public Layer readImpl(string filename)
{
// split filename in path and filename
string[] split = filename.Split('\\');
string name = split.Last();
// remove extension
name = name.Substring(0, name.Length - 4);
string path = filename.Substring(0, filename.Length - name.Length - 4);
layer = new Layer(name);
// read .prj-file with same name or with name 'default.prj'
string prjName = filename.Substring(0, filename.Length - 3) + "prj";
if (File.Exists(prjName))
layer.Projection = PrjReader.read(prjName);
else if (File.Exists(path + "default.prj"))
layer.Projection = PrjReader.read(path + "default.prj");
else
{
// warning message if missing prj file
string msg = "No projection da found. Assuming " + SGIS.App.getSrsName();
MessageBox.Show(msg, "Missing spatial reference system: " + name, MessageBoxButtons.OK, MessageBoxIcon.Warning);
}
// try reading attribute file with same name
string dbfName = filename.Substring(0, filename.Length - 3) + "dbf";
if (File.Exists(dbfName))
layer.DataTable = DbfReader.read(dbfName);
// create stream from file
FileStream f = File.Open(filename, FileMode.Open);
br = new BinaryReaderExtension(f);
pos = 0;
length = (int)br.BaseStream.Length;
readHeader();
// set bounding box from values in header
layer.Boundingbox = new Envelope(minx, maxx, miny, maxy);
layer.createQuadTree();
// content starts at pos 100
pos = 100;
// read all shapes until end
while (pos < length)
readShape();
br.Close();
// features now converted to application srs
layer.Projection = SGIS.App.SRS;
return layer;
}