Subversion Repositories mkgmap

/*
 * Copyright (C) 2006 Steve Ratcliffe
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 *
 *  This program 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 for more details.
 *
 *
 * Author: Steve Ratcliffe
 * Create date: 11-Dec-2006
 */
package uk.me.parabola.imgfmt.app;

import java.util.Formatter;
import java.util.Locale;

import uk.me.parabola.imgfmt.Utils;

/**
 * A point coordinate in unshifted map-units.
 * A map unit is 360/2^24 degrees.  In some places <i>shifted</i> coordinates
 * are used, which means that they are divided by some power of two to save
 * space in the file.
 *
 * You can create one of these with lat/long by calling the constructor with
 * double args.
 *
 * This is an immutable class.
 *
 * @author Steve Ratcliffe
 */
public class Coord implements Comparable<Coord> {
        private final static byte ON_BOUNDARY_MASK = 0x01; // bit in flags is true if point lies on a boundary
        private final static byte PRESERVED_MASK = 0x02; // bit in flags is true if point should not be filtered out
        private final static byte REPLACED_MASK = 0x04;  // bit in flags is true if point was replaced
        private final static byte TREAT_AS_NODE_MASK = 0x08; // bit in flags is true if point should be treated as a node
        private final static byte FIXME_NODE_MASK = 0x10; // bit in flags is true if a node with this coords has a fixme tag
        private final int latitude;
        private final int longitude;
        private byte highwayCount; // number of highways that use this point
        private byte flags; // further attributes

        /**
         * Construct from co-ordinates that are already in map-units.
         * @param latitude The latitude in map units.
         * @param longitude The longitude in map units.
         */
        public Coord(int latitude, int longitude) {
                this.latitude = latitude;
                this.longitude = longitude;
        }

        /**
         * Construct from regular latitude and longitude.
         * @param latitude The latitude in degrees.
         * @param longitude The longitude in degrees.
         */
        public Coord(double latitude, double longitude) {
                this.latitude = Utils.toMapUnit(latitude);
                this.longitude = Utils.toMapUnit(longitude);
        }

        public int getLatitude() {
                return latitude;
        }

        public int getLongitude() {
                return longitude;
        }

        public long getId() {
                return 0;
        }

        public int getHighwayCount() {
                return highwayCount;
        }

        public void incHighwayCount() {
                // don't let it wrap
                if(highwayCount < Byte.MAX_VALUE)
                        ++highwayCount;
        }

        public boolean getOnBoundary() {
                return (flags & ON_BOUNDARY_MASK) != 0;
        }

        public void setOnBoundary(boolean onBoundary) {
                if (onBoundary)
                        this.flags |= ON_BOUNDARY_MASK;
                else
                        this.flags &= ~ON_BOUNDARY_MASK;
        }

        public boolean preserved() {
                return (flags & PRESERVED_MASK) != 0;
        }

        public void preserved(boolean preserved) {
                if (preserved)
                        this.flags |= PRESERVED_MASK;
                else
                        this.flags &= ~PRESERVED_MASK;
        }

        /**
         * Returns if this coord was marked to be replaced in short arc removal.
         * @return True means the replacement has to be looked up.
         */
        public boolean isReplaced() {
                return (flags & REPLACED_MASK) != 0;
        }

        /**
         * Mark a point as replaced in short arc removal process.
         * @param replaced true or false
         */
        public void setReplaced(boolean replaced) {
                if (replaced)
                        this.flags |= REPLACED_MASK;
                else
                        this.flags &= ~REPLACED_MASK;
        }

        /**
         * Should this Coord be treated like a Node in short arc removal?
         * The value has no meaning outside of short arc removal.
         * @return
         */
        public boolean isTreatAsNode() {
                return (flags & TREAT_AS_NODE_MASK) != 0;
        }

        /**
         * Mark the Coord to be treated like a Node in short arc removal
         * @param treatAsNode true or false
         */
        public void setTreatAsNode(boolean treatAsNode) {
                if (treatAsNode)
                        this.flags |= TREAT_AS_NODE_MASK;
                else
                        this.flags &= ~TREAT_AS_NODE_MASK;
        }

