/// <summary>
/// returns only the features that have envelopes that
/// intersect with the specified envelope. If in indexMode, this uses the ShapeIndices to create
/// features on demand, rather than loading all the features. It is much faster to use selectIndices
/// when in index mode.
/// </summary>
/// <param name="region">The specified region to test for intersect with</param>
/// <param name="affectedRegion">This returns the geographic extents that contains the modified contents.</param>
/// <returns>A List of the IFeature elements that are contained in this region</returns>
public virtual List<IFeature> Select(IEnvelope region, out IEnvelope affectedRegion)
{
List<IFeature> result = new List<IFeature>();
if(IndexMode)
{
ShapeRange aoi = new ShapeRange(new Extent(region));
IEnvelope env = region.Copy();
Extent affected = new Extent();
List<ShapeRange> shapes = ShapeIndices;
if(shapes != null)
{
for(int shp = 0; shp < shapes.Count; shp++)
{
if (!shapes[shp].Intersects(aoi)) continue;
IFeature f = GetFeature(shp);
affected.ExpandToInclude(shapes[shp].Extent);
result.Add(f);
}
}
affectedRegion = affected.ToEnvelope();
return result;
}
affectedRegion = new Envelope();
foreach (IFeature feature in Features)
{
if (!feature.Envelope.Intersects(region)) continue;
result.Add(feature);
affectedRegion.ExpandToInclude(feature.Envelope);
}
return result;
}
///// <summary>
///// Obsolete and slow. First get the X and Y array once, and then access the members directly from that array.
///// </summary>
//public double[][] Vertices
//{
// get
// {
// int len = _vertices.Length/2;
// double[][] result = new double[len][];
// for (int i = 0; i < len; i++)
// {
// result[i] = new[] { _vertices[i*2], _vertices[i*2+1] };
// }
// return result;
// }
// protected set
// {
// for(int i = 0; i < value.Length; i++)
// {
// _vertices[i*2] = value[i][0];
// _vertices[i*2 + 1] = value[i][1];
// }
// }
//}
/// <summary>
/// After changing coordinates, this will force the re-calculation of envelopes on a feature
/// level as well as on the featureset level. If this featureset is in index mode,
/// this will update the shape extents instead.
/// </summary>
public void UpdateEnvelopes()
{
if (InternalDataSet != null)
{
InternalDataSet.UpdateEnvelopes();
return;
}
_envelope = new Envelope();
_extent = new Extent();
if(!_indexMode)
{
if (Features == null || Features.Count <= 0)
{
_extent = new Extent(-180, -90, 180, 90);
_envelope = _extent.ToEnvelope();
return;
}
for (int shp = 0; shp < Features.Count; shp++)
{
Features[shp].UpdateEnvelope();
_envelope.ExpandToInclude(Features[shp].Envelope);
}
_extent = new Extent(_envelope);
}
else
{
if(_shapeIndices == null || _shapeIndices.Count == 0)
{
_extent = new Extent(-180, -90, 180, 90);
_envelope = _extent.ToEnvelope();
return;
}
foreach (ShapeRange range in _shapeIndices)
{
_extent.ExpandToInclude(range.Extent);
}
_envelope = _extent.ToEnvelope();
}
}
/// <summary>
/// Obtains a typed list of ShapefilePoint structures with double values associated with the various coordinates.
/// </summary>
/// <param name="filename">A string filename</param>
/// <param name="progressHandler">A progress indicator</param>
private void FillPoints(string filename, IProgressHandler progressHandler)
{
// Check to ensure the filename is not null
if (filename == null)
{
throw new NullReferenceException(MessageStrings.ArgumentNull_S.Replace("%S",filename));
}
if (File.Exists(filename) == false)
{
throw new FileNotFoundException(MessageStrings.FileNotFound_S.Replace("%S", filename));
}
// Reading the headers gives us an easier way to track the number of shapes and their overall length etc.
List<ShapeHeader> shapeHeaders = ReadIndexFile(filename);
// Get the basic header information.
ShapefileHeader header = new ShapefileHeader(filename);
Extent = new Extent(new[] { header.Xmin, header.Ymin, header.Xmax, header.Ymax });
Envelope = Extent.ToEnvelope();
// Check to ensure that the filename is the correct shape type
if (header.ShapeType != ShapeTypes.Point && header.ShapeType != ShapeTypes.PointM && header.ShapeType != ShapeTypes.PointZ)
{
throw new ApplicationException(MessageStrings.FileNotPoints_S.Replace("%S", filename));
}
// This will set up a reader so that we can read values in huge chunks, which is much faster than one value at a time.
IO.BufferedBinaryReader bbReader = new IO.BufferedBinaryReader(filename, progressHandler);
if (bbReader.FileLength == 100)
{
bbReader.Close();
// the file is empty so we are done reading
return;
}
// Skip the shapefile header by skipping the first 100 bytes in the shapefile
bbReader.Seek(100, SeekOrigin.Begin);
int numShapes = shapeHeaders.Count;
byte[] bigEndian = new byte[numShapes * 8];
byte[] allCoords = new byte[numShapes * 16];
bool isM = false;
bool isZ = false;
if(header.ShapeType == ShapeTypes.PointM || header.ShapeType == ShapeTypes.PointZ)
{
isM = true;
}
if (header.ShapeType == ShapeTypes.PointZ)
{
isZ = true;
}
byte[] allM = new byte[8];
if(isM) allM = new byte[numShapes * 8];
byte[] allZ = new byte[8];
if(isZ) allZ = new byte[numShapes * 8];
for (int shp = 0; shp < numShapes; shp++)
{
// Read from the index file because some deleted records
// might still exist in the .shp file.
long offset = (shapeHeaders[shp].ByteOffset);
bbReader.Seek(offset, SeekOrigin.Begin);
bbReader.Read(bigEndian, shp * 8, 8);
ShapeTypes type = (ShapeTypes)bbReader.ReadInt32();
//bbReader.Seek(4, SeekOrigin.Current);
bbReader.Read(allCoords, shp * 16, 16);
if(isZ)
{
bbReader.Read(allZ, shp*8, 8);
}
if (isM)
{
bbReader.Read(allM, shp*8, 8);
}
ShapeRange shape = new ShapeRange(FeatureTypes.Point);
shape.StartIndex = shp;
shape.ContentLength = 8;
shape.NumPoints = 1;
shape.NumParts = 1;
ShapeIndices.Add(shape);
}
double[] vert = new double[2 * numShapes];
Buffer.BlockCopy(allCoords, 0, vert, 0, numShapes*16);
Vertex = vert;
if(isM)
{
double[] m = new double[numShapes];
Buffer.BlockCopy(allM, 0, m, 0, numShapes * 8);
M = m;
}
if(isZ)
{
double[] z = new double[numShapes];
Buffer.BlockCopy(allZ, 0, z, 0, numShapes * 8);
Z = z;
}
for (int shp = 0; shp < numShapes; shp++)
{
PartRange part = new PartRange(vert, shp, 0, FeatureTypes.Point);
part.NumVertices = 1;
ShapeRange shape = ShapeIndices[shp];
shape.Parts.Add(part);
shape.Extent = new Extent(new[] {vert[shp*2], vert[shp*2 + 1], vert[shp*2], vert[shp*2 + 1]});
}
bbReader.Dispose();
}
