public void Save(Stream stream)
{
var objectMap = new DwgObjectMap();
AssignHandles(objectMap);
// write the file header; this will be re-written again once the pointers have been calculated
var writer = new BitWriter(stream);
var fileHeaderLocation = writer.Position;
FileHeader.Write(writer);
var variablesStart = writer.Position;
Variables.Write(writer, FileHeader.Version);
FileHeader.HeaderVariablesLocator = DwgFileHeader.DwgSectionLocator.HeaderVariablesLocator(variablesStart - fileHeaderLocation, writer.Position - variablesStart);
var classesStart = writer.Position;
DwgClasses.Write(Classes, writer);
FileHeader.ClassSectionLocator = DwgFileHeader.DwgSectionLocator.ClassSectionLocator(classesStart - fileHeaderLocation, writer.Position - classesStart);
var paddingStart = writer.Position;
writer.WriteBytes(new byte[0x200]); // may contain the MEASUREMENT variable as the first 4 bytes, but not required
FileHeader.UnknownSection_PaddingLocator = DwgFileHeader.DwgSectionLocator.UnknownSection_PaddingLocator(paddingStart - fileHeaderLocation, writer.Position - paddingStart);
var objectDataStart = writer.Position;
SaveObjects(writer, objectMap, objectDataStart);
var objectMapStart = writer.Position;
objectMap.Write(writer);
FileHeader.ObjectMapLocator = DwgFileHeader.DwgSectionLocator.ObjectMapLocator(objectMapStart - fileHeaderLocation, writer.Position - objectMapStart);
var unknownR13C3Start = writer.Position;
DwgUnknownSectionR13C3.Write(writer);
FileHeader.UnknownSection_R13C3AndLaterLocator = DwgFileHeader.DwgSectionLocator.UnknownSection_R13C3AndLaterLocator(unknownR13C3Start - fileHeaderLocation, writer.Position - unknownR13C3Start);
var secondHeaderStart = writer.Position;
FileHeader.WriteSecondHeader(writer, Variables, secondHeaderStart - fileHeaderLocation);
var imageDataStart = writer.Position;
ImageData.Write(writer, imageDataStart - fileHeaderLocation);
FileHeader.ImagePointer = imageDataStart - fileHeaderLocation;
// re-write the file header now that the pointer values have been set
var endPos = writer.Position;
writer.BaseStream.Seek(fileHeaderLocation, SeekOrigin.Begin);
FileHeader.Write(writer);
writer.BaseStream.Seek(endPos, SeekOrigin.Begin);
}
public static DwgDrawing Load(byte[] data)
{
var reader = new BitReader(data);
var drawing = new DwgDrawing();
drawing.FileHeader = DwgFileHeader.Parse(reader);
drawing.Variables = DwgHeaderVariables.Parse(reader.FromOffset(drawing.FileHeader.HeaderVariablesLocator.Pointer), drawing.FileHeader.Version);
drawing.Classes = DwgClasses.Parse(reader.FromOffset(drawing.FileHeader.ClassSectionLocator.Pointer), drawing.FileHeader.Version);
// don't read the R13C3 and later unknown section
drawing.FileHeader.ValidateSecondHeader(reader, drawing.Variables);
drawing.ImageData = DwgImageData.Parse(reader.FromOffset(drawing.FileHeader.ImagePointer));
var objectCache = DwgObjectCache.Parse(reader.FromOffset(drawing.FileHeader.ObjectMapLocator.Pointer), drawing.FileHeader.Version);
drawing.LoadObjects(reader, objectCache);
return(drawing);
}