datetime.cpp

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//                                                       //
//                         SAGA                          //
//                                                       //
//      System for Automated Geoscientific Analyses      //
//                                                       //
//           Application Programming Interface           //
//                                                       //
//                  Library: SAGA_API                    //
//                                                       //
//-------------------------------------------------------//
//                                                       //
//                     datetime.cpp                      //
//                                                       //
//          Copyright (C) 2015 by Olaf Conrad            //
//                                                       //
//-------------------------------------------------------//
//                                                       //
// This file is part of 'SAGA - System for Automated     //
// Geoscientific Analyses'.                              //
//                                                       //
// This library is free software; you can redistribute   //
// it and/or modify it under the terms of the GNU Lesser //
// General Public License as published by the Free       //
// Software Foundation, either version 2.1 of the        //
// License, or (at your option) any later version.       //
//                                                       //
// 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 Lesser General Public //
// License for more details.                             //
//                                                       //
// You should have received a copy of the GNU Lesser     //
// General Public License along with this program; if    //
// not, see <http://www.gnu.org/licenses/>.              //
//                                                       //
//-------------------------------------------------------//
//                                                       //
//    contact:    Olaf Conrad                            //
//                Institute of Geography                 //
//                University of Hamburg                  //
//                Germany                                //
//                                                       //
//    e-mail:     oconrad@saga-gis.org                   //
//                                                       //
 
//---------------------------------------------------------
#include <time.h>
 
#include <wx/datetime.h>
 
#include "datetime.h"
 

//                                                       //
//                                                       //
//                                                       //
 
//---------------------------------------------------------
CSG_String CSG_TimeSpan::Format(const CSG_String &Format) const
{
        wxTimeSpan      ts((wxLongLong(m_span)));
 
        wxString        s       = !Format.is_Empty() ? ts.Format(Format.c_str()) : ts.Format(wxDefaultTimeSpanFormat);
 
        return( CSG_String(&s) );
}
 

//                                                       //
//                                                       //
//                                                       //
 
//---------------------------------------------------------
CSG_DateTime::CSG_DateTime(void)
{
        m_pDateTime     = new wxDateTime(wxDateTime::Now());
}
 
//---------------------------------------------------------
CSG_DateTime::CSG_DateTime(const CSG_DateTime &DateTime)
{
        m_pDateTime     = new wxDateTime(*DateTime.m_pDateTime);
}
 
//---------------------------------------------------------
CSG_DateTime::CSG_DateTime(double JDN)
{
        m_pDateTime     = new wxDateTime(JDN);
}
 
//---------------------------------------------------------
CSG_DateTime::CSG_DateTime(const CSG_String &ISODate)
{
        m_pDateTime     = new wxDateTime(wxDateTime::Now());
 
        Set(ISODate);
}
 
//---------------------------------------------------------
CSG_DateTime::CSG_DateTime(TSG_DateTime Hour, TSG_DateTime Minute, TSG_DateTime Second, TSG_DateTime Millisec)
{
        m_pDateTime     = new wxDateTime(Hour, Minute, Second, Millisec);
}
 
//---------------------------------------------------------
CSG_DateTime::CSG_DateTime(TSG_DateTime Day, Month Month, int Year, TSG_DateTime Hour, TSG_DateTime Minute, TSG_DateTime Second, TSG_DateTime Millisec)
{
        m_pDateTime     = new wxDateTime(Day, (wxDateTime::Month)Month, Year, Hour, Minute, Second, Millisec);
}
 
//---------------------------------------------------------
CSG_DateTime::~CSG_DateTime(void)
{
        delete(m_pDateTime);
}
 

