Public Member Functions
	GeodeticCalculator (const Ellipsoid &e=Ellipsoid::WGS84())
	Performs geodetic calculations on an ellipsoid.
double	azimuth ()
bool	checkOrthodromicDistance ()
	Computes the orthodromic distance using the algorithm implemented in the Geotools's ellipsoid class (if available), and check if the error is smaller than some tolerance error.
bool	computeDestinationPoint ()
	Computes the destination point from the starting point, the azimuth and the orthodromic distance.
bool	computeDirection ()
	Computes the azimuth and orthodromic distance from the startingGeographicPoint starting point and the destinationGeographicPoint destination point.
QPointF	destinationGeographicPoint ()
bool	destinationGeographicPoint (double longitude, double latitude)
Ellipsoid	ellipsoid () const
double	meridianArcLength (double latitude1, double latitude2)
	Calculates the meridian arc length between two points in the same meridian in the referenced ellipsoid.
double	meridianArcLengthRadians (double P1, double P2)
	Calculates the meridian arc length between two points in the same meridian in the referenced ellipsoid.
double	orthodromicDistance ()
void	setDestinationGeographicPoint (double longitude, double latitude)
	Set the destination point in geographic coordinates.
void	setDirection (double azimuth, double distance)
	Set the azimuth and the distance from the startingGeographicPoint starting point.
void	setStartingGeographicPoint (double longitude, double latitude)
	Set the starting point in geographic coordinates.

Protected Member Functions
double	castToAngleRange (const double alpha)
bool	checkAzimuth (double *azimuth)
	Checks the azimuth validity.
bool	checkLatitude (double *latitude)
	Checks the latitude validity.
bool	checkLongitude (double *longitude)
	Checks the longitude validity.
bool	checkOrthodromicDistance (const double distance)
	Checks the orthodromic distance validity.

Protected Attributes
double	a01 = 0.0
	Parameters computed from the ellipsoid.
double	a02 = 0.0
double	a03 = 0.0
double	a21 = 0.0
double	a22 = 0.0
double	a23 = 0.0
double	a42 = 0.0
double	a43 = 0.0
double	a63 = 0.0
double	f = 0.0
double	f2 = 0.0
double	f3 = 0.0
double	f4 = 0.0
double	fo = 0.0
	GPNHRI parameters computed from the ellipsoid.
double	m_A = 0.0
	GPNARC parameters computed from the ellipsoid.
double	m_azimuth = 0.0
double	m_B = 0.0
double	m_C = 0.0
double	m_D = 0.0
bool	m_destinationValid = false
	Tell if the destination point is valid.
bool	m_directionValid = false
	Tell if the azimuth and the distance are valids.
double	m_distance = 0.0
	The distance and azimuth (in radians) from the starting point (long1, lat1) to the destination point (long2, lat2).
double	m_E = 0.0
double	m_eccentricitySquared = 0.0
	The eccentricity squared of the referenced ellipsoid.
Ellipsoid	m_ellipsoid
	The encapsulated ellipsoid.
double	m_F = 0.0
double	m_lat1 = 0.0
	The (latitude, longitude) coordinate of the first point in radians.
double	m_lat2 = 0.0
	The (latitude, longitude) coordinate of the destination point in radians.
double	m_long1 = 0.0
double	m_long2 = 0.0
double	m_maxOrthodromicDistance = 0.0
	The maximum orthodromic distance that could be calculated onto the referenced ellipsoid.
double	m_semiMajorAxis = 0.0
	The semi major axis of the referenced ellipsoid.
double	m_semiMinorAxis = 0.0
	The semi minor axis of the referenced ellipsoid.
double	m_TOLERANCE_0 = 5.0e-15
	Tolerance factors from the strictest (`TOLERANCE_0`) to the most relax one (`TOLERANCE_3`).
double	m_TOLERANCE_1 = 5.0e-14
double	m_TOLERANCE_2 = 5.0e-13
double	m_TOLERANCE_3 = 7.0e-3
double	m_TOLERANCE_CHECK = 1E-8
	Tolerance factor for assertions.
double	T1 = 1.0
	Parameters computed from the ellipsoid.
double	T2 = 0.0
double	T4 = 0.0
double	T6 = 0.0

