private CacheHeader(Stream stream)
{
using (var binaryReader = new BinaryReader(stream, Encoding.Default, true))
{
// read the fourcc tag and throw on incorrect value
HeadFourCC = binaryReader.ReadTagClass();
if (HeadFourCC != (TagClass)"head")
{
throw new InvalidDataException();
}
EngineVersion = binaryReader.ReadInt32();
FileSize = binaryReader.ReadInt32();
stream.Seek(4, SeekOrigin.Current);
// Check the BuildVersion then return to the last stream position
stream.Seek(0x11C, SeekOrigin.Current);
var test = Encoding.ASCII.GetString(binaryReader.ReadBytes(32)).Trim(Char.MinValue);
Version = test == @"11081.07.04.30.0934.main" ? HaloVersion.PC_RETAIL : HaloVersion.XBOX_RETAIL;
stream.Seek(-0x13C, SeekOrigin.Current);
IndexInfo = IndexInfoStruct.DeserializeFrom(stream);
// move the stream past some unused/zeroed bytes
if (Version == HaloVersion.PC_RETAIL)
{
SharedInfoStruct.DeserializeFrom(stream);
}
stream.Seek(32 + 224, SeekOrigin.Current);
// read the build string and remove the trailing null bytes
BuildString = Encoding.ASCII.GetString(binaryReader.ReadBytes(32)).Trim(Char.MinValue);
// read the map type (ie: singleplayer, multiplayer, shared, singleplayershared, mainmenu).
Type = (MapType)binaryReader.ReadInt32();
stream.Seek(28, SeekOrigin.Current);
StringsInfo = StringsInfoStruct.DeserializeFrom(stream);
stream.Seek(36, SeekOrigin.Current);
// read the name string and remove the trailing null bytes
Name = Encoding.ASCII.GetString(binaryReader.ReadBytes(32)).Trim(Char.MinValue);
stream.Seek(4, SeekOrigin.Current);
// read the scenario string and remove the trailing null bytes
Scenario = Encoding.ASCII.GetString(binaryReader.ReadBytes(128)).Trim(Char.MinValue);
stream.Seek(128, SeekOrigin.Current);
stream.Seek(4, SeekOrigin.Current);
PathsInfo = PathsInfoStruct.DeserializeFrom(stream);
if (Version == HaloVersion.PC_RETAIL)
{
UnknownInfo = UnknownInfoStruct.DeserializeFrom(stream);
}
Checksum = binaryReader.ReadInt32();
// seek the last 4 bytes before the end of the header
stream.Seek(2044 - (int)stream.Position, SeekOrigin.Current);
FootFourCC = binaryReader.ReadTagClass();
}
}
/// <summary>
/// Copies the paths from the Index into the given stream at the current address
/// note: Creates the table on an align(512) address then creates the table-index on
/// an align(512) address following it.
/// </summary>
/// <param name="outputStream">The stream to write to</param>
/// <returns>PathInfoStruct containing addresses/info of the paths table & index</returns>
private PathsInfoStruct GeneratePathsTable(Stream outputStream)
{
var info = new PathsInfoStruct( );
// extract the paths from the index and copy them into a local list object.
var paths = Index.Select(x => x.Path).ToList( );
info.PathCount = paths.Count;
info.PathTableAddress = outputStream.Align(512);
// pad the stream to align(512) and assign the new address to PathTableAddress.
GenerateStringEntries(outputStream, paths);
// Write the paths into the stream and subtract the PathTableAddress from the new stream position
// to get the PathTableLength.
info.PathTableLength = ( int )outputStream.Position - info.PathTableAddress;
// pad the stream to align(512) and assign the new address to PathIndexAddress.
info.PathIndexAddress = outputStream.Align(512);
// write the index for the path table
GenerateTableIndex(outputStream, paths);
// finish on the next 512 alignment boundary
outputStream.Align(512);
Padding.AssertIsAligned(512, outputStream);
// return the struct that contains the information about where in the stream this
// resource was written
return(info);
}
