Alone in the Dark 1

ABOUT THE GUIDE

• Most of the information here is derived from testing the English CD-ROM version (GOG). If you want to study AitD 1 more, you should consider using a different version, since no other version has been tested nearly as thoroughly. The French CD version in specific is a good choice because of reasons explained under "known version differences".

• Mostly Emily was used in testing, there being no known reasons to go with Edward in a speedrun.

• The division into topics is sometimes quite arbitrary. Feel free to discuss the format on the discussion page (top left) so future guides may be better-organized. That having been said, to get well-enough versed in the game's/games' workings to be able to competently run them or build on the theory, you will have to cut through a very decent portion of the guide regardless of its exact structure.

• Inevitably some points are made more than once so edits should ideally happen in both, and even more vague and more detailed bullets may be given on the same topics. The notes were generally made from a segmented run's point of view, being able to abuse saving and loading at will with the small natural penalty segmented runs incur for this. Some save/load tricks may sound too optimistic though, and this is because I (LotBlind) made the false assumption the time in the menu before reaching the save menu would not be counted (which would have meant the penalty was diminutive).

• Because of some issues with file conversions, I may have been working with files that were at 25 FPS instead of 60 FPS (what you should use) sometimes when counting frames between events happening. Thus there may be a small amount of incorrect frame counts given in the guide. Please report this and any other mistakes.

• Feel free to contact the primary author of the guide (LotBlind) or tigrou (code-related and more technical questions) through the SDA forums for consultancy during any serious [speedrunning] endeavours. Also the guide is in a wiki format for a reason: it may be edited by anyone. Use the discussion page for relevant questions.

GLOSSARY

Game-internal terms

Game-internal terms	Meaning
object	the entities in the OBJETS.ITD file that have properties like BODY, LIFE, FOUNDLIFE etc., but in the guide this may have been used in the everyday sense as well
actor	refers to any object that has been moved into the active actors' array in the RAM, but may have been confused with objects in some places
FRAME	the game uses this to refer to keyframes, confusingly
TRACK	pre-scripted movement, defined in LISTTRAK
BODY	3D models defined in the LISTBODY and LISTBOD2 files
ANIM	animations defined in the LISTANIM and LISTANI2 files
LIFE	the game's scripts are called LIFEs. The term "script" has been used sometimes. Stored in a file called LISTLIFE.
LIFE_MODE	called LIFEMODE in the guide, determines if an actor is active at a given time based on focused actor location
MOVE	movement mode
TRACK_MODE	deprecated term for "MOVE"
animActionType	an actor field, ACTIONTYPE in the guide
HIT	This is all of: a possible actor ACTIONTYPE field value; the name of the command that causes an actor to enter the PRE_HIT and HIT ACTIONTYPEs (in the LIFEs); and an actor field that stores the ID of the actor that has just been HIT by it.
IN_HAND	the item currently equipped, e.g. a weapon
VAR/CVAR	the variables and constant variables the game writes into during gameplay
ExRy	floor and room, as given in the game files and shown in the Room Viewer
Example	Example

Additional terms	Meaning
focused actor	actor that was set as the CAMERA_TARGET, usually the PC
PC	player character
EM/ED	Emily/Edward
"having control"	VAR 0 being 1
INV	ALLOW_INVENTORY = inventory being accessible
OOB	[to go] out-of-bounds (verb, noun, adjective...)
IB	in-bounds
desync	by default means desync of the ZV and ROOM Y-coordinates from their normal difference = vertical desync
kf	keyframe inside an ANIM
subframe	really sub-keyframe (one frame within a keyframe: what's normally called a "frame")
hitbox	the box that is used to check whether a melee attack is connecting with another actor, displayed in red in the RV
bbox	bounding box (also known as "zv"): the box used for collision checks with other actors and colliders, displayed in green (or white) in the RV
transition	the PC hitting a floor/transition trigger to move onto another floor
s/l	save and reload the same file
slt	save/load turn
ftt	deprecated term "first-time turn" referring to an incomplete slt
Cx	camera with ID x
ExCy	camera on floor x with ID y
RV/Viewer	Room Viewer
MV	Memory Viewer
CV	Cache Viewer
FitD	Free in the Dark; a very accurate source port of Alone in the Dark.
Example	Example

• LIFE, ANIM etc. numbers are given in the guide with a space in-between for clarity (ANIM 55, LIFE 112) even though in the scripts they're always spelled together. Also in the scripts CVAR is spelled C_VAR.