//                                                       //
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set(const CSG_DateTime &DateTime)
{
        m_pDateTime->Set(DateTime.m_pDateTime->GetTm());
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set(double JDN)
{
        m_pDateTime->Set(JDN);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set(const CSG_String &ISODate)
{
        // 0123456789
        // YYYY-MM-DD
 
        if( ISODate.Length() >= 10 && ISODate[4] == '-' && ISODate[7] == '-' )
        {
                int     y       = ISODate.Left (   4).asInt();
                int     m       = ISODate.Mid  (5, 2).asInt();
                int     d       = ISODate.Right(   2).asInt();
 
                Set((TSG_DateTime)d, (Month)(m - 1), y);
        }
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set(TSG_DateTime Hour, TSG_DateTime Minute, TSG_DateTime Second, TSG_DateTime Millisec)
{
        m_pDateTime->Set(Hour, Minute, Second, Millisec);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set(TSG_DateTime Day, Month Month, int Year, TSG_DateTime Hour, TSG_DateTime Minute, TSG_DateTime Second, TSG_DateTime Millisec)
{
        m_pDateTime->Set(Day, (wxDateTime::Month)Month, Year, Hour, Minute, Second, Millisec);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Millisecond(unsigned short Value)
{
        m_pDateTime->SetMillisecond(Value);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Second(unsigned short Value)
{
        m_pDateTime->SetSecond(Value);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Minute(unsigned short Value)
{
        m_pDateTime->SetMinute(Value);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Hour(unsigned short Value)
{
        m_pDateTime->SetHour(Value);
 
        return( *this );
}
 
CSG_DateTime & CSG_DateTime::Set_Hour(double Value)
{
        m_pDateTime->ResetTime();
 
        Value   = fmod(Value, 24.0); if( Value < 0.0 ) Value += 24.0;
 
        m_pDateTime->SetHour       ((wxDateTime::wxDateTime_t)Value);   Value   = (Value - (wxDateTime::wxDateTime_t)Value) *   60.0;
        m_pDateTime->SetMinute     ((wxDateTime::wxDateTime_t)Value);   Value   = (Value - (wxDateTime::wxDateTime_t)Value) *   60.0;
        m_pDateTime->SetSecond     ((wxDateTime::wxDateTime_t)Value);   Value   = (Value - (wxDateTime::wxDateTime_t)Value) * 1000.0;
        m_pDateTime->SetMillisecond((wxDateTime::wxDateTime_t)Value);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Day(unsigned short Value)
{
        m_pDateTime->SetDay(Value);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Month(unsigned short Value)
{
        m_pDateTime->SetMonth((wxDateTime::Month)Value);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Year(int Value)
{
        m_pDateTime->SetYear(Value);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_DayOfYear(unsigned short Value)
{
        m_pDateTime->SetToYearDay(Value);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_To_Current(void)
{
        m_pDateTime->SetToCurrent();
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Reset_Time(void)
{
        m_pDateTime->ResetTime();
 
        return( *this );
}
 

//                                                       //
 
//---------------------------------------------------------
CSG_DateTime CSG_DateTime::From_UTC(bool noDST) const
{
        return( CSG_DateTime(m_pDateTime->FromUTC(noDST).GetJDN()) );
 
//      CSG_DateTime dt; dt.m_pDateTime->Set(m_pDateTime->FromUTC(noDST).GetTm()); return( dt );
}
 
//---------------------------------------------------------
CSG_DateTime CSG_DateTime::To_UTC(bool noDST) const
{
        return( CSG_DateTime(m_pDateTime->ToUTC(noDST).GetJDN()) );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Make_UTC(bool noDST)
{
        m_pDateTime->MakeUTC(noDST);
 
        return( *this );
}
 
//---------------------------------------------------------
bool CSG_DateTime::is_DST(void)     const
{
        return( m_pDateTime->IsDST() != 0 );
}
 

//                                                       //
 
//---------------------------------------------------------
sLong CSG_DateTime::Get_Value(void) const
{
        return( m_pDateTime->GetValue().GetValue() );
}
 

