/// <summary>
/// Reads a geometry from an BinaryReader containing of Well Known Binary.
/// </summary>
/// <param name="data">A BinaryReader containing Well Known Binary</param>
/// <returns>A geometry object.</returns>
public async Task <Geometry> Read(BinaryReader reader)
{
// Get the first Byte in the array. This specifies if the WKB is in
// XDR (big-endian) format of NDR (little-endian) format.
ByteOrder wkbByteOrder = (ByteOrder)reader.ReadByte();
// Get the type of this geometry.
WKBShapeType type = (WKBShapeType)NumberReader.ReadUInt32(reader, wkbByteOrder);
bool includeAltitude = false, includeM = false;
//check to see if the coordinates should include the Z coordinate
if (((type > ((WKBShapeType)0x3e8)) && (type < ((WKBShapeType)0x7d0))) || (type > ((WKBShapeType)0xbb8)))
{
includeAltitude = true;
}
//check to see if the coordinates should include a Measure
if (type > ((WKBShapeType)0x7d0))
{
includeM = true;
}
return(await ReadGeometry(reader, wkbByteOrder, type, includeAltitude, includeM));
}
private async Task <GeometryCollection> ReadGeometryCollection(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
// The next byte in the array tells the number of geometries in this collection.
int numGeometries = (int)NumberReader.ReadUInt32(reader, wkbByteOrder);
// Create a new array for the geometries.
var geographies = new GeometryCollection(numGeometries);
Geometry g;
// Loop on the number of geometries.
for (int i = 0; i < numGeometries; i++)
{
g = await ReadGeometry(reader, wkbByteOrder, type, includeAltitude, includeM);
// Call the main create function with the next geometry.
geographies.Geometries.Add(g);
}
// Create and return the next geometry.
return(geographies);
}
private async Task <MultiPolygon> ReadMultiPolygon(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
// Get the number of Polygons.
int numPolygons = (int)NumberReader.ReadUInt32(reader, wkbByteOrder);
// Create a new array for the Polygons.
MultiPolygon polygons = new MultiPolygon(numPolygons);
Polygon p;
// Loop on the number of polygons.
for (int i = 0; i < numPolygons; i++)
{
// read polygon header
reader.ReadByte();
NumberReader.ReadUInt32(reader, wkbByteOrder);
p = await ReadPolygon(reader, wkbByteOrder, type, includeAltitude, includeM);
// Create the next polygon and add it to the array.
polygons.Geometries.Add(p);
}
//Create and return the MultiPolygon.
return(polygons);
}
private async Task <MultiLineString> ReadMultiLineString(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
// Get the number of linestrings in this multLineString.
int numLineStrings = (int)NumberReader.ReadUInt32(reader, wkbByteOrder);
// Create a new array for the linestrings .
MultiLineString mline = new MultiLineString(numLineStrings);
LineString line;
// Loop on the number of linestrings.
for (int i = 0; i < numLineStrings; i++)
{
// Read linestring header
reader.ReadByte();
NumberReader.ReadUInt32(reader, wkbByteOrder);
line = await ReadLineString(reader, wkbByteOrder, type, includeAltitude, includeM);
// Create the next linestring and add it to the array.
mline.Geometries.Add(line);
}
// Create and return the MultiLineString.
return(mline);
}
private MultiPoint ReadMultiPoint(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
// Get the number of points in this multPoint.
int numPoints = (int)NumberReader.ReadUInt32(reader, wkbByteOrder);
// Create a new array for the points.
MultiPoint points = new MultiPoint();
// Loop on the number of points.
for (int i = 0; i < numPoints; i++)
{
// Read point header
reader.ReadByte();
NumberReader.ReadUInt32(reader, wkbByteOrder);
// Create the next point and add it to the point array.
points.Geometries.Add(ReadPoint(reader, wkbByteOrder, type, includeAltitude, includeM));
}
return(points);
}
private async Task <Polygon> ReadPolygon(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
// Get the Number of rings in this Polygon.
int numRings = (int)NumberReader.ReadUInt32(reader, wkbByteOrder);
var c = await ReadLinearRing(reader, wkbByteOrder, type, includeAltitude, includeM);
Polygon shell = new Polygon(c);
// Create a new array of linearrings for the interior rings.
for (int i = 0; i < (numRings - 1); i++)
{
c = await ReadLinearRing(reader, wkbByteOrder, type, includeAltitude, includeM);
shell.InteriorRings.Add(c);
}
// Create and return the Poylgon.