• All of the VARs, CVARs, ANIMs, BODYs etc. were named by LotBlind and those names are, as such, unofficial. All the names were written into a file called vars.txt. The game doesn't come with human-readable names for most things, except for items that you pick up which have the names shown in-game. Even those are only referred to by their IDs in the code if vars.txt was not present during decompiling LISTLIFE.ITD.

• Some variables and such may be referred to with different names/typography since during the project, tigrou may have renamed game-internal fields to be easier to understand, and in some cases, the original terminology was returned to afterwards. An attempt was made to conformize everything. Then again, the information is often too technical to get a perfect grasp of through this guide alone anyway.

META

USEFUL FILES

• If you aren't sure where to find a particular file or program, look here.

DOSBOX/EMULATORS

• While runs can only officially be recorded on whatever GOG or Steam copies are packaged with (unless the SDA rules have changed since writing this), other emulators may offer features beneficial to testing.

• While it would make a big difference in lag times, you're not allowed to change the default GOG CPU cycles setting of 11.000.

• If DOSBox has been left in the background while you're doing something else, it sometimes fails to refresh the window when you refocus it. Just minimize and un-minimize it until it shows right.

• ALT-F12 in DOSBox fast-forwards the game. This is not supposed to affect its functioning.

• DOSBox SVN-Daum has save states and other features that make it superior to DOSBox 1.4. It was not utilized at all.

• The state of PCem as a TAS-ready emulator should be kept an eye on. It seems the most likely candidate that could actually allow to TAS AitD for TASVideos.org.

ROOM VIEWER

• The Room Viewer (Viewer, RV) is a custom-made RAM watch utility coded by tigrou for Alone in the Dark series games that was gradually expanded on over the course of the segmented run project. Its functionalities are the widest in scope when used in conjunction with AitD 1. It comes with an attached readme for instructions but here are some additional notes as well.

• The RV has a built-in function (hit the "1" and "2" keys) to quickly test the workings of the two timers by winding them back 5 seconds at a time, and get specifically Timer 2 closer to a desired value. The game state that results, however, is not the same one it would have been had the timer been reset by rebooting the game, and so this is definitely not allowed during actual running.

• When recording runs and other material for AITD, please set up also recording two instances of the Room Viewer at the same time (one for the game world, one for the VARs), because this helps to analyse your work afterwards. In order to record both instances, you need two differently named copies of the Viewer. Recording your key presses will also help immensely. This can be done using NohBoard with THIS PRESET.

EDIT IN NOHBOARD AND THE PRESET FILE, MAKE SURE THE SECOND VERSION OF THE VIEWER IS PROVIDED?

• • You might also find this Windows .bat file handy:
    • ECHO "Remember Num Lock on!"

PAUSE start "" "AITD room viewer" -screen-width 960 -screen-height 720 -screen-fullscreen 0 -speedrun start "" "AITD room viewer 2" -screen-width 1627 -screen-height 360 -screen-fullscreen 0 -speedrun start "" "NohBoard\NohBoard.exe"

• • Just create a .bat file in the same folder as the .exes and that should work. Change the width and height to match your screen. The NUMLOCK reminder is there because NohBoard needs it to be on to see the keypad, but feel free to delete it. Also to make NohBoard see the inputs in the first place, you have to run it as administrator, which is a setting you can change through right-clicking and going to the compatibility tab.
  • "-speedrun" makes the Viewer use default settings that make recording speedruns etc. more convenient and consistent: for example always making sure the extra info is shown on the bottom right with the player actor being focused. It may also cause some data to be displayed that wouldn't be otherwise.
  • In order to avoid having to give every program permission to run separately, you can also just make a shortcut to the .bat file, and choose the "run as administrator" option for it.

• The Viewer cannot follow the player around during the intro cutscene unless you manually go to the right rooms. This is because it's set to track the actor that has TRACK_MODE 1 (manual movement) that only the PC has during regular gameplay. The actors used in the intro and outro are actually different from the usual PC actor.

• The Viewer's Model Viewer shows not only the BODYs but also can play ANIMs on top of them (indiscriminately). It also gives you the keyframe lengths and offsets.

• The warp command, even when just changing the actor's angle, can desync its coordinates. If it's happened to the PC, it should be reflected on by a new red bbox being drawn where the ROOM coordinates are. To avoid this, you should pause the game or make sure the actor isn't moving when you warp it.
  • You can only get some actors (most monsters and all pushables) to move between rooms, not e.g. any room script actors.

• The Viewer refreshes its memory (reads from the game process) at the same speed as your display refresh.
• There may be very small (e.g. one-frame) delays before a changed memory value shows in the Viewer. This may explain why it sometimes seems things that are supposed to happen on the same frame do not. You shouldn't always read too much into discrepancies of this size.
  • The same goes for any keyboard visualizers you're using. I've seen the Room Viewer reacting to a key press before NohBoard did (which means the game reacted even quicker).

