    001    //$HeadURL: https://svn.wald.intevation.org/svn/deegree/base/branches/2.4_testing/src/org/deegree/crs/projections/conic/ConicProjection.java $
    002    /*----------------------------------------------------------------------------
    003     This file is part of deegree, http://deegree.org/
    004     Copyright (C) 2001-2009 by:
    005       Department of Geography, University of Bonn
    006     and
    007       lat/lon GmbH
    008
    009     This library is free software; you can redistribute it and/or modify it under
    010     the terms of the GNU Lesser General Public License as published by the Free
    011     Software Foundation; either version 2.1 of the License, or (at your option)
    012     any later version.
    013     This library is distributed in the hope that it will be useful, but WITHOUT
    014     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    015     FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
    016     details.
    017     You should have received a copy of the GNU Lesser General Public License
    018     along with this library; if not, write to the Free Software Foundation, Inc.,
    019     59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
    020
    021     Contact information:
    022
    023     lat/lon GmbH
    024     Aennchenstr. 19, 53177 Bonn
    025     Germany
    026     http://lat-lon.de/
    027
    028     Department of Geography, University of Bonn
    029     Prof. Dr. Klaus Greve
    030     Postfach 1147, 53001 Bonn
    031     Germany
    032     http://www.geographie.uni-bonn.de/deegree/
    033
    034     e-mail: info@deegree.org
    035    ----------------------------------------------------------------------------*/
    036
    037    package org.deegree.crs.projections.conic;
    038
    039    import static org.deegree.crs.projections.ProjectionUtils.EPS11;
    040    import static org.deegree.crs.projections.ProjectionUtils.WORLD_BOUNDS_RAD;
    041
    042    import javax.vecmath.Point2d;
    043
    044    import org.deegree.crs.Identifiable;
    045    import org.deegree.crs.components.Unit;
    046    import org.deegree.crs.coordinatesystems.GeographicCRS;
    047    import org.deegree.crs.projections.Projection;
    048
    049    /**
    050     * The <code>ConicProjection</code> is a super class for all conic projections.
    051     * <p>
    052     * <q>(From Snyder p.97)</q>
    053     * </p>
    054     * <p>
    055     * To show a region for which the greatest extent is from east to west in the temperate zones, conic projections are
    056     * usually preferable to cylindrical projections.
    057     * </p>
    058     * <p>
    059     * Normal conic projections are distinguished by the use of arcs of concentric circles for parallesl of latitude and
    060     * equally spaced straight radii of these circles for meridians. The angles between the meridians on the map are smaller
    061     * than the actual differences in longitude. The circular arcs may or may not be equally spaced, depending on the
    062     * projections. The polyconic projections and the oblique conic projections have characteristcs different from these.
    063     * </p>
    064     * <p>
    065     * There are three important classes of conic projections:
    066     * <ul>
    067     * <li>The equidistant</li>
    068     * <li>the conformal</li>
    069     * <li>the equal area</li>
    070     * </ul>
    071     * </p>
    072     *
    073     * @author <a href="mailto:bezema@lat-lon.de">Rutger Bezema</a>
    074     *
    075     * @author last edited by: $Author: mschneider $
    076     *
    077     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18. Jun 2009) $
    078     *
    079     */
    080
    081    public abstract class ConicProjection extends Projection {
    082
    083        private static final long serialVersionUID = -1642488930917290590L;
    084
    085        private double firstParallelLatitude;
    086
    087        private double secondParallelLatitude;
    088
    089        /**
    090         * @param firstParallelLatitude
    091         *            the latitude (in radians) of the first parallel. (Snyder phi_1).
    092         * @param secondParallelLatitude
    093         *            the latitude (in radians) of the second parallel. (Snyder phi_2).
