SGTime::SGTime( const string& root )
{
- if (cur_time_params) {
- FG_LOG( FG_GENERAL, FG_ALERT,
- "Error: only one instance of SGTime allowed" );
- exit(-1);
- }
-
- cur_time_params = this;
-
FGPath zone( root );
- zone.append( "Timezone" );
zone.append( "zone.tab" );
- FG_LOG( FG_EVENT, FG_INFO, "Reading timezone info from: " << zone.str() );
+ FG_LOG( FG_EVENT, FG_DEBUG, "Reading timezone info from: " << zone.str() );
tzContainer = new TimezoneContainer( zone.c_str() );
- // warp=0;
- // warp_delta=0;
+
+ zonename = NULL;
}
SGTime::~SGTime()
{
delete tzContainer;
- delete zonename;
-}
-void SGTime::updateLocal( double lon, double lat, const string& root )
-{
- 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;
+ if ( zonename != NULL ) {
+ delete zonename;
+ }
}
-// Initialize the time dependent variables (maybe I'll put this in the
-// constructor later)
+
+// Initialize the time related variables
void SGTime::init( double lon, double lat, const string& root )
-// time_t timeOffset, sgTimingOffsetType offsetType )
{
FG_LOG( FG_EVENT, FG_INFO, "Initializing Time" );
gst_diff = -9999.0;
- time_t currGMT;
- time_t systemLocalTime;
- time_t aircraftLocalTime;
+ // time_t currGMT;
+ // time_t systemLocalTime;
+ // time_t aircraftLocalTime;
// would it be better to put these sanity checks in the options
// parsing code? (CLO)
GeoCoord* nearestTz = tzContainer->getNearest(location);
FGPath zone( root );
- zone.append( "Timezone" );
zone.append( nearestTz->getDescription() );
- cout << "Using " << zone.str() << " for timezone information" << endl;
+ // cout << "Using " << zone.str() << " for timezone information" << endl;
zonename = strdup( zone.c_str() );
- cout << "zonename = " << zonename << endl;
+ // 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;
+ // currGMT = get_gmt( gmtime(&cur_time) );
+ // cout << "currGMT = " << currGMT << endl;
- systemLocalTime = get_gmt( localtime(&cur_time) );
- cout << "systemLocalTime = " << systemLocalTime << endl;
+ // systemLocalTime = get_gmt( localtime(&cur_time) );
+ // cout << "systemLocalTime = " << systemLocalTime << endl;
- aircraftLocalTime = get_gmt( fgLocaltime(&cur_time, zone.c_str()) );
+ // 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)));
-
- //printf("LT = %d\n", computerLocalTime);
- // Okay, in principle, this trick allows to calculate the
- // difference between GMT and localtime, in seconds.
- // printf("Gmt = %d, SLT = %d, (difference = %d)\n", currGMT, systemLocalTime, (currGMT - systemLocalTime));
- // printf("Gmt = %d, ALT = %d, (difference = %d)\n", currGMT, aircraftLocalTime, (currGMT - aircraftLocalTime));
- // exit(1);
-
-#if 0
- // Okay, we now have six possible scenarios
- switch (offsetType)
- {
- case SG_TIME_SYS_OFFSET:
- warp = timeOffset;
- break;
- case SG_TIME_GMT_OFFSET:
- warp = timeOffset - (currGMT - systemLocalTime);
- break;
- case SG_TIME_LAT_OFFSET:
- // warp = timeOffset - (currGMT - systemLocalTime +
- // (currGMT - aircraftLocalTime));
- warp = timeOffset - (aircraftLocalTime - systemLocalTime);
- break;
- case SG_TIME_SYS_ABSOLUTE:
- warp = timeOffset - cur_time;
- //printf("warp = %d\n", warp);
- break;
- case SG_TIME_GMT_ABSOLUTE:
- warp = timeOffset - currGMT;
- break;
- case SG_TIME_LAT_ABSOLUTE:
- warp = timeOffset - (aircraftLocalTime - systemLocalTime) -
- cur_time;
- break;
- default:
- printf("Unsupported type\n");
- exit(1);
- }
-
- warp_delta = 0;
- // pause = current_options.get_pause();
-#endif
-
-}
-
-
-// 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.
