Tonight's game on OpenPOWER: Doom64EX and Doom64EX-Plus

Date: 2023-08-11T18:40:00-07:00


We haven't done one of these in awhile because it's been a bad, busy summer. I won't bore you with my personal life; there's obvious catharsis when you can unwind mowing down hordes of hell after a long day at the office. Rather than the same old Doom, though (which was the mistake they made with Nintendo 64 Quake), Midway Games made an actual sequel to Doom on the Nintendo 64 using an enhanced engine supporting more advanced level geometry and lighting effects. Monster sprites were higher resolution, sounds were updated and the music changed from Bobby Prince's synthetic metaloid to deeply unsettling ambient by Aubrey Hodges. Plus, all new levels and a new weapon! And that was Doom 64.

Well, N64 decompilations and re-creations have really come into their own, and you can play Doom 64 on your desktop computer too with Doom64EX (done by the same guy who did Strife) or the updated Doom64EX-Plus which instead supports the Nightdive Studios 2020 remaster (Steam link provided for your convenience; I'm not affiliated and I don't get a cut). [UPDATE: Also on] Both releases have improved mouse and keyboard controls and support oodles of resolutions including widescreen.

However, unlike most of the re-creations we've talked about before, there's no getting around it: if you're not playing the remaster you'll need an N64 ROM. And that's all I'm going to say about that. If you have the N64 cartridge and a dump of it, play Doom64EX (it can't play the remaster); if you bought the remaster and have the data files, play EX-Plus (it can't play the original).

Anyhoo, if you want to build the original Doom64EX, it (at least with gcc on Fedora 38) has a glitch where you can't walk backwards. This took a little while to figure out but fortunately is easily fixed, and is already part of Doom64EX-Plus.

diff --git a/src/engine/doom_main/d_ticcmd.h b/src/engine/doom_main/d_ticcmd.h
index 2352bb2..1eef4bc 100644
--- a/src/engine/doom_main/d_ticcmd.h
+++ b/src/engine/doom_main/d_ticcmd.h
@@ -30,18 +30,18 @@
 #pragma interface
 // The data sampled per tick (single player)
 // and transmitted to other peers (multiplayer).
 // Mainly movements/button commands per game tick,
 // plus a checksum for internal state consistency.
 typedef struct {
-    char    forwardmove;    // *2048 for move
-    char    sidemove;    // *2048 for move
+    signed char    forwardmove;    // *2048 for move
+    signed char    sidemove;    // *2048 for move
     short    angleturn;    // <<16 for angle delta
     short    pitch;
     byte    consistency;    // checks for net game
     byte    chatchar;
     byte    buttons;
     byte    buttons2;
 } ticcmd_t;

For classic Doom 64 EX, to compile you'll need CMake, SDL2,






, which odds are you have already. I also recommend building using your system FluidSynth instead of the vendored FluidSynth-lite, so

mkdir build; cd build; cmake -DENABLE_SYSTEM_FLUIDSYNTH=ON ..; make -j24 # or whatever

to build. Finally, generate the WAD data from the totally legally acquired N64 ROM you have with

./doom64ex -wadgen [path]

, which will digest the ROM and automatically start the game. (For future starts you can just run


directly and it will use the cached WAD.)

For the updated Doom64EX-Plus, cd src/engine && ./ to build; you don't need CMake. Then put the remaster game data in the same directory or /usr/local/share/doom64ex-plus or /usr/share/games/doom64ex-plus, and start the game with ./DOOM64EX-Plus.

Either way, you have a feeling it wasn't meant to be touched.