Astronomy.h

/*
This file is part of Caelum.
See http://www.ogre3d.org/wiki/index.php/Caelum 

Copyright (c) 2008 Caelum team. See Contributors.txt for details.

Caelum 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 3 of the License, or
(at your option) any later version.

Caelum 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 Caelum. If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef CAELUM__ASTRONOMY_H
#define CAELUM__ASTRONOMY_H

#include "CaelumPrerequisites.h"

namespace Caelum
{
    class CAELUM_EXPORT Astronomy
    {
    private:
        Astronomy() {}

        static const LongReal PI;

        static LongReal normalizeDegrees (LongReal x);

        static LongReal radToDeg (LongReal x);

        static LongReal degToRad (LongReal x);

        static LongReal sinDeg (LongReal x);
        static LongReal cosDeg (LongReal x);
        static LongReal atan2Deg (LongReal y, LongReal x);

    public:
        static const LongReal J2000;

        static void convertEclipticToEquatorialRad (
                LongReal lon, LongReal lat,
                LongReal& rasc, LongReal& decl);

        static void convertRectangularToSpherical (
                LongReal x, LongReal y, LongReal z,
                LongReal &rasc, LongReal &decl, LongReal &dist);

        static void convertSphericalToRectangular (
                LongReal rasc, LongReal decl, LongReal dist,
                LongReal &x, LongReal &y, LongReal &z);

        static void convertEquatorialToHorizontal (
                LongReal jday,
                LongReal longitude, LongReal latitude,
                LongReal rasc,      LongReal decl,
                LongReal &azimuth,  LongReal &altitude);

        static void getHorizontalSunPosition (
                LongReal jday,
                LongReal longitude, LongReal latitude,
                LongReal &azimuth, LongReal &altitude);

        static void getHorizontalSunPosition (
                LongReal jday,
                Ogre::Degree longitude, Ogre::Degree latitude,
                Ogre::Degree &azimuth, Ogre::Degree &altitude);

        static void getEclipticMoonPositionRad (
                LongReal jday,
                LongReal &lon,
                LongReal &lat);

        static void getHorizontalMoonPosition (
                LongReal jday,
                LongReal longitude, LongReal latitude,
                LongReal &azimuth, LongReal &altitude);
        static void getHorizontalMoonPosition (
                LongReal jday,
                Ogre::Degree longitude, Ogre::Degree latitude,
                Ogre::Degree &azimuth, Ogre::Degree &altitude);

        static void getHorizontalNorthEclipticPolePosition (
                LongReal jday,
                Ogre::Degree longitude, Ogre::Degree latitude,
                Ogre::Degree &azimuth, Ogre::Degree &altitude);
        
        static int getJulianDayFromGregorianDate (
                int year, int month, int day); 

        static LongReal getJulianDayFromGregorianDateTime (
                int year, int month, int day,
                int hour, int minute, LongReal second); 

        static LongReal getJulianDayFromGregorianDateTime (
                int year, int month, int day,
                LongReal secondsFromMidnight); 

        static void getGregorianDateFromJulianDay (
                int julianDay, int &year, int &month, int &day);

        static void getGregorianDateTimeFromJulianDay (
                LongReal julianDay, int &year, int &month, int &day,
                int &hour, int &minute, LongReal &second);

        static void getGregorianDateFromJulianDay (
                LongReal julianDay, int &year, int &month, int &day);

        static int enterHighPrecissionFloatingPointMode ();

        static void restoreFloatingPointMode (int oldMode);
    };

    class CAELUM_EXPORT ScopedHighPrecissionFloatSwitch
    {
    private:
        int mOldFpMode;

    public:
        inline ScopedHighPrecissionFloatSwitch() {
            mOldFpMode = Astronomy::enterHighPrecissionFloatingPointMode ();
        }

        inline ~ScopedHighPrecissionFloatSwitch() {
            Astronomy::restoreFloatingPointMode (mOldFpMode);
        }
    };
}

#endif // CAELUM__ASTRONOMY_H