This class defines the Gnomonic projection. More...

#include <ilviews/maps/projection/gnomonic.h>

Inheritance diagram for IlvGnomonicProjection:

Public Member Functions
	IlvGnomonicProjection ()
	Initializes a new `IlvGnomonicProjection` instance.

virtual void	setLLCenter (IlDouble, IlDouble)
	Specifies the central meridian and the central parallel (in radian) associated with the projection. More...

Public Member Functions inherited from IlvProjection
virtual IlvProjection *	copy () const =0
	Returns a copy of the projection. More...

virtual IlvMapsError	forward (const IlvCoordinate &llIn, IlvCoordinate &xyOut) const
	Converts a latitude and a longitude to Cartesian coordinates (x, y). More...

virtual IlvMapsError	forward (IlvCoordinate &coords) const
	Projects a latitude and a longitude pair to Cartesian coordinates. More...

IlDouble	getCentralMeridian () const
	Returns the central meridian of the projection. More...

IlDouble	getCentralParallel () const
	Returns the central parallel of the projection. More...

virtual IlvProjectionClassInfo *	getClassInfo () const
	Returns the class information for the projection. More...

const IlvHorizontalDatum *	getDatum (void) const
	Returns the horizontal datum used for the projection. More...

const IlvEllipsoid *	getEllipsoid () const
	Returns the ellipsoid used for the projection. More...

IlvMapsError	getError () const
	Returns the status of the projection. More...

IlDouble	getFalseEasting () const
	Returns the false easting of the projection. More...

IlDouble	getFalseNorthing () const
	Returns the false northing of the projection. More...

IlvProjectionInterface *	getInterface ()
	Returns the interface of the projection. More...

IlvCoordinate	getLLCenter (void) const
	Returns the central meridian and the central parallel associated with the projection (0-0 by default). More...

IlvProjectionGeometricProperty	getProperty () const
	Returns the geometric property of the projection. More...

const IlvUnitConverter *	getUnitConverter () const
	Returns the unit converter. More...

IlvCoordinate	getXYOffset () const
	Returns the false easting and the false northing of the projection. More...

virtual IlvMapsError	inverse (const IlvCoordinate &xyIn, IlvCoordinate &llOut) const
	Converts the specified coordinate to a latitude and a longitude. More...

virtual IlvMapsError	inverse (IlvCoordinate &coords) const
	Invserse-projects Cartesian coordinates to a latitude and a longitude. More...

IlBoolean	isBad () const
	Checks for an inconsistent state of the projection. More...

IlBoolean	isEllipsoidEnabled () const
	Indicates if non spherical ellipsoids can be used for the projection. More...

IlBoolean	isGeocentric () const
	Checks if the projection uses geocentric latitudes. More...

IlBoolean	isInverseEnabled () const
	Indicates if the inverse function is supported by the projection. More...

IlBoolean	isShared () const
	Indicates that the projection is shared. More...

IlBoolean	isUsingLongitudeReduction () const
	Returns `IlTrue` if the projection uses range reduction for longitudes. More...

void	lock ()
	Locks the projection.

virtual std::ostream &	printPROJ4Descriptor (std::ostream &ostr, IlvMapsError *status=0) const
	This virtual member function converts the projection to a string in the `PROJ4` format. More...

void	save (IlvOutputFile &outputFile) const
	Saves an instance of a subclass of `IlvProjection` to the specified output file. More...

void	setCentralMeridian (IlDouble lon)
	Sets the central meridian of the projection. More...

void	setCentralParallel (IlDouble lat)
	Sets the central parallel of the projection. More...

virtual IlvMapsError	setDatum (const IlvHorizontalDatum *datum)
	Sets the datum used for the projection. More...

virtual IlvMapsError	setEllipsoid (const IlvEllipsoid &ellipsoid)
	Sets the ellipsoid used for the projection. More...

void	setFalseEasting (IlDouble falseEasting)
	Sets the false easting of the projection. More...

void	setFalseNorthing (IlDouble falseNorthing)
	Sets the false northing of the projection. More...

void	setGeocentric (IlBoolean geoc)
	Specifies whether the projection uses geocentric or geodetic latitudes. More...

void	setShared ()
	Specifies that the projection will be shared. More...

void	setUnitConverter (const IlvUnitConverter &converter)
	Sets the unit converter of the projection. More...

void	setUsingLongitudeReduction (IlBoolean use)
	Specifies whether the projection uses longitude reduction. More...

virtual void	setXYOffset (IlDouble x0, IlDouble y0)
	Specifies the false easting and the false northing. More...

void	unLock ()
	Unlocks the object. More...

virtual void	write (IlvOutputFile &outputFile) const
	Saves the parameters of a projection to the specified output file. More...

