+++ /dev/null
-/*
- * Copyright © 2010 Keith Packard <keithp@keithp.com>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; version 2 of the License.
- *
- * 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.
- *
- * You should have received a copy of the GNU General Public License along
- * with this program; if not, write to the Free Software Foundation, Inc.,
- * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
- */
-
-package altosui;
-
-import java.lang.Math;
-import org.altusmetrum.AltosLib.*;
-
-public class AltosGreatCircle {
- double distance;
- double bearing;
-
- double sqr(double a) { return a * a; }
-
- static final double rad = Math.PI / 180;
- static final double earth_radius = 6371.2 * 1000; /* in meters */
-
- static int BEARING_LONG = 0;
- static int BEARING_SHORT = 1;
- static int BEARING_VOICE = 2;
- String bearing_words(int length) {
- String [][] bearing_string = {
- {
- "North", "North North East", "North East", "East North East",
- "East", "East South East", "South East", "South South East",
- "South", "South South West", "South West", "West South West",
- "West", "West North West", "North West", "North North West"
- }, {
- "N", "NNE", "NE", "ENE",
- "E", "ESE", "SE", "SSE",
- "S", "SSW", "SW", "WSW",
- "W", "WNW", "NW", "NNW"
- }, {
- "north", "nor nor east", "north east", "east nor east",
- "east", "east sow east", "south east", "sow sow east",
- "south", "sow sow west", "south west", "west sow west",
- "west", "west nor west", "north west", "nor nor west "
- }
- };
- return bearing_string[length][(int)((bearing / 90 * 8 + 1) / 2)%16];
- }
-
- public AltosGreatCircle (double start_lat, double start_lon,
- double end_lat, double end_lon)
- {
- double lat1 = rad * start_lat;
- double lon1 = rad * -start_lon;
- double lat2 = rad * end_lat;
- double lon2 = rad * -end_lon;
-
- double d_lon = lon2 - lon1;
-
- /* From http://en.wikipedia.org/wiki/Great-circle_distance */
- double vdn = Math.sqrt(sqr(Math.cos(lat2) * Math.sin(d_lon)) +
- sqr(Math.cos(lat1) * Math.sin(lat2) -
- Math.sin(lat1) * Math.cos(lat2) * Math.cos(d_lon)));
- double vdd = Math.sin(lat1) * Math.sin(lat2) + Math.cos(lat1) * Math.cos(lat2) * Math.cos(d_lon);
- double d = Math.atan2(vdn,vdd);
- double course;
-
- if (Math.cos(lat1) < 1e-20) {
- if (lat1 > 0)
- course = Math.PI;
- else
- course = -Math.PI;
- } else {
- if (d < 1e-10)
- course = 0;
- else
- course = Math.acos((Math.sin(lat2)-Math.sin(lat1)*Math.cos(d)) /
- (Math.sin(d)*Math.cos(lat1)));
- if (Math.sin(lon2-lon1) > 0)
- course = 2 * Math.PI-course;
- }
- distance = d * earth_radius;
- bearing = course * 180/Math.PI;
- }
-
- public AltosGreatCircle(AltosGPS start, AltosGPS end) {
- this(start.lat, start.lon, end.lat, end.lon);
- }
-
- public AltosGreatCircle() {
- distance = 0;
- bearing = 0;
- }
-}