEGREES);
+
+ // Calculate local side real time
+ if ( gst_diff < -100.0 ) {
+ // first time through do the expensive calculation & cheap
+ // calculation to get the difference.
+ SG_LOG( SG_EVENT, SG_INFO, " First time, doing precise gst" );
+ gst_precise = gst = sidereal_precise( mjd, 0.00 );
+ gst_course = sidereal_course( cur_time, gmt, 0.00 );
+
+ gst_diff = gst_precise - gst_course;
+
+ lst = sidereal_course( cur_time, gmt,
+ -(lon_rad * SGD_RADIANS_TO_DEGREES) ) + gst_diff;
+ } else {
+ // course + difference should drift off very slowly
+ gst = sidereal_course( cur_time, gmt, 0.00 ) + gst_diff;
+ lst = sidereal_course( cur_time, gmt,
+ -(lon_rad * SGD_RADIANS_TO_DEGREES) ) + gst_diff;
+ }
+
+ SG_LOG( SG_EVENT, SG_DEBUG,
+ " Current lon=0.00 Sidereal Time = " << gst );
+ SG_LOG( SG_EVENT, SG_DEBUG,
+ " Current LOCAL Sidereal Time = " << lst << " ("
+ << sidereal_precise( mjd, -(lon_rad * SGD_RADIANS_TO_DEGREES) )
+ << ") (diff = " << gst_diff << ")" );
+}
+
+
+// Given lon/lat, update timezone information and local_offset
+void SGTime::updateLocal( double lon_rad, double lat_rad, const string& root ) {
+ // sanity checking
+ if ( lon_rad < -SGD_PI || lon_rad> SGD_PI ) {
+ // not within -180 ... 180
+ lon_rad = 0.0;
+ }
+ if ( lat_rad < -SGD_PI_2 || lat_rad > SGD_PI_2 ) {
+ // not within -90 ... 90
+ lat_rad = 0.0;
+ }
+ if ( lon_rad != lon_rad ) {
+ // only true if lon_rad == nan
+ SG_LOG( SG_EVENT, SG_ALERT,
+ " Detected lon_rad == nan, resetting to 0.0" );
+ lon_rad = 0.0;
+ }
+ if ( lat_rad != lat_rad ) {
+ // only true if lat_rad == nan
+ SG_LOG( SG_EVENT, SG_ALERT,
+ " Detected lat_rad == nan, resetting to 0.0" );
+ lat_rad = 0.0;
+ }
+ time_t currGMT;
+ time_t aircraftLocalTime;
+ SGGeod location(SGGeod::fromRad(lon_rad, lat_rad));
+ SGTimeZone* nearestTz = tzContainer->getNearest(location);
+ SGPath zone( root );
+ zone.append ( nearestTz->getDescription() );
+ zonename = zone.str();
+
+ //Avoid troubles when zone.tab hasn't got the right line endings
+ if (zonename[zonename.size()-1] == '\r')
+ {
+ zonename[zonename.size()-1]=0;
+ zone.set( zonename );
+ }
+
+ currGMT = sgTimeGetGMT( gmtime(&cur_time) );
+ aircraftLocalTime = sgTimeGetGMT( (fgLocaltime(&cur_time, zone.c_str())) );
+ local_offset = aircraftLocalTime - currGMT;
+ // cout << "Using " << local_offset << " as local time offset Timezone is "
+ // << zonename << endl;
}
}
+// return the current modified Julian date (number of days elapsed
+// since 1900 jan 0.5), mjd.
+double sgTimeCurrentMJD( time_t ct, long int warp ) {
+
+ struct tm m_gmt; // copy of system gmtime(&time_t) structure
+ struct tm *gmt = &m_gmt;
+
+ // get current Unix calendar time (in seconds)
+ // warp += warp_delta;
+ time_t cur_time;
+ if ( ct ) {
+ cur_time = ct + warp;
+ } else {
+ cur_time = time(NULL) + warp;
+ }
+ SG_LOG( SG_EVENT, SG_DEBUG,
+ " Current Unix calendar time = " << cur_time
+ << " warp = " << warp );
+
+ // get GMT break down for current time
+ memcpy( gmt, gmtime(&cur_time), sizeof(tm) );
+ SG_LOG( SG_EVENT, SG_DEBUG,
+ " Current GMT = " << gmt->tm_mon+1 << "/"
+ << gmt->tm_mday << "/" << (1900 + gmt->tm_year) << " "
+ << gmt->tm_hour << ":" << gmt->tm_min << ":"
+ << gmt->tm_sec );
+
+ // calculate modified Julian date
+ // t->mjd = cal_mjd ((int)(t->gmt->tm_mon+1), (double)t->gmt->tm_mday,
+ // (int)(t->gmt->tm_year + 1900));
+ double mjd = sgTimeCalcMJD( (int)(gmt->tm_mon+1), (double)gmt->tm_mday,
+ (int)(gmt->tm_year + 1900) );
+
+ return mjd;
+}
+
+
// given an mjd, calculate greenwich mean sidereal time, gst
double sgTimeCalcGST( double mjd ) {
double gst;
x /= 3600.0;
gst = (1.0/SIDRATE)*hr + x;
- FG_LOG( FG_EVENT, FG_DEBUG, " gst => " << gst );
+ SG_LOG( SG_EVENT, SG_DEBUG, " gst => " << gst );
return gst;
}
// If you are having problems with incorrectly positioned astronomical
// bodies, this is a really good place to start looking.
