public Scene Read()
{
//The 12-byte header consists of three 4-byte entries:
_header = new GlbHeader();
//magic equals 0x46546C67. It is ASCII string glTF, and can be used to identify data as Binary glTF.
_header.Magic = _stream.ReadUInt <LittleEndianConverter>();
//version indicates the version of the Binary glTF container format. This specification defines version 2.
_header.Version = _stream.ReadUInt <LittleEndianConverter>();
//length is the total length of the Binary glTF, including Header and all Chunks, in bytes.
_header.Length = _stream.ReadUInt <LittleEndianConverter>();
if (_header.Version != 2)
{
throw new NotImplementedException($"Version {_header.Version} not implemented");
}
//Chunk 0 Json
uint jsonChunkLength = _stream.ReadUInt <LittleEndianConverter>();
string jsonChunkType = _stream.ReadString(4);
if (jsonChunkType != "JSON")
{
throw new GltfReaderException("Chunk type does not match", _stream.Position);
}
_root = JsonConvert.DeserializeObject <GltfRoot>(_stream.ReadString((int)jsonChunkLength));
//Chunk 1 bin
uint binChunkLength = _stream.ReadUInt <LittleEndianConverter>();
string binChunkType = _stream.ReadString(4);
//Check the chunk type
if (binChunkType != "BIN\0")
{
throw new GltfReaderException("Chunk type does not match", _stream.Position);
}
byte[] binChunk = _stream.ReadBytes((int)binChunkLength);
_binaryStream = new StreamIO(binChunk);
return(GltfBinaryReaderBase.GetBynaryReader((int)_header.Version, _root, binChunk).Read());
}
/// <summary>
/// Check if the file format is in binary.
/// </summary>
/// <param name="stream"></param>
/// <returns></returns>
public static bool IsBinary(Stream stream)
{
string sentinel = "AutoCAD Binary DXF";
StreamIO sio = new StreamIO(stream);
sio.Position = 0;
string sn = sio.ReadString(sentinel.Length);
return(sn == sentinel);
}
private void parseHeader()
{
switch (headerType)
{
case HeaderType.Traditional:
tHeader.DateTime = sHelper.ReadString(8);
tHeader.Padding = sHelper.ReadBytes(120);
tHeader.RowCount = sHelper.ReadInt32;
break;
case HeaderType.Defined:
Row row = new Row(dHeader_Template);
populateRow(ref row, SenderType.PARSE_HEADER);
dHeader = row;
break;
}
}