/// <summary>
/// Takes the input stream and does any version specific
/// data operations to get the tag manager ready for reading
/// </summary>
void CalculateVersion()
{
InputStream.Seek(60);
InputStream.State = BlamLib.IO.EndianState.Little;
uint group_tag = InputStream.ReadTagUInt();
BlamBuild bb = FromSignature(group_tag);
#region Endian handling
if (bb == BlamBuild.Halo1)
{
endianState = BlamLib.IO.EndianState.Big;
}
else
{
endianState = BlamLib.IO.EndianState.Little;
}
if (InputStream != null)
{
InputStream.State = endianState;
}
if (OutputStream != null)
{
OutputStream.State = endianState;
}
#endregion
if (engine == BlamVersion.Unknown)
{
engine = bb.ToVersion();
ManageSetupTagGroup();
}
}
/// <summary>
/// Validates the cache's header for proper signatures
/// </summary>
/// <param name="s">cache stream</param>
/// <param name="header_sizes">size of a single header</param>
/// <remarks>Assumes the header is at the start of the stream</remarks>
/// <returns>The header size entry that matches this cache or -1 if no matches</returns>
internal static int ValidateHeader(IO.EndianReader s, params int[] header_sizes)
{
bool invalid = true;
int result = -1;
foreach (int header_size in header_sizes)
{
s.Seek(0);
if (s.ReadTagUInt() == MiscGroups.head.ID && s.Length >= header_size) // it HAS to be more than the size of a header...
{
s.Seek(header_size - sizeof(uint));
if (s.ReadTagUInt() == MiscGroups.foot.ID)
{
invalid = false;
result = header_size;
}
}
if (!invalid)
{
break;
}
}
if (invalid)
{
throw new InvalidCacheFileException(s.FileName);
}
return(result);
}
internal static int ValidateHeaderAdjustEndian(IO.EndianReader s, params int[] header_sizes)
{
bool invalid = true;
int result = -1;
foreach (int header_size in header_sizes)
{
if (s.Length < header_size)
{
continue; // it HAS to be more than the size of a header...
}
s.Seek(0);
uint head = s.ReadTagUInt();
if (head != MiscGroups.head.ID)
{
if (IO.ByteSwap.SwapUDWord(head) == MiscGroups.head.ID)
{
s.State = s.State.Invert();
}
}
s.Seek(header_size - sizeof(uint));
if (s.ReadTagUInt() == MiscGroups.foot.ID)
{
invalid = false;
result = header_size;
}
if (!invalid)
{
break;
}
}
if (invalid)
{
throw new InvalidCacheFileException(s.FileName);
}
return(result);
}
