/// <summary>
/// A Shapefile MultiPoint Shape
/// </summary>
/// <param name="recordNumber">The record number in the Shapefile</param>
/// <param name="metadata">Metadata about the shape</param>
/// <param name="reader">Reader associated with the metadata</param>
/// <param name="shapeData">The shape record as a byte array</param>
/// <exception cref="ArgumentNullException">Thrown if shapeData is null</exception>
/// <exception cref="InvalidOperationException">Thrown if an error occurs parsing shapeData</exception>
protected internal ShapeMultiPoint(int recordNumber, StringDictionary metadata, Reader reader, byte[] shapeData)
: base(ShapeType.MultiPoint, recordNumber, metadata, reader)
{
// metadata is validated by the base class
if (shapeData == null)
{
throw new ArgumentNullException("shapeData");
}
// Note, shapeData includes an 8 byte header so positions below are +8
// Position Field Value Type Number Order
// Byte 0 Shape Type 8 Integer 1 Little
// Byte 4 Box Box Double 4 Little
// Byte 36 NumPoints Num Points Integer 1 Little
// Byte 40 Points Points Point NumPoints Little
// validation step 1 - must have at least 8 + 4 + (4*8) + 4 bytes = 48
if (shapeData.Length < 48)
{
throw new InvalidOperationException("Invalid shape data");
}
// extract bounding box and points
_boundingBox = ParseBoundingBox(shapeData, 12, ProvidedOrder.Little);
int numPoints = EndianBitConverter.ToInt32(shapeData, 44, ProvidedOrder.Little);
// validation step 2 - we're expecting 16 * numPoints + 48 bytes total
if (shapeData.Length != 48 + (16 * numPoints))
{
throw new InvalidOperationException("Invalid shape data");
}
// now extract the points
_points = new PointD[numPoints];
for (int pointNum = 0; pointNum < numPoints; pointNum++)
{
_points[pointNum] = new PointD(EndianBitConverter.ToDouble(shapeData, 48 + (16 * pointNum), ProvidedOrder.Little),
EndianBitConverter.ToDouble(shapeData, 56 + (16 * pointNum), ProvidedOrder.Little));
}
}
/// <summary>
/// The PolyLine and Polygon shapes share the same structure, this method parses the bounding box
/// and list of parts for both
/// </summary>
/// <param name="shapeData">The shape record as a byte array</param>
/// <param name="boundingBox">Returns the bounding box</param>
/// <param name="parts">Returns the list of parts</param>
protected void ParsePolyLineOrPolygon(byte[] shapeData, out RectangleD boundingBox, out List <PointD[]> parts)
{
boundingBox = new RectangleD();
parts = null;
// metadata is validated by the base class
if (shapeData == null)
{
throw new ArgumentNullException("shapeData");
}
// Note, shapeData includes an 8 byte header so positions below are +8
// Position Field Value Type Number Order
// Byte 0 Shape Type 3 or 5 Integer 1 Little
// Byte 4 Box Box Double 4 Little
// Byte 36 NumParts NumParts Integer 1 Little
// Byte 40 NumPoints NumPoints Integer 1 Little
// Byte 44 Parts Parts Integer NumParts Little
// Byte X Points Points Point NumPoints Little
//
// Note: X = 44 + 4 * NumParts
// validation step 1 - must have at least 8 + 4 + (4*8) + 4 + 4 bytes = 52
if (shapeData.Length < 44)
{
throw new InvalidOperationException("Invalid shape data");
}
// extract bounding box, number of parts and number of points
boundingBox = ParseBoundingBox(shapeData, 12, ProvidedOrder.Little);
int numParts = EndianBitConverter.ToInt32(shapeData, 44, ProvidedOrder.Little);
int numPoints = EndianBitConverter.ToInt32(shapeData, 48, ProvidedOrder.Little);
// validation step 2 - we're expecting 4 * numParts + 16 * numPoints + 52 bytes total
if (shapeData.Length != 52 + (4 * numParts) + (16 * numPoints))
{
throw new InvalidOperationException("Invalid shape data");
}
// now extract the parts
int partsOffset = 52 + (4 * numParts);
parts = new List <PointD[]>(numParts);
for (int part = 0; part < numParts; part++)
{
// this is the index of the start of the part in the points array