//                                                       //
 
//---------------------------------------------------------
CSG_DateTime CSG_DateTime::Add(const CSG_TimeSpan &TimeSpan)   const
{
        CSG_DateTime        dt(*this);
 
        return( dt.Add(TimeSpan) );
}
 
CSG_DateTime & CSG_DateTime::Add(const CSG_TimeSpan &TimeSpan)
{
        m_pDateTime->Add(wxTimeSpan((wxLongLong)TimeSpan.m_span));
 
        return( *this);
}
 
//---------------------------------------------------------
CSG_DateTime CSG_DateTime::Subtract(const CSG_TimeSpan &TimeSpan) const
{
        CSG_DateTime        dt(*this);
 
        return( dt.Subtract(TimeSpan) );
}
 
CSG_DateTime & CSG_DateTime::Subtract(const CSG_TimeSpan &TimeSpan)
{
        m_pDateTime->Subtract(wxTimeSpan((wxLongLong)TimeSpan.m_span));
 
        return( *this);
}
 
//---------------------------------------------------------
CSG_TimeSpan CSG_DateTime::Subtract(const CSG_DateTime &DateTime) const
{
        CSG_TimeSpan        Span((sLong)m_pDateTime->Subtract(*DateTime.m_pDateTime).GetValue().GetValue());
 
        return( Span );
}
 

//                                                       //
 
//---------------------------------------------------------
bool CSG_DateTime::is_Valid(void) const
{
        return( m_pDateTime->IsValid() );
}
 
//---------------------------------------------------------
unsigned short CSG_DateTime::Get_Millisecond(void) const   {       return( m_pDateTime->GetMillisecond() );        }
unsigned short CSG_DateTime::Get_Second     (void)      const   {       return( m_pDateTime->GetSecond     () );        }
unsigned short CSG_DateTime::Get_Minute     (void)      const   {       return( m_pDateTime->GetMinute     () );        }
unsigned short CSG_DateTime::Get_Hour       (void)        const   {       return( m_pDateTime->GetHour       () );        }
unsigned short CSG_DateTime::Get_Day        (void) const   {       return( m_pDateTime->GetDay        () );        }

CSG_DateTime::Month CSG_DateTime::Get_Month(void)     const
{
        return( (Month)m_pDateTime->GetMonth() );
}

int CSG_DateTime::Get_Month(bool bZeroBased)     const
{
        return( bZeroBased ? (int)m_pDateTime->GetMonth() : 1 + (int)m_pDateTime->GetMonth() );
}
 
int CSG_DateTime::Get_Year(void)  const
{
        return( m_pDateTime->GetYear() );
}
 
//---------------------------------------------------------
unsigned short CSG_DateTime::Get_DayOfYear(void)     const
{
        return( m_pDateTime->GetDayOfYear() );
}
 
CSG_DateTime::WeekDay CSG_DateTime::Get_WeekDay(void)     const
{
        return( (WeekDay)m_pDateTime->GetWeekDay() );
}
 
CSG_DateTime::TSG_DateTime CSG_DateTime::Get_WeekOfMonth(void)   const
{
        return( (TSG_DateTime)m_pDateTime->GetWeekOfMonth() );
}
 
CSG_DateTime::TSG_DateTime CSG_DateTime::Get_WeekOfYear(void)     const
{
        return( (TSG_DateTime)m_pDateTime->GetWeekOfYear() );
}
 
//---------------------------------------------------------
double CSG_DateTime::Get_JDN(void) const
{
        return( m_pDateTime->GetJDN() );
}
 
double CSG_DateTime::Get_MJD(void) const
{
        return( m_pDateTime->GetMJD() );
}
 
sLong CSG_DateTime::Get_Unix_Time(void) const
{
        return( m_pDateTime->GetTicks() );
}

