/// <summary>
/// Initializes a new instance of the Shapefile class with the given parameters.
/// </summary>
/// <param name="filename">The filename of the shape file to read (with .shp).</param>
/// <param name="geometryFactory">The GeometryFactory to use when creating Geometry objects.</param>
public ShapefileReader(string filename, GeometryFactory geometryFactory)
{
if (filename == null)
{
throw new ArgumentNullException("filename");
}
if (geometryFactory == null)
{
throw new ArgumentNullException("geometryFactory");
}
_filename = filename;
_geometryFactory = geometryFactory;
// read header information. note, we open the file, read the header information and then
// close the file. This means the file is not opened again until GetEnumerator() is requested.
// For each call to GetEnumerator() a new BinaryReader is created.
FileStream stream = new FileStream(filename, System.IO.FileMode.Open, FileAccess.Read, FileShare.Read);
BigEndianBinaryReader shpBinaryReader = new BigEndianBinaryReader(stream);
_mainHeader = new ShapefileHeader(shpBinaryReader);
shpBinaryReader.Close();
}
/// <summary>
/// Reads a stream and converts the shapefile record to an equilivent geometry object.
/// </summary>
/// <param name="file">The stream to read.</param>
/// <param name="geometryFactory">The geometry factory to use when making the object.</param>
/// <returns>The Geometry object that represents the shape file record.</returns>
public override IGeometry Read(BigEndianBinaryReader file, IGeometryFactory geometryFactory)
{
int shapeTypeNum = file.ReadInt32();
ShapeGeometryTypes shapeType = (ShapeGeometryTypes)Enum.Parse(typeof(ShapeGeometryTypes), shapeTypeNum.ToString());
if (!(shapeType == ShapeGeometryTypes.Polygon || shapeType == ShapeGeometryTypes.PolygonM ||
shapeType == ShapeGeometryTypes.PolygonZ || shapeType == ShapeGeometryTypes.PolygonZM))
{
throw new ShapefileException("Attempting to load a non-polygon as polygon.");
}
// Read and for now ignore bounds.
double[] box = new double[4];
for (int i = 0; i < 4; i++)
{
box[i] = file.ReadDouble();
}
int[] partOffsets;
int numParts = file.ReadInt32();
int numPoints = file.ReadInt32();
partOffsets = new int[numParts];
for (int i = 0; i < numParts; i++)
{
partOffsets[i] = file.ReadInt32();
}
ArrayList shells = new ArrayList();
ArrayList holes = new ArrayList();
int start, finish, length;
for (int part = 0; part < numParts; part++)
{
start = partOffsets[part];
if (part == numParts - 1)
{
finish = numPoints;
}
else
{
finish = partOffsets[part + 1];
}
length = finish - start;
CoordinateList points = new CoordinateList();
points.Capacity = length;
for (int i = 0; i < length; i++)
{
Coordinate external = new Coordinate(file.ReadDouble(), file.ReadDouble());
new PrecisionModel(geometryFactory.PrecisionModel).MakePrecise(external);
Coordinate internalCoord = external;
points.Add(internalCoord);
}
ILinearRing ring = geometryFactory.CreateLinearRing((Coordinate[])points.ToArray(typeof(Coordinate)));
// If shape have only a part, jump orientation check and add to shells
if (numParts == 1)
{
shells.Add(ring);
}
else
{
// Orientation check
if (CGAlgorithms.IsCCW((Coordinate[])points.ToArray(typeof(Coordinate))))
{
holes.Add(ring);
}
else
{
shells.Add(ring);
}
}
}
// Now we have a list of all shells and all holes
ArrayList holesForShells = new ArrayList(shells.Count);
for (int i = 0; i < shells.Count; i++)
{
holesForShells.Add(new ArrayList());
}
// Find holes
for (int i = 0; i < holes.Count; i++)
{
LinearRing testRing = (LinearRing)holes[i];
LinearRing minShell = null;
IEnvelope minEnv = null;
IEnvelope testEnv = testRing.EnvelopeInternal;
ICoordinate testPt = testRing.GetCoordinateN(0);
LinearRing tryRing;
for (int j = 0; j < shells.Count; j++)
{
tryRing = (LinearRing)shells[j];
IEnvelope tryEnv = tryRing.EnvelopeInternal;
if (minShell != null)
{
minEnv = minShell.EnvelopeInternal;
}
bool isContained = false;
CoordinateList coordList = new CoordinateList(tryRing.Coordinates);
if (tryEnv.Contains(testEnv) &&
(CGAlgorithms.IsPointInRing(testPt, (Coordinate[])coordList.ToArray(typeof(Coordinate))) ||
(PointInList(testPt, coordList))))
{
isContained = true;
}
// Check if this new containing ring is smaller than the current minimum ring
if (isContained)
{
if (minShell == null || minEnv.Contains(tryEnv))
{
minShell = tryRing;
}
// Suggested by Brian Macomber and added 3/28/2006:
// holes were being found but never added to the holesForShells array
// so when converted to geometry by the factory, the inner rings were never created.
