Package org.deegree.crs.projections

A map projection create a 2D view of the 3D-Object 'earth', by doing so, some information is inevitably lost.

See:
Description

Class Summary

Projection	Map conversion is the process of changing the map grid coordinates (usually, but not always, Easting & Northing) of a Projected Coordinate Reference System to its corresponding geographical coordinates (Latitude & Longitude) or vice versa.
ProjectionUtils	The Utils class combines some helpful constants and forms.

Package org.deegree.crs.projections Description

A map projection create a 2D view of the 3D-Object 'earth', by doing so, some information is inevitably lost.

Because of this and because of the fact, the earth isn't a perfect sphere --or even a perfect ellipsoid for that matter--, there is no 'best' projection for the projection of every region on earth. Hence a lot of different mathematical projectional functions have been developed over the years. It is possible to categorize these functions into three groups:

• Cylindric projections
• Conic projections
• Azimuthal projections

Automatic loading of projection classes

It is possible to create your own projection classes, which can be automatically loaded by the DeegreeCRSProvider class.

You can achieve this loading by supplying the class attribute to a crs:projectedCRS/crs:projection element in the 'deegree-crs-configuration.xml'. This attribute must contain the full class name (with package), e.g. <crs:projection class='my.package.and.projection.Implementation'>

Because the loading is done with reflections your classes must sustain following criteria:

Projections

1. It must be a sub class of Projection
2. A constructor with following signature must be supplied:
   public MyProjection(
    GeographicCRS underlyingCRS,
    double falseNorthing,
    double falseEasting,
    javax.vecmath.Point2d naturalOrigin,
    Unit units,
    double scale,
    java.util.List<org.w3c.dom.Element> yourProjectionElements
);


   The first six parameters are common to all projections (for an explanation of their meaning take a look at Projection). The last list, will contain all xml-dom elements you supplied in the deegree configuration (child elements of the crs:projection/crs:MyProjection), thus relieving you of the parsing of the deegree-crs-configuration.xml document.

Version:

$Revision: 15008 $, $Date: 2007-03-20 10:15:15 +0100 (Di, 20 Mrz 2007)$

Author:

Rutger Bezema, last edited by: $Author: rbezema $