/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2001-2008, Open Source Geospatial Foundation (OSGeo)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License.
*
* This library 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
* Lesser General Public License for more details.
*
* This package contains documentation from OpenGIS specifications.
* OpenGIS consortium's work is fully acknowledged here.
*/
package org.geotools.referencing.crs;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
import javax.measure.unit.Unit;
import javax.measure.unit.NonSI;
import javax.measure.quantity.Angle;
import org.opengis.referencing.cs.AxisDirection;
import org.opengis.referencing.cs.CoordinateSystem;
import org.opengis.referencing.cs.CoordinateSystemAxis;
import org.opengis.referencing.cs.EllipsoidalCS;
import org.opengis.referencing.datum.Ellipsoid;
import org.opengis.referencing.datum.GeodeticDatum;
import org.opengis.referencing.crs.GeographicCRS;
import org.opengis.geometry.MismatchedDimensionException;
import org.geotools.measure.Measure;
import org.geotools.metadata.iso.extent.ExtentImpl;
import org.geotools.referencing.wkt.Formatter;
import org.geotools.referencing.AbstractReferenceSystem; // For javadoc
import org.geotools.referencing.cs.DefaultEllipsoidalCS;
import org.geotools.referencing.datum.DefaultEllipsoid;
import org.geotools.referencing.datum.DefaultGeodeticDatum;
import org.geotools.util.UnsupportedImplementationException;
/**
* A coordinate reference system based on an ellipsoidal approximation of the geoid; this provides
* an accurate representation of the geometry of geographic features for a large portion of the
* earth's surface.
*
* <TABLE CELLPADDING='6' BORDER='1'>
* <TR BGCOLOR="#EEEEFF"><TH NOWRAP>Used with CS type(s)</TH></TR>
* <TR><TD>
* {@link EllipsoidalCS Ellipsoidal}
* </TD></TR></TABLE>
*
* @since 2.1
* @source $URL$
* @version $Id$
* @author Martin Desruisseaux (IRD)
*/
public class DefaultGeographicCRS extends AbstractSingleCRS implements GeographicCRS {
/**
* Serial number for interoperability with different versions.
*/
private static final long serialVersionUID = 861224913438092335L;
/**
* A two-dimensional geographic coordinate reference system using WGS84 datum.
* This CRS uses (<var>longitude</var>,<var>latitude</var>) ordinates with longitude values
* increasing East and latitude values increasing North. Angular units are decimal degrees and
* prime meridian is Greenwich.
*/
public static final DefaultGeographicCRS WGS84;
/**
* A three-dimensional geographic coordinate reference system using WGS84 datum.
* This CRS uses (<var>longitude</var>,<var>latitude</var>,<var>height</var>)
* ordinates with longitude values increasing East, latitude values increasing
* North and height above the ellipsoid in metres. Angular units are decimal degrees and
* prime meridian is Greenwich.
*/
public static final DefaultGeographicCRS WGS84_3D;
static {
final Map<String,Object> properties = new HashMap<String,Object>(4);
properties.put(NAME_KEY, "WGS84(DD)"); // Name used in WCS 1.0.
final String[] alias = {
"WGS84",
"WGS 84" // EPSG name.
};
properties.put(ALIAS_KEY, alias);
properties.put(DOMAIN_OF_VALIDITY_KEY, ExtentImpl.WORLD);
WGS84 = new DefaultGeographicCRS(properties, DefaultGeodeticDatum.WGS84,
DefaultEllipsoidalCS.GEODETIC_2D);
alias[1] = "WGS 84 (geographic 3D)"; // Replaces the EPSG name.
WGS84_3D = new DefaultGeographicCRS(properties, DefaultGeodeticDatum.WGS84,
DefaultEllipsoidalCS.GEODETIC_3D);
}
/**
* Constructs a new geographic CRS with the same values than the specified one.
* This copy constructor provides a way to wrap an arbitrary implementation into a
* Geotools one or a user-defined one (as a subclass), usually in order to leverage
* some implementation-specific API. This constructor performs a shallow copy,
* i.e. the properties are not cloned.
*
* @param crs The coordinate reference system to copy.
*
* @since 2.2
*/
public DefaultGeographicCRS(final GeographicCRS crs) {
super(crs);
}
/**
* Constructs a geographic CRS with the same properties than the given datum.
* The inherited properties include the {@linkplain #getName name} and aliases.
*
* @param datum The datum.
* @param cs The coordinate system.
*
* @since 2.5
*/
public DefaultGeographicCRS(final GeodeticDatum datum, final EllipsoidalCS cs) {
this(getProperties(datum), datum, cs);
}
/**
* Constructs a geographic CRS from a name.
*
* @param name The name.
* @param datum The datum.
* @param cs The coordinate system.
