com.codename1.maps.Mercator Maven / Gradle / Ivy
/*
* Copyright (c) 2010, 2011 Itiner.pl. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Itiner designates this
* particular file as subject to the "Classpath" exception as provided
* by Itiner in the LICENSE.txt file that accompanied this code.
*
* This code 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
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*/
package com.codename1.maps;
import com.codename1.util.MathUtil;
/**
* Represents a Mercator projection http://en.wikipedia.org/wiki/Mercator_projection
*
* @author Roman Kamyk
*/
public class Mercator extends Projection {
// http://wiki.osgeo.org/wiki/WMS_Tiling_Client_Recommendation
private final static double SIZE = 20037508.34;
/**
* Creates a new Mercator projection
*/
public Mercator() {
super(new BoundingBox(new Coord(-SIZE, -SIZE, true), new Coord(SIZE, SIZE, true)));
}
/**
* Create a projected Mercator Coord from the given coordinate
* @param latitude to project
* @param longitude to project
* @return a projected Mercator
*/
public static Coord forwardMercator(double latitude, double longitude) {
double x = longitude * SIZE / 180;
double y = MathUtil.log(Math.tan((90 + latitude) * Math.PI / 360)) / (Math.PI / 180) * SIZE / 180;
return new Coord(y, x, true);
}
/**
* Create a unprojected Coord(Latitude, Longitude) from the projected Coord
* @param latitude projected latitude
* @param longitude projected longitude
* @return unprojected Coord
*/
public static Coord inverseMercator(double latitude, double longitude) {
double x = (longitude / SIZE) * 180;
double y = (latitude / SIZE) * 180;
y = 180.0 / Math.PI * (2 * MathUtil.atan(MathUtil.exp(y * Math.PI / 180)) - Math.PI / 2);
return new Coord(y, x, false);
}
/**
* Create a projected Mercator Coord from the given coordinate
* @param wgs84 coordinate to project
* @return projected Mercator Coord
*/
public Coord fromWGS84(Coord wgs84) {
if(wgs84.isProjected()){
return wgs84;
}
return forwardMercator(wgs84.getLatitude(), wgs84.getLongitude());
}
/**
* Create a Coord(Latitude, Longitude) from the projected Coord
* @param wgs84 projected Coord
* @return unprojected Latitude, Longitude
*/
public Coord toWGS84(Coord projection) {
if(!projection.isProjected()){
return projection;
}
return inverseMercator(projection.getLatitude(), projection.getLongitude());
}
}