//                                                       //
 
//---------------------------------------------------------
bool CSG_DateTime::is_EarlierThan    (const CSG_DateTime &DateTime)     const   {       return( m_pDateTime->IsEarlierThan(*DateTime.m_pDateTime) );    }
bool CSG_DateTime::is_EqualTo        (const CSG_DateTime &DateTime) const   {       return( m_pDateTime->IsEqualTo    (*DateTime.m_pDateTime) );    }
bool CSG_DateTime::is_LaterThan      (const CSG_DateTime &DateTime)       const   {       return( m_pDateTime->IsLaterThan  (*DateTime.m_pDateTime) );    }
 
//---------------------------------------------------------
bool CSG_DateTime::is_SameDate       (const CSG_DateTime &DateTime)        const   {       return( m_pDateTime->IsSameDate   (*DateTime.m_pDateTime) );    }
bool CSG_DateTime::is_SameTime       (const CSG_DateTime &DateTime)        const   {       return( m_pDateTime->IsSameTime   (*DateTime.m_pDateTime) );    }
 
//---------------------------------------------------------
bool CSG_DateTime::is_Between        (const CSG_DateTime &t1, const CSG_DateTime &t2)   const   {       return( m_pDateTime->IsBetween        (*t1.m_pDateTime, *t2.m_pDateTime) );     }
bool CSG_DateTime::is_StrictlyBetween(const CSG_DateTime &t1, const CSG_DateTime &t2)   const   {       return( m_pDateTime->IsStrictlyBetween(*t1.m_pDateTime, *t2.m_pDateTime) );     }
 

//                                                       //
 
//---------------------------------------------------------
CSG_String CSG_DateTime::Format(const CSG_String &Format) const
{
        wxString        s(m_pDateTime->Format(Format.c_str()));   CSG_String _s(&s); return( _s );
}
 
CSG_String CSG_DateTime::Format_Date(void)   const
{
        wxString        s(m_pDateTime->FormatDate());                   CSG_String _s(&s); return( _s );
}
 
CSG_String CSG_DateTime::Format_Time(void)   const
{
        wxString        s(m_pDateTime->FormatTime());                   CSG_String _s(&s); return( _s );
}
 
CSG_String CSG_DateTime::Format_ISODate(void)     const
{
        wxString        s(m_pDateTime->FormatISODate());                CSG_String _s(&s); return( _s );
}
 
CSG_String CSG_DateTime::Format_ISOTime(void)     const
{
        wxString        s(m_pDateTime->FormatISOTime());                CSG_String _s(&s); return( _s );
}
 
CSG_String CSG_DateTime::Format_ISOCombined(char sep) const
{
        wxString        s(m_pDateTime->FormatISOCombined(sep)); CSG_String _s(&s); return( _s );
}
 
//---------------------------------------------------------
bool CSG_DateTime::Parse_Date(const CSG_String &date)
{
        wxString::const_iterator        end;    return( m_pDateTime->ParseDate(date.c_str(), &end) );
}
 
bool CSG_DateTime::Parse_DateTime(const CSG_String &datetime)
{
        wxString::const_iterator        end;    return( m_pDateTime->ParseDateTime(datetime.c_str(), &end) );
}
 
bool CSG_DateTime::Parse_Format(const CSG_String &date, const CSG_String &format, const CSG_DateTime &dateDef)
{
        wxString::const_iterator        end;    return( m_pDateTime->ParseFormat(date.c_str(), format.c_str(), *dateDef.m_pDateTime, &end) );
}
 
bool CSG_DateTime::Parse_Format(const CSG_String &date, const CSG_String &format)
{
        wxString::const_iterator        end;    return( m_pDateTime->ParseFormat(date.c_str(), format.c_str(), &end) );
}
 
bool CSG_DateTime::Parse_Format(const CSG_String &date)
{
        wxString::const_iterator        end;    return( m_pDateTime->ParseFormat(date.c_str(), &end) );
}
 
