init commit
This commit is contained in:
232
LocationLib/src/com/TwentyCodes/android/location/GeoUtils.java
Normal file
232
LocationLib/src/com/TwentyCodes/android/location/GeoUtils.java
Normal file
@@ -0,0 +1,232 @@
|
||||
/**
|
||||
* @author Twenty Codes, LLC
|
||||
* @author Google Inc.
|
||||
* @author ricky barrette
|
||||
* @date Oct 2, 2010
|
||||
*
|
||||
* Some Code here is Copyright (C) 2008 Google Inc.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
package com.TwentyCodes.android.location;
|
||||
|
||||
import java.util.ArrayList;
|
||||
import java.util.List;
|
||||
|
||||
import android.graphics.Point;
|
||||
|
||||
import com.google.android.maps.GeoPoint;
|
||||
import com.google.android.maps.MapView;
|
||||
|
||||
/**
|
||||
* This class contains common tools for computing common geological problems
|
||||
* @author ricky barrette
|
||||
* @author Google Inc.
|
||||
*/
|
||||
public class GeoUtils {
|
||||
|
||||
public static final int EARTH_RADIUS_KM = 6371;
|
||||
public static final double MILLION = 1000000;
|
||||
|
||||
/**
|
||||
* computes the bearing of lat2/lon2 in relationship from lat1/lon1 in degrees East
|
||||
* @param lat1 source lat
|
||||
* @param lon1 source lon
|
||||
* @param lat2 destination lat
|
||||
* @param lon2 destination lon
|
||||
* @return the bearing of lat2/lon2 in relationship from lat1/lon1 in degrees East
|
||||
* @author Google Inc.
|
||||
*/
|
||||
public static double bearing(double lat1, double lon1, double lat2, double lon2) {
|
||||
double lat1Rad = Math.toRadians(lat1);
|
||||
double lat2Rad = Math.toRadians(lat2);
|
||||
double deltaLonRad = Math.toRadians(lon2 - lon1);
|
||||
double y = Math.sin(deltaLonRad) * Math.cos(lat2Rad);
|
||||
double x = Math.cos(lat1Rad) * Math.sin(lat2Rad) - Math.sin(lat1Rad) * Math.cos(lat2Rad) * Math.cos(deltaLonRad);
|
||||
return radToBearing(Math.atan2(y, x));
|
||||
}
|
||||
|
||||
/**
|
||||
* computes the bearing of lat2/lon2 in relationship from lat1/lon1 in degrees East
|
||||
* @param p1 source geopoint
|
||||
* @param p2 destination geopoint
|
||||
* @return the bearing of p2 in relationship from p1 in degrees East
|
||||
* @author Google Inc.
|
||||
*/
|
||||
public static Double bearing(GeoPoint p1, GeoPoint p2) {
|
||||
double lat1 = p1.getLatitudeE6() / MILLION;
|
||||
double lon1 = p1.getLongitudeE6() / MILLION;
|
||||
double lat2 = p2.getLatitudeE6() / MILLION;
|
||||
double lon2 = p2.getLongitudeE6() / MILLION;
|
||||
return bearing(lat1, lon1, lat2, lon2);
|
||||
}
|
||||
|
||||
/**
|
||||
* Calculates a geopoint x meters away of the geopoint supplied. The new geopoint
|
||||
* shares the same latitude as geopoint point, this way they are on the same latitude arc.
