SO3::SAstronomy Class Reference

#include <SO3Astronomy.h>

Static Public Member Functions
static double	NormalizeDegrees (double x)
static double	RadToDeg (double x)
static double	DegToRad (double x)
static double	SinDeg (double x)
static double	CosDeg (double x)
static double	Atan2Deg (double y, double x)
static void	ConvertEclipticToEquatorialRad (double lon, double lat, double &rasc, double &decl)
static void	ConvertRectangularToSpherical (double x, double y, double z, double &rasc, double &decl, double &dist)
static void	ConvertSphericalToRectangular (double rasc, double decl, double dist, double &x, double &y, double &z)
static void	ConvertEquatorialToHorizontal (double jday, double longitude, double latitude, double rasc, double decl, double &azimuth, double &altitude)
static void	GetEclipticSunPosition (double jday, double &lambda, double &beta)
static void	GetEquatorialSunPosition (double jday, double &sunRightAscension, double &sunDeclinaison)
static void	GetHorizontalSunPosition (double jday, double longitude, double latitude, double &azimuth, double &altitude)
static void	GetHorizontalSunPosition (double jday, Ogre::Degree longitude, Ogre::Degree latitude, Ogre::Degree &azimuth, Ogre::Degree &altitude)
static void	GetEclipticMoonPositionRad (double jday, double &lon, double &lat)
static void	GetHorizontalMoonPosition (double jday, double longitude, double latitude, double &azimuth, double &altitude)
static void	GetHorizontalMoonPosition (double jday, Ogre::Degree longitude, Ogre::Degree latitude, Ogre::Degree &azimuth, Ogre::Degree &altitude)
static void	GetMoonPhase (double jday, float &moonPhase)
static int	GetJulianDayFromGregorianDate (int year, int month, int day)
static double	GetJulianDayFromGregorianDateTime (int year, int month, int day, int hour, int minute, double second)
static double	GetJulianDayFromGregorianDateTime (int year, int month, int day, double secondsFromMidnight)
static void	GetGregorianDateFromJulianDay (int julianDay, int &year, int &month, int &day)
static void	GetGregorianDateTimeFromJulianDay (double julianDay, int &year, int &month, int &day, int &hour, int &minute, double &second)
static void	GetGregorianDateFromJulianDay (double julianDay, int &year, int &month, int &day)
static int	EnterHighPrecissionFloatingPointMode ()
static void	RestoreFloatingPointMode (int oldMode)
static void	GetEclipticSunMeanLongitude (double jday, double &sunlon)
Static Public Attributes
static const double	J2000 = 2451545.0
	January 1, 2000, noon.

Detailed Description

Static class with astronomy routines. This class contains various astronomical routines useful in Caelum. Most of the formulas are from http://stjarnhimlen.se/comp/ppcomp.html That site contains much more than was implemented here; it has code for determining the positions of all the planets. Only the sun and moon are actually useful for caelum. The formulas are isolated here in pure procedural code for easier testing (Tests are done as assertions in the demo). Precision is vital here, so this class uses double instead of float for precission. All angles are in degrees unless otherwise mentioned.

Definition at line 51 of file SO3Astronomy.h.

Member Function Documentation

double SO3::SAstronomy::Atan2Deg	(	double	y,
		double	x
	)			`[static]`

Definition at line 61 of file SO3Astronomy.cpp.

void SO3::SAstronomy::ConvertEclipticToEquatorialRad	(	double	lon,
		double	lat,
		double &	rasc,
		double &	decl
	)			`[static]`

Convert from ecliptic to ecuatorial spherical coordinates, in radians.

Parameters:

	lon	Ecliptic longitude
	lat	Ecliptic latitude
	rasc	Right ascension
	decl	Declination

Warning:: : This function works in radians.

Definition at line 76 of file SO3Astronomy.cpp.

void SO3::SAstronomy::ConvertEquatorialToHorizontal	(	double	jday,
		double	longitude,
		double	latitude,
		double	rasc,
		double	decl,
		double &	azimuth,
		double &	altitude
	)			`[static]`

Convert from equatorial to horizontal coordinates. This function converts from angles relative to the earth's equator to angle relative to the horizon at a given point.

Parameters:

	jday	Astronomical time as julian day.
	longitude	Observer's longitude in degrees east.
	latitude	Observer's latitude in degrees north.
	rasc	Object's right ascension.
	decl	Object's declination.
	azimuth	Object's azimuth (clockwise degrees from true north).
	altitude	Object's altitude (degrees above the horizon).

Definition at line 103 of file SO3Astronomy.cpp.

void SO3::SAstronomy::ConvertRectangularToSpherical	(	double	x,
		double	y,
		double	z,
		double &	rasc,
		double &	decl,
		double &	dist
	)			`[static]`

Definition at line 89 of file SO3Astronomy.cpp.

void SO3::SAstronomy::ConvertSphericalToRectangular	(	double	rasc,
		double	decl,
		double	dist,
		double &	x,
		double &	y,
		double &	z
	)			`[static]`

Definition at line 96 of file SO3Astronomy.cpp.

double SO3::SAstronomy::CosDeg ( double x ) [static]

Definition at line 56 of file SO3Astronomy.cpp.

double SO3::SAstronomy::DegToRad ( double x ) [static]

Convert degrees to radians.

Definition at line 46 of file SO3Astronomy.cpp.

int SO3::SAstronomy::EnterHighPrecissionFloatingPointMode ( ) [static]

Enter high-precission floating-point mode. By default Direct3D decreases the precission of ALL floating point calculations, enough to stop Caelum's astronomy routines from working correctly. To trigger this behaviour in a standard ogre demo select the Direct3D render system and set "Floating-point mode" to "Fastest". Otherwise it's not a problem. It can be fixed by changing the precission only inside caelum's astronomy routines using the _controlfp function. This only works for MSVC on WIN32; This is a no-op on other compilers.