Constructor & Destructor Documentation

◆ GeodeticCalculator()

Digikam::GeodeticCalculator::GeodeticCalculator ( const Ellipsoid & e = Ellipsoid::WGS84() )

explicit

This class encapsulates a generic ellipsoid and calculates the following properties:

Distance and azimuth between two points. Point located at a given distance and azimuth from an other point.

The calculation use the following information:

The starting position (setStartingPosition), which is always considered valid. It is initially set at (0,0) and can only be changed to another legitimate value. Only one of the following:

  The destination position (setDestinationPosition), or
  An azimuth and distance (setDirection).

The latest one set overrides the other and determines what will be calculated.

Member Function Documentation

◆ azimuth()

double Digikam::GeodeticCalculator::azimuth ( )

Returns: the azimuth. This method returns the value set by the last call to setDirection(double,double) setDirection(azimuth,distance), except if setDestinationGeographicPoint(double,double) setDestinationGeographicPoint(...) has been invoked after. In this later case, the azimuth will be computed from the startingGeographicPoint starting point to the destination point.; The azimuth, in decimal degrees from -180° to +180°.

◆ checkAzimuth()

bool Digikam::GeodeticCalculator::checkAzimuth ( double * azimuth )

protected

The argument azimuth should be greater or equal than -180 degrees and lower or equals than +180 degrees. As a convenience, this method converts the azimuth to radians.

Parameters

azimuth The azimuth value in decimal degrees.

◆ checkLatitude()

bool Digikam::GeodeticCalculator::checkLatitude ( double * latitude )

protected

The argument latitude should be greater or equal than -90 degrees and lower or equals than +90 degrees. As a convenience, this method converts the latitude to radians.

Parameters

latitude The latitude value in decimal degrees.

◆ checkLongitude()

bool Digikam::GeodeticCalculator::checkLongitude ( double * longitude )

protected

The argument longitude should be greater or equal than -180 degrees and lower or equals than +180 degrees. As a convenience, this method converts the longitude to radians.

Parameters

longitude The longitude value in decimal degrees.

◆ checkOrthodromicDistance()

bool Digikam::GeodeticCalculator::checkOrthodromicDistance ( const double distance )

protected

Arguments orthodromicDistance should be greater or equal than 0 and lower or equals than the maximum orthodromic distance.

Parameters

distance The orthodromic distance value.

◆ computeDirection()

bool Digikam::GeodeticCalculator::computeDirection ( )

Computes the azimuth and orthodromic distance from the startingGeographicPoint() and the destinationGeographicPoint().

◆ destinationGeographicPoint()

bool Digikam::GeodeticCalculator::destinationGeographicPoint	(	double *	longitude,
		double *	latitude )

Returns: the destination point. This method returns the point set by the last call to a setDestinationGeographicPoint(...) method, except if setDirection(...) has been invoked after. In this later case, the destination point will be computed from the starting point to the azimuth and distance specified. Coordinates positive North and East.; The destination point. The x and y coordinates are the longitude and latitude in decimal degrees, respectively.

◆ ellipsoid()

Ellipsoid Digikam::GeodeticCalculator::ellipsoid ( ) const

Returns: the referenced ellipsoid.

◆ meridianArcLength()

double Digikam::GeodeticCalculator::meridianArcLength	(	double	latitude1,
		double	latitude2 )

Parameters

latitude1	The latitude of the first point (in decimal degrees).
latitude2	The latitude of the second point (in decimal degrees).