        /**
         * Does this coordinate belong to a node with a fixme tag?
         * Note that the value is set after evaluating the points style.
         * @return
         */
        public boolean isFixme() {
                return (flags & FIXME_NODE_MASK) != 0;
        }
       
        public void setFixme(boolean b) {
                if (b)
                        this.flags |= FIXME_NODE_MASK;
                else
                        this.flags &= ~FIXME_NODE_MASK;
        }
       
        public int hashCode() {
                // Use a factor for latitude to span over the whole integer range:
                // max lat: 4194304
                // max lon: 8388608
                // max hashCode: 2118123520 < 2147483647 (Integer.MAX_VALUE)
                return 503 * latitude + longitude;
        }

        public boolean equals(Object obj) {
                if (obj == null || !(obj instanceof Coord))
                        return false;
                Coord other = (Coord) obj;
                return latitude == other.latitude && longitude == other.longitude;
        }

        /**
         * Distance to other point in meters.
         */
        public double distance(Coord other) {
                return quickDistance(other);
        }

        protected double slowDistance(Coord other) {
                if (equals(other))
                        return 0;

                double lat1 = Utils.toRadians(latitude);
                double lat2 = Utils.toRadians(other.getLatitude());
                double lon1 = Utils.toRadians(getLongitude());
                double lon2 = Utils.toRadians(other.getLongitude());

                double R = 6371000; // meters

                // cosine of great circle angle between points
                double cangle = Math.sin(lat1)*Math.sin(lat2) +
                                Math.cos(lat1)*Math.cos(lat2) * Math.cos(lon2-lon1);

                return Math.acos(cangle) * R;
        }

        public double quickDistance(Coord other){
                return 40075000 * Math.sqrt(distanceInDegreesSquared(other)) / 360;
        }

        public double distanceInDegreesSquared(Coord other) {
                if (equals(other))
                        return 0;

                double lat1 = Utils.toDegrees(getLatitude());
                double lat2 = Utils.toDegrees(other.getLatitude());
                double long1 = Utils.toDegrees(getLongitude());
                double long2 = Utils.toDegrees(other.getLongitude());
                               
                double latDiff;
                if (lat1 < lat2)
                        latDiff = lat2 - lat1;
                else
                        latDiff = lat1 - lat2; 
                if (latDiff > 90)
                        latDiff -= 180;

                double longDiff;
                if (long1 < long2)
                        longDiff = long2 - long1;
                else
                        longDiff = long1 - long2;
                if (longDiff > 180)
                        longDiff -= 360;

                // scale longDiff by cosine of average latitude
                longDiff *= Math.cos(Math.PI / 180 * Math.abs((lat1 + lat2) / 2));

                return (latDiff * latDiff) + (longDiff * longDiff);
        }

        public Coord makeBetweenPoint(Coord other, double fraction) {
                return new Coord((int)(latitude + (other.latitude - latitude) * fraction),
                                                 (int)(longitude + (other.longitude - longitude) * fraction));
        }


        // returns bearing (in degrees) from current point to another point
        public double bearingTo(Coord point) {
                double lat1 = Utils.toRadians(latitude);
                double lat2 = Utils.toRadians(point.latitude);
                double lon1 = Utils.toRadians(longitude);
                double lon2 = Utils.toRadians(point.longitude);

                double dlon = lon2 - lon1;

                double y = Math.sin(dlon) * Math.cos(lat2);
                double x = Math.cos(lat1)*Math.sin(lat2) -
                        Math.sin(lat1)*Math.cos(lat2)*Math.cos(dlon);
                return Math.atan2(y, x) * 180 / Math.PI;
        }

        /**
         * Sort lexicographically by longitude, then latitude.
         *
         * This ordering is used for sorting entries in NOD3.
         */
        public int compareTo(Coord other) {
                if (longitude == other.getLongitude())
                        if (latitude == other.getLatitude()) return 0;
                        else return latitude > other.getLatitude() ? 1 : -1;
                else
                        return longitude > other.getLongitude()? 1: -1;
        }                      

        /**
         * Returns a string representation of the object.
         *
         * @return a string representation of the object.
         */
        public String toString() {
                return (latitude) + "/" + (longitude);
        }

        public String toDegreeString() {
                Formatter fmt = new Formatter();
                return fmt.format("%.5f/%.5f",
                        Utils.toDegrees(latitude),
                        Utils.toDegrees(longitude)).toString();
        }

        protected String toOSMURL(int zoom) {
                return ("http://www.openstreetmap.org/?mlat=" +
                        new Formatter(Locale.ENGLISH).format("%.5f", Utils.toDegrees(latitude)) +
                        "&mlon=" +
                        new Formatter(Locale.ENGLISH).format("%.5f", Utils.toDegrees(longitude)) +
                        "&zoom=" +
                        zoom);
        }

        public String toOSMURL() {
                return toOSMURL(17);
        }

}