internal static DxfEntitiesSection EntitiesSectionFromBuffer(DxfCodePairBufferReader buffer)
{
var entities = new List <DxfEntity>();
entities.Clear();
while (buffer.ItemsRemain)
{
var pair = buffer.Peek();
if (DxfCodePair.IsSectionEnd(pair))
{
// done reading entities
buffer.Advance(); // swallow (0, ENDSEC)
break;
}
if (pair.Code != 0)
{
throw new DxfReadException("Expected new entity.", pair);
}
var entity = DxfEntity.FromBuffer(buffer);
if (entity != null)
{
entities.Add(entity);
}
}
var section = new DxfEntitiesSection();
var collected = GatherEntities(entities);
section.Entities.AddRange(collected);
return(section);
}
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;
}