return(shell);
}
private async Task <LineString> ReadLineString(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
var c = await ReadCoordinates(reader, wkbByteOrder, type, includeAltitude, includeM);
return(new LineString(c));
}
private Point ReadPoint(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
return(new Point(ReadCoordinate(reader, wkbByteOrder, type, includeAltitude, includeM)));
}
private async Task <Geometry> ReadGeometry(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
switch (type)
{
case WKBShapeType.WkbPoint:
case WKBShapeType.WkbPointZ:
case WKBShapeType.WkbPointM:
case WKBShapeType.WkbPointZM:
return(ReadPoint(reader, wkbByteOrder, type, includeAltitude, includeM));
case WKBShapeType.WkbLineString:
case WKBShapeType.WkbLineStringZ:
case WKBShapeType.WkbLineStringM:
case WKBShapeType.WkbLineStringZM:
return(await ReadLineString(reader, wkbByteOrder, type, includeAltitude, includeM));
case WKBShapeType.WkbPolygon:
case WKBShapeType.WkbPolygonZ:
case WKBShapeType.WkbPolygonM:
case WKBShapeType.WkbPolygonZM:
return(await ReadPolygon(reader, wkbByteOrder, type, includeAltitude, includeM));
case WKBShapeType.WkbMultiPoint:
case WKBShapeType.WkbMultiPointZ:
case WKBShapeType.WkbMultiPointM:
case WKBShapeType.WkbMultiPointZM:
return(ReadMultiPoint(reader, wkbByteOrder, type, includeAltitude, includeM));
case WKBShapeType.WkbMultiLineString:
case WKBShapeType.WkbMultiLineStringZ:
case WKBShapeType.WkbMultiLineStringM:
case WKBShapeType.WkbMultiLineStringZM:
return(await ReadMultiLineString(reader, wkbByteOrder, type, includeAltitude, includeM));
case WKBShapeType.WkbMultiPolygon:
case WKBShapeType.WkbMultiPolygonZ:
case WKBShapeType.WkbMultiPolygonM:
case WKBShapeType.WkbMultiPolygonZM:
return(await ReadMultiPolygon(reader, wkbByteOrder, type, includeAltitude, includeM));
case WKBShapeType.WkbGeometryCollection:
case WKBShapeType.WkbGeometryCollectionZ:
case WKBShapeType.WkbGeometryCollectionM:
case WKBShapeType.WkbGeometryCollectionZM:
return(await ReadGeometryCollection(reader, wkbByteOrder, type, includeAltitude, includeM));
default:
if (!Enum.IsDefined(typeof(WKBShapeType), type))
{
throw new ArgumentException("Geometry type not recognized");
}
else
{
throw new NotSupportedException("Geometry type '" + type + "' not supported");
}
}
}
private async Task <CoordinateCollection> ReadLinearRing(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
var ring = await ReadCoordinates(reader, wkbByteOrder, type, includeAltitude, includeM);
int count = ring.Count;
//Check to see if ring is closed. If not add the first point to the end.
if (count > 0 && ring[0] != ring[count - 1])
{
ring.Add(ring[0]);
}
return(ring);
}
private async Task <CoordinateCollection> ReadCoordinates(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
// Get the number of points in this linestring.
int numPoints = (int)NumberReader.ReadUInt32(reader, wkbByteOrder);
// Create a new array of coordinates.
var coords = new CoordinateCollection();
// Loop on the number of points in the ring.
for (int i = 0; i < numPoints; i++)
{
coords.Add(ReadCoordinate(reader, wkbByteOrder, type, includeAltitude, includeM));
}
if (optimize)
{
coords = await SpatialTools.VertexReductionAsync(coords, tolerance);
}
return(coords);
}
private Coordinate ReadCoordinate(BinaryReader reader, ByteOrder wkbByteOrder, WKBShapeType type, bool includeAltitude, bool includeM)
{
double lon = NumberReader.ReadDouble(reader, wkbByteOrder);
double lat = NumberReader.ReadDouble(reader, wkbByteOrder);
Coordinate coordinate;
if (!includeAltitude)
{
coordinate = new Coordinate(lat, lon);
}
else
{
double z = NumberReader.ReadDouble(reader, wkbByteOrder);
coordinate = new Coordinate(lat, lon, z);
}
if (includeM)
{
//Read past the measure value if included
NumberReader.ReadDouble(reader, wkbByteOrder);
}
return(coordinate);
}