-time_t SGTime::get_gmt(int year, int month, int day, int hour, int min, int sec)
+time_t sgTimeGetGMT(int year, int month, int day, int hour, int min, int sec)
{
struct tm mt;
# define MK_TIME_IS_GMT 1
#endif
-#if defined( HAVE_TIMEGM )
+#if defined( HAVE_TIMEGM )
return ( timegm(&mt) );
#elif defined( MK_TIME_IS_GMT )
- return ( mktime(&mt) );
+ time_t ret = mktime(&mt);
+
+#ifdef __CYGWIN__
+ ret -= _timezone;
+#endif
+
+ // This is necessary as some mktime() calls may
+ // try to access the system timezone files
+ // if this open fails errno is set to 2
+ // CYGWIN for one does this
+ // if ( errno ) {
+ // perror( "sgTimeGetGMT()" );
+ // errno = 0;
+ // }
+
+ // reset errno in any event.
+ errno = 0;
+
+ return ret;
#else // ! defined ( MK_TIME_IS_GMT )
// timezone seems to work as a proper offset for Linux & Solaris
-# if defined( __linux__ ) || defined( __sun__ )
+# if defined( __linux__ ) || defined(__sun) ||defined(__CYGWIN__)
# define TIMEZONE_OFFSET_WORKS 1
# endif
- long int start = mktime(&mt);
+#if defined(__CYGWIN__)
+#define TIMEZONE _timezone
+#else
+#define TIMEZONE timezone
+#endif
+
+ time_t start = mktime(&mt);
- FG_LOG( FG_EVENT, FG_DEBUG, "start1 = " << start );
+ SG_LOG( SG_EVENT, SG_DEBUG, "start1 = " << start );
// the ctime() call can screw up time progression on some versions
// of Linux
- // fgPrintf( FG_EVENT, FG_DEBUG, "start2 = %s", ctime(&start));
- FG_LOG( FG_EVENT, FG_DEBUG, "(tm_isdst = " << mt.tm_isdst << ")" );
+ // fgPrintf( SG_EVENT, SG_DEBUG, "start2 = %s", ctime(&start));
+ SG_LOG( SG_EVENT, SG_DEBUG, "(tm_isdst = " << mt.tm_isdst << ")" );
- timezone = fix_up_timezone( timezone );
+ TIMEZONE = fix_up_timezone( TIMEZONE );
# if defined( TIMEZONE_OFFSET_WORKS )
- FG_LOG( FG_EVENT, FG_DEBUG,
- "start = " << start << ", timezone = " << timezone );
- return( start - timezone );
+ SG_LOG( SG_EVENT, SG_DEBUG,
+ "start = " << start << ", timezone = " << TIMEZONE );
+ return( start - TIMEZONE );
# else // ! defined( TIMEZONE_OFFSET_WORKS )
daylight = mt.tm_isdst;
if ( daylight > 0 ) {
daylight = 1;
} else if ( daylight < 0 ) {
- FG_LOG( FG_EVENT, FG_WARN,
+ SG_LOG( SG_EVENT, FG_WARN,
"OOOPS, problem in sg_time.cxx, no daylight savings info." );
}
- long int offset = -(timezone / 3600 - daylight);
+ long int offset = -(TIMEZONE / 3600 - daylight);
- FG_LOG( FG_EVENT, FG_DEBUG, " Raw time zone offset = " << timezone );
- FG_LOG( FG_EVENT, FG_DEBUG, " Daylight Savings = " << daylight );
- FG_LOG( FG_EVENT, FG_DEBUG, " Local hours from GMT = " << offset );
+ SG_LOG( SG_EVENT, SG_DEBUG, " Raw time zone offset = " << TIMEZONE );
+ SG_LOG( SG_EVENT, SG_DEBUG, " Daylight Savings = " << daylight );
+ SG_LOG( SG_EVENT, SG_DEBUG, " Local hours from GMT = " << offset );
- long int start_gmt = start - timezone + (daylight * 3600);
+ long int start_gmt = start - TIMEZONE + (daylight * 3600);
- FG_LOG( FG_EVENT, FG_DEBUG, " March 21 noon (CST) = " << start );
+ SG_LOG( SG_EVENT, SG_DEBUG, " March 21 noon (CST) = " << start );
return ( start_gmt );
# endif // ! defined( TIMEZONE_OFFSET_WORKS )
projects / simgear.git / blobdiff