1 package com.cooliris.media;
3 public class LocationMediaFilter extends MediaFilter {
4 private double mRadius;
5 private double mCenterLat;
6 private double mCenterLon;
7 public static final int EARTH_RADIUS_METERS = 6378137;
8 public static final int LAT_MIN = -90;
9 public static final int LAT_MAX = 90;
10 public static final int LON_MIN = -180;
11 public static final int LON_MAX = 180;
13 LocationMediaFilter(double centerLatitude, double centerLongitude, double thresholdRadius) {
14 mCenterLat = centerLatitude;
15 mCenterLon = centerLongitude;
16 mRadius = thresholdRadius;
19 LocationMediaFilter(double latitude1, double longitude1, double latitude2, double longitude2) {
20 mCenterLat = centerLat(latitude1, latitude2);
21 mCenterLon = centerLon(longitude1, longitude2);
22 mRadius = distanceBetween(latitude1, longitude1, latitude2, longitude2);
25 public static final double centerLat(double lat1, double lat2) {
26 return (centerOfAngles(lat1, lat2, LAT_MAX));
29 public static final double centerLon(double lon1, double lon2) {
30 return (centerOfAngles(lon1, lon2, LON_MAX));
33 private static final double centerOfAngles(double ang1, double ang2, int wrapAroundThreshold) {
34 boolean wrapAround = false;
35 if (Math.abs(ang1 - ang2) > wrapAroundThreshold) {
38 double center = (ang1 + ang2) * 0.5;
40 center += wrapAroundThreshold;
41 center %= wrapAroundThreshold;
46 public static double distanceBetween(double lat1, double lon1, double lat2, double lon2) {
47 double dLat = Math.toRadians(lat2 - lat1);
48 double dLon = Math.toRadians(lon2 - lon1);
49 double a = Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(Math.toRadians(lat1)) * Math.cos(Math.toRadians(lat2))
50 * Math.sin(dLon / 2) * Math.sin(dLon / 2);
51 double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
52 return EARTH_RADIUS_METERS * c;
55 public static final double toKm(double meter) {
59 public static final double toMile(double meter) {
64 public boolean pass(MediaItem item) {
65 double radius = distanceBetween(mCenterLat, mCenterLon, item.mLatitude, item.mLongitude);
66 if (radius <= mRadius) {