-
-void SGTime::cal_mjd (int mn, double dy, int yr)
-{
- //static double last_mjd, last_dy;
- //double mjd;
- //static int last_mn, last_yr;
- int b, d, m, y;
- long c;
-
- if (mn == last_mn && yr == last_yr && dy == last_dy) {
- mjd = last_mjd;
- }
-
- m = mn;
- y = (yr < 0) ? yr + 1 : yr;
- if (mn < 3) {
- m += 12;
- y -= 1;
- }
-
- if (yr < 1582 || (yr == 1582 && (mn < 10 || (mn == 10 && dy < 15)))) {
- b = 0;
- } else {
- int a;
- a = y/100;
- b = 2 - a + a/4;
- }
-
- if (y < 0) {
- c = (long)((365.25*y) - 0.75) - 694025L;
- } else {
- c = (long)(365.25*y) - 694025L;
- }
-
- d = (int)(30.6001*(m+1));
-
- mjd = b + c + d + dy - 0.5;
-
- last_mn = mn;
- last_dy = dy;
- last_yr = yr;
- last_mjd = mjd;
-}
-
-
-// given an mjd, calculate greenwich mean sidereal time, gst
-void SGTime::utc_gst ()
-{
- double day = floor(mjd-0.5)+0.5;
- double hr = (mjd-day)*24.0;
- double T, x;
-
- T = ((int)(mjd - 0.5) + 0.5 - J2000)/36525.0;
- x = 24110.54841 + (8640184.812866 + (0.093104 - 6.2e-6 * T) * T) * T;
- x /= 3600.0;
- gst = (1.0/SIDRATE)*hr + x;
-
- FG_LOG( FG_EVENT, FG_INFO, " gst => " << gst );
}
// 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); */
lng *= DEG_TO_RAD;
// compute LST and print
- utc_gst();
- 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, struct tm *gmt, double lng )
{
- //struct tm *gmt;
- //double lstTmp;
time_t start_gmt, now;
double diff, part, days, hours, lstTmp;
char tbuf[64];
- //gmt = t->gmt;
- //now = t->cur_time;
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 = " << format_time(gmt, tbuf) );
+ FG_LOG( FG_EVENT, FG_DEBUG, " COURSE: GMT = "
+ << sgTimeFormatTime(gmt, tbuf) );
FG_LOG( FG_EVENT, FG_DEBUG, " March 21 noon (GMT) = " << start_gmt );
diff = (now - start_gmt) / (3600.0 * 24.0);
" days = " << days << " hours = " << hours << " lon = "
<< lng << " lst = " << lstTmp );
- return(lstTmp);
+ return lstTmp;
}
-// Update time variables such as gmt, julian date, and sidereal time
-void SGTime::update( double lon, double lat, double alt_m, long int warp ) {
+// Update the time related variables
+void SGTime::update( double lon, double lat, long int warp ) {
double gst_precise, gst_course;
- FG_LOG( FG_EVENT, FG_INFO, "Updating time" );
+ 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_INFO,
+ 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_INFO,
+ FG_LOG( FG_EVENT, FG_DEBUG,
" Current GMT = " << gmt->tm_mon+1 << "/"
<< gmt->tm_mday << "/" << gmt->tm_year << " "
<< gmt->tm_hour << ":" << gmt->tm_min << ":"
// 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));
- cal_mjd ((int)(gmt->tm_mon+1), (double)gmt->tm_mday,
- (int)(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)) +
// convert "back" to Julian date + partial day (as a fraction of one)
jd = mjd + MJD0;
- FG_LOG( FG_EVENT, FG_INFO, " Current Julian Date = " << jd );
+ FG_LOG( FG_EVENT, FG_DEBUG, " Current Julian Date = " << jd );
// printf(" Current Longitude = %.3f\n", FG_Longitude * RAD_TO_DEG);
// 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_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(-(lon * RAD_TO_DEG)) + gst_diff;
+ lst = sidereal_course( cur_time, gmt, -(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;
+ gst = sidereal_course( cur_time, gmt, 0.00 ) + gst_diff;
+ lst = sidereal_course( cur_time, gmt, -(lon * RAD_TO_DEG) ) + gst_diff;
}
- FG_LOG( FG_EVENT, FG_INFO,