• There's information that will only be displayed in the RV for the CD-ROM release of AitD 1. This includes everything to do with timers.

• The delay/lag meter is set to only time instances of lag of over 100ms long (i.e. major loading lag). The total lag -counter, on the other hand, adds up everything.

• The Room Viewer gives you back the player character's information automatically if the currently selected thing is clicked on again to deselect it. This is so speedruns etc. recordings are less likely to drop that information. However, if you never deselect that other entity before it's disappeared from memory (as when moving between floors), it will not revert to the player. This is because of another feature that's designed to make it easier to monitor some actor from the moment it's been loaded into memory. This is generally when you go back to the floor or area it's in.

• SUB_KEYFRAMEs as shown in the RV are not reset when the game is reloaded. The field only exists in the RV, not in RAM.
  • Just in general, the RV does not directly know if the game has been reloaded.

• There is another branch of the RV called "highlighting" that highlights changes in all or most of the actor fields etc. shown in its window like they are in the VARs mode. This was deemed to make the screen too busy, and thus removed from the master.

• There are a few kinds of artifacts shown in the RV that look like the game glitches for a frame in a way that you can't see in the game's own window. Most of these are explained by the RV reading memory more frequently than the game updates it, thus showing mid-frame states as well as completed frame ones. The common trait is that you can't ever pause the game in the glitched state, which is how you can tell as well.

LIFEDISA/TRACKDISA/MEMORY VIEWER

• The "DISAs" are the tools used to unpack the game's scripts and tracks and the Memory Viewer shows the game's entire RAM.

Instructions:

1. Create a new folder.
2. Unpack all files of LISTLIFE.PAK to that folder with quickBMS.
3. Search for a file named "OBJETS.ITD" (in AITD root folder) and copy it there as well
4. Unpack ENGLISH.PAK (or FRANCAIS.PAK if you have the French version). Search for a file named 00000000.dat. Rename it to "ENGLISH.TXT". Copy that file to the same folder.
5. Copy LifeDISA.exe to the folder and run it.
6. A file named "output.txt" with all scripts will be created.

The files ENGLISH.TXT and OBJETS.ITD allow the tool to convert objects' hard-coded IDs inside scripts (e.g.: 50, 201, 203) to human-readable names (e.g.: "A rifle", "A letter", "A key", ...). In addition, the file called vars.txt can optionally be placed in the same folder before running LifeDISA to replace a lot of other names as well, including all the ANIMs, LIFE names and VARs. This will make the output file more cluttered but a lot easier to understand.

• After you have obtained output.txt, opening it with something like NotePad++ choosing "Assembly" as the language is recommended to make it even easier to read.

• TrackDISA works the same, except it extracts the file called LISTTRAK.PAK that contains the game's TRACK scripts. vars.txt also helps make TrackDISA's output file easier to read.

• The Memory Viewer reads the first two megabytes of DOSBox RAM (more than enough to see all of AitD's memory) and displays it using the in-game palette so that you can clearly see where the two background images and the backbuffer are stored. Launch the program before or after AitD and it should recognize when it's running. Give it admin privileges if DOSBox also has those.
  • The exact positions of items in the memory are dynamically allocated and so might not be exactly the same from time to time but they're always stored in the same order. In practice, if you launch the game the same way, the DOSBox RAM should also be identical.

CACHE VIEWER

• A program that displays the contents of the cache in detail. Works best if launched after the game is already running. The data shown is as follows:

Bytes Used – Bytes Maximum ... Number of Entries – Maximum Number of Entries

Then for each entry (sorted by last access time): ID – Size – Timestamp

• You have to use the following as arguments (case sensitive), depending on what you want to display:

ListSamp ListLife ListBody / ListBod2 ListAnim / ListAni2 ListTrak

• • You can combine up to five arguments. ListBod2 and ListAni2 are for Emily.

FREE IN THE DARK / FITD HACK

• Free in the Dark is a very accurate source port whose history is unknown, though it is suspected someone might have had access to the AitD source in order to be able to make it. It is part of the reason so much is known about various aspects of how AitD works.

• There is a hacked .exe for the "Free in the Dark" port of Alone in the Dark that makes it easier to study the render bug specifically (see "render bug"). It is capable of rendering 32000 units of the game world in a given resolution (e.g. 1080p) while the camera still uses the same 320x200 projection settings.
  • Just copy the files in your INDARK folder into the port's folder and you are good to go. If asked to overwrite SDL.dll or SDL_mixer.dll files, say no.
  • The .exe, like FitD in general, is not compatible with the Room Viewer.

