TNT Pack is intended to help the distribution of TA third party maps by converting them to a format that requires a vastly smaller filesize - 20:1 ratios quite possible. The downside is that packed maps cannot be directly read by TA, so they have to be unpacked after download. However, while disk space is generally not an issue nowadays, bandwidth is still pretty much so.

For the techies:
TNT Pack simply replaces the 1024-byte tiles by a 64-bit CRC and some extra information. On unpacking, these CRCs are compared to a table of CRCs of tiles in the unpacked maps the user already has on disk. Each CRC in the packed map is then replaced by the tile it identifies.

Prior to any operation, TNT Pack will need to build a table of tile information (called 'CRC list' here). It will have to dig through all the maps it will later take tiles from, a lengthy process on fast computers and likely one that requires a lot of patience on slower ones. In order to avoid repeating this step every time the program is launched, the CRC list will be stored to a file first time it runs for retrieval on subsequent executions.

TNT Pack will attempt to find TA on your disk, and will then offer a sensible default selection of files that all the original TA maps are contained in. In other words, for now just click OK and wait a minute or two. Don't add any files if you don't understand the effect.

Just hit Extract map, select the .YMF file you want to unpack, specify a location to store the unpacked map, and watch the progressbar for half a minute. That's all!

In case it is a map using with a custom tileset, you will need to get the tileset as well. Store it in a convenient directory, then launch TNT Pack and use the File / Add files to CRC list... command to make the tileset's contents known to TNT Pack. The tileset file must stay in the location it was when you added it. The directory your copy of Total Annihilation is installed in is proposed. TNT Pack will detect the absence of files and prompt to rebuild the CRC list if so.

Some more consideration goes into packing maps. The basic mode of operation is almost identical to unpacking a map; obviously this time you hit Compress map, then specify the .UFO file first and the .YMF file afterwards. However, achieved compression can be disappointing, as tiles that do not exist in the common maps will remain in the packed map. In maps with custom or even unique tilesets, this will probably be the majority.

Therefor, you can go about it with a different approach. Create a file with the tileset, then either use File / Delete CRC files to delete the existing CRC list or rename the CRCLIST.CRC and CRCLIST.MCF file in the program directory to WHATEVER.CRC and WHATEVER.MCF, respectively. The loaded CRC list is kept in memory though, so you need to restart the program. Then add the .UFO file containing your tileset when prompted for files to scan for the list. Now, tiles from that tileset will also be replaced by references when packing a map. The resulting file will be much smaller than when packing with just the Cavedog map tiles available.

• First released version