source: josm/trunk/src/org/openstreetmap/josm/data/projection/Projections.java @ 5241

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

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.data.coor.EastNorth;
import org.openstreetmap.josm.data.coor.LatLon;
import org.openstreetmap.josm.data.projection.datum.Datum;
import org.openstreetmap.josm.data.projection.datum.NTV2GridShiftFileWrapper;
import org.openstreetmap.josm.data.projection.datum.WGS84Datum;
import org.openstreetmap.josm.data.projection.proj.ClassProjFactory;
import org.openstreetmap.josm.data.projection.proj.LambertConformalConic;
import org.openstreetmap.josm.data.projection.proj.LonLat;
import org.openstreetmap.josm.data.projection.proj.Proj;
import org.openstreetmap.josm.data.projection.proj.ProjFactory;
import org.openstreetmap.josm.data.projection.proj.SwissObliqueMercator;
import org.openstreetmap.josm.data.projection.proj.TransverseMercator;
import org.openstreetmap.josm.io.MirroredInputStream;

/**
 * Class to handle projections
 *
 */
public class Projections {

    public static EastNorth project(LatLon ll) {
        if (ll == null) return null;
        return Main.getProjection().latlon2eastNorth(ll);
    }

    public static LatLon inverseProject(EastNorth en) {
        if (en == null) return null;
        return Main.getProjection().eastNorth2latlon(en);
    }

    /*********************************
     * Registry for custom projection
     *
     * should be compatible to PROJ.4
     */
    public static Map<String, ProjFactory> projs = new HashMap<String, ProjFactory>();
    public static Map<String, Ellipsoid> ellipsoids = new HashMap<String, Ellipsoid>();
    public static Map<String, Datum> datums = new HashMap<String, Datum>();
    public static Map<String, NTV2GridShiftFileWrapper> nadgrids = new HashMap<String, NTV2GridShiftFileWrapper>();
    public static Map<String, String> inits = new HashMap<String, String>();

    static {
        registerBaseProjection("lonlat", LonLat.class, "core");
        registerBaseProjection("josm:smerc", org.openstreetmap.josm.data.projection.proj.Mercator.class, "core");
        registerBaseProjection("lcc", LambertConformalConic.class, "core");
        registerBaseProjection("somerc", SwissObliqueMercator.class, "core");
        registerBaseProjection("tmerc", TransverseMercator.class, "core");

        ellipsoids.put("intl", Ellipsoid.hayford);
        ellipsoids.put("GRS80", Ellipsoid.GRS80);
        ellipsoids.put("WGS84", Ellipsoid.WGS84);
        ellipsoids.put("bessel", Ellipsoid.Bessel1841);

        datums.put("WGS84", WGS84Datum.INSTANCE);

        nadgrids.put("BETA2007.gsb", NTV2GridShiftFileWrapper.BETA2007);
        nadgrids.put("ntf_r93_b.gsb", NTV2GridShiftFileWrapper.ntf_rgf93);

        loadInits();
    }

    /**
     * Plugins can register additional base projections.
     *
     * @param id The "official" PROJ.4 id. In case the projection is not supported
     * by PROJ.4, use some prefix, e.g. josm:myproj or gdal:otherproj.
     * @param fac The base projection factory.
     * @param origin Multiple plugins may implement the same base projection.
     * Provide plugin name or similar string, so it be differentiated.
     */
    public static void registerBaseProjection(String id, ProjFactory fac, String origin) {
        projs.put(id, fac);
    }

    public static void registerBaseProjection(String id, Class<? extends Proj> projClass, String origin) {
        registerBaseProjection(id, new ClassProjFactory(projClass), origin);
    }

    public static Proj getBaseProjection(String id) {
        ProjFactory fac = projs.get(id);
        if (fac == null) return null;
        return fac.createInstance();
    }

    public static Ellipsoid getEllipsoid(String id) {
        return ellipsoids.get(id);
    }

    public static Datum getDatum(String id) {
        return datums.get(id);
    }

    public static NTV2GridShiftFileWrapper getNTV2Grid(String id) {
        return nadgrids.get(id);
    }

    public static String getInit(String id) {
        return inits.get(id);
    }

    /**
     * Load +init "presets" from file
     */
    private static void loadInits() {
        Pattern epsgPattern = Pattern.compile("\\A<(\\d+)>(.*)<>\\Z");
        try {
            InputStream in = new MirroredInputStream("resource://data/epsg");
            BufferedReader r = new BufferedReader(new InputStreamReader(in));
            String line;
            while ((line = r.readLine()) != null) {
                line = line.trim();
                if (!line.startsWith("#") && !line.isEmpty()) {
                    Matcher m = epsgPattern.matcher(line);
                    if (m.matches()) {
                        inits.put("epsg:" + m.group(1), m.group(2).trim());
                    } else {
                        System.err.println("Warning: failed to parse line from the epsg projection definition: "+line);
                    }
                }
            }
        } catch (IOException ex) {
            throw new RuntimeException();
        }
    }
}