IlvStereographicProjection Class Reference

This class defines the Stereographic projection. More...

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

Inheritance diagram for IlvStereographicProjection:

List of all members.

Public Member Functions
	IlvStereographicProjection ()
	Constructor.
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.
IlDouble	getLatitudeOfTrueScale () const
	Returns the latitude of the true scale in radian.
IlDouble	getScaleFactor () const
	Returns the scale factor applied to the central meridian.
virtual IlvMapsError	setEllipsoid (const IlvEllipsoid &ellipsoid)
	Sets the ellipsoid used for the projection.
void	setLatitudeOfTrueScale (IlDouble latitudeOfTrueScale)
	Sets the latitude of the true scale in radian.
virtual void	setLLCenter (IlDouble lon, IlDouble lat)
	Specifies the central meridian and the central parallel (in radian) associated with the projection.
virtual void	setScaleFactor (IlDouble k0)
	Sets the scale factor k0 applied to the central meridian.
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 Stereographic projection.

The Stereographic projection is an Azimuthal projection, that is, a projection onto a plane tangent to the earth at a point specified by the central meridian and the central parallel. By default, the latitude of the true scale is PI/2.
This projection applies both to spherical and non-spherical ellipsoids and implements an inverse function.
This projection is Conformal.

Stereographic Projection

Library: ilvmaps

See also:

IlvUniversalPolarStereographicProjection.

---

Constructor & Destructor Documentation

IlvStereographicProjection::IlvStereographicProjection

(

)

Constructor.

Initializes an instance of the class IlvStereographicProjection.

---

Member Function Documentation

static IlvProjectionClassInfo* IlvStereographicProjection::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.

Reimplemented in IlvUniversalPolarStereographicProjection.

static IlvClassInfo** IlvStereographicProjection::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.

Reimplemented in IlvUniversalPolarStereographicProjection.

virtual IlvProjection* IlvStereographicProjection::copy

(

)

const [virtual]

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

Returns:

The copy of the object.

Implements IlvProjection.

Reimplemented in IlvUniversalPolarStereographicProjection.

virtual IlvMapsError IlvStereographicProjection::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 IlvStereographicProjection::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* IlvStereographicProjection::getClassInfo

(

)

const [virtual]

Returns the class information for the projection.

Returns:

The class information for the projection.

Reimplemented from IlvProjection.

Reimplemented in IlvUniversalPolarStereographicProjection.

IlDouble IlvStereographicProjection::getLatitudeOfTrueScale

(

)

const

Returns the latitude of the true scale in radian.

Returns:

The latitude of the true scale.

IlDouble IlvStereographicProjection::getScaleFactor

(

)

const

Returns the scale factor applied to the central meridian.

Returns:

The scale factor applied to the central meridian.

virtual IlvMapsError IlvStereographicProjection::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 IlvStereographicProjection::setLatitudeOfTrueScale

(

IlDouble

latitudeOfTrueScale

)

Sets the latitude of the true scale in radian.

Warning:

[note] The latitude of the true scale is used only if the central parallel of the projection is located at +PI/2 (North Pole) or -PI/2 (South Pole).

Parameters:

latitudeOfTrueScale

The latitude of the true scale.

virtual void IlvStereographicProjection::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.

Reimplemented in IlvUniversalPolarStereographicProjection.

virtual void IlvStereographicProjection::setScaleFactor

(

IlDouble

k0

)

[virtual]

Sets the scale factor k0 applied to the central meridian.

By default, the scale factor is 1.

Warning:

[note] The scale factor is not used if the central parallel of the projection is located at +PI/2 (north pole) or -PI/2 (south pole).

Parameters:

k0

The scale factor applied to the central meridian.

Reimplemented in IlvUniversalPolarStereographicProjection.

virtual IlvMapsError IlvStereographicProjection::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 IlvStereographicProjection::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 IlvStereographicProjection::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.

Reimplemented in IlvUniversalPolarStereographicProjection.