Application: gvSIG desktop

/*

 * Created on 29-jun-2006

 *

 * gvSIG. Sistema de Informaci?n Geogr?fica de la Generalitat Valenciana

 *

 * Copyright (C) 2004 IVER T.I. and Generalitat Valenciana.

 *

 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307,USA.

 *

 * For more information, contact:

 *

 *  Generalitat Valenciana

 *   Conselleria d'Infraestructures i Transport

 *   Av. Blasco Ib??ez, 50

 *   46010 VALENCIA

 *   SPAIN

 *

 *      +34 963862235

 *   gvsig@gva.es

 *      www.gvsig.gva.es

 *

 *    or

 *

 *   IVER T.I. S.A

 *   Salamanca 50

 *   46005 Valencia

 *   Spain

 *

 *   +34 963163400

 *   dac@iver.es

 */

/* CVS MESSAGES:

*

* $Id$

* $Log$

* Revision 1.3.2.4  2007-01-12 13:25:53  caballero

* unidades de mapa y medida

*

* Revision 1.3.2.3  2006/12/22 10:15:07  caballero

* unidades de mapa y de medida

*

* Revision 1.3.2.2  2006/12/21 18:21:52  azabala

* Bug fixed: change getMapUnits for getDistanceUnits

*

* Revision 1.3.2.1  2006/11/15 00:08:17  jjdelcerro

* *** empty log message ***

*

* Revision 1.4  2006/09/15 10:42:54  caballero

* extensibilidad de documentos

*

* Revision 1.3  2006/08/29 07:56:30  cesar

* Rename the *View* family of classes to *Window* (ie: SingletonView to SingletonWindow, ViewInfo to WindowInfo, etc)

*

* Revision 1.2  2006/08/29 07:21:09  cesar

* Rename com.iver.cit.gvsig.fmap.Fmap class to com.iver.cit.gvsig.fmap.MapContext

*

* Revision 1.1  2006/06/29 17:30:36  azabala

* first version in cvs

*

*

*/

package com.iver.cit.gvsig.geoprocess.core.util;

import org.cresques.cts.IProjection;

import org.cresques.cts.gt2.CSUTM;

import com.iver.andami.PluginServices;

import com.iver.cit.gvsig.fmap.MapContext;

import com.iver.cit.gvsig.project.documents.view.gui.View;

/**

 * Utility methods to manage distances

 * (conversion from user entries to internal units,

 * verifying if projection is planar or we are

 * working with geographic coordinates, etc.)

 * @author azabala

 *

 */

public class UnitUtils {

        public static final double EARTH_RADIUS = 6378137d;

        /**

         * For computing with geodetic coordinates:

         * returns the angular measure (in radians)

         * for a distance over the earth along a

         * meridiam.

         * Because this consideration is an approximation,

         * we consideer the eart like an sphere (not an

         * ellipsoid)

         * @param dist distance in meters

         * @return arc of meridian whose length is the specified

         * distance

         */

        public static double toSexaAngularMeasure(double dist){

                /*

                 *  dist = 6378km(terrestrial radius) -> 2PI

                 *  passed distance -> incognite

                 */

                return Math.toDegrees((2 * Math.PI * dist)/EARTH_RADIUS);

        }

        /**

         * Converts a distance entered by user in the GUI in the same distance

         * in internal units (measure units)

         *

         * */

        public static double getInInternalUnits(double userEntryDistance){

                // VCN he modificado esto a como creo que deber?a de estar, as? tiene en cuenta para calcular la distancia tanto las unidades

                //en las que se encuentra la cartograf?a como las unidades de medida seleccionadas por el usuario.

                int distanceUnits = ((View)PluginServices.

                                getMDIManager().

                                getActiveWindow()).getMapControl().getViewPort().getDistanceUnits();

                int mapUnits = ((View)PluginServices.

                                getMDIManager().

                                getActiveWindow()).getMapControl().getViewPort().getMapUnits();

                double distInInternalUnits = (userEntryDistance/MapContext.CHANGEM[mapUnits]) * MapContext.CHANGEM[distanceUnits];

                /*

                 * if layer's projections is in geographics

                coords, pass distance to a angular measure

                */

                IProjection proj =  ((View)PluginServices.

                                                                getMDIManager().

                                                                getActiveWindow()).

                                                                getMapControl().

                                                                getViewPort().

                                                                getProjection();

                if( (proj != null) && !(proj instanceof CSUTM)){

                        distInInternalUnits =

                                UnitUtils.toSexaAngularMeasure(distInInternalUnits);

                }

                return distInInternalUnits;

        }

}