THOR
CreatedThor is the patch container file created and used by the Thor Patcher
Files are saved in little-endian.
| Label | Bytes | Type | Condition | Description |
|---|---|---|---|---|
| signature | 24 bytes | char | "ASSF (C) 2007 Aeomin DEV". "ASSF" stands for "Aeomin simple structured formate"1. |
|
| mergeMode | 1 byte | ubyte | Whether to merge the files into a GRF or store them in e.g. the data directory. Filesystem (0x00), GRF (0x01). |
|
| numFiles | 4 bytes | uint32 | The number of files in this thor container. | |
| containerMode | 2 bytes | uint16 | Indicates if the thor container has a single file or multiple files. Depending on the mode the structure changes. Single file (0x21), Multiple files (0x30). |
|
| targetGRFNameLen | 1 byte | ubyte | The length of the target grf name string that follows. | |
| targetGRFName | targetGRFNameLen | char | The name of the target GRF in which the files should be merged into (if mergeMode is GRF (0x01)). |
|
| filetableSizeCompressed | 4 bytes | int32 | Multiple files |
ZLib compressed size of the filetable. |
| filetableOffset | 4 bytes | int32 | Multiple files |
The absolute position of the compressed filetable. |
| filetableOffset | 1 byte | ubyte | Single file |
Ignored. |
Filetable ¶
If the containerMode is Single file then there is no filetable and the file entry directly follows.
Otherwise the filetable is compressed with zlib and must be decompressed first.
After decompression read the following entries numFiles times.
| Label | Bytes | Type | Condition | Description |
|---|---|---|---|---|
| filenameLen | 1 byte | ubyte | Length of the filename that follows. | |
| filename | filenameLen | char | Full filename. | |
| flags | 1 byte | ubyte | Flags of the file. Remove (0x01). If the remove flag is set the file should be deleted from the filesystem/grf. |
|
| offset | 4 bytes | uint32 | not Remove (0x01) |
Data offset of the file inside the thor container. |
| sizeCompressed | 4 bytes | int32 | not Remove (0x01) |
ZLib compressed filesize. |
| size | 4 bytes | int32 | not Remove (0x01) |
Uncompressed filesize. |
Single file ¶
If the containerMode is Single file then instead of the filetable info the file is directly read.
| Label | Bytes | Type | Condition | Description |
|---|---|---|---|---|
| sizeCompressed | 4 bytes | int32 | ZLib compressed filesize. | |
| size | 4 bytes | int32 | Uncompressed filesize. | |
| filenameLen | 1 byte | ubyte | Length of the filename that follows. | |
| filename | filenameLen | char | Full filename. | |
| data | sizeCompressed | ubyte | ZLib compressed file data. |
Links & Sources ¶
Unfortunately I am not aware of any official documentation of the file format. There exists a prototype of the original author Aeomin but it doesn't use the same format anymore. Luckily Tokeiburu open-sourced parts of his GRF Editor (source link at the end of the description or below) which supports the THOR format. Later on LinkZ created an open-source drop-in replacement for the Thor Patcher called rpatchur which also supports the format.