Application: gvSIG desktop » gvSIG projections

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2018 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.proj.catalogue;

import java.util.List;

import java.util.Set;

import org.gvsig.proj.catalogue.datum.Datum;

import org.gvsig.proj.catalogue.ref.Extent;

/**

 * Definition of a Coordinate Reference System (CRS).

 * 

 * A CRS defines how a set of coordinates relate to real positions (on earth, on other

 * planet or in the space). A CRS defines the number of coordinate axis, its name, order and

 * direction, its units, the mathematical model used to define the geometric figure (ellipsoid)

 * to approximate the shape of the earth, the relationship of this mathematical model with the

 * earth (datum), among other concepts and parameters. Some CRSs include a projection, which

 * defines a mathematical model to approximate the surface of an area of the earth using a

 * planar surface.

 * 

 * Note that a set of coordinates is meaningless if their CRS is not defined, as these

 * values can refer to different locations on the Earth depending on the CRS being used.

 * 

 * @author  gvSIG Team

 * @author  Cesar Martinez Izquierdo

 */

public interface CRSDefinition {

    /**

     * A common name for this coordinate reference system

     * 

     * @return the name, or {@code null} if none.

     */

        String getName();

    /**

     * Gets a code that references an unambiguous definition of the coordinate reference

     * system for some authority. Examples: "EPSG:4326", "EPSG:25830".

     * 

     * @return the identifier which was used to instantiate the object, or the

     * identifier that more closely matches the information used to instantiate

     * the object (e.g. if derived from an WKT definition)

     */

    String getIdentifier();

    /**

     * Gets the list of identifiers which describe this coordinate reference system

     * definition.

     *

     * @return the list of object identifiers, or an empty collection if there is none.

     */

    Set<String> getIdentifiers();

    /**

     * FIXME: GeoAPI

     * Area or region or timeframe in which this (coordinate) reference system is valid.

     *

     * @return the reference system valid domain, or {@code null} if not available.

     * @since 2.1

     */

        Extent getDomainOfValidity();

    /**

     * Textual description of the coordinate reference system, including remarks

     * and its scope. 

     *

     * @return the description, or {@code null} if none.

     */

    String getDescription();

    /**

     * Some CRSs include a projection, which defines a mathematical model to approximate

     * the surface of an area of the earth using a planar surface. CRS including a

     * projection are called projected CRSs

     * 

     * @return true if the CRS is projected, false otherwise

     */

    boolean isProjected();

    /**

     * Gets the type of coordinate reference system

     * 

     * @return

     */

    CRSType getType();

    /**

     * FIXME: GeoAPI

     * Returns a <cite>Well-Known Text</cite> (WKT) for this object.

     * Well-Known Texts (WKT) may come in two formats:

     *

     * <ul>

     *   <li>The current standard, WKT 2, is defined by ISO 19162.</li>

     *   <li>The legacy format, WKT 1, was defined by {@linkplain org.opengis.annotation.Specification#OGC_01009 OGC 01-009}

     *       and is shown using Extended Backus Naur Form (EBNF) <a href="doc-files/WKT.html">here</a>.</li>

     * </ul>

     *

     * Implementations are encouraged to format according the most recent standard.

     * This operation may fail if unsupported or if this instance contains elements that do not have

     * WKT representation.

     *

     * @return the Well-Known Text (WKT) for this object.

     * @throws UnsupportedOperationException if this object can not be formatted as WKT.

     *

     * @departure extension

     *   This method is not part of the OGC specification. It has been added in order to provide

     *   the converse of the <code>CRSFactory.createFromWKT(String)</code> method, which is

     *   defined in OGC 01-009.

     *

     * @see org.opengis.referencing.crs.CRSFactory#createFromWKT(String)

     */

        String toWKT() throws UnsupportedOperationException;

        /**

        * FIXME: GeoAPI & review definition

    * The ordered list of coordinate reference systems.

    *

    * @return the ordered list of coordinate reference systems.

    *

    * @departure generalization

    *   ISO 19111 said <cite>"nesting of compound CRSs shall not be permitted; the individual single systems

    *   shall be aggregated together"</cite>. However this approach causes data lost: it is difficult to add

    *   a temporal CRS to an existing three-dimensional compound CRS without loosing the name and identifiers

    *   of the 3D CRS, unless nesting is permitted. It is programmatically easier to convert nested CRSs to a

    *   flat list of single CRSs when needed than to reconstruct the 3D CRS from the single components.

    *   Consequently GeoAPI has been keep conformant with the legacy OGC 01-009 specification in this aspect,

    *   which were allowing nested compound CRS.

    *

    * @since 2.3

    */

        List<CRSDefinition> getComponents();

        /**

         * Gets the number of axis of the associated CoordinateSystem

         * 

         * @return

         */

        int getAxisCount();

        /**

         * Returns the axis for the associated coordinate system at the specified dimension,

         * as officially defined by the authority. 

         * 

         * @param dimension

         * @return

         * @throws IndexOutOfBoundsException

         */

        CoordinateSystemAxis getAxis(int dimension) throws IndexOutOfBoundsException;

        /**

         * Returns the axis for the associated coordinate system at the specified

         * dimension as internally used by gvSIG, which will sometimes differ from

         * the order officially defined by the authority.

         * 

         * The internal order is used for convenience and performance. gvSIG geometries

         * and gvSIG coordinate transformations always expect coordinates to be provided

         * using the internal order (xy axis order). However, some

         * protocols or formats require the coordinates to be encoded using the

         * official order. 

         * 

         * @param dimension

         * @return

         * @throws IndexOutOfBoundsException

         */

        CoordinateSystemAxis getAxisInternal(int dimension) throws IndexOutOfBoundsException;

    /**

     * For derived CRSs, it returns the base coordinate reference system.

     *

     * @return the base coordinate reference system or null if the CRS is not

     * derived

     * @see CRSType#isDerived()

     * @see CRSType#ProjectedCRSType

     * @see CRSType#OtherDerivedCRSType

     */

        CRSDefinition getBaseCRS();

    /**

     * For derived CRSs, it returns the conversion from the {@linkplain #getBaseCRS() base CRS}

     * to this CRS.

     *

     * @return the conversion from the base CRS or null if the CRS is not derived

     *

     * @see CRSType#isDerived()

     * @see CRSType#ProjectedCRSType

     * @see CRSType#OtherDerivedCRSType

     */

        TransformationDefinition getConversionFromBase();

    /**

     * Returns the datum associated directly or indirectly to this CRS.

     * In the case of a derived CRS, this method returns the

     * datum of the {@linkplain #getBaseCRS() base CRS}. In the case of

     * a compound CRS, it returns the datum associated to the horizontal component.

     *

     * @return the datum

     */

    Datum getDatum();

}