//
// Copyright (C) 1997 Curtis L. Olson - curt@infoplane.com
//
-// 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 <simgear/compiler.h>
-#ifdef FG_HAVE_STD_INCLUDES
+#include <errno.h> // for errno
+
+#ifdef SG_HAVE_STD_INCLUDES
# include <cmath>
# include <cstdio>
# include <cstdlib>
#define DEGHR(x) ((x)/15.)
-#define RADHR(x) DEGHR(x*RAD_TO_DEG)
+#define RADHR(x) DEGHR(x*SGD_RADIANS_TO_DEGREES)
+
+
+static const double MJD0 = 2415020.0;
+static const double J2000 = 2451545.0 - MJD0;
+static const double SIDRATE = 0.9972695677;
SGTime::SGTime( double lon, double lat, const string& root )
// cout << "Current local time = "
// << asctime(localtime(&cur_time)) << endl;
- FGPath zone( root );
- zone.append( "zone.tab" );
- FG_LOG( FG_EVENT, FG_DEBUG, "Reading timezone info from: " << zone.str() );
- tzContainer = new TimezoneContainer( zone.c_str() );
+ if ( root != (string)"" ) {
+ FGPath zone( root );
+ zone.append( "zone.tab" );
+ FG_LOG( FG_EVENT, FG_DEBUG, "Reading timezone info from: "
+ << zone.str() );
+ tzContainer = new TimezoneContainer( zone.c_str() );
- GeoCoord location( RAD_TO_DEG * lat, RAD_TO_DEG * lon );
- GeoCoord* nearestTz = tzContainer->getNearest(location);
+ GeoCoord location( SGD_RADIANS_TO_DEGREES * lat, SGD_RADIANS_TO_DEGREES * lon );
+ GeoCoord* nearestTz = tzContainer->getNearest(location);
- FGPath name( root );
- name.append( nearestTz->getDescription() );
- zonename = strdup( name.c_str() );
- // cout << "Using zonename = " << zonename << endl;
+ FGPath name( root );
+ name.append( nearestTz->getDescription() );
+ zonename = strdup( name.c_str() );
+ // cout << "Using zonename = " << zonename << endl;
+ } else {
+ tzContainer = NULL;
+ zonename = NULL;
+ }
}
}
+SGTime::SGTime() {
+ SGTime( 0.0, 0.0, "" );
+}
+
+
SGTime::~SGTime()
{
- delete tzContainer;
+ if ( tzContainer != NULL ) {
+ delete tzContainer;
+ }
if ( zonename != NULL ) {
delete zonename;
mjd + MJD0, lng); */
// convert to required internal units
- lng *= DEG_TO_RAD;
+ lng *= SGD_DEGREES_TO_RADIANS;
// compute LST and print
double gst = sgTimeCalcGST( mjd );
jd = mjd + MJD0;
FG_LOG( FG_EVENT, FG_DEBUG, " Current Julian Date = " << jd );
- // printf(" Current Longitude = %.3f\n", FG_Longitude * RAD_TO_DEG);
+ // printf(" Current Longitude = %.3f\n", FG_Longitude * SGD_RADIANS_TO_DEGREES);
// Calculate local side real time
if ( gst_diff < -100.0 ) {
gst_diff = gst_precise - gst_course;
- lst = sidereal_course( cur_time, gmt, -(lon * RAD_TO_DEG) ) + gst_diff;
+ lst = sidereal_course( cur_time, gmt, -(lon * 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_TO_DEG) ) + gst_diff;
+ lst = sidereal_course( cur_time, gmt, -(lon * SGD_RADIANS_TO_DEGREES) ) + 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( mjd, -(lon * RAD_TO_DEG) )
+ << sidereal_precise( mjd, -(lon * SGD_RADIANS_TO_DEGREES) )
<< ") (diff = " << gst_diff << ")" );
}
{
time_t currGMT;
time_t aircraftLocalTime;
- GeoCoord location( RAD_TO_DEG * lat, RAD_TO_DEG * lon );
+ GeoCoord location( SGD_RADIANS_TO_DEGREES * lat, SGD_RADIANS_TO_DEGREES * lon );
GeoCoord* nearestTz = tzContainer->getNearest(location);
FGPath zone( root );
zone.append ( nearestTz->getDescription() );
# 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);
+ // 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;
+ }
+ 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__ )
# define TIMEZONE_OFFSET_WORKS 1
# endif
- long int start = mktime(&mt);
+ time_t start = mktime(&mt);
FG_LOG( FG_EVENT, FG_DEBUG, "start1 = " << start );
// the ctime() call can screw up time progression on some versions
timezone = fix_up_timezone( timezone );
# if defined( TIMEZONE_OFFSET_WORKS )
- FG_LOG( FG_EVENT, FG_DEBUG,
+ FG_LOG( FG_EVENT, FG_DEBUG,
"start = " << start << ", timezone = " << timezone );
return( start - timezone );
# else // ! defined( TIMEZONE_OFFSET_WORKS )
projects / simgear.git / blobdiff