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();

    /**

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

     * Note that there are different versions of the WKT specification

     * (the older WKT defined by OGC 01-009 and the newer one, defined by OGC 12-063r5

     * and ISO 19162). Also note that ESRI uses different names to refer to CRSs, datums,

     * ellipsoids, etc. compared to OGC, so OGC and ESRI WKTs can be considered as different

     * dialects.

     * 

     * Whenever possible, this method will return a WKT following the same specification and

     * dialect that the one used to instantiate this CRSDefinition. If the original

     * specification or dialect are unknown, implementations are encouraged to format according

     * to the most recent standard and following OGC dialect.

     *

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

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

     */

        String toWKT() throws UnsupportedOperationException;

        /**

         * If the CRS type is {@link CRSType#CompoundCRSType}, this method returns the ordered

         * list of coordinate reference systems which are its components.

         *

         * @return the ordered list of coordinate reference systems, or <code>null if the CRS

         * is not compound

         * @see #getType()

         * @see CRSType#CompoundCRSType

         */

        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();

    /**

     * Calculates the distance between 2 points on the surface of the Earth.

     * 

     * The distances are calculated based on the characteristics of CRSDefinition,

     * using geodetic distances when possible. Geodetic distances offer highly

     * accurate measurements and are based on the exact shape of the ellipsoid.

     * 

     * If this CRSDefinition is projected, then the geodetic calculations are done

     * using its base (geographic) CRS. If this CRSDefinition is not geodetic nor

     * projected, then Euclidean distances are calculated.

     * 

     * The provided points are considered to be 2D points

     * (additional dimensions are ignored).

     * 

     * @return The distance between point1 and point2 in the same units as the

     * ellipsoid axis (for geodetic CRSs) or in the same units as defined by the

     * first axis dimension (for non-geodetic CRSs).

     */

    double getDistance(double[] point1, double[] point2);

    /**

     * Calculates the distance between 2 points on the surface of the Earth.

     *  

     * If this CRS is projected and useBaseCRS is <code>false</code>, then

     * the Euclidean distance is calculated. If the CRS is projected and

     * <code>useBaseCRS</code> is <code>true<code>, then the

     * geodetic distance is calculated, using its base (geographic) CRS.

     * 

     * If the CRS is geodetic, then the geodetic distance is calculated.

     * If the CRS is not projected nor geometric, then the Euclidean distance

     * is calculated.

     * 

     * Geodetic distances offer highly accurate measurements and are based on

     * the exact shape of the ellipsoid.

     * 

     * The provided points are considered to be 2D points

     * (additional dimensions are ignored).

     * 

     * @return The distance between point1 and point2 in the same units as the

     * ellipsoid axis (for geodetic CRSs) or in the same units as defined by the

     * first axis dimension (for non-geodetic CRSs).

     */

    double getDistance(double[] point1, double[] point2, boolean useBaseCRS);

}