Returns: Returned the meridian arc length between latitude1 and latitude2

◆ meridianArcLengthRadians()

double Digikam::GeodeticCalculator::meridianArcLengthRadians	(	double	P1,
		double	P2 )

Parameters

P1	The latitude of the first point (in radians).
P2	The latitude of the second point (in radians).

Returns: Returned the meridian arc length between P1 and P2

◆ orthodromicDistance()

double Digikam::GeodeticCalculator::orthodromicDistance ( )

Returns: the orthodromic distance. This method returns the value set by the last call to setDirection(double,double) setDirection(azimuth,distance), except if setDestinationGeographicPoint(double,double) setDestinationGeographicPoint(...) has been invoked after. In this later case, the distance will be computed from the startingGeographicPoint starting point to the destination point.; The orthodromic distance, in the same units as the getEllipsoid ellipsoid axis.

◆ setDestinationGeographicPoint()

void Digikam::GeodeticCalculator::setDestinationGeographicPoint	(	double	longitude,
		double	latitude )

The azimuth and distance values will be updated as a side effect of this call. They will be recomputed the next time getAzimuth() or getOrthodromicDistance() are invoked. Coordinates positive North and East.

Parameters

longitude	The longitude in decimal degrees between -180 and +180°
latitude	The latitude in decimal degrees between -90 and +90°

◆ setDirection()

void Digikam::GeodeticCalculator::setDirection	(	double	azimuth,
		double	distance )

The destination point will be updated as a side effect of this call. It will be recomputed the next time destinationGeographicPoint() is invoked. Azimuth 0° North.

Parameters

azimuth	The azimuth in decimal degrees from -180° to 180°.
distance	The orthodromic distance in the same units as the ellipsoid axis.

◆ setStartingGeographicPoint()

void Digikam::GeodeticCalculator::setStartingGeographicPoint	(	double	longitude,
		double	latitude )

The azimuth, the orthodromic distance and the destination point are discarded. They will need to be specified again. Coordinates positive North and East.

Parameters

longitude	The longitude in decimal degrees between -180 and +180°
latitude	The latitude in decimal degrees between -90 and +90°

Member Data Documentation

◆ fo

double Digikam::GeodeticCalculator::fo = 0.0

protected

f if the flattening of the referenced ellipsoid. f2, f3 and f4 are f², f³ and f⁴ respectively.

◆ m_destinationValid

bool Digikam::GeodeticCalculator::m_destinationValid = false

protected

false if long2 and lat2 need to be computed.

◆ m_directionValid

bool Digikam::GeodeticCalculator::m_directionValid = false

protected

false if distance and azimuth need to be computed.

◆ m_lat1

double Digikam::GeodeticCalculator::m_lat1 = 0.0

protected

This point is set by setStartingGeographicPoint.

◆ m_lat2

double Digikam::GeodeticCalculator::m_lat2 = 0.0

protected

This point is set by setDestinationGeographicPoint.

◆ m_TOLERANCE_CHECK

double Digikam::GeodeticCalculator::m_TOLERANCE_CHECK = 1E-8

protected

It has no impact on computed values.

	digiKam Developer Documentation Professional Photo Management with the Power of Open Source

Public Member Functions

Protected Member Functions

Protected Attributes

Constructor & Destructor Documentation

◆ GeodeticCalculator()

Member Function Documentation

◆ azimuth()

◆ checkAzimuth()

◆ checkLatitude()

◆ checkLongitude()

◆ checkOrthodromicDistance()

◆ computeDirection()

◆ destinationGeographicPoint()

◆ ellipsoid()

◆ meridianArcLength()

◆ meridianArcLengthRadians()

◆ orthodromicDistance()

◆ setDestinationGeographicPoint()

◆ setDirection()

◆ setStartingGeographicPoint()

Member Data Documentation

◆ fo

◆ m_destinationValid

◆ m_directionValid

◆ m_lat1

◆ m_lat2

◆ m_TOLERANCE_CHECK