private GeoHash(double latitude, double longitude, int desiredPrecision)
{
m_point = new WGS84Point(latitude, longitude);
desiredPrecision = Math.Min(desiredPrecision, MAX_BIT_PRECISION);
bool isEvenBit = true;
double[] latitudeRange = new double[] { -90, 90 };
double[] longitudeRange = new double[] { -180, 180 };
while (m_significantBits < desiredPrecision)
{
if (isEvenBit)
{
DivideRangeEncode(longitude, longitudeRange);
}
else
{
DivideRangeEncode(latitude, latitudeRange);
}
isEvenBit = !isEvenBit;
}
SetBoundingBox(this, latitudeRange, longitudeRange);
m_bits <<= (MAX_BIT_PRECISION - desiredPrecision);
}
public static HashSet<GeoObj> SearchGeoHashIndex(SessionBase session, double lat, double lon, double radius)
{
HashSet<GeoObj> resultSet = new HashSet<GeoObj>();
WGS84Point center = new WGS84Point(lat, lon);
GeoHashCircleQuery query = new GeoHashCircleQuery(center, radius); // radius in meters
BoundingBox bbox = query.BoundingBox;
var btreeSet = session.AllObjects<BTreeSet<GeoObj>>().FirstOrDefault();
foreach (GeoHash hash in query.SearchHashes)
{
var itr = btreeSet.Iterator();
itr.GoTo(new GeoObj(hash.LongValue));
var current = itr.Current();
while (current != null)
{
GeoHash geoHash = GeoHash.FromLongValue(current.GeoHash);
if ((geoHash.SignificantBits >= hash.SignificantBits && geoHash.Within(hash)) || (geoHash.SignificantBits < hash.SignificantBits && hash.Within(geoHash)))
{
if (!(current.Latitude < bbox.MinLat || current.Latitude > bbox.MaxLat || current.Longitude < bbox.MinLon || current.Longitude > bbox.MaxLon))
resultSet.Add(current);
current = itr.Next();
}
else
break;
}
}
return resultSet;
}
public override bool Equals(object obj)
{
if (obj is WGS84Point)
{
WGS84Point other = (WGS84Point)obj;
return(m_latitude == other.m_latitude && m_longitude == other.m_longitude);
}
return(false);
}
public static HashSet<GeoObj> SearchGeoHashIndex(SessionBase session, double minLat, double minLon, double maxLat, double maxLon)
{
HashSet<GeoObj> resultSet = new HashSet<GeoObj>();
if (minLat > maxLat)
{
double t = minLat;
minLat = maxLat;
maxLat = t;
}
if (minLon > maxLon)
{
double t = minLon;
minLon = maxLon;
maxLon = t;
}
WGS84Point min = new WGS84Point(minLat, minLon);
WGS84Point max = new WGS84Point(maxLat, maxLon);
BoundingBox bbox = new BoundingBox(min, max);
GeoHashBoundingBoxQuery query = new GeoHashBoundingBoxQuery(bbox);
var btreeSet = session.AllObjects<BTreeSet<GeoObj>>().FirstOrDefault();
foreach (GeoHash hash in query.SearchHashes)
{
var itr = btreeSet.Iterator();
itr.GoTo(new GeoObj(hash.LongValue));
var current = itr.Current();
while (current != null)
{
GeoHash geoHash = GeoHash.FromLongValue(current.GeoHash);
if ((geoHash.SignificantBits >= hash.SignificantBits && geoHash.Within(hash)) || (geoHash.SignificantBits < hash.SignificantBits && hash.Within(geoHash)))
{
if (!(current.Latitude < bbox.MinLat || current.Latitude > bbox.MaxLat || current.Longitude < bbox.MinLon || current.Longitude > bbox.MaxLon))
resultSet.Add(current);
current = itr.Next();
}
else
break;
}
}
return resultSet;
}
public WGS84Point(WGS84Point other) : this(other.m_latitude, other.m_longitude)
{
}
public static GeoHash withBitPrecision(WGS84Point point, int numberOfBits)
{
