/// <summary>
/// Read a shapefile Polygon record.
/// </summary>
/// <param name="stream">Input stream.</param>
/// <param name="record">Shapefile record to be updated.</param>
private static void ReadPolygon(Stream stream, ShapeFileRecord record)
{
// Bounding Box.
record.XMin = ShapeFile.ReadDouble64_LE(stream);
record.YMin = ShapeFile.ReadDouble64_LE(stream);
record.XMax = ShapeFile.ReadDouble64_LE(stream);
record.YMax = ShapeFile.ReadDouble64_LE(stream);
// Num Parts and Points.
int numParts = ShapeFile.ReadInt32_LE(stream);
int numPoints = ShapeFile.ReadInt32_LE(stream);
// Parts.
for (int i = 0; i < numParts; i++)
{
record.Parts.Add(ShapeFile.ReadInt32_LE(stream));
}
// Points.
for (int i = 0; i < numPoints; i++)
{
PointF p = new PointF();
p.X = (float)ShapeFile.ReadDouble64_LE(stream);
p.Y = (float)ShapeFile.ReadDouble64_LE(stream);
record.Points.Add(p);
}
}
/// <summary>
/// Read a shapefile Point record.
/// </summary>
/// <param name="stream">Input stream.</param>
/// <param name="record">Shapefile record to be updated.</param>
private static void ReadPoint(Stream stream, ShapeFileRecord record)
{
// Points - add a single point.
PointF p = new PointF();
p.X = (float)ShapeFile.ReadDouble64_LE(stream);
p.Y = (float)ShapeFile.ReadDouble64_LE(stream);
record.Points.Add(p);
// Bounding Box.
record.XMin = p.X;
record.YMin = p.Y;
record.XMax = record.XMin;
record.YMax = record.YMin;
}
/// <summary>
/// Read the file header of the shapefile.
/// </summary>
/// <param name="stream">Input stream.</param>
public void ReadShapeFileHeader(Stream stream)
{
// File Code.
this.fileHeader.FileCode = ShapeFile.ReadInt32_BE(stream);
if (this.fileHeader.FileCode != ShapeFile.expectedFileCode)
{
string msg = String.Format(System.Globalization.CultureInfo.InvariantCulture, "Invalid FileCode encountered. Expecting {0}.", ShapeFile.expectedFileCode);
throw new ApplicationException(msg);
}
// 5 unused values.
ShapeFile.ReadInt32_BE(stream);
ShapeFile.ReadInt32_BE(stream);
ShapeFile.ReadInt32_BE(stream);
ShapeFile.ReadInt32_BE(stream);
ShapeFile.ReadInt32_BE(stream);
// File Length.
this.fileHeader.FileLength = ShapeFile.ReadInt32_BE(stream);
// Version.
this.fileHeader.Version = ShapeFile.ReadInt32_LE(stream);
// Shape Type.
this.fileHeader.ShapeType = ShapeFile.ReadInt32_LE(stream);
// Bounding Box.
this.fileHeader.XMin = ShapeFile.ReadDouble64_LE(stream);
this.fileHeader.YMin = ShapeFile.ReadDouble64_LE(stream);
this.fileHeader.XMax = ShapeFile.ReadDouble64_LE(stream);
this.fileHeader.YMax = ShapeFile.ReadDouble64_LE(stream);
// Adjust the bounding box in case it is too small.
if (Math.Abs(this.fileHeader.XMax - this.fileHeader.XMin) < 1)
{
this.fileHeader.XMin -= 5;
this.fileHeader.XMax += 5;
}
if (Math.Abs(this.fileHeader.YMax - this.fileHeader.YMin) < 1)
{
this.fileHeader.YMin -= 5;
this.fileHeader.YMax += 5;
}
// Skip the rest of the file header.
stream.Seek(100, SeekOrigin.Begin);
}