Note:: : Must be paired with restoreFloatingPointMode.

Returns:: Value to pass to restoreFloatingModeMode.

Definition at line 330 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetEclipticMoonPositionRad	(	double	jday,
		double &	lon,
		double &	lat
	)			`[static]`

Gets the moon position at a specific time in ecliptic coordinates

Parameters:

	lon,:	Ecliptic longitude, in radians.
	lat,:	Ecliptic latitude, in radians.

Definition at line 187 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetEclipticSunMeanLongitude	(	double	jday,
		double &	sunlon
	)			`[static]`

Definition at line 128 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetEclipticSunPosition	(	double	jday,
		double &	lambda,
		double &	beta
	)			`[static]`

Definition at line 153 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetEquatorialSunPosition	(	double	jday,
		double &	sunRightAscension,
		double &	sunDeclinaison
	)			`[static]`

Definition at line 162 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetGregorianDateFromJulianDay	(	double	julianDay,
		int &	year,
		int &	month,
		int &	day
	)			`[static]`

Get gregorian date from floating point julian day.

Definition at line 321 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetGregorianDateFromJulianDay	(	int	julianDay,
		int &	year,
		int &	month,
		int &	day
	)			`[static]`

Get gregorian date from integer julian day.

Definition at line 284 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetGregorianDateTimeFromJulianDay	(	double	julianDay,
		int &	year,
		int &	month,
		int &	day,
		int &	hour,
		int &	minute,
		double &	second
	)			`[static]`

Get gregorian date time from floating point julian day.

Definition at line 305 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetHorizontalMoonPosition	(	double	jday,
		Ogre::Degree	longitude,
		Ogre::Degree	latitude,
		Ogre::Degree &	azimuth,
		Ogre::Degree &	altitude
	)			`[static]`

Definition at line 238 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetHorizontalMoonPosition	(	double	jday,
		double	longitude,
		double	latitude,
		double &	azimuth,
		double &	altitude
	)			`[static]`

Definition at line 220 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetHorizontalSunPosition	(	double	jday,
		Ogre::Degree	longitude,
		Ogre::Degree	latitude,
		Ogre::Degree &	azimuth,
		Ogre::Degree &	altitude
	)			`[static]`

Definition at line 179 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetHorizontalSunPosition	(	double	jday,
		double	longitude,
		double	latitude,
		double &	azimuth,
		double &	altitude
	)			`[static]`

Get the sun's position in the sky in, relative to the horizon.

Parameters:

	jday	Astronomical time as julian day.
	longitude	Observer longitude
	latitude	Observer latitude
	azimuth	Astronomical azimuth, measured clockwise from North = 0.
	altitude	Astronomical altitude, elevation above the horizon.

Definition at line 171 of file SO3Astronomy.cpp.

int SO3::SAstronomy::GetJulianDayFromGregorianDate	(	int	year,
		int	month,
		int	day
	)			`[static]`

Get astronomical julian day from normal gregorian calendar. From wikipedia: the integer number of days that have elapsed since the initial epoch defined as noon Universal Time (UT) Monday, January 1, 4713 BC

Note:: this is the time at noon, not midnight.

Definition at line 256 of file SO3Astronomy.cpp.

double SO3::SAstronomy::GetJulianDayFromGregorianDateTime	(	int	year,
		int	month,
		int	day,
		double	secondsFromMidnight
	)			`[static]`

Get astronomical julian day from normal gregorian calendar.

Definition at line 277 of file SO3Astronomy.cpp.

double SO3::SAstronomy::GetJulianDayFromGregorianDateTime	(	int	year,
		int	month,
		int	day,
		int	hour,
		int	minute,
		double	second
	)			`[static]`

Get astronomical julian day from normal gregorian calendar. Calculate julian day from a day in the normal gregorian calendar. Time should be given as UTC.

See also:: http://en.wikipedia.org/wiki/Julian_day

Definition at line 267 of file SO3Astronomy.cpp.

void SO3::SAstronomy::GetMoonPhase	(	double	jday,
		float &	moonPhase
	)			`[static]`

Compute the moon phase at a given date.

Definition at line 246 of file SO3Astronomy.cpp.

double SO3::SAstronomy::NormalizeDegrees ( double x ) [static]

Normalize an angle to the 0, 360 range.

Parameters:

x

The angle to normalize

Definition at line 66 of file SO3Astronomy.cpp.

double SO3::SAstronomy::RadToDeg ( double x ) [static]

Convert radians to degrees.

Definition at line 41 of file SO3Astronomy.cpp.

void SO3::SAstronomy::RestoreFloatingPointMode ( int oldMode ) [static]

Definition at line 337 of file SO3Astronomy.cpp.

double SO3::SAstronomy::SinDeg ( double x ) [static]

Definition at line 51 of file SO3Astronomy.cpp.

Member Data Documentation

const double SO3::SAstronomy::J2000 = 2451545.0 [static]

January 1, 2000, noon.

Definition at line 54 of file SO3Astronomy.h.

The documentation for this class was generated from the following files:

SO3Engine/SO3Utils/SO3Astronomy.h
SO3Engine/SO3Utils/SO3Astronomy.cpp

SO3::SAstronomy Class Reference

Static Public Member Functions

Static Public Attributes

Detailed Description

Member Function Documentation

Member Data Documentation