+ FG_LOG( FG_EVENT, FG_DEBUG,
" Current lon=0.00 Sidereal Time = " << gst );
- FG_LOG( FG_EVENT, FG_INFO,
+ FG_LOG( FG_EVENT, FG_DEBUG,
" Current LOCAL Sidereal Time = " << lst << " ("
- << sidereal_precise(-(lon * RAD_TO_DEG))
+ << sidereal_precise( mjd, -(lon * RAD_TO_DEG) )
<< ") (diff = " << gst_diff << ")" );
}
+// Given lon/lat, update timezone information and local_offset
+void SGTime::updateLocal( double lon, double lat, const string& root )
+{
+ 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 ( nearestTz->getDescription() );
+ if ( zonename ) {
+ delete zonename;
+ }
+ zonename = strdup( zone.c_str() );
+ 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;
+}
+
+
+// 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) {
+ double mjd;
+
+ // internal book keeping data
+ static double last_mjd, last_dy;
+ static int last_mn, last_yr;
+
+ int b, d, m, y;
+ long c;
+
+ if (mn == last_mn && yr == last_yr && dy == last_dy) {
+ mjd = last_mjd;
+ }
+
+ m = mn;
+ y = (yr < 0) ? yr + 1 : yr;
+ if (mn < 3) {
+ m += 12;
+ y -= 1;
+ }
+
+ if (yr < 1582 || (yr == 1582 && (mn < 10 || (mn == 10 && dy < 15)))) {
+ b = 0;
+ } else {
+ int a;
+ a = y/100;
+ b = 2 - a + a/4;
+ }
+
+ if (y < 0) {
+ c = (long)((365.25*y) - 0.75) - 694025L;
+ } else {
+ c = (long)(365.25*y) - 694025L;
+ }
+
+ d = (int)(30.6001*(m+1));
+
+ mjd = b + c + d + dy - 0.5;
+
+ last_mn = mn;
+ last_dy = dy;
+ last_yr = yr;
+ last_mjd = mjd;
+
+ return mjd;
+}
+
+
+// given an mjd, calculate greenwich mean sidereal time, gst
+double sgTimeCalcGST( double mjd ) {
+ double gst;
+
+ double day = floor(mjd-0.5)+0.5;
+ double hr = (mjd-day)*24.0;
+ double T, x;
+
+ T = ((int)(mjd - 0.5) + 0.5 - J2000)/36525.0;
+ x = 24110.54841 + (8640184.812866 + (0.093104 - 6.2e-6 * T) * T) * T;
+ x /= 3600.0;
+ gst = (1.0/SIDRATE)*hr + x;
+
+ FG_LOG( FG_EVENT, FG_DEBUG, " gst => " << gst );
+
+ return gst;
+}
+
+
+#if defined( HAVE_TIMEGM )
+ // ignore this function
+#elif defined( MK_TIME_IS_GMT )
+ // ignore this function
+#else // ! defined ( MK_TIME_IS_GMT )
+
+ // Fix up timezone if using ftime()
+ static long int fix_up_timezone( long int timezone_orig ) {
+# if !defined( HAVE_GETTIMEOFDAY ) && defined( HAVE_FTIME )
+ // ftime() needs a little extra help finding the current timezone
+ struct timeb current;
+ ftime(¤t);
+ return( current.timezone * 60 );
+# else
+ return( timezone_orig );
+# endif
+ }
+#endif
+
+
/******************************************************************
* The following are some functions that were included as SGTime
* members, although they currently don't make use of any of the
// 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;
#endif // ! defined ( MK_TIME_IS_GMT )
}
-// Fix up timezone if using ftime()
-long int SGTime::fix_up_timezone( long int timezone_orig )
-{
-#if !defined( HAVE_GETTIMEOFDAY ) && defined( HAVE_FTIME )
- // ftime() needs a little extra help finding the current timezone
- struct timeb current;
- ftime(¤t);
- return( current.timezone * 60 );
-#else
- return( timezone_orig );
-#endif
-}
-
-char* SGTime::format_time( const struct tm* p, char* buf )
+// format time
+char* sgTimeFormatTime( const struct tm* p, char* buf )
{
sprintf( buf, "%d/%d/%2d %d:%02d:%02d",
p->tm_mon, p->tm_mday, p->tm_year,
p->tm_hour, p->tm_min, p->tm_sec);
return buf;
}
-
-
-SGTime* SGTime::cur_time_params = 0;
projects / simgear.git / blobdiff