Mercator.java

// License: GPL. Copyright 2007 by Immanuel Scholz and others
package org.openstreetmap.josm.data.projection;

import org.openstreetmap.josm.data.Bounds;
import org.openstreetmap.josm.data.coor.EastNorth;
import org.openstreetmap.josm.data.coor.LatLon;

/**
 * GWT
 *
 * note
 *  for now support one projection only, so most
 *  methods are not needed
 */

/**
 * Implement Mercator Projection code, coded after documentation
 * from wikipedia.
 *
 * The center of the mercator projection is always the 0 grad
 * coordinate.
 *
 * See also USGS Bulletin 1532
 * (http://egsc.usgs.gov/isb/pubs/factsheets/fs08799.html)
 *
 * @author imi
 */
public class Mercator implements Projection {

    final double radius = 6378137.0;

    public EastNorth latlon2eastNorth(LatLon p) {
        return new EastNorth(
                p.lon()*Math.PI/180*radius,
                Math.log(Math.tan(Math.PI/4+p.lat()*Math.PI/360))*radius);
    }

    public LatLon eastNorth2latlon(EastNorth p) {
        return new LatLon(
                Math.atan(Math.sinh(p.north()/radius))*180/Math.PI,
                p.east()/radius*180/Math.PI);
    }

//        @Override public String toString() {
//            return tr("Mercator");
//        }
//
//        public String toCode() {
//            return "EPSG:3857"; /* initially they used 3785 but that has been superseded, see http://www.epsg-registry.org/ */
//        }
//
//        @Override
//        public int hashCode() {
//            return getClass().getName().hashCode(); // we have no variables
//        }
//
//        public String getCacheDirectoryName() {
//            return "mercator";
//        }

        public Bounds getWorldBoundsLatLon()
        {
            return new Bounds(
                    new LatLon(-85.05112877980659, -180.0),
                    new LatLon(85.05112877980659, 180.0));
        }

        public double getDefaultZoomInPPD() {
            // This will set the scale bar to about 100 km
            return 1000.0;/*0.000158*/
        }
}