|
||||
*
|
||||
* @param point central geopoint
|
||||
* @param distance in meters from the geopoint
|
||||
* @return geopoint that is x meters away from the geopoint supplied
|
||||
* @author ricky barrette
|
||||
*/
|
||||
public static GeoPoint distanceFrom(GeoPoint point, double distance){
|
||||
//convert meters into kilometers
|
||||
distance = distance / 1000;
|
||||
|
||||
// convert lat and lon of geopoint to radians
|
||||
double lat1Rad = Math.toRadians((point.getLatitudeE6() / 1e6));
|
||||
double lon1Rad = Math.toRadians((point.getLongitudeE6() / 1e6));
|
||||
|
||||
/*
|
||||
* kilometers = acos(sin(lat1Rad)sin(lat2Rad)+cos(lat1Rad)cos(lat2Rad)cos(lon2Rad-lon1Rad)6371
|
||||
*
|
||||
* we are solving this equation for lon2Rad
|
||||
*
|
||||
* lon2Rad = lon1Rad+acos(cos(meters/6371)sec(lat1Rad)sec(lat2Rad)-tan(lat1Rad)tan(lat2Rad))
|
||||
*
|
||||
* NOTE: sec(x) = 1/cos(x)
|
||||
*
|
||||
* NOTE: that lat2Rad is = lat1Rad because we want to keep the new geopoint on the same lat arc
|
||||
* therefore i saw no need to create a new variable for lat2Rad,
|
||||
* and simply inputed lat1Rad in place of lat2Rad in the equation
|
||||
*
|
||||
* NOTE: this equation has be tested in the field against another gps device, and the distanceKm() from google
|
||||
* and has been proven to be damn close
|
||||
*/
|
||||
double lon2Rad = lon1Rad + Math.acos( Math.cos((distance/6371)) * (1 / Math.cos(lat1Rad))
|
||||
* (1 / Math.cos(lat1Rad)) - Math.tan(lat1Rad) * Math.tan(lat1Rad));
|
||||
|
||||
//return a geopoint that is x meters away from the geopoint supplied
|
||||
return new GeoPoint(point.getLatitudeE6(), (int) (Math.toDegrees(lon2Rad) * 1e6));
|
||||
}
|
||||
|
||||
/**
|
||||
* computes the distance between to lat1/lon1 and lat2/lon2 based on the curve of the earth
|
||||
* @param lat1 source lat
|
||||
* @param lon1 source lon
|
||||
* @param lat2 destination lat
|
||||
* @param lon2 destination lon
|
||||
* @return the distance between to lat1/lon1 and lat2/lon2
|
||||
* @author Google Inc.
|
||||
*/
|
||||
public static double distanceKm(double lat1, double lon1, double lat2, double lon2) {
|
||||
double lat1Rad = Math.toRadians(lat1);
|
||||
double lat2Rad = Math.toRadians(lat2);
|
||||
double deltaLonRad = Math.toRadians(lon2 - lon1);
|
||||
return Math.acos(Math.sin(lat1Rad) * Math.sin(lat2Rad) + Math.cos(lat1Rad) * Math.cos(lat2Rad) * Math.cos(deltaLonRad)) * EARTH_RADIUS_KM;
|
||||
}
|
||||
|
||||
/**
|
||||
* a convince method for testing if 2 circles on the the surface of the earth intersect.
|
||||
* we will use this method to test if the users accuracy circle intersects a marked locaton's radius
|
||||
* if ( (accuracyCircleRadius + locationRadius) - fudgeFactor) > acos(sin(lat1Rad)sin(lat2Rad)+cos(lat1Rad)cos(lat2Rad)cos(lon2Rad-lon1Rad)6371
|
||||
* @param userPoint
|
||||
* @param accuracyRadius in KM
|
||||
* @param locationPoint
|
||||
* @param locationRadius in KM
|
||||
* @param fudgeFactor how many KM the circles have to intersect
|
||||
* @return true if the circles intersect
|
||||
* @author ricky barrette
|
||||
*/
|
||||
public static boolean isIntersecting(GeoPoint userPoint, float accuracyRadius, GeoPoint locationPoint, float locationRadius, float fudgeFactor){
|
||||
if(((accuracyRadius + locationRadius) - fudgeFactor) > distanceKm(locationPoint, userPoint))
|
||||
return true;
|
||||
return false;
|
||||
}
|
||||
|
||||
/**
|
||||
* computes the distance between to p1 and p2 based on the curve of the earth
|
||||
* @param p1
|
||||
* @param p2
|
||||
* @return the distance between to p1 and p2
|
||||
* @author Google Inc.
