public static LzmaHeader Read(Stream stream)
{
var header = new LzmaHeader();
byte[] buffer = new byte[5];
stream.Read(buffer, 0, 4);
header.Identifier = BitConverter.ToUInt32(buffer, 0);
if (header.Identifier != LZMA_ID)
{
throw new NotSupportedException($"Unrecognized identifier {header.Identifier}");
}
stream.Read(buffer, 0, 4);
header.ActualSize = BitConverter.ToUInt32(buffer, 0);
stream.Read(buffer, 0, 4);
header.LzmaSize = BitConverter.ToUInt32(buffer, 0);
stream.Read(buffer, 0, 5);
header.Properties = buffer;
return(header);
}
public Stream GetLumpStream(LumpType type)
{
var info = GetLumpInfo(type);
if (info.UncompressedSize == 0)
{
return(GetSubStream(info.Offset, info.Length));
}
using (var stream = GetSubStream(info.Offset, LzmaHeader.Size))
{
var lzmaHeader = LzmaHeader.Read(stream);
using (var compressedStream = GetSubStream(info.Offset + LzmaHeader.Size, lzmaHeader.LzmaSize))
{
var uncompressedStream = new MemoryStream(info.UncompressedSize);
Decoder decoder = new Decoder();
decoder.SetDecoderProperties(lzmaHeader.Properties);
decoder.Code(compressedStream, uncompressedStream, lzmaHeader.LzmaSize, lzmaHeader.ActualSize, null);
uncompressedStream.Seek(0, SeekOrigin.Begin);
return(uncompressedStream);
}
}
}
private int ReadLumpValues <T>(LumpType type, int srcOffset, T[] dst, int dstOffset, int count)
where T : struct
{
var info = GetLumpInfo(type);
// 0 = no compression
if (info.UncompressedSize == 0)
{
var tSize = Marshal.SizeOf <T>();
var length = info.Length / tSize;
if (srcOffset > length)
{
srcOffset = length;
}
if (srcOffset + count > length)
{
count = length - srcOffset;
}
if (count <= 0)
{
return(0);
}
using (var stream = GetLumpStream(type))
{
stream.Seek(tSize * srcOffset, SeekOrigin.Begin);
LumpReader <T> .ReadLumpFromStream(stream, count, dst, dstOffset);
}
}
else
{
// LZMA compressed lump
if (type == LumpType.GAME_LUMP)
{
// game lumps are compressed individually
// https://developer.valvesoftware.com/wiki/Source_BSP_File_Format#Lump_compression
throw new NotImplementedException();
}
using (var stream = GetSubStream(info.Offset, LzmaHeader.Size))
{
var lzmaHeader = LzmaHeader.Read(stream);
using (var compressedStream = GetSubStream(info.Offset + LzmaHeader.Size, lzmaHeader.LzmaSize))
{
using (var uncompressedStream = new MemoryStream(info.UncompressedSize))
{
Decoder decoder = new Decoder();
decoder.SetDecoderProperties(lzmaHeader.Properties);
decoder.Code(compressedStream, uncompressedStream, lzmaHeader.LzmaSize, lzmaHeader.ActualSize, null);
var tSize = Marshal.SizeOf <T>();
var length = info.UncompressedSize / tSize;
if (srcOffset > length)
{
srcOffset = length;
}
if (srcOffset + count > length)
{
count = length - srcOffset;
}
if (count <= 0)
{
return(0);
}
uncompressedStream.Seek(tSize * srcOffset, SeekOrigin.Begin);
LumpReader <T> .ReadLumpFromStream(uncompressedStream, count, dst, dstOffset);
if (type == LumpType.PLANES)
{
return(count);
}
}
}
}
}
return(count);
}
public Stream OpenItem(string id)
{
EnsureLoaded();
var item = _items[id];
// Find index of current lump
var keyArray = _items.Keys.ToArray();
int index = -1;
for (int i = 0; i < keyArray.Length; i++)
{
if (keyArray[i] == id)
{
index = i;
break;
}
}
// https://developer.valvesoftware.com/wiki/Source_BSP_File_Format#Lump_compression
// Get the actual length of the item using offset of the next item.
var valueArray = _items.Values.ToArray();
var actualLength = item.FileLength;
if (index != -1)
{
if (index < _items.Count - 1)
{
// The last game lump is /supposed/ to be a dummy containing nothing but the offset,
// but sometimes the offset is 0 which would result in negative actualLength.
if (valueArray[index + 1].FileOffset > valueArray[index].FileOffset)
{
actualLength = valueArray[index + 1].FileOffset - valueArray[index].FileOffset;
}
}
}
var stream = _bspFile.GetSubStream(item.FileOffset, actualLength);
LzmaHeader lzmaHeader;
try
{
lzmaHeader = LzmaHeader.Read(stream);
}
catch (NotSupportedException e)
{
stream.Seek(0, SeekOrigin.Begin);
return(stream);
}
using (var compressedStream =
_bspFile.GetSubStream(item.FileOffset + LzmaHeader.Size, lzmaHeader.LzmaSize))
{
using (var uncompressedStream = new MemoryStream(( int )lzmaHeader.ActualSize))
{
Decoder decoder = new Decoder();
decoder.SetDecoderProperties(lzmaHeader.Properties);
decoder.Code(compressedStream, uncompressedStream, lzmaHeader.LzmaSize,
lzmaHeader.ActualSize, null);
stream = new MemoryStream(( int )stream.Length);
uncompressedStream.Seek(0, SeekOrigin.Begin);
uncompressedStream.CopyTo(stream);
}
}
stream.Seek(0, SeekOrigin.Begin);
return(stream);
}