//---------------------------------------------------------
bool CSG_DateTime::Parse_ISOCombined(const CSG_String &date, char sep)
{
        return( m_pDateTime->ParseISOCombined(date.c_str(), sep) );
}
 
bool CSG_DateTime::Parse_ISODate(const CSG_String &date)
{
        return( m_pDateTime->ParseISODate(date.c_str()) );
}
 
bool CSG_DateTime::Parse_ISOTime(const CSG_String &date)
{
        return( m_pDateTime->ParseISOTime(date.c_str()) );
}
 

//                                                       //
 
//---------------------------------------------------------
CSG_DateTime::TSG_DateTime CSG_DateTime::Get_Current_Day(void)
{
        CSG_DateTime Now;
        
        Now.Set_To_Current();
        
        return( Now.Get_Day() );
}
 
CSG_DateTime::Month CSG_DateTime::Get_Current_Month(void)
{
        return( (Month)wxDateTime::GetCurrentMonth() );
}
 
int CSG_DateTime::Get_Current_Year(void)
{
        return( wxDateTime::GetCurrentYear() );
}
 
//---------------------------------------------------------
CSG_String CSG_DateTime::Get_MonthName(Month month, NameFlags flags)
{
        wxString        s(wxDateTime::GetMonthName         ((wxDateTime::Month)month    , (wxDateTime::NameFlags)flags));       CSG_String _s(&s); return( _s );
}
 
CSG_String CSG_DateTime::Get_EnglishMonthName(Month month, NameFlags flags)
{
        wxString        s(wxDateTime::GetEnglishMonthName  ((wxDateTime::Month)month    , (wxDateTime::NameFlags)flags));       CSG_String _s(&s); return( _s );
}
 
CSG_String CSG_DateTime::Get_WeekDayName(WeekDay weekday, NameFlags flags)
{
        wxString        s(wxDateTime::GetWeekDayName       ((wxDateTime::WeekDay)weekday, (wxDateTime::NameFlags)flags));       CSG_String _s(&s); return( _s );
}
 
CSG_String CSG_DateTime::Get_EnglishWeekDayName(WeekDay weekday, NameFlags flags)
{
        wxString        s(wxDateTime::GetEnglishWeekDayName((wxDateTime::WeekDay)weekday, (wxDateTime::NameFlags)flags));       CSG_String _s(&s); return( _s );
}
 
//---------------------------------------------------------
CSG_DateTime::TSG_DateTime CSG_DateTime::Get_NumberOfDays(int year)
{
        return( (TSG_DateTime)wxDateTime::GetNumberOfDays(year) );
}
 
CSG_DateTime::TSG_DateTime CSG_DateTime::Get_NumberOfDays(Month month, int year)
{
        return( (TSG_DateTime)wxDateTime::GetNumberOfDays((wxDateTime::Month)month, year) );
}
 
//---------------------------------------------------------
bool CSG_DateTime::is_LeapYear(int year)
{
        return( wxDateTime::IsLeapYear(year) );
}
 
//---------------------------------------------------------
CSG_DateTime CSG_DateTime::Now(void)
{
        CSG_DateTime        DateTime;       *DateTime.m_pDateTime   = wxDateTime::Now();
 
        return( DateTime );
}
 

//                                                       //
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Unix_Time(sLong Seconds)
{
        time_t          tUnix   = Seconds;
        struct tm       t;
 
        #ifdef _SAGA_LINUX
                t       = *gmtime(&tUnix);
        #else
                gmtime_s(&t, &tUnix);
        #endif
 
