kstars/kstars/kstarsdatetime.h

   1 /***************************************************************************
   2                           kstarsdatetime.h  -  K Desktop Planetarium
   3                              -------------------
   4     begin                : Tue 05 May 2004
   5     copyright            : (C) 2001 by Jason Harris
   6     email                : jharris@30doradus.org
   7  ***************************************************************************/
   8
   9 /***************************************************************************
  10  *                                                                         *
  11  *   This program is free software; you can redistribute it and/or modify  *
  12  *   it under the terms of the GNU General Public License as published by  *
  13  *   the Free Software Foundation; either version 2 of the License, or     *
  14  *   (at your option) any later version.                                   *
  15  *                                                                         *
  16  ***************************************************************************/
  17
  18 #ifndef KSTARSDATETIME_H
  19 #define KSTARSDATETIME_H
  20
  21 #define J2000 2451545.0 //Julian Date for noon on Jan 1, 2000 (epoch J2000)
  22                        //defined here because this file is included in every other class.
  23 #define B1950 2433282.4235  // Julian date for Jan 0.9235, 1950
  24 #define SIDEREALSECOND 1.002737909 //number of sidereal seconds in one solar second
  25
  26 #include "libkdeedu/extdate/extdatetime.h"
  27
  28 class dms;
  29
  30 /**@class KStarsDateTime
  31         *@short Extension of ExtDateTime for KStars
  32         *@author Jason Harris
  33         *@version 1.0
  34         */
  35
  36 class KStarsDateTime : public ExtDateTime
  37 {
  38 public:
  39         KStarsDateTime();
  40         KStarsDateTime( long int jd );
  41         KStarsDateTime( const KStarsDateTime &kdt );
  42         KStarsDateTime( const ExtDateTime &kdt );
  43         KStarsDateTime( const ExtDate &_d, const QTime &_t );
  44         KStarsDateTime( double djd );
  45         KStarsDateTime( long double djd );
  46
  47         void setDJD( long double jd );
  48         void setDate( const ExtDate &d );
  49         void setTime( const QTime &t );
  50
  51         KStarsDateTime addSecs( long double s ) const { return KStarsDateTime( djd() + s/86400. ); }
  52         KStarsDateTime addDays( int nd ) const { return KStarsDateTime( djd() + (long double)nd ); }
  53
  54         bool operator == ( const KStarsDateTime &d ) const { return DJD == d.djd(); }
  55         bool operator != ( const KStarsDateTime &d ) const { return DJD != d.djd(); }
  56         bool operator  < ( const KStarsDateTime &d ) const { return DJD  < d.djd(); }
  57         bool operator <= ( const KStarsDateTime &d ) const { return DJD <= d.djd(); }
  58         bool operator  > ( const KStarsDateTime &d ) const { return DJD  > d.djd(); }
  59         bool operator >= ( const KStarsDateTime &d ) const { return DJD >= d.djd(); }
  60
  61         /**@return the date and time according to the CPU clock (note that this is not
  62                 *necessarily UT)
  63                 */
  64         static KStarsDateTime currentDateTime();
  65
  66 /**@return the julian day as a long double, including the time as the fractional portion.
  67         */
  68         long double djd() const { return DJD; }
  69
  70 /**@return the fraction of the Julian Day corresponding to the current time.
  71         *
  72         *Because the integer Julian Day value jd() is referenced to Noon on the current date,
  73         *jdFrac() ranges between values of -0.5 and +0.5 for the previous and next midnights,
  74         *respectively.
  75         */
  76         double jdFrac() const { return ((time().hour()-12) + (time().minute()
  77                         + (time().second() + time().msec()/1000.)/60.)/60.)/24.; }
  78         long double JDat0hUT() const { return int( djd() - 0.5 ) + 0.5; }
  79
  80         dms gst() const;
  81         QTime GSTtoUT( dms GST ) const;
  82
  83         double epoch() const { return ( double( date().year() )
  84                         + double( date().dayOfYear() )/double( date().daysInYear() ) ); }
  85         void setFromEpoch( double e );
  86 private:
  87         dms GSTat0hUT() const;
  88         long double DJD;
  89 };
  90
  91 #endif  //KSTARSDATETIME_H
  92