int startPart = (EndianBitConverter.ToInt32(shapeData, 52 + (4 * part), ProvidedOrder.Little) * 16) + partsOffset;
int numBytes;
if (part == numParts - 1)
{
// it's the last part so we go to the end of the point array
numBytes = shapeData.Length - startPart;
}
else
{
// we need to get the next part
int nextPart = (EndianBitConverter.ToInt32(shapeData, 52 + (4 * (part + 1)), ProvidedOrder.Little) * 16) + partsOffset;
numBytes = nextPart - startPart;
}
// the number of 16-byte points to read for this segment
int numPointsInPart = numBytes / 16;
PointD[] points = new PointD[numPointsInPart];
for (int point = 0; point < numPointsInPart; point++)
{
points[point] = new PointD(EndianBitConverter.ToDouble(shapeData, startPart + (16 * point), ProvidedOrder.Little),
EndianBitConverter.ToDouble(shapeData, startPart + 8 + (16 * point), ProvidedOrder.Little));
}
parts.Add(points);
}
}
/// <summary>
/// Create a new Shapefile object and open a Shapefile. Note that three files are required -
/// the main file (.shp), the index file (.shx) and the dBASE table (.dbf). The three files
/// must all have the same filename (i.e. shapes.shp, shapes.shx and shapes.dbf). Set path
/// to any one of these three files to open the Shapefile.
/// </summary>
/// <param name="path">Path to the .shp, .shx or .dbf file for this Shapefile</param>
/// <exception cref="ObjectDisposedException">Thrown if the Shapefile has been disposed</exception>
/// <exception cref="ArgumentNullException">Thrown if the path parameter is null</exception>
/// <exception cref="ArgumentException">Thrown if the path parameter is empty</exception>
/// <exception cref="FileNotFoundException">Thrown if one of the three required files is not found</exception>
/// <exception cref="InvalidOperationException">Thrown if an error occurs parsing file headers</exception>
public void Open(string path)
{
if (_disposed)
{
throw new ObjectDisposedException("Shapefile");
}
if (path == null)
{
throw new ArgumentNullException("path");
}
if (path.Length <= 0)
{
throw new ArgumentException("path parameter is empty", "path");
}
_shapefileMainPath = Path.ChangeExtension(path, MainPathExtension);
_shapefileIndexPath = Path.ChangeExtension(path, IndexPathExtension);
_shapefileDbasePath = Path.ChangeExtension(path, DbasePathExtension);
if (!File.Exists(_shapefileMainPath))
{
throw new FileNotFoundException("Shapefile main file not found", _shapefileMainPath);
}
if (!File.Exists(_shapefileIndexPath))
{
throw new FileNotFoundException("Shapefile index file not found", _shapefileIndexPath);
}
if (!File.Exists(_shapefileDbasePath))
{
throw new FileNotFoundException("Shapefile dBase file not found", _shapefileDbasePath);
}
_mainStream = File.Open(_shapefileMainPath, FileMode.Open, FileAccess.Read, FileShare.Read);
_indexStream = File.Open(_shapefileIndexPath, FileMode.Open, FileAccess.Read, FileShare.Read);
if (_mainStream.Length < Header.HeaderLength)
{
throw new InvalidOperationException("Shapefile main file does not contain a valid header");
}
if (_indexStream.Length < Header.HeaderLength)
{
throw new InvalidOperationException("Shapefile index file does not contain a valid header");
}
// read in and parse the headers
byte[] headerBytes = new byte[Header.HeaderLength];
_mainStream.Read(headerBytes, 0, Header.HeaderLength);
_mainHeader = new Header(headerBytes);
_indexStream.Read(headerBytes, 0, Header.HeaderLength);
_indexHeader = new Header(headerBytes);
// set properties from the main header
_type = _mainHeader.ShapeType;
_boundingBox = new RectangleD(_mainHeader.XMin, _mainHeader.YMin, _mainHeader.XMax, _mainHeader.YMax);
// index header length is in 16-bit words, including the header - number of
// shapes is the number of records (each 4 workds long) after subtracting the header bytes
_count = (_indexHeader.FileLength - (Header.HeaderLength / 2)) / 4;
// open the metadata database
OpenDb(_encoding);
_opened = true;
}