X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=simgear%2Ftiming%2Fsg_time.cxx;h=d32302ee1eef9c5575a5595f82ea612ea1ce734d;hb=b47d1ad5fd8ed111cae99c1f65f5bb65a5371501;hp=4c0222199d850e1a8d0a86404fbdcb0bf1e2ed8a;hpb=cb29dcc2388c9c000b9bcd8c08d1b2ccd0059bcc;p=simgear.git diff --git a/simgear/timing/sg_time.cxx b/simgear/timing/sg_time.cxx index 4c022219..d32302ee 100644 --- a/simgear/timing/sg_time.cxx +++ b/simgear/timing/sg_time.cxx @@ -2,215 +2,128 @@ // // 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 +# include #endif #include -#ifdef FG_HAVE_STD_INCLUDES -# include -# include -# include -# include -#else -# include -# include -# include -# include -#endif +#include // for errno + +#include +#include +#include +#include +#include + +#ifdef HAVE_SYS_TIME_H +# include // for get/setitimer, gettimeofday, struct timeval +#endif #ifdef HAVE_SYS_TIMEB_H # include // for ftime() and struct timeb #endif #ifdef HAVE_UNISTD_H # include // for gettimeofday() #endif -#ifdef HAVE_SYS_TIME_H -# include // for get/setitimer, gettimeofday, struct timeval -#endif + +#include // for NAN #include #include -#include +#include #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; } @@ -218,44 +131,41 @@ void SGTime::updateLocal( double lon, double lat, const string& root ) // 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); @@ -268,11 +178,130 @@ double SGTime::sidereal_course( double lng ) 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; } @@ -327,6 +356,43 @@ double sgTimeCalcMJD(int mn, double dy, int yr) { } +// 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; @@ -340,7 +406,7 @@ double sgTimeCalcGST( double mjd ) { 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; } @@ -397,7 +463,7 @@ double sgTimeCalcGST( double mjd ) { // 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; @@ -417,50 +483,74 @@ time_t SGTime::get_gmt(int year, int month, int day, int hour, int min, int sec) # 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 )