ArrayList holesForThisShell = (ArrayList)holesForShells[j];
holesForThisShell.Add(holes[i]);
}
}
}
IPolygon[] polygons = new Polygon[shells.Count];
for (int i = 0; i < shells.Count; i++)
{
polygons[i] = geometryFactory.CreatePolygon((LinearRing)shells[i],
(LinearRing[])((ArrayList)holesForShells[i]).ToArray(typeof(LinearRing)));
}
if (polygons.Length == 1)
{
return(polygons[0]);
}
// It's a multi part
return(geometryFactory.CreateMultiPolygon(polygons));
}
/// <summary>
///
/// </summary>
/// <param name="beReader"></param>
private void ReadFeatureHeader(BigEndianBinaryReader beReader)
{
int recordNumber = beReader.ReadInt32BE();
int contentLength = beReader.ReadInt32BE();
int shapeType = beReader.ReadInt32();
}
/// <summary>
/// Reads a generic stream containing geographic data saved as shapefile structure,
/// and returns a collection of all the features contained.
/// Since NTS Geometry Model not support Z and M data, those informations are ignored if presents in shapefile.
/// </summary>
/// <param name="stream">Shapefile data stream.</param>
/// <returns><c>GeometryCollection</c> containing all geometries in shapefile.</returns>
protected virtual IGeometryCollection Read(Stream stream)
{
// Read big endian values
using (BigEndianBinaryReader beReader = new BigEndianBinaryReader(stream))
{
// Verify File Code
int fileCode = beReader.ReadInt32BE();
Debug.Assert(fileCode == 9994);
stream.Seek(20, SeekOrigin.Current);
length = beReader.ReadInt32BE();
// Read little endian values
using (BinaryReader leReader = new BinaryReader(stream))
{
ArrayList list = null;
// Verify Version
int version = leReader.ReadInt32();
Debug.Assert(version == 1000);
// ShapeTypes
int shapeType = leReader.ReadInt32();
switch ((ShapeGeometryTypes)shapeType)
{
case ShapeGeometryTypes.Point:
case ShapeGeometryTypes.PointZ:
case ShapeGeometryTypes.PointM:
case ShapeGeometryTypes.PointZM:
list = new ArrayList(ReadPointData(stream));
break;
case ShapeGeometryTypes.LineString:
case ShapeGeometryTypes.LineStringZ:
case ShapeGeometryTypes.LineStringM:
case ShapeGeometryTypes.LineStringZM:
list = new ArrayList(ReadLineStringData(stream));
break;
case ShapeGeometryTypes.Polygon:
case ShapeGeometryTypes.PolygonZ:
case ShapeGeometryTypes.PolygonM:
case ShapeGeometryTypes.PolygonZM:
list = new ArrayList(ReadPolygonData(stream));
break;
case ShapeGeometryTypes.MultiPoint:
case ShapeGeometryTypes.MultiPointZ:
case ShapeGeometryTypes.MultiPointM:
case ShapeGeometryTypes.MultiPointZM:
list = new ArrayList(ReadMultiPointData(stream));
break;
case ShapeGeometryTypes.MultiPatch:
throw new NotImplementedException("FeatureType " + shapeType + " not supported.");
default:
throw new ArgumentOutOfRangeException("FeatureType " + shapeType + " not recognized by the system");
}
IGeometryCollection collection = shapeReader.CreateGeometryCollection(list);
return(collection);
}
}
}
/// <summary> /// Reads a stream and converts the shapefile record to an equilivent geometry object. /// </summary> /// <param name="file">The stream to read.</param> /// <param name="geometryFactory">The geometry factory to use when making the object.</param> /// <returns>The Geometry object that represents the shape file record.</returns> public abstract IGeometry Read(BigEndianBinaryReader file, IGeometryFactory geometryFactory);
