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);
}
public DwgDrawing()
{
FileHeader = new DwgFileHeader(DwgVersionId.Default, 0, 0, 0);
Variables = new DwgHeaderVariables();
Classes = new List <DwgClassDefinition>();
var continuous = new DwgLineType("CONTINUOUS")
{
Description = "Solid line"
};
var defaultLayer = new DwgLayer("0")
{
LineType = continuous
};
var standardStyle = new DwgStyle("STANDARD");
var standardMLineStyle = DwgMLineStyle.GetDefaultMLineStyle();
BlockHeaders = new DwgBlockControlObject()
{
DwgBlockHeader.GetPaperSpaceBlockRecord(defaultLayer),
DwgBlockHeader.GetModelSpaceBlockRecord(defaultLayer)
};
Layers = new DwgLayerControlObject
{
defaultLayer
};
Styles = new DwgStyleControlObject()
{
standardStyle
};
LineTypes = new DwgLineTypeControlObject()
{
new DwgLineType("BYLAYER"),
new DwgLineType("BYBLOCK"),
continuous
};
Views = new DwgViewControlObject();
UCSs = new DwgUCSControlObject();
ViewPorts = new DwgViewPortControlObject()
{
DwgViewPort.GetActiveViewPort()
};
AppIds = new DwgAppIdControlObject()
{
DwgAppId.GetAcadAppId(),
DwgAppId.GetAcadMLeaderVersionAppId()
};
DimStyles = new DwgDimStyleControlObject()
{
DwgDimStyle.GetStandardDimStyle(standardStyle)
};
ViewPortEntityHeaders = new DwgViewPortEntityHeaderControlObject();
GroupDictionary = new DwgDictionary();
MLineStyleDictionary = new DwgDictionary()
{
{ standardMLineStyle.Name, standardMLineStyle }
};
NamedObjectDictionary = new DwgDictionary();
PaperSpaceBlockRecord = BlockHeaders["*PAPER_SPACE"];
ModelSpaceBlockRecord = BlockHeaders["*MODEL_SPACE"];
ByLayerLineType = LineTypes["BYLAYER"];
ByBlockLineType = LineTypes["BYBLOCK"];
ContinuousLineType = LineTypes["CONTINUOUS"];
CurrentLayer = Layers["0"];
TextStyle = Styles["STANDARD"];
CurrentEntityLineType = LineTypes["BYBLOCK"];
DimensionStyle = DimStyles["STANDARD"];
CurrentMultiLineStyle = (DwgMLineStyle)MLineStyleDictionary["Standard"];
DimensionTextStyle = Styles["STANDARD"];
}
internal static DwgFileHeader Parse(BitReader reader)
{
reader.StartCrcCheck();
var versionString = reader.ReadStringAscii(6);
var version = DwgVersionIdExtensions.VersionIdFromString(versionString);
var unknown1 = reader.ReadBytes(6);
var maintVer = 0;
if (version == DwgVersionId.R14)
{
maintVer = unknown1[5];
}
var marker = reader.ReadByte();
if (marker != 1)
{
throw new DwgReadException("Expected value of 1 at offset 13.");
}
var imagePointer = reader.ReadInt();
var unknown2 = reader.ReadBytes(2);
var codePage = reader.ReadShort();
var header = new DwgFileHeader(version, maintVer, imagePointer, codePage);
var recordLocatorCount = reader.ReadInt();
for (int i = 0; i < recordLocatorCount; i++)
{
var locator = DwgSectionLocator.Parse(reader);
switch (i)
{
case 0:
header.HeaderVariablesLocator = locator;
break;
case 1:
header.ClassSectionLocator = locator;
break;
case 2:
header.ObjectMapLocator = locator;
break;
case 3:
header.UnknownSection_R13C3AndLaterLocator = locator;
break;
case 4:
header.UnknownSection_PaddingLocator = locator;
break;
}
}
ushort crcXorValue;
switch (recordLocatorCount)
{
case 0:
case 1:
case 2:
crcXorValue = 0;
break;
case 3:
crcXorValue = 0xAD98;
break;
case 4:
crcXorValue = 0x8101;
break;
case 5:
crcXorValue = 0x3CC4;
break;
case 6:
crcXorValue = 0x8461;
break;
default:
throw new DwgReadException("Unsupported record locator count.");
}
reader.ValidateCrc(xorValue: crcXorValue);
reader.ValidateSentinel(HeaderSentinel);
return(header);
}