*/
public DefaultGeographicCRS(final String name,
final GeodeticDatum datum,
final EllipsoidalCS cs)
{
this(Collections.singletonMap(NAME_KEY, name), datum, cs);
}
/**
* Constructs a geographic CRS from a set of properties. The properties are given unchanged to
* the {@linkplain AbstractReferenceSystem#AbstractReferenceSystem(Map) super-class constructor}.
*
* @param properties Set of properties. Should contains at least {@code "name"}.
* @param datum The datum.
* @param cs The coordinate system.
*/
public DefaultGeographicCRS(final Map<String,?> properties,
final GeodeticDatum datum,
final EllipsoidalCS cs)
{
super(properties, datum, cs);
}
/**
* Returns the coordinate system.
*/
@Override
public EllipsoidalCS getCoordinateSystem() {
return (EllipsoidalCS) super.getCoordinateSystem();
}
/**
* Returns the datum.
*/
@Override
public GeodeticDatum getDatum() {
return (GeodeticDatum) super.getDatum();
}
/**
* Computes the orthodromic distance between two points. This convenience method delegates
* the work to the underlyling {@linkplain DefaultEllipsoid ellipsoid}, if possible.
*
* @param coord1 Coordinates of the first point.
* @param coord2 Coordinates of the second point.
* @return The distance between {@code coord1} and {@code coord2}.
* @throws UnsupportedOperationException if this coordinate reference system can't compute
* distances.
* @throws MismatchedDimensionException if a coordinate doesn't have the expected dimension.
*/
@Override
public Measure distance(final double[] coord1, final double[] coord2)
throws UnsupportedOperationException, MismatchedDimensionException
{
final DefaultEllipsoidalCS cs;
final DefaultEllipsoid e;
if (!(coordinateSystem instanceof DefaultEllipsoidalCS)) {
throw new UnsupportedImplementationException(coordinateSystem.getClass());
}
final Ellipsoid ellipsoid = ((GeodeticDatum) datum).getEllipsoid();
if (!(ellipsoid instanceof DefaultEllipsoid)) {
throw new UnsupportedImplementationException(ellipsoid.getClass());
}
cs = (DefaultEllipsoidalCS) coordinateSystem;
e = (DefaultEllipsoid) ellipsoid;
if (coord1.length!=2 || coord2.length!=2 || cs.getDimension()!=2) {
/*
* Not yet implemented (an exception will be thrown later).
* We should probably revisit the way we compute distances.
*/
return super.distance(coord1, coord2);
}
return new Measure(e.orthodromicDistance(cs.getLongitude(coord1),
cs.getLatitude (coord1),
cs.getLongitude(coord2),
cs.getLatitude (coord2)), e.getAxisUnit());
}
/**
* Returns a hash value for this geographic CRS.
*
* @return The hash code value. This value doesn't need to be the same
* in past or future versions of this class.
*/
@Override
public int hashCode() {
return (int)serialVersionUID ^ super.hashCode();
}
/**
* Returns the angular unit of the specified coordinate system.
* The preference will be given to the longitude axis, if found.
*/
static Unit<Angle> getAngularUnit(final CoordinateSystem coordinateSystem) {
Unit<Angle> unit = NonSI.DEGREE_ANGLE;
for (int i=coordinateSystem.getDimension(); --i>=0;) {
final CoordinateSystemAxis axis = coordinateSystem.getAxis(i);
final Unit<?> candidate = axis.getUnit();
if (NonSI.DEGREE_ANGLE.isCompatible(candidate)) {
unit = candidate.asType(Angle.class);
if (AxisDirection.EAST.equals(axis.getDirection().absolute())) {
break; // Found the longitude axis.
}
}
}
return unit;
}
/**
* Format the inner part of a
* <A HREF="http://geoapi.sourceforge.net/snapshot/javadoc/org/opengis/referencing/doc-files/WKT.html"><cite>Well
* Known Text</cite> (WKT)</A> element.
*
* @param formatter The formatter to use.
* @return The name of the WKT element type, which is {@code "GEOGCS"}.
*/
@Override
protected String formatWKT(final Formatter formatter) {
final Unit<Angle> oldUnit = formatter.getAngularUnit();
final Unit<Angle> unit = getAngularUnit(coordinateSystem);
formatter.setAngularUnit(unit);
formatter.append(datum);
formatter.append(((GeodeticDatum) datum).getPrimeMeridian());
formatter.append(unit);
final int dimension = coordinateSystem.getDimension();
for (int i=0; i<dimension; i++) {
formatter.append(coordinateSystem.getAxis(i));
}
if (!unit.equals(getUnit())) {
formatter.setInvalidWKT(GeographicCRS.class);
}
formatter.setAngularUnit(oldUnit);
return "GEOGCS";
}
}