Protected Member Functions
virtual IlvMapsError	sForward (IlvCoordinate &) const
	Must be redefined in subclasses to implement the projection for a sphere. More...

virtual IlvMapsError	sInverse (IlvCoordinate &) const
	Must be redefined in subclasses to implement the inverse projection for a sphere. More...

Protected Member Functions inherited from IlvProjection
	IlvProjection (IlBoolean ellipsoidEnabled, IlBoolean inverseEnabled, IlvProjectionGeometricProperty property)
	Initializes a new `IlvProjection` instance. More...

void	addError (IlvMapsError error)
	Used by the constructors of subclasses if an error occurs during an object initialization. More...

virtual IlvMapsError	eForward (IlvCoordinate &ll) const
	Must be redefined in subclasses to implement the projection for a non spherical ellipsoid. More...

virtual IlvMapsError	eInverse (IlvCoordinate &xy) const
	Implements the inverse projection for a non spherical ellipsoid. More...

virtual bool	isUsingProj4 () const
	Are we using proj4 implementation. More...

void	setError (IlvMapsError error)
	Sets the status of this projection. More...

Additional Inherited Members
Static Public Member Functions inherited from IlvProjection
static IlvProjectionClassInfo *	ClassInfo ()
	Returns the class information of the class. More...

static IlvClassInfo **	ClassInfoRef ()
	Returns the address of the class information of the class. More...

static IlvMapsError	InputError ()
	Indicates that the coordinates passed to the forward function are not in a valid range for radian angles.

static IlvMapsError	InvalidEllipsoidError ()
	Indicates that you attempt to set a non spherical ellipsoid to a projection that does not support non spherical ellipsoids.

static IlvProjection *	Load (IlvInputFile &inputFile)
	Loads a projection from the specified file. More...

static IlvProjection *	PROJ4ToIlvProjection (const char proj4Descriptor, IlvMapsError status=0)
	Creates the projection from a `PROJ4` descriptor. More...

static IlvMapsError	ToleranceConditionError ()
	Indicates that an internal projection computation failed. More...

static IlvMapsError	UnsupportedFeatureError ()
	Indicates that an unsupported projection feature is requested, like inverse projection for a projection that does not support inverse projection.

Detailed Description

This class defines the Gnomonic projection.

Library: ilvmaps

The Gnomonic projection is an azimuthal projection. Because of distortions with increasing distance from the center of the projection, this projection is used to show areas of less than a hemisphere.

This projection applies only to spherical ellipsoids and implements an inverse function.

This projection is neither conformal nor equal area.

Gnomonic Projection

Member Function Documentation

◆ setLLCenter()

virtual void IlvGnomonicProjection::setLLCenter	(	IlDouble	lon,
		IlDouble	lat
	)

virtual

Specifies the central meridian and the central parallel (in radian) associated with the projection.

By default, theses values are set to 0.

This function is virtual because it can be overridden by subclasses of IlvProjection to update the internal parameters when the center is changed.

Parameters

lon	The central meridian in radian.
lat	The central parallel in radian.

Reimplemented from IlvProjection.

◆ sForward()

virtual IlvMapsError IlvGnomonicProjection::sForward ( IlvCoordinate & ll ) const

protectedvirtual

Must be redefined in subclasses to implement the projection for a sphere.

Parameters

ll	Contains the longitude and latitude coordinates in radian.

Returns: An error code.

Implements IlvProjection.

◆ sInverse()

virtual IlvMapsError IlvGnomonicProjection::sInverse ( IlvCoordinate & xy ) const

protectedvirtual

Must be redefined in subclasses to implement the inverse projection for a sphere.

The default implementation returns IlvProjection::UnsupportedFeatureError().

Parameters

xy	Contains the Cartesian coordinates to inverse.

Returns: An error code.

Reimplemented from IlvProjection.

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Member Function Documentation

◆ setLLCenter()

◆ sForward()

◆ sInverse()