IlvMercatorProjection Class Reference

This class defines the Mercator projection. More...

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

Inheritance diagram for IlvMercatorProjection:

List of all members.

Public Member Functions
	IlvMercatorProjection (IlDouble latitudeOfTrueScale=0.)
	Creates an instance of the class IlvMercatorProjection and specifies the latitude of the true scale.
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.
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	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 Mercator projection.

The Mercator projection, also known as the Wright projection, is the projection of a sphere on a cylinder that is tangent to the equator. Mercator projections should be limited to equatorial regions, but are frequently used for navigational charts with a latitude of the true scale specified within or near the chart boundaries. With this projection, the regions near the poles cannot be shown.
This projection applies both to spherical and non-spherical ellipsoids and implements an inverse function.
This projection is Conformal.

Mercator Projection

Library: ilvmaps

---

Constructor & Destructor Documentation

IlvMercatorProjection::IlvMercatorProjection

(

IlDouble

latitudeOfTrueScale = 0.

)

Creates an instance of the class IlvMercatorProjection and specifies the latitude of the true scale.

Parameters:

latitudeOfTrueScale

The latitude of the true scale.

---

Member Function Documentation

static IlvProjectionClassInfo* IlvMercatorProjection::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** IlvMercatorProjection::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* IlvMercatorProjection::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 IlvMercatorProjection::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 IlvMercatorProjection::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* IlvMercatorProjection::getClassInfo

(

)

const [virtual]

Returns the class information for the projection.

Returns:

The class information for the projection.

Reimplemented from IlvProjection.

IlDouble IlvMercatorProjection::getLatitudeOfTrueScale

(

)

const

Returns the latitude of the true scale in radian.

Returns:

The latitude of the true scale.

virtual IlvMapsError IlvMercatorProjection::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 IlvMercatorProjection::setLatitudeOfTrueScale

(

IlDouble

latitudeOfTrueScale

)

Sets the latitude of the true scale in radian.

Parameters:

latitudeOfTrueScale

The latitude of the true scale.

virtual IlvMapsError IlvMercatorProjection::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 IlvMercatorProjection::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 IlvMercatorProjection::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.