        Set(t.tm_mday, (CSG_DateTime::Month)(t.tm_mon), t.tm_year + 1900, t.tm_hour, t.tm_min, t.tm_sec);
 
        return( *this );
}
 
//---------------------------------------------------------
CSG_DateTime & CSG_DateTime::Set_Hours_AD(int Hours)
{
        long    d, n;
        double  h;
 
        h               = 1721424.0 + (Hours - 12.0) / 24.0;
        d               = (long)h;              // Truncate to integral day
        h               = h - d + 0.5;  // Fractional part of calendar day
        if( h >= 1.0 )                  // Is it really the next calendar day?
        {
                h--;
                d++;
        }
 
        int     day, mon, year, hour, min, sec;
 
        h               = 24.0 * (h);
        hour    = (int)h;
        h               = 60.0 * (h - hour);
        min             = (int)h;
        h               = 60.0 * (h - min);
        sec             = (int)h;
 
        d               = d + 68569;
        n               = 4 * d / 146097;
        d               = d - (146097 * n + 3) / 4;
        year    = 4000 * (d + 1) / 1461001;
        d               = d - 1461 * year / 4 + 31;     // 1461 = 365.25 * 4
        mon             = 80 * d / 2447;
        day             = d - 2447 * mon / 80;
        d               = mon / 11;
        mon             = mon + 2 - 12 * d;
        year    = 100 * (n - 49) + year + d;
 
        Set(day, (CSG_DateTime::Month)(mon - 1), year, hour, min, sec);
 
        return( *this );
}
 

//                                                       //
 
//---------------------------------------------------------
CSG_String CSG_DateTime::Get_Month_Choices(void)
{
        CSG_String    Choices;
 
        Choices.Printf("%s|%s|%s|%s|%s|%s|%s|%s|%s|%s|%s|%s|",
                _TL("January"), _TL("February"), _TL("March"    ), _TL("April"  ), _TL("May"     ), _TL("June"    ),
                _TL("July"   ), _TL("August"  ), _TL("September"), _TL("October"), _TL("November"), _TL("December")
        );
 
        return( Choices );
}
 

//                                                       //
 
//---------------------------------------------------------
//---------------------------------------------------------
bool            SG_JulianDayNumber_To_Date(double JDN, int &y, int &m, int &d)
{
        double Z = floor(JDN + 0.5);
        double F = JDN + 0.5 - Z;
        double a = floor((Z - 1867216.25) / 36524.25);
        double A = Z + 1 + a - floor(a / 4);
        double B = A + 1524;
        double C = floor((B - 122.1) / 365.25);
        double D = floor(365.25 * C);
        double E = floor((B - D) / 30.6001);
 
        d = int(B - D - floor(30.6001 * E) + F);
 
        if( E <= 13 )
        {
                m = E -  1; y = C - 4716;
        }
        else
        {
                m = E - 13; y = C - 4715;
        }
 
        return( true );
}
 
//---------------------------------------------------------
//---------------------------------------------------------
CSG_String            SG_JulianDayNumber_To_Date(double JDN)
{
        CSG_String Date; int y, m, d;
 
        if( SG_JulianDayNumber_To_Date(JDN, y, m, d) )
        {
                Date.Printf("%04d-%02d-%02d", y, m, d);   // yyyy-mm-dd (ISO 8601)
        }
 
        return( Date );
}
 
//---------------------------------------------------------
//---------------------------------------------------------
CSG_String            SG_JulianDayNumber_To_Date(int JDN)
{
        return( SG_JulianDayNumber_To_Date(JDN + 0.5) );
}
 
//---------------------------------------------------------
//---------------------------------------------------------
double                  SG_Date_To_JulianDayNumber(int Year, int Month, int Day)
{
        if( Month <= 2 ) { Year--; Month += 12; }
 
        return( floor(365.25 * (Year + 4716)) + floor(30.6001 * (Month + 1)) + Day + 2. - floor(Year / 100) + floor(Year / 400) - 1524.5 );
}
 
//---------------------------------------------------------
//---------------------------------------------------------
double                  SG_Date_To_JulianDayNumber(const CSG_String &Date)
{
        if( Date.Length() >= 10 )
        {
                bool BC = Date[0] == '-';
 
                CSG_Strings ymd(SG_String_Tokenize(BC ? Date.AfterFirst('-') : Date, "-./"));
 
                if( ymd.Get_Count() >= 3 )
                {
                        bool inv = ymd[2].Length() == 4;
 
