Patching levels with lump files

Ep1 added a simple system to allow mapmakers to patch levels by shipping only the level lumps that have changed. It was written to handle any .bsp file lump, but right now it's really only useful for lumps that don't depend on other lumps, until a tool exists that will find all the changed lumps for you. For example, changing geometry in your map changes many lumps, and you would have to select each changed lump by hand. Once you've changed many lumps, you may as well ship a new .bsp.

For now, it's a great way of shipping new entity lumps, or new game data lumps without having to re-ship the entire .bsp. The steps involved are as follows (assuming that you've already shipped a previous version of the .bsp file):

1. Make the desired changes to the level, and compile the new .bsp
2. Use vbspinfo -X to extract the desired lumps into .lmp files.
3. Put the .lmp files into your GAME\maps directory, ensure their <id>s are correct (see below).
4. Ship the .lmp files

.lmp files are automatically named in the following format:

<bsp name>_l_<id>.lmp

After loading the .bsp, the engine will then load .lmp files starting at id 0, and stopping as soon as it fails to find a .lmp for the next id. Each .lmp file overrides any existing lump in the .bsp, or preceding .lmp files. So if you have already shipped a new lump in your <bsp_name>_l_0.lmp file, you can override it with a <bsp_name>_l_1.lmp file.