/// <summary>
/// Gets the elevation.
/// </summary>
/// <returns>
/// The height. Null, if elevation is not available.
/// </returns>
/// <param name='coordinates'>
/// Coordinates.
/// </param>
/// <exception cref='Exception'>
/// Represents errors that occur during application execution.
/// </exception>
public int?GetElevation(IGeographicalCoordinates coordinates)
{
int localLat = (int)((coordinates.Latitude - Latitude) * PointsPerCell);
int localLon = (int)(((coordinates.Longitude - Longitude)) * PointsPerCell);
int bytesPos = ((PointsPerCell - localLat - 1) * PointsPerCell * 2) + localLon * 2;
if (bytesPos < 0 || bytesPos > PointsPerCell * PointsPerCell * 2)
{
throw new ArgumentOutOfRangeException("Coordinates out of range.", "coordinates");
}
if ((HgtData [bytesPos] == 0x80) && (HgtData [bytesPos + 1] == 0x00))
{
return(null);
}
// Motorola "big-endian" order with the most significant byte first
return((HgtData [bytesPos]) << 8 | HgtData [bytesPos + 1]);
}
/// <summary>
/// Gets the elevation.
/// </summary>
/// <returns>
/// The height. Null, if elevation is not available.
/// </returns>
/// <param name='coordinates'>
/// Coordinates.
/// </param>
/// <exception cref='Exception'>
/// Represents errors that occur during application execution.
/// </exception>
public int?GetElevation(IGeographicalCoordinates coordinates)
{
int cellLatitude = (int)Math.Floor(Math.Abs(coordinates.Latitude));
if (coordinates.Latitude < 0)
{
cellLatitude *= -1;
cellLatitude -= 1; // because negative so in bottom tile
}
int cellLongitude = (int)Math.Floor(Math.Abs(coordinates.Longitude));
if (coordinates.Longitude < 0)
{
cellLongitude *= -1;
cellLongitude -= 1; // because negative so in left tile
}
SrtmDataCell dataCell = DataCells.Where(dc => dc.Latitude == cellLatitude && dc.Longitude == cellLongitude).FirstOrDefault();
if (dataCell != null)
{
return(dataCell.GetElevation(coordinates));
}
string filename = string.Format("{0}{1:D2}{2}{3:D3}.hgt",
cellLatitude < 0 ? "S" : "N",
Math.Abs(cellLatitude),
cellLongitude < 0 ? "W" : "E",
Math.Abs(cellLongitude));
string filePath = Path.Combine(DataDirectory, filename);
if (!File.Exists(filePath))
{
throw new Exception("SRTM data cell not found: " + filePath);
}
dataCell = new SrtmDataCell(filePath);
DataCells.Add(dataCell);
return(dataCell.GetElevation(coordinates));
}
/// <summary>
/// Gets the height.
/// </summary>
/// <returns>
/// The height.
/// </returns>
/// <param name='coordinates'>
/// Coordinates.
/// </param>
/// <exception cref='ArgumentOutOfRangeException'>
/// Is thrown when an argument passed to a method is invalid because it is outside the allowable range of values as
/// specified by the method.
/// </exception>
public int GetHeight (IGeographicalCoordinates coordinates)
{
int localLat = (int)((coordinates.Latitude - Latitude) * PointsPerCell);
int localLon = (int)(((coordinates.Longitude - Longitude)) * PointsPerCell);
int bytesPos = ((PointsPerCell - localLat - 1) * PointsPerCell * 2) + localLon * 2;
Console.WriteLine (bytesPos);
if (bytesPos < 0 || bytesPos > PointsPerCell * PointsPerCell * 2)
throw new ArgumentOutOfRangeException ("Coordinates out of range.", "coordinates");
// Motorola "big-endian" order with the most significant byte first
return (HgtData [bytesPos]) << 8 | HgtData [bytesPos + 1];
}
/// <summary>
/// Gets the height.
/// </summary>
/// <returns>
/// The height.
/// </returns>
/// <param name='coordinates'>
/// Coordinates.
/// </param>
/// <exception cref='Exception'>
/// Represents errors that occur during application execution.
/// </exception>
public int GetHeight (IGeographicalCoordinates coordinates)
{
int cellLatitude = (int)Math.Floor (Math.Abs (coordinates.Latitude));
if (coordinates.Latitude < 0)
cellLatitude *= -1;
int cellLongitude = (int)Math.Floor (Math.Abs (coordinates.Longitude));
if (coordinates.Longitude < 0)
cellLongitude *= -1;
SrtmDataCell dataCell = DataCells.Where (dc => dc.Latitude == cellLatitude && dc.Longitude == cellLongitude).FirstOrDefault ();
if (dataCell != null)
return dataCell.GetHeight (coordinates);
string filename = string.Format ("{0}{1:D2}{2}{3:D3}.hgt",
cellLatitude < 0 ? "S" : "N",
Math.Abs (cellLatitude),
cellLongitude < 0 ? "W" : "E",
Math.Abs (cellLongitude));
string filePath = Path.Combine (DataDirectory, filename);
if (!File.Exists (filePath))
throw new Exception ("SRTM data cell not found: "+filePath);
dataCell = new SrtmDataCell (filePath);
DataCells.Add (dataCell);
return dataCell.GetHeight (coordinates);
}