                        int y = ymd[inv ? 2 : 0].asInt(); if( BC ) { y = -y; }
                        int m = ymd[          1].asInt(); if( m < 1 ) { m = 1; } else if( m > 12 ) { m = 12; }
                        int d = ymd[inv ? 0 : 2].asInt(); if( d < 1 ) { d = 1; } else if( d > 31 ) { d = 31; }
 
                        return( SG_Date_To_JulianDayNumber(y, m, d) );
                }
        }
 
        return( 0. );
}
 

//                                                       //
 
//---------------------------------------------------------
//---------------------------------------------------------
int SG_Get_Day_MidOfMonth(int Month, bool bLeapYear)
{
        static const int        MidOfMonth[12]  =
        // JAN  FEB  MAR  APR  MAY  JUN  JUL  AUG  SEP  OCT  NOV  DEC
        //      31,  28,  31,  30,  31,  30,  31,  31,  30,  31,  30,  31
        //       0,  31,  59,  90, 120, 151, 181, 212, 243, 273, 304, 334
        {       15,  45,  74, 105, 135, 166, 196, 227, 258, 288, 319, 349       };
 
        int     Day;
 
        if( Month < 0 )
        {
                Month   = (Month % 12) + 12;
                Day             = MidOfMonth[Month] - 365;
        }
        else if( Month >= 12 )
        {
                Month   = (Month % 12);
                Day             = MidOfMonth[Month] + 365;
        }
        else
        {
                Day             = MidOfMonth[Month];
        }
 
        if( bLeapYear && Month > 1 )
        {
                Day++;
        }
 
        return( Day );
}
 

//                                                       //
//                                                       //
//                                                       //
 
//---------------------------------------------------------
#include "mat_tools.h"
 
//---------------------------------------------------------
//---------------------------------------------------------
bool SG_Get_Sun_Position(double JDN, double &RA, double &Dec)
{
        double T = (JDN - 2451545.) / 36525.; // Number of Julian centuries since 2000-01-01 at 12 UT (JDN = 2451545.0)
 
        double M =  357.52910 + 35999.05030 * T - 0.0001559 * T*T - 0.00000048 * T*T*T; // mean anomaly
 
        M *= M_DEG_TO_RAD;
 
        double L = (280.46645 + 36000.76983 * T + 0.0003032 * T*T)                      // mean longitude
                 + ((1.914600 - 0.004817 * T - 0.000014  * T*T) * sin(M)
                 +  (0.019993 - 0.000101 * T) * sin(2. * M) + 0.000290 * sin(3. * M));  // true longitude
 
        L *= M_DEG_TO_RAD;
 
        //-----------------------------------------------------
        // convert ecliptic longitude to right ascension RA and declination delta
 
        static const double     Ecliptic_Obliquity = M_DEG_TO_RAD * 23.43929111;
 
        double X = cos(L);
        double Y = cos(Ecliptic_Obliquity) * sin(L);
        double Z = sin(Ecliptic_Obliquity) * sin(L);
        double R = sqrt(1. - Z*Z); 
 
        Dec     = atan2(Z, R);
        RA      = 2. * atan2(Y, (X + R));
 
        return( true );
}
 
//---------------------------------------------------------
bool SG_Get_Sun_Position(const CSG_DateTime &Time, double &RA, double &Dec)
{
        return( SG_Get_Sun_Position(Time.Get_JDN(), RA, Dec) );
}
 
//---------------------------------------------------------
//---------------------------------------------------------
bool SG_Get_Sun_Position(double JDN, double Longitude, double Latitude, double &Height, double &Azimuth, bool bRefraction)
{
        //-----------------------------------------------------
        // 1. Get right ascension RA and declination delta
 
        double RA, Dec; SG_Get_Sun_Position(JDN, RA, Dec);
 
