The goal of dhewm 3 is bring DOOM 3 with the help of SDL to all suitable
platforms.

Compared to the original DOOM 3, the changes of dhewm 3 worth mentioning
are:

* 64bit port
* SDL for low level OS support, OpenGL and input handling
* OpenAL for audio output, all OS specific audio backends are gone
* OpenAL EFX for EAX reverb effects (read: EAX-like sound effects on all
  platforms/hardware)
* Better support for widescreen (and arbitrary display resolutions)
* A portable build system based on CMake

This engine will only work with the original Doom 3 and Resurrection of
Evil expansion pack and not the newer Doom 3 BFG.

To build the dedicated server or to disable building the base game code,
the core or d3xp game code, use:

BASE="no" CORE="no" D3XP="no" SERVER="yes" ./dhewm3.SlackBuild

Doom 3 and the Resurrection of Evil expansion pack data are not included
with dhewm 3 and are still covered by the original EULA. They must be
acquired separately such as from the retail DVDs or with SteamCMD. The
data pak00*.pk4 files need to be placed in the Doom 3 data directory
(/usr/share/games/dhewm3/base). For RoE (/usr/share/games/dhewm3/d3xp),
symbolic links to the data directories will work.

For those using the CDs/DVD to obtain the game data, the official 1.3.1
patch for Linux will also be needed. For example:

  sh /path/to/doom3-linux-1.3.1.1304.x86.run \
     --tar xvf --wildcards base/pak* d3xp/pak*