return(WithBitPrecision(point.Latitude, point.Longitude, numberOfBits));
}
public bool EnclosesCircleAroundPoint(WGS84Point point, double radius)
{
return(false);
}
/// <summary>
/// find out if the given point lies within this hashes bounding box.<br>
/// <i>Note: this operation checks the bounding boxes coordinates, i.e. does
/// not use the <seealso cref="GeoHash"/>s special abilities.s</i>
/// </summary>
public bool Contains(WGS84Point point)
{
return(m_boundingBox.Contains(point));
}
public WGS84Point(WGS84Point other) : this(other.m_latitude, other.m_longitude)
{
}
public static HashSet<Person> SearchGeoHashIndex(string bootDirectory, double minLat, double minLon, double maxLat, double maxLon)
{
HashSet<Person> resultSet = new HashSet<Person>();
if (minLat > maxLat)
{
double t = minLat;
minLat = maxLat;
maxLat = t;
}
if (minLon > maxLon)
{
double t = minLon;
minLon = maxLon;
maxLon = t;
}
WGS84Point min = new WGS84Point(minLat, minLon);
WGS84Point max = new WGS84Point(maxLat, maxLon);
BoundingBox bbox = new BoundingBox(min, max);
GeoHashBoundingBoxQuery query = new GeoHashBoundingBoxQuery(bbox);
using (SessionNoServer session = new SessionNoServer(bootDirectory))
{
session.BeginRead();
BTreeMap<Int64, VelocityDbList<Person>> btreeMap = session.AllObjects<BTreeMap<Int64, VelocityDbList<Person>>>().FirstOrDefault();
foreach (GeoHash hash in query.SearchHashes)
{
BTreeMapIterator<Int64, VelocityDbList<Person>> itr = btreeMap.Iterator();
itr.GoTo(hash.LongValue);
var current = itr.Current();
while (current.Value != null)
{
GeoHash geoHash = GeoHash.FromLongValue(current.Key);
if (geoHash.Within(hash) || (geoHash.SignificantBits > hash.SignificantBits && hash.Within(geoHash)))
{
foreach (Person person in current.Value)
{
resultSet.Add(person);
}
current = itr.Next();
}
else
break;
}
}
// actual geohash bounding box may be including some that are not within requested bounding box so remove such items if any
HashSet<Person> notWithin = new HashSet<Person>();
foreach (Person person in resultSet)
{
if (person.Lattitude < min.Latitude || person.Lattitude > max.Latitude || person.Longitude < min.Longitude || person.Lattitude > max.Latitude)
notWithin.Add(person);
}
foreach (Person person in notWithin)
resultSet.Remove(person);
foreach (Person person in resultSet)
{
Console.WriteLine(person.ToString() + " Lattitude: " + person.Lattitude + " Longitude: " + person.Longitude);
}
session.Commit();
}
return resultSet;
}
/// <summary>
/// create a bounding box defined by two coordinates
/// </summary>
public BoundingBox(WGS84Point p1, WGS84Point p2) : this(p1.Latitude, p2.Latitude, p1.Longitude, p2.Longitude)
{
}
public virtual bool Contains(WGS84Point point)
{
return (point.Latitude >= m_minLat) && (point.Longitude >= m_minLon) && (point.Latitude <= m_maxLat) && (point.Longitude <= m_maxLon);
}
/// <summary>
/// create a bounding box defined by two coordinates
/// </summary>
public BoundingBox(WGS84Point p1, WGS84Point p2) : this(p1.Latitude, p2.Latitude, p1.Longitude, p2.Longitude)
{
}
public virtual bool Contains(WGS84Point point)
{
return((point.Latitude >= m_minLat) && (point.Longitude >= m_minLon) && (point.Latitude <= m_maxLat) && (point.Longitude <= m_maxLon));
}