• FitD keys: T - top camera, C - no hard clipping, B - 3D mode, N - 2D mode.
• Hack keys: +, -, * and /.
  • You can zoom with O and P, at least after you've hit B/N or T to give the top-down view.
  • The red lines are the -32768/32767 range (so 65536 values) to give an idea of when the 2D array should be about to overflow.
  • You can import a save file from AitD (FitD scans for SAVE0.ITD in its folder). This means you can first set up whatever situation you like in AitD with the help of the Viewer, then quickly copy-paste the resulting save file and resume inside the FitD hack to see what the full projection looks like.

• FitD is very buggy...
  • In case the character suddenly starts to spin uncontrollably, you have to restart the program.

• If you get "The procedure entry point SDL_getenv could not be located in the dynamic link library E:\GOG Games\Alone in the Dark\INDARK\FITD.exe", you have to make a backup of the DLLs in the INDARK folder and replace them with the ones in the zip.

GAME

GAME FILES

File	-	CAMERAXX.PAK	All background camera images (in 320x200 8-bit 256 color). Can be opened in Photoshop etc. as RAW images.
ENDSEQ.PAK	Various resources (e.g. backgrounds) related to the end sequence (after Pregzt is defeated).
ETAGEXX.PAK	Room and camera information, used by the Room Viewer.
ENGLISH.PAK	00000000.dat is the English translation for the object names and also user interface/messages, the other files are the readables. There are also other language files with obvious names.
LISTANIM/LISTANI2.PAK	3D models' skeletal animation data. Can be viewed in the Room Viewer.
LISTBODY/LISTBOD2.PAK	3D models. Can be viewed in the Room Viewer.
LISTLIFE.PAK	Scripts.
LISTMUS.PAK	Music files in the ADL format.
LISTSAMP.PAK	Sound samples (8000 Hz 8-bit mono VOC files). Can be opened in many audio programs like GoldWave.
LISTTRAK.PAK	Pre-recorded 2D paths for actors (e.g. when climbing stairs).
PRESENT.PAK	The screenshots shown in attract mode (let it idle in the main menu).
ITD_RESS.PAK	Various GUI/gfx data (e.g.: menus, fonts...)
VARS.ITD	The initial values of variables.
DEFINES.ITD	The initial values of flags.
PRIORITY.ITD	???
OBJECTS.ITD	A table with all objects used in the game and their properties (e.g.: name, room, 3D position, ...). Unpacked into the AitD Objects worksheet.

• Save files are called SAVE0.ITD – SAVE5.ITD. The one shown up top in the save menu is SAVE0.

KNOWN VERSION DIFFERENCES

• These are the versions that the most is known about:
  • The GOG release, which is probably just the old official English CD-ROM version.
  • French floppy version.
  • French CD-ROM (same download page).

• Only the original French CD-ROM version seems to have been released in debug mode (accidentally), meaning it's a lot easier to reverse-engineer. In fact this version was used for that purpose.
  • Despite debug versions normally running slower than release versions, this doesn't seem to be the case with the debug/non-debug versions of AitD (tested using the RV).
  • The downside to it being in debug mode means direct file comparisons are impossible and so it's not really known which differences may exist between French CD and other versions.

• Version difference: the French CD-ROM version doesn't crash coming form a save file where reaching the actor limit was otherwise causing crashing (the file seems to be missing).

• Some Room Viewer data is only displayed for the CD/GOG releases of the game. This includes anything to do with the game's timers (FPS meter, lagometer, CHRONO...).
  • Also ALLOW_INVENTORY is only shown for the GOG release.

• Some typos were corrected between the initial floppy and later CD-ROM releases.

• The CD-ROM version does not have a copy protection screen.

• The floppy version (tested on the English one) seems to crash a lot more seldom due to the render bug though generally similar outcomes are seen. It's not known why. The CPU values were matched with the GOG version to make sure that's not the cause.

• The CD version has a slightly different tracklist, and changes in associated logic. Also the READ commands in the LIFEs have a third parameter: the voice file to play back.
  • These differences are in at least all of these LIFEs: 15, 118, 140, 175, 185, 191, 192, 193, 194, 265, 380, 430, 438.
  • No other kinds of differences exist in the scripts.

• The orchestral hit sound sample played when entering dangerous areas such as E1R7 has been replaced with a short piece of music (string cacophony).

• There are no differences in the trigger or camera trigger data.

