File indexing completed on 2023-10-01 07:41:14

 /*
     SPDX-FileCopyrightText: 2009 Prakash Mohan <prakash.mohan@kdemail.net>
 
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 
 #include "ksalmanac.h"
 
 #include "geolocation.h"
 #include "ksnumbers.h"
 #include "kstarsdata.h"
 
 KSAlmanac::KSAlmanac()
 {
     KStarsData *data = KStarsData::Instance();
 
     /*dt  = KStarsDateTime::currentDateTime();
     geo = data->geo();
     dt.setTime(QTime());
     dt  = geo->LTtoUT(dt);*/
 
     // Jasem 2015-08-24 Do NOT use KStarsDataTime for local time, it is only for UTC
     QDateTime midnight = QDateTime(data->lt().date(), QTime());
     geo                = data->geo();
     dt                 = geo->LTtoUT(KStarsDateTime(midnight));
     update();
 }
 
 KSAlmanac::KSAlmanac(const KStarsDateTime &midnight, const GeoLocation *g)
 {
     geo = g ? g : KStarsData::Instance()->geo();
 
     dt = midnight.isValid() ?
                 midnight.timeSpec() == Qt::LocalTime ?
                     geo->LTtoUT(midnight) :
                     midnight :
                 KStarsData::Instance()->ut();
 
     update();
 }
 
 void KSAlmanac::update()
 {
     RiseSetTime(&m_Sun, &SunRise, &SunSet, &SunRiseT, &SunSetT);
     RiseSetTime(&m_Moon, &MoonRise, &MoonSet, &MoonRiseT, &MoonSetT);
     //    qDebug() << Q_FUNC_INFO << "Sun rise: " << SunRiseT.toString() << " Sun set: " << SunSetT.toString() << " Moon rise: " << MoonRiseT.toString() << " Moon set: " << MoonSetT.toString();
     findDawnDusk();
     findMoonPhase();
 }
 
 void KSAlmanac::RiseSetTime(SkyObject *o, double *riseTime, double *setTime, QTime *RiseTime, QTime *SetTime)
 {
     // Compute object rise and set times
     const KStarsDateTime today = dt;
     const GeoLocation *_geo    = geo;
     *RiseTime                  = o->riseSetTime(
         today, _geo,
         true); // FIXME: Should we add a day here so that we report future rise time? Not doing so produces the right results for the moon. Not sure about the sun.
     *SetTime  = o->riseSetTime(today, _geo, false);
     *riseTime = -1.0 * RiseTime->secsTo(QTime(0, 0, 0, 0)) / 86400.0;
     *setTime  = -1.0 * SetTime->secsTo(QTime(0, 0, 0, 0)) / 86400.0;
 
     // Check to see if the object is circumpolar
     // NOTE: Since we are working on a local copy of the Sun / Moon,
     //       we freely change the geolocation / time without setting
     //       them back.
 
     KSNumbers num(dt.djd());
     CachingDms LST = geo->GSTtoLST(dt.gst());
     o->updateCoords(&num, true, geo->lat(), &LST, true);
     if (o->checkCircumpolar(geo->lat()))
     {
         if (o->alt().Degrees() > 0.0)
         {
             //Circumpolar, signal it this way:
             *riseTime = 0.0;
             *setTime  = 1.0;
         }
         else
         {
             //never rises, signal it this way:
             *riseTime = 0.0;
             *setTime  = -1.0;
         }
     }
 }
 
 void KSAlmanac::findDawnDusk(double altitude)
 {
     KStarsDateTime today = dt;
     KSNumbers num(today.djd());
     CachingDms LST = geo->GSTtoLST(today.gst());
 
     // Relocate our local Sun to this almanac time - local midnight
     m_Sun.updateCoords(&num, true, geo->lat(), &LST, true);
 
     // Granularity
     int const h_inc = 5;
 
     // Compute the altitude of the Sun twelve hours before this almanac time
     int const start_h = -1200, end_h = +1200;
     double last_alt = findAltitude(&m_Sun, start_h/100.0);
 
     int dawn = -1300, dusk = -1300, min_alt_time = -1300;
     double max_alt = -100.0, min_alt = +100.0;
 
     // Compute the dawn and dusk times in a [-12,+12] hours around the day midnight of this almanac as well as min and max altitude
     // See the header comment about dawn and dusk positions
     for (int h = start_h + h_inc; h <= end_h; h += h_inc)
     {
         // Compute the Sun's altitude in an increasing hour interval
         double const alt = findAltitude(&m_Sun, h/100.0);
 
         // Deduce whether the Sun is rising or setting
         bool const rising = alt - last_alt > 0;
 
         // Extend min/max altitude interval, push minimum time down
         if (max_alt < alt)
         {
             max_alt = alt;
         }
         else if (alt < min_alt)
         {
             min_alt = alt;
             min_alt_time = h;
         }
 
         // Dawn is when the Sun is rising and crosses an altitude of -18 degrees
         if (dawn < 0)
             if (rising)
                 if (last_alt <= altitude && altitude <= alt)
                     dawn = h - h_inc * (alt == last_alt ? 0 : (alt - altitude)/(alt - last_alt));
 
         // Dusk is when the Sun is setting and crosses an altitude of -18 degrees
         if (dusk < 0)
             if (!rising)
                 if (last_alt >= altitude && altitude >= alt)
                     dusk = h - h_inc * (alt == last_alt ? 0 : (alt - altitude)/(alt - last_alt));
 
         last_alt = alt;
     }
 
     // If the Sun did not cross the astronomical twilight altitude, use the minimal altitude
     if (dawn < start_h || dusk < start_h)
     {
         DawnAstronomicalTwilight = static_cast <double> (min_alt_time) / 2400.0;
         DuskAstronomicalTwilight = static_cast <double> (min_alt_time) / 2400.0;
     }
     // If the Sun did cross the astronomical twilight, use the computed time offsets
     else
     {
         DawnAstronomicalTwilight = static_cast <double> (dawn) / 2400.0;
         DuskAstronomicalTwilight = static_cast <double> (dusk) / 2400.0;
     }
 
     SunMaxAlt = max_alt;
     SunMinAlt = min_alt;
 }
 
 void KSAlmanac::findMoonPhase()
 {
     const KStarsDateTime today = dt;
     KSNumbers num(today.djd());
     CachingDms LST = geo->GSTtoLST(today.gst());
 
     m_Sun.updateCoords(&num, true, geo->lat(), &LST, true); // We can abuse our own copy of the sun and/or moon
     m_Moon.updateCoords(&num, true, geo->lat(), &LST, true);
     m_Moon.findPhase(&m_Sun);
     MoonPhase = m_Moon.phase().Degrees();
 }
 
 void KSAlmanac::setDate(const KStarsDateTime &utc_midnight)
 {
     dt = utc_midnight;
     update();
 }
 
 void KSAlmanac::setLocation(const GeoLocation *geo_)
 {
     geo = geo_;
     update();
 }
 
 double KSAlmanac::sunZenithAngleToTime(double z) const
 {
     // TODO: Correct for movement of the sun
     double HA       = acos((cos(z * dms::DegToRad) - m_Sun.dec().sin() * geo->lat()->sin()) /
                      (m_Sun.dec().cos() * geo->lat()->cos()));
     double HASunset = acos((-m_Sun.dec().sin() * geo->lat()->sin()) / (m_Sun.dec().cos() * geo->lat()->cos()));
     return SunSet + (HA - HASunset) / 24.0;
 }
 
 double KSAlmanac::findAltitude(const SkyPoint *p, double hour)
 {
     return SkyPoint::findAltitude(p, dt, geo, hour).Degrees();
 }