private MemoryRasterHeader GetHeader(ISpatialReference spatialRef, CoordEnvelope coordEnvelope)
{
MemoryRasterHeader header = new MemoryRasterHeader();
header.Identify = MemoryRasterDriver.FileIdentify;
//
if (spatialRef != null)
{
Datum datum = spatialRef.GeographicsCoordSystem.Datum ?? new Datum();
if (spatialRef.ProjectionCoordSystem != null)
{
header.PrjId = int.Parse(spatialRef.ProjectionCoordSystem.Name.ENVIName);
header.A = (float)datum.Spheroid.SemimajorAxis;
header.B = (float)datum.Spheroid.SemiminorAxis;
header.K0 = (float)datum.Spheroid.InverseFlattening;
IProjectionCoordSystem prjCoordSystem = spatialRef.ProjectionCoordSystem;
header.SP1 = GetPrjParaValue(prjCoordSystem, "sp1");
header.SP2 = GetPrjParaValue(prjCoordSystem, "sp2");
header.Lat0 = GetPrjParaValue(prjCoordSystem, "lat0");
header.Lon0 = GetPrjParaValue(prjCoordSystem, "lon0");
header.X0 = GetPrjParaValue(prjCoordSystem, "x0");
header.Y0 = GetPrjParaValue(prjCoordSystem, "y0");
}
}
//
if (coordEnvelope != null)
{
header.MinX = (float)coordEnvelope.MinX;
header.MaxX = (float)coordEnvelope.MaxX;
header.MinY = (float)coordEnvelope.MinY;
header.MaxY = (float)coordEnvelope.MaxY;
}
return(header);
}
private ISpatialReference GetSpatialRef(MemoryRasterHeader header)
{
using (SpatialReferenceBuilder b = new SpatialReferenceBuilder())
{
return(b.GetSpatialRef(header.PrjId, header.SP1,
header.SP2, header.Lat0, header.Lon0,
header.X0, header.Y0, header.K0));
}
}
private void SetFieldsByHeader(MemoryRasterHeader header)
{
_bandCount = header.BandCount;
_width = header.Width;
_height = header.Height;
_dataType = (enumDataType)header.DataType;
_dataTypeSize = DataTypeHelper.SizeOf(_dataType);
_spatialRef = GetSpatialRef(header);
SetCoordType(_spatialRef);
_headerSize = Marshal.SizeOf(header) + header.ExtendHeaderLength;
TryCreateCoordTransform(header);
}
private void TryCreateCoordTransform(MemoryRasterHeader header)
{
if (_spatialRef == null)
{
_coordTransform = CoordTransoformFactory.GetCoordTransform(null, null, _width, _height);
}
else
{
_coordTransform = CoordTransoformFactory.GetCoordTransform(
new Point(0, 0),
new Point(_width, _height),
new double[] { double.Parse(header.MinX.ToString()), double.Parse(header.MaxY.ToString()) },
new double[] { double.Parse(header.MaxX.ToString()), double.Parse(header.MinY.ToString()) });
}
}
public override IRasterDataProvider Create(string fileName, int xSize, int ySize, int bandCount, enumDataType dataType, params object[] options)
{
ISpatialReference spatialRef;
CoordEnvelope coordEnvelope;
bool isWithHdr;
int extHeaderSize = 0;
HdrMapInfo mapInfo;
ParseOptions(xSize, ySize, options, out spatialRef, out coordEnvelope, out mapInfo, out isWithHdr, out extHeaderSize);
MemoryRasterHeader h = GetHeader(spatialRef, coordEnvelope);
h.BandCount = bandCount;
h.DataType = (int)dataType;
h.Width = xSize;
h.Height = ySize;
h.ExtendHeaderLength = extHeaderSize;
byte[] headerBytes = new byte[1024];
using (FileStream fs = new FileStream(fileName, FileMode.Create))
{
int headerSize = Marshal.SizeOf(typeof(MemoryRasterHeader));
byte[] buffer = new byte[headerSize];
GCHandle handle = GCHandle.Alloc(buffer, GCHandleType.Pinned);
Marshal.StructureToPtr((object)h, handle.AddrOfPinnedObject(), true);
handle.Free();
fs.SetLength(headerSize + extHeaderSize + (long)xSize * (long)ySize * (long)bandCount * (long)DataTypeHelper.SizeOf(dataType));
fs.Write(buffer, 0, buffer.Length);
fs.Seek(0, SeekOrigin.Begin);
fs.Read(headerBytes, 0, (int)Math.Min(headerBytes.Length, fs.Length));
}
HdrFile hdrFile = h.ToHdrFile();
if (spatialRef != null)
{
hdrFile.HdrProjectionInfo = GetHdrProjectionInfo(spatialRef);
}
if (mapInfo != null)
{
hdrFile.MapInfo = mapInfo;
}
hdrFile.SaveTo(HdrFile.GetHdrFileName(fileName));
IGeoDataProvider provider = BuildDataProvider(fileName, headerBytes, enumDataProviderAccess.Update, options);
return(provider as IRasterDataProvider);
}
public MemoryRasterDataProvider(string mmfName, string fname, enumDataProviderAccess access, IGeoDataDriver driver)
: base(fname, driver)
{
_mmfName = GetMmfName(mmfName);
_fileName = fname;
_access = access == enumDataProviderAccess.ReadOnly ? MemoryMappedFileAccess.Read : MemoryMappedFileAccess.ReadWrite;
string hdrfile = HdrFile.GetHdrFileName(_fileName);
if (File.Exists(hdrfile))
{
_filelist = new string[] { _fileName, hdrfile }
}
;
else
{
_filelist = new string[] { _fileName }
};
_header = GetHeader(fname);
SetFieldsByHeader(_header);
TrySetEnvelopeAndResolutions();
LoadBands();
}
