File Format Documentation

GXT

Header:

size	description
4 bytes	The size of the header.
4 bytes	The number of files in this gxt file.
4 bytes	The total size of this file.
4 byte array	Reads until end of header, contains all of the offsets where the files start, starting from the end of the header.

Data:

The rest of the file contains all of the files data.

CAT (Texture)

Header:

size	description
4 bytes	The size of the header.
4 byte array	The offset of where the extra data segments start.
4 bytes	Always seems to be -1
The remainder of the header seems to always contain nothing.

Intermediate Data:

This seems to be a double comma separated list starting at the end of the header that includes the filenames of every file that is contained in this file, the filename includes a trailing period. This always seems to start with "GXT,conv1," at the start of the list, I'm not sure what this is referencing. The end of this data segment is indicated by two 0 bytes (30H 30H).

Extra Data:

size	description
4 bytes	The size of the extra data segment.
4 bytes	The number of files in this data segment.
4 bytes	The size of this segment starting from the previous 4 bytes. *This is kind-of odd but seems to match up in the files I tested.
4 byte array	Reads until the end of the extra data segment, contains the offsets of where every file starts contained within this file starting at the end of the extra data segment.

Data:

The rest of the file contains all of the files data.