/// <summary>
/// Bounding Polygon
/// Get all the hashString covered by the polygon in numberOfChars
/// </summary>
/// <param name="polygon">array of coordinates describes the polygon</param>
/// <param name="numberOfChars"></param>
/// <returns>array of hash string</returns>
public static string[] Bpolygon(Coordinates[] polygon, int numberOfChars = 9)
{
var hashList = new List <string>();
// Get all bounding boxes that are possible be covered by polygon
Coordinates max = new Coordinates {
Lat = -90, Lon = -180
};
Coordinates min = new Coordinates {
Lat = 90, Lon = 180
};
foreach (Coordinates c in polygon)
{
max.Lat = Math.Max(max.Lat, c.Lat);
max.Lon = Math.Max(max.Lon, c.Lon);
min.Lat = Math.Min(min.Lat, c.Lat);
min.Lon = Math.Min(min.Lon, c.Lon);
}
string[] bboxHash = GeoHash.Bboxes(min.Lat, min.Lon, max.Lat, max.Lon, numberOfChars);
foreach (string hash in bboxHash)
{
BoundingBox box = GeoHash.DecodeBbox(hash);
if (BoxOverlapPolygon(box, polygon))
{
hashList.Add(hash);
}
}
return(hashList.ToArray());
}
/// <summary>
/// Bounding Box Coordinates
/// Get all coordinates covered by the box in numberOfChars
/// </summary>
/// <param name="minLat"></param>
/// <param name="minLon"></param>
/// <param name="maxLat"></param>
/// <param name="maxLon"></param>
/// <param name="numberOfChars"></param>
/// <returns>all coordinates covered by the box in numberOfChars</returns>
public Coordinates[] BboxCoordinates(double minLat, double minLon, double maxLat, double maxLon, int numberOfChars = 9)
{
var coorList = new List <Coordinates>();
string[] hashList = GeoHash.Bboxes(minLat, minLon, maxLat, maxLat, numberOfChars);
foreach (string hash in hashList)
{
// TODO: search all level or search current level only?
Coordinates[] coors = GetCoordinates(hash);
BoundingBox box = GeoHash.DecodeBbox(hash);
if (BoxInBoxRange(box, minLat, minLon, maxLat, maxLon))
{
// All covered by box
coorList.AddRange(coors);
}
else
{
// Not all covered by box
foreach (Coordinates c in coors)
{
if (CoordinateInBoxRange(c, minLat, minLon, maxLat, maxLon))
{
coorList.Add(c);
}
}
}
}
return(coorList.ToArray());
}
/// <summary>
/// Get all bounding boxes covered by box
/// </summary>
/// <param name="minLat"></param>
/// <param name="minLon"></param>
/// <param name="maxLat"></param>
/// <param name="maxLon"></param>
/// <param name="numberOfChars"></param>
/// <returns></returns>
public static BoundingBox[] BboxBoxes(double minLat, double minLon, double maxLat, double maxLon, int numberOfChars = 9)
{
var boxList = new List <BoundingBox>();
string[] hashList = GeoHash.Bboxes(minLat, minLon, maxLat, maxLon, numberOfChars);
foreach (string hash in hashList)
{
boxList.Add(GeoHash.DecodeBbox(hash));
}
return(boxList.ToArray());
}
public static void BoundingBoxTest()
{
// Bounding box
Coordinates coor1 = new Coordinates {
Lat = 41.85776407, Lon = -87.73420671
};
Coordinates coor2 = new Coordinates {
Lat = 41.89993156, Lon = -87.60380377
};
var watch = System.Diagnostics.Stopwatch.StartNew();
string[] hashlist = GeoHash.Bboxes(coor1.Lat, coor1.Lon, coor2.Lat, coor2.Lon, mLevel);
watch.Stop();
var elapsedMs = watch.ElapsedMilliseconds;
Console.WriteLine("Get bounding box, time elapsed: " + elapsedMs + " ms | " + hashlist.Length + " results get");
KMLGenerator.GenerateKMLBoundingBoxes(hashlist, coor1, coor2, "bounding box");
}
public void BBoxes_ReturnsHashStringsBetweenCoordinates()
{
var bBoxes = GeoHash.Bboxes(30, 120, 30.0001, 120.0001, 8);
Assert.Equal(GeoHash.Encode(30.0001, 120.0001, 8), bBoxes[bBoxes.Length - 1]);
}