        //-----------------------------------------------------
        // 2. compute sidereal time (radians) at Greenwich local sidereal time at longitude (radians)
 
        double T     = (JDN - 2451545.) / 36525.;
 
        double Theta = Longitude + M_DEG_TO_RAD * (280.46061837 + 360.98564736629 * (JDN - 2451545.) + T*T * (0.000387933 - T / 38710000.));
 
        double HA    = Theta - RA; // compute local hour angle (radians)
 
        //-----------------------------------------------------
        // 3. convert (HA, Dec) to horizon coordinates (height, azimuth) of the observer
 
        Height  = asin ( sin(Latitude) * sin(Dec) + cos(Latitude) * cos(Dec) * cos(HA));
        Azimuth = atan2(-sin(HA) * cos(Dec), cos(Latitude) * sin(Dec) - sin(Latitude) * cos(Dec) * cos(HA));
//      Azimuth = atan2(-sin(HA), cos(Latitude) * tan(Dec) - sin(Latitude) * cos(HA)); // previous formula gives same result but is better because of division by zero effects...
 
        if( bRefraction )
        {
                double Refraction = SG_Get_Sun_Refraction(Height, true);
 
                if( Refraction >= 0. )
                {
                        Height += Refraction;
                }
        }
 
        return( Height > 0. );
}
 
//---------------------------------------------------------
bool SG_Get_Sun_Position(const CSG_DateTime &Time, double Longitude, double Latitude, double &Height, double &Azimuth, bool bRefraction)
{
        return( SG_Get_Sun_Position(Time.Get_JDN(), Longitude, Latitude, Height, Azimuth, bRefraction) );
}
 
//---------------------------------------------------------
bool SG_Get_Sun_Position(double JDN, double Longitude, double Latitude, CSG_Vector &Position, bool bRefraction)
{
        Position.Create(2); return( SG_Get_Sun_Position(JDN, Longitude, Latitude, Position[0], Position[1], bRefraction) );
}
 
//---------------------------------------------------------
bool SG_Get_Sun_Position(const CSG_DateTime &Time, double Longitude, double Latitude, CSG_Vector &Position, bool bRefraction)
{
        Position.Create(2); return( SG_Get_Sun_Position(Time.Get_JDN(), Longitude, Latitude, Position[0], Position[1], bRefraction) );
}
 
//---------------------------------------------------------
//---------------------------------------------------------
double SG_Get_Sun_Refraction(double Height, bool bRadians)
{
        // 3.51823 = 1013.25mb / 288K
 
        double z = bRadians ? M_RAD_TO_DEG * Height : Height;
 
        if( z > -0.766 )
        {
                if( z >= 19.225 )
                {
                        z = 3.51823 * 0.00452 / tan(z * M_DEG_TO_RAD);
                }
                else
                {
                        z = 3.51823 * (0.1594 + z * (0.0196 + 0.00002 * z) ) / (1. + z * (0.505 + 0.0845 * z));
                }
 
                return( bRadians ? M_DEG_TO_RAD * z : z );
        }
 
        return( -1. );
}
 

//                                                       //
 
//---------------------------------------------------------
double SG_Get_Day_Length(int DayOfYear, double Latitude)
{
        double tanLat = tan(Latitude * M_DEG_TO_RAD);
 
        double JD     = DayOfYear * M_PI_360 / 365.;
 
        double SunDec = 0.4093 * sin(JD - 1.405); // solar declination
 
        double d      = -tanLat * tan(SunDec); // sunset hour angle
 
        return( acos(d < -1 ? -1 : d < 1 ? d : 1) * 24. / M_PI );
}
 
//---------------------------------------------------------
double SG_Get_Day_Length(const CSG_DateTime &Date, double Latitude)
{
        return( SG_Get_Day_Length(Date.Get_DayOfYear(), Latitude) );
}
 

//                                                       //
//                                                       //
//                                                       //
 
//---------------------------------------------------------