/// <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>
/// A Shapefile Point 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 ShapePoint(int recordNumber, StringDictionary metadata, Reader reader, byte[] shapeData)
: base(ShapeType.Point, 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 1 Integer 1 Little
// Byte 4 X X Double 1 Little
// Byte 12 Y Y Double 1 Little
// validation - shapedata should be 8 + 4 + 8 + 8 = 28 bytes long
if (shapeData.Length != 28)
{
throw new InvalidOperationException("Invalid shape data");
}
_point = new PointD(EndianBitConverter.ToDouble(shapeData, 12, ProvidedOrder.Little),
EndianBitConverter.ToDouble(shapeData, 20, 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>
/// Creates a Shape object (or derived object) from a shape record
/// </summary>
/// <param name="shapeData">The shape record as a byte array</param>
/// <param name="metadata">Metadata associated with this shape (optional)</param>
/// <param name="reader">Reader associated with the metadata</param>
/// <returns>A Shape, or derived class</returns>
/// <exception cref="ArgumentNullException">Thrown if shapeData or metadata are null</exception>
/// <exception cref="ArgumentException">Thrown if shapeData is less than 12 bytes long</exception>
/// <exception cref="InvalidOperationException">Thrown if an error occurs parsing shapeData</exception>
public static Shape ParseShape(byte[] shapeData, StringDictionary metadata, Reader reader)// IDataRecord dataRecord)
{
if (shapeData == null)
{
throw new ArgumentNullException("shapeData");
}
if (shapeData.Length < 12)
{
throw new ArgumentException("shapeData must be at least 12 bytes long");
}
// shape data contains a header (shape number and content length)
// the first field in each shape is the shape type
//Position Field Value Type Order
//Byte 0 Record Number Record Number Integer Big
//Byte 4 Content Length Content Length Integer Big
//Position Field Value Type Number Order
//Byte 0 Shape Type Shape Type Integer 1 Little
int recordNumber = EndianBitConverter.ToInt32(shapeData, 0, ProvidedOrder.Big);
int contentLengthInWords = EndianBitConverter.ToInt32(shapeData, 4, ProvidedOrder.Big);
ShapeType shapeType = (ShapeType)EndianBitConverter.ToInt32(shapeData, 8, ProvidedOrder.Little);
// test that we have the expected amount of data - need to take the 8 byte header into account
if (shapeData.Length != (contentLengthInWords * 2) + 8)
{
throw new InvalidOperationException("Shape data length does not match shape header length");
}
Shape shape = null;
switch (shapeType)
{
case ShapeType.Null:
shape = new Shape(shapeType, recordNumber, metadata, reader);
break;
case ShapeType.Point:
shape = new ShapePoint(recordNumber, metadata, reader, shapeData);
break;
case ShapeType.MultiPoint:
shape = new ShapeMultiPoint(recordNumber, metadata, reader, shapeData);
break;
case ShapeType.PolyLine:
shape = new ShapePolyLine(recordNumber, metadata, reader, shapeData);
break;
case ShapeType.PolyLineM:
shape = new ShapePolyLineM(recordNumber, metadata, reader, shapeData);
break;
case ShapeType.Polygon:
shape = new ShapePolygon(recordNumber, metadata, reader, shapeData);
break;
default:
throw new NotImplementedException(string.Format("Shapetype {0} is not implemented", shapeType));
}
return(shape);
}