Application: gvSIG desktop » gvSIG projections

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2018 gvSIG Association.

 * 

 * This file has been adapted from GeoAPI, see 

 * the original copyright headers bellow.

 *

 * 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.

 * 

 * ----------

 * 

 *    GeoAPI - Java interfaces for OGC/ISO standards

 *    http://www.geoapi.org

 *

 *    Copyright (C) 2004-2017 Open Geospatial Consortium, Inc.

 *    All Rights Reserved. http://www.opengeospatial.org/ogc/legal

 *

 *    Permission to use, copy, and modify this software and its documentation, with

 *    or without modification, for any purpose and without fee or royalty is hereby

 *    granted, provided that you include the following on ALL copies of the software

 *    and documentation or portions thereof, including modifications, that you make:

 *

 *    1. The full text of this NOTICE in a location viewable to users of the

 *       redistributed or derivative work.

 *    2. Notice of any changes or modifications to the OGC files, including the

 *       date changes were made.

 *

 *    THIS SOFTWARE AND DOCUMENTATION IS PROVIDED "AS IS," AND COPYRIGHT HOLDERS MAKE

 *    NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED

 *    TO, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE OR THAT

 *    THE USE OF THE SOFTWARE OR DOCUMENTATION WILL NOT INFRINGE ANY THIRD PARTY

 *    PATENTS, COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS.

 *

 *    COPYRIGHT HOLDERS WILL NOT BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL OR

 *    CONSEQUENTIAL DAMAGES ARISING OUT OF ANY USE OF THE SOFTWARE OR DOCUMENTATION.

 *

 *    The name and trademarks of copyright holders may NOT be used in advertising or

 *    publicity pertaining to the software without specific, written prior permission.

 *    Title to copyright in this software and any associated documentation will at all

 *    times remain with copyright holders.

 */

package org.gvsig.proj.catalogue.datum;

import javax.measure.quantity.Angle;

import javax.measure.unit.Unit;

/**

 * A prime meridian defines the origin from which longitude values are determined.

 * Most geodetic datums use Greenwich as their prime meridian.

 *

 * <p>Constraints:</p>

 * <ul>

 *   <li>If the prime meridian {@linkplain #getName() name} is "Greenwich" then the value of

 *       {@linkplain #getGreenwichLongitude() Greenwich longitude} shall be 0 degrees.</li>

 *   <li>Conversely if the Greenwich longitude value is zero, then the prime meridian name

 *       shall be "Greenwich".</li>

 * </ul>

 * 

 * Note: gvSIG derived these interfaces from GeoAPI in order to have a simpler API and also to

 * avoid namespace collisions (e.g. GeoAPI 3 vs GeoTools interfaces). There is no plans

 * to evolve these interfaces to adapt them to future GeoAPI versions.

 * 

 * @author  gvSIG Team

 * @author  Martin Desruisseaux (IRD)

 * @version 3.0.1

 * @since   1.0

 *

 * @see DatumAuthorityFactory#createPrimeMeridian(String)

 * @see DatumFactory#createPrimeMeridian(Map, double, Unit)

 */

public interface PrimeMeridian {

    /**

     * Longitude of the prime meridian measured from the Greenwich meridian, positive eastward.

     * The {@code greenwichLongitude} default value is zero, and that value shall be used

     * when the {@linkplain #getName() meridian name} value is "Greenwich".

     *

     * @return the prime meridian Greenwich longitude, in {@linkplain #getAngularUnit angular unit}.

     * @unitof Angle

     */

    double getGreenwichLongitude();

    /**

     * Returns the angular unit of the {@linkplain #getGreenwichLongitude() Greenwich longitude}.

     *

     * @departure historic

     *   This attribute is inherited from an older OGC specification.

     *   In ISO 19111, <code>greenwichLongitude</code> is a property of type <code>Angle</code>

     *   rather than <code>double</code>, and the unit of measure is part of the <code>Angle</code> value.

     *

     * @return the angular unit of Greenwich longitude.

     */

    Unit<Angle> getAngularUnit();

}