|
||||
*/
|
||||
public static double distanceKm(GeoPoint p1, GeoPoint p2) {
|
||||
//if we are handed a null, return -1 so we don't break
|
||||
if(p1 == null || p2 == null)
|
||||
return -1;
|
||||
|
||||
double lat1 = p1.getLatitudeE6() / MILLION;
|
||||
double lon1 = p1.getLongitudeE6() / MILLION;
|
||||
double lat2 = p2.getLatitudeE6() / MILLION;
|
||||
double lon2 = p2.getLongitudeE6() / MILLION;
|
||||
return distanceKm(lat1, lon1, lat2, lon2);
|
||||
}
|
||||
|
||||
/**
|
||||
* determines when the specified point is off the map
|
||||
* @param point
|
||||
* @return true is the point is off the map
|
||||
* @author ricky barrette
|
||||
*/
|
||||
public static boolean isPointOffMap(MapView map , GeoPoint point){
|
||||
if(map == null)
|
||||
return false;
|
||||
if (point == null)
|
||||
return false;
|
||||
GeoPoint center = map.getMapCenter();
|
||||
double distance = GeoUtils.distanceKm(center, point);
|
||||
double distanceLat = GeoUtils.distanceKm(center, new GeoPoint((center.getLatitudeE6() + (int) (map.getLatitudeSpan() / 2)), center.getLongitudeE6()));
|
||||
double distanceLon = GeoUtils.distanceKm(center, new GeoPoint(center.getLatitudeE6(), (center.getLongitudeE6() + (int) (map.getLongitudeSpan() / 2))));
|
||||
if (distance > distanceLat || distance > distanceLon){
|
||||
return true;
|
||||
}
|
||||
return false;
|
||||
}
|
||||
|
||||
/**
|
||||
* computes a geopoint the is the central geopoint between p1 and p1
|
||||
* @param p1 first geopoint
|
||||
* @param p2 second geopoint
|
||||
* @return a MidPoint object
|
||||
* @author ricky barrette
|
||||
*/
|
||||
public static MidPoint midPoint(GeoPoint p1, GeoPoint p2) {
|
||||
int minLatitude = (int)(+81 * 1E6);
|
||||
int maxLatitude = (int)(-81 * 1E6);
|
||||
int minLongitude = (int)(+181 * 1E6);
|
||||
int maxLongitude = (int)(-181 * 1E6);
|
||||
List<Point> mPoints = new ArrayList<Point>();
|
||||
int latitude = p1.getLatitudeE6();
|
||||
int longitude = p1.getLongitudeE6();
|
||||
if (latitude != 0 && longitude !=0) {
|
||||
minLatitude = (minLatitude > latitude) ? latitude : minLatitude;
|
||||
maxLatitude = (maxLatitude < latitude) ? latitude : maxLatitude;
|
||||
minLongitude = (minLongitude > longitude) ? longitude : minLongitude;
|
||||
maxLongitude = (maxLongitude < longitude) ? longitude : maxLongitude;
|
||||
mPoints.add(new Point(latitude, longitude));
|
||||
}
|
||||
|
||||
latitude = p2.getLatitudeE6();
|
||||
longitude = p2.getLongitudeE6();
|
||||
if (latitude != 0 && longitude !=0) {
|
||||
minLatitude = (minLatitude > latitude) ? latitude : minLatitude;
|
||||
maxLatitude = (maxLatitude < latitude) ? latitude : maxLatitude;
|
||||
minLongitude = (minLongitude > longitude) ? longitude : minLongitude;
|
||||
maxLongitude = (maxLongitude < longitude) ? longitude : maxLongitude;
|
||||
mPoints.add(new Point(latitude, longitude));
|
||||
}
|
||||
return new MidPoint(new GeoPoint((maxLatitude + minLatitude)/2, (maxLongitude + minLongitude)/2 ), minLatitude, minLongitude, maxLatitude, maxLongitude);
|
||||
}
|
||||
|
||||
/**
|
||||
* converts radians to bearing
|
||||
* @param rad
|
||||
* @return bearing
|
||||
* @author Google Inc.
|
||||
*/
|
||||
public static double radToBearing(double rad) {
|
||||
return (Math.toDegrees(rad) + 360) % 360;
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user