internal static DxfBlock FromBuffer(DxfCodePairBufferReader buffer)
{
if (!buffer.ItemsRemain)
{
return null;
}
var block = new DxfBlock();
var readingBlockStart = true;
var readingBlockEnd = false;
var entities = new List<DxfEntity>();
while (buffer.ItemsRemain)
{
var pair = buffer.Peek();
if (DxfCodePair.IsSectionEnd(pair))
{
// done reading blocks
buffer.Advance(); // swallow (0, ENDSEC)
break;
}
else if (IsBlockStart(pair))
{
if (readingBlockStart)
{
// if another block is found, stop reading this one because some blocks don't specify (0, ENDBLK)
break;
}
break;
}
else if (IsBlockEnd(pair))
{
if (!readingBlockStart) throw new DxfReadException("Unexpected block end", pair);
readingBlockStart = false;
readingBlockEnd = true;
buffer.Advance(); // swallow (0, ENDBLK)
}
else if (pair.Code == 0)
{
// should be an entity
var entity = DxfEntity.FromBuffer(buffer);
if (entity != null)
{
// entity could be null if it's unsupported
entities.Add(entity);
}
}
else
{
// read value pair
if (readingBlockStart)
{
buffer.Advance();
switch (pair.Code)
{
case 1:
block.XrefName = pair.StringValue;
break;
case 2:
block.Name = pair.StringValue;
break;
case 3:
break;
case 4:
block.Description = pair.StringValue;
break;
case 5:
((IDxfItemInternal)block).Handle = DxfCommonConverters.UIntHandle(pair.StringValue);
break;
case 8:
block.Layer = pair.StringValue;
break;
case 10:
block.BasePoint = block.BasePoint.WithUpdatedX(pair.DoubleValue);
break;
case 20:
block.BasePoint = block.BasePoint.WithUpdatedY(pair.DoubleValue);
break;
case 30:
block.BasePoint = block.BasePoint.WithUpdatedZ(pair.DoubleValue);
break;
case 67:
block.IsInPaperSpace = DxfCommonConverters.BoolShort(pair.ShortValue);
break;
case 70:
block.Flags = pair.ShortValue;
break;
case 330:
((IDxfItemInternal)block).OwnerHandle = DxfCommonConverters.UIntHandle(pair.StringValue);
break;
case DxfCodePairGroup.GroupCodeNumber:
var groupName = DxfCodePairGroup.GetGroupName(pair.StringValue);
block.ExtensionDataGroups.Add(DxfCodePairGroup.FromBuffer(buffer, groupName));
break;
case (int)DxfXDataType.ApplicationName:
block.XData = DxfXData.FromBuffer(buffer, pair.StringValue);
break;
}
}
else if (readingBlockEnd)
{
block.EndBlock.ApplyCodePairs(buffer);
}
else
{
throw new DxfReadException("Unexpected pair in block", pair);
}
}
}
var collected = DxfEntitiesSection.GatherEntities(entities);
foreach (var entity in collected)
{
block.Entities.Add(entity);
}
return block;
}
public DxfFile ReadFile(BinaryReader reader)
{
// swallow next two characters
var sub = reader.ReadChar();
Debug.Assert(sub == 0x1A);
var nul = reader.ReadChar();
Debug.Assert(nul == 0x00);
DxfPoint?blockBase = null;
var entities = new List <DxfEntity>();
var stillReading = true;
Action <Func <BinaryReader, DxfEntity> > addEntity = (entityReader) =>
{
var entity = entityReader(reader);
AssignCommonValues(entity);
entities.Add(entity);
};
Func <DxfVertex> getLastVertex = () => entities.LastOrDefault() as DxfVertex;
while (stillReading)
{
var itemType = (DxbItemType)reader.ReadByte();
switch (itemType)
{
case DxbItemType.Line:
addEntity(ReadLine);
break;
case DxbItemType.Point:
addEntity(ReadPoint);
break;
case DxbItemType.Circle:
addEntity(ReadCircle);
break;
case DxbItemType.Arc:
addEntity(ReadArc);
break;
case DxbItemType.Trace:
addEntity(ReadTrace);
break;
case DxbItemType.Solid:
addEntity(ReadSolid);
break;
case DxbItemType.Seqend:
addEntity(ReadSeqend);
break;
case DxbItemType.Polyline:
addEntity(ReadPolyline);
break;
case DxbItemType.Vertex:
addEntity(ReadVertex);
break;
case DxbItemType.Face:
addEntity(ReadFace);
break;
case DxbItemType.ScaleFactor:
_scaleFactor = ReadF(reader);
break;
case DxbItemType.NewLayer:
var sb = new StringBuilder();
for (int b = reader.ReadByte(); b != 0; b = reader.ReadByte())
{
sb.Append((char)b);
}
_layerName = sb.ToString();
break;
case DxbItemType.LineExtension:
addEntity(ReadLineExtension);
break;
case DxbItemType.TraceExtension:
addEntity(ReadTraceExtension);
break;
case DxbItemType.BlockBase:
var x = ReadN(reader);
var y = ReadN(reader);
if (blockBase == null && entities.Count == 0)
{
// only if this is the first item encountered
blockBase = new DxfPoint(x, y, 0.0);
}
break;
case DxbItemType.Bulge:
{
var bulge = ReadU(reader);
var lastVertex = getLastVertex();
if (lastVertex != null)
{
lastVertex.Bulge = bulge;
}
}
break;
case DxbItemType.Width:
{
var startWidth = ReadN(reader);
var endWidth = ReadN(reader);
var lastVertex = getLastVertex();
if (lastVertex != null)
{
lastVertex.StartingWidth = startWidth;
lastVertex.EndingWidth = endWidth;
}
}
break;
case DxbItemType.NumberMode:
_isIntegerMode = ReadW(reader) == 0;
break;
case DxbItemType.NewColor:
_color = DxfColor.FromRawValue((short)ReadW(reader));
break;
case DxbItemType.LineExtension3D:
addEntity(ReadLineExtension3D);
break;
case 0:
stillReading = false;
break;
}
}
var file = new DxfFile();
foreach (var section in file.Sections)
{
section.Clear();
}
// collect the entities (e.g., polylines, etc.)
entities = DxfEntitiesSection.GatherEntities(entities);
if (blockBase != null)
{
// entities are all contained in a block
var block = new DxfBlock();
block.BasePoint = blockBase.GetValueOrDefault();
foreach (var entity in entities)
{
block.Entities.Add(entity);
}
file.Blocks.Add(block);
}
else
{
// just a normal collection of entities
foreach (var entity in entities)
{
file.Entities.Add(entity);
}
}
return(file);
}
