IlvAzimuthalEquidistantProjection Class Reference

This class defines the Azimuthal Equidistant projection. More...

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

Inheritance diagram for IlvAzimuthalEquidistantProjection:

List of all members.

Public Member Functions
	IlvAzimuthalEquidistantProjection ()
	Initializes an instance of the class IlvAzimuthalEquidistantProjection.
virtual IlvProjection *	copy () const
	Returns a copy of the projection. It must be overridden in each subclass.
virtual IlvProjectionClassInfo *	getClassInfo () const
	Returns the class information for the projection.
IlBoolean	isGuam () const
	Returns IlTrue if the Guam elliptical equation is used.
virtual IlvMapsError	setEllipsoid (const IlvEllipsoid &ellipsoid)
	Sets the ellipsoid used for the projection.
void	setGuam (IlBoolean guam)
	Sets the projection to use the Guam equation, which is an alternate form of the projection for an ellipsoid.
virtual void	setLLCenter (IlDouble lon, IlDouble lat)
	Specifies the central meridian and the central parallel (in radian) associated with the projection.
virtual void	write (IlvOutputFile &) const
	Saves the parameters of a projection to the specified output file.
Static Public Member Functions
static IlvProjectionClassInfo *	ClassInfo ()
	Returns the class information of the class.
static IlvClassInfo **	ClassInfoRef ()
	Returns the address of the class information of the class.
Protected Member Functions
virtual IlvMapsError	eForward (IlvCoordinate &ll) const
	Must be redefined in subclasses to implement the projection for a non spherical ellipsoid.
virtual IlvMapsError	eInverse (IlvCoordinate &xy) const
	Implements the inverse projection for a non spherical ellipsoid.
virtual IlvMapsError	sForward (IlvCoordinate &ll) const
	Must be redefined in subclasses to implement the projection for a sphere.
virtual IlvMapsError	sInverse (IlvCoordinate &xy) const
	Must be redefined in subclasses to implement the inverse projection for a sphere.

---

Detailed Description

This class defines the Azimuthal Equidistant projection.

With Azimuthal projections, also called planar projections, the spherical globe is projected onto a flat surface. This type of projection is often used to represent the regions around the Poles. The plane surface is therefore generally placed above the North or the South Pole.
With Azimuthal Equidistant projections, distances from the center are true. These projections are used to show air-route distances, which appear as straight lines when drawn from the projection center.
CADGR files representing polar areas are projected with this projection.
This class applies both to spherical and nonspherical ellipsoids and implements an inverse function.
This projection is neither Conformal nor Equal Area.

Library: ilvmaps

---

Member Function Documentation

static IlvProjectionClassInfo* IlvAzimuthalEquidistantProjection::ClassInfo

(

)

[static]

Returns the class information of the class.

This static function is also available for the subclasses of IlvProjection.

Returns:

The IlvProjectionClassInfo of the class.

Reimplemented from IlvProjection.

static IlvClassInfo** IlvAzimuthalEquidistantProjection::ClassInfoRef

(

)

[static]

Returns the address of the class information of the class.

This static function is also available for the subclasses of IlvProjection.

Returns:

The address of the IlvProjectionClassInfo of the class.

Reimplemented from IlvProjection.

virtual IlvProjection* IlvAzimuthalEquidistantProjection::copy

(

)

const [virtual]

Returns a copy of the projection. It must be overridden in each subclass.

Returns:

The copy of the object.

Implements IlvProjection.

virtual IlvMapsError IlvAzimuthalEquidistantProjection::eForward

(

IlvCoordinate &

ll

)

const [protected, virtual]

Must be redefined in subclasses to implement the projection for a non spherical ellipsoid.

The default implementation returns IlvProjection::UnsupportedFeatureError().

Parameters:

ll

Contains the longitude and latitude coordinates in radian (x = longitude, y = latitude).

Returns:

An error code.

Reimplemented from IlvProjection.

virtual IlvMapsError IlvAzimuthalEquidistantProjection::eInverse

(

IlvCoordinate &

xy

)

const [protected, virtual]

Implements the inverse projection for a non spherical ellipsoid.

The default implementation returns IlvProjection::UnsupportedFeatureError().

Parameters:

xy

Contains the Cartesian coordinates to inverse.

Returns:

An error code.

Reimplemented from IlvProjection.

virtual IlvProjectionClassInfo* IlvAzimuthalEquidistantProjection::getClassInfo

(

)

const [virtual]

Returns the class information for the projection.

Returns:

The class information for the projection.

Reimplemented from IlvProjection.

IlBoolean IlvAzimuthalEquidistantProjection::isGuam

(

)

const

Returns IlTrue if the Guam elliptical equation is used.

Returns:

IlTrue if the Guam elliptical equation is used, IlFalse otherwise.

virtual IlvMapsError IlvAzimuthalEquidistantProjection::setEllipsoid

(

const IlvEllipsoid &

ellipsoid

)

[virtual]

Sets the ellipsoid used for the projection.

This virtual member function sets the ellipsoid used for the projection. Most of the projections are initialized with a spherical ellipsoid with a radius of 6,370,997 meters.
This function returns IlvMaps::NoError() if the operation is successful or an error status if you specify a non spherical ellipsoid and your type does not support non spherical.

Parameters:

ellipsoid

The ellipsoid used for the projection.

Returns:

IlvMapsError if the ellipsoid does not match the projection.

Reimplemented from IlvProjection.

void IlvAzimuthalEquidistantProjection::setGuam

(

IlBoolean

guam

)

Sets the projection to use the Guam equation, which is an alternate form of the projection for an ellipsoid.

If the Guam argument is set to IlTrue, the Guam elliptical equation is used. By default, it is set to IlFalse, which means that the Guam equation is not used.

Parameters:

guam

Specifies if the Guam equation is to be used.

virtual void IlvAzimuthalEquidistantProjection::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.

virtual IlvMapsError IlvAzimuthalEquidistantProjection::sForward

(

IlvCoordinate &

ll

)

const [protected, virtual]

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

Parameters:

ll

Contains the longitude and latitude coordinates in radian (x = longitude, y = latitude).

Implements IlvProjection.

virtual IlvMapsError IlvAzimuthalEquidistantProjection::sInverse

(

IlvCoordinate &

xy

)

const [protected, virtual]

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.

virtual void IlvAzimuthalEquidistantProjection::write

(

IlvOutputFile &

outputFile

)

const [virtual]

Saves the parameters of a projection to the specified output file.

It must be overridden by subclasses of IlvProjection that need to save additional parameters. This function should not be directly called; use the save function instead.

Parameters:

outputFile

The file to write the projection parameters to.

Reimplemented from IlvProjection.