    094         * @param geographicCRS
    095         * @param falseNorthing
    096         * @param falseEasting
    097         * @param naturalOrigin
    098         * @param units
    099         * @param scale
    100         * @param conformal
    101         * @param equalArea
    102         * @param id
    103         *            an identifiable instance containing information about this projection
    104         */
    105        public ConicProjection( double firstParallelLatitude, double secondParallelLatitude, GeographicCRS geographicCRS,
    106                                double falseNorthing, double falseEasting, Point2d naturalOrigin, Unit units, double scale,
    107                                boolean conformal, boolean equalArea, Identifiable id ) {
    108            super( geographicCRS, falseNorthing, falseEasting, naturalOrigin, units, scale, conformal, equalArea, id );
    109
    110            if ( Double.isNaN( firstParallelLatitude ) || firstParallelLatitude == 0
    111                 || Math.abs( firstParallelLatitude ) < EPS11 || firstParallelLatitude < WORLD_BOUNDS_RAD.getMinY()
    112                 || firstParallelLatitude > WORLD_BOUNDS_RAD.getMaxY() ) {
    113                this.firstParallelLatitude = getProjectionLatitude();
    114                this.secondParallelLatitude = getProjectionLatitude();
    115            } else {
    116                this.firstParallelLatitude = firstParallelLatitude;
    117                this.secondParallelLatitude = secondParallelLatitude;
    118                if ( this.secondParallelLatitude < WORLD_BOUNDS_RAD.getMinY()
    119                     || this.secondParallelLatitude > WORLD_BOUNDS_RAD.getMaxY() ) {
    120                    this.secondParallelLatitude = Double.NaN;
    121                }
    122            }
    123        }
    124
    125        /**
    126         * @return the latitude of the first parallel which is the intersection of the earth with the cone or the
    127         *         projectionLatitude if the cone is tangential with earth (e.g. one standard parallel).
    128         */
    129        public final double getFirstParallelLatitude() {
    130            return firstParallelLatitude;
    131        }
    132
    133        /**
    134         * @return the latitude of the first parallel which is the intersection of the earth with the cone or the
    135         *         projectionLatitude if the cone is tangential with earth (e.g. one standard parallel).
    136         */
    137        public final double getSecondParallelLatitude() {
    138            return secondParallelLatitude;
    139        }
    140
    141        @Override
    142        public boolean equals( Object other ) {
    143            if ( other != null && other instanceof ConicProjection ) {
    144                final ConicProjection that = (ConicProjection) other;
    145                return super.equals( other )
    146                       && ( Double.isNaN( this.firstParallelLatitude ) ? Double.isNaN( that.firstParallelLatitude )
    147                                                                      : Math.abs( this.firstParallelLatitude
    148                                                                                  - that.firstParallelLatitude ) < EPS11 )
    149                       && ( Double.isNaN( this.secondParallelLatitude ) ? Double.isNaN( that.secondParallelLatitude )
    150                                                                       : Math.abs( this.secondParallelLatitude
    151                                                                                   - that.secondParallelLatitude ) < EPS11 );
    152            }
    153            return false;
    154        }
    155
    156        /**
    157         * Implementation as proposed by Joshua Block in Effective Java (Addison-Wesley 2001), which supplies an even
    158         * distribution and is relatively fast. It is created from field <b>f</b> as follows:
    159         * <ul>
    160         * <li>boolean -- code = (f ? 0 : 1)</li>
    161         * <li>byte, char, short, int -- code = (int)f</li>
    162         * <li>long -- code = (int)(f ^ (f &gt;&gt;&gt;32))</li>
    163         * <li>float -- code = Float.floatToIntBits(f);</li>
    164         * <li>double -- long l = Double.doubleToLongBits(f); code = (int)(l ^ (l &gt;&gt;&gt; 32))</li>
    165         * <li>all Objects, (where equals(&nbsp;) calls equals(&nbsp;) for this field) -- code = f.hashCode(&nbsp;)</li>
    166         * <li>Array -- Apply above rules to each element</li>
    167         * </ul>
    168         * <p>
    169         * Combining the hash code(s) computed above: result = 37 * result + code;
    170         * </p>
    171         *
    172         * @return (int) ( result >>> 32 ) ^ (int) result;
    173         *
    174         * @see java.lang.Object#hashCode()
    175         */
    176        @Override
    177        public int hashCode() {
    178            // the 2nd millionth prime, :-)
    179            long code = 32452843;
    180            code = code * 37 + super.hashCode();
    181
    182            long tmp = Double.doubleToLongBits( firstParallelLatitude );
    183            code = code * 37 + (int) ( tmp ^ ( tmp >>> 32 ) );
    184
    185            tmp = Double.doubleToLongBits( secondParallelLatitude );
    186            code = code * 37 + (int) ( tmp ^ ( tmp >>> 32 ) );
    187
    188            return (int) ( code >>> 32 ) ^ (int) code;
    189        }
    190    }