• There are small differences in the room/collider data, from the floppy to the CD-ROM version:
  • E3R2:
    • 3 colliders have their width increased by 200 units, including two that overlap (on the W side, they actually reach into R3 in a way that might make some theoretical difference in getting OOB from one of the two rooms if you had to get OOB from that area)
    • 2 colliders have flag set to 0 instead of 1 (not known why)
  • E5R0:
    • 6 colliders have been added. They are all the walls around the bridge. For some reason, the long E wall is 10 units lower than the rest.
  • E5R7:
    • 4 colliders have been changed (size+position):
      • 6950, -3000, -100 (made thicker along Z-axis to prevent the player from getting into a blind corner)
      • 5949, -1000, 3000 (made thicker along X-axis so it overlaps with E wall, preventing clipping into corner)
      • 6800, -1000, -2000 (made thicker along Z-axis so it overlaps with the collider to the N of it, preventing clipping into it)
      • -5699, -1000, -5650 (made thicker along Z-axis so it overlaps with S wall, preventing clipping into corner)
    • 2 colliders were moved inside the list for some reason, but otherwise left unchanged.

• Because the lagometer only works for the CD-ROM version, it's difficult to tell exactly which version has the most lag, or if there even is a difference. The CD-ROM music is played off the CD image directly, so it's not cached and thus doesn't cause lag. The midi files loaded in by the floppy version might cause a bit of lag?

• The headers of room data files: In the floppy version some of them contained garbage (they pointed to areas outside the file). In GOG/CDROM version those had been set to zero (cleaned by the devs?). No known relevance.

• The floppy version seems to temporarily store some other data right after starting a new game in the part of RAM where the VARs are kept during gameplay.

• The Japanese release (3DO/FM Towns) has the known difference of taking more damage from some sources such as the smoke in the smoke room. It is unknown which other ports were the same. Generally no testing was done on non-PC versions.

• In the earlier of the two demo versions, spending time in the menu still causes the CHRONO to advance.

GENERAL

CONTROLS

MEMORY/CACHES/BUFFERS/SOUND SAMPLES

SAVING/LOADING

PAUSING

LIFE SCRIPTS

IMPORTANT/SPECIAL LIFES

IMPORTANT/SPECIAL VARS, CVARS, AND OTHER VARIABLES

INTERRUPTS

RENDERER

PALETTE

GAME WORLD

COLLIDER FLAGS

TRIGGERS

TRACKS

STAIRS/TRANSITIONS

DOORS

FRONT DOORS/JELLY

CAMERAS

CAMERA VIEWS

CAMERA DEFOCUS TRICK

WRONG PICKUPS/WRONG TRIGGERS

ROOM/VIEW DESYNC

OBJECTS AND ACTORS

OBJECTS

ACTORS/ACTIONTYPES

ACTOR SERIALIZATION INTO OBJECTS/OBJECT FIELDS/ACTOR FIELDS

BODYS

ANIMS/ANIMATIONS (GENERAL, NOT MOVEMENT)

ACTOR FLAGS

PLAYER CHARACTER

EMILY AND EDWARD DIFFERENCES (ANIMS)

PLAYER STATE

BODY/IN_HAND

BODY/IN_HAND DESYNC

SPACE

MOVEMENT

MODX/MODY/MODZ

ANIMATIONS (MOVEMENT)

EMILY AND EDWARD DIFFERENCES

SPEED

CORNERING

ROTATION

ACTIONS

(SPACE)

PUSHING

JUMPING/HOVERING

CLIMBING

GRAVITY/FALLING

VERTICAL DESYNCING

ITEMS/INVENTORY/MENUS

INVENTORY/ITEMS

FLASKS

THROWING THINGS

BOW/FIRING ARROWS

FIRING A GUN

ENEMIES/FIGHTING

PREGZT/BOSS FIGHT

CTHONIAN (WORM)

E2 ARROWS/AXES

OTHER ENEMIES

= HITFORCE/DAMAGE MANIPULATION

[NOT] DYING

TIMERS/CHRONO/TIMER MANIPULATION

LAGGING/FRAMERATE

SNAPBACK

DELAY TURN/DELAY SNAP

PICKUP TURN/SNAP

PICKUP TURN/PICKUP SNAP

LAMP TURN/LAMP SNAP

SAVE/LOAD TURN (SLT)

QUICK ROTATION

OOB/CLIPPING

SIDEWAYS CLIPPING

CONVEX CLIPPING

OPENING CLIPPING

LAG MANIPULATION/LAG SNAP/LAG OOB

SNAPBACK CLIP

TRIGGER BOUNCE OOB

PUSHