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);
}
internal static DwgImageData Parse(BitReader reader)
{
var imageData = new DwgImageData();
reader.ValidateSentinel(StartSentinel);
var overallSize = reader.Read_RL();
var startOffset = reader.Offset;
var imageCount = reader.Read_RC();
var headerStart = 0;
var headerSize = 0;
var bmpStart = 0;
var bmpSize = 0;
var wmfStart = 0;
var wmfSize = 0;
for (int i = 0; i < imageCount; i++)
{
var code = reader.Read_RC();
var start = reader.Read_RL();
var size = reader.Read_RL();
switch (code)
{
case 1:
headerStart = start;
headerSize = size;
break;
case 2:
bmpStart = start;
bmpSize = size;
break;
case 3:
wmfStart = start;
wmfSize = size;
break;
}
}
if (headerSize > 0)
{
if (reader.Offset != headerStart)
{
throw new DwgReadException("Unexpected image data header start.");
}
imageData.HeaderData = reader.ReadBytes(headerSize);
}
if (bmpSize > 0)
{
if (reader.Offset != bmpStart)
{
throw new DwgReadException("Unexpected BMP data start.");
}
imageData.BmpData = reader.ReadBytes(bmpSize);
}
if (wmfSize > 0)
{
if (reader.Offset != wmfStart)
{
throw new DwgReadException("Unexpected WMF data start.");
}
imageData.WmfData = reader.ReadBytes(wmfSize);
}
var endOffset = reader.Offset;
var readBytes = endOffset - startOffset;
if (readBytes != overallSize)
{
throw new DwgReadException($"Invalid count of read image data bytes. Expected: {overallSize}, Actual: {readBytes}");
}
reader.ValidateSentinel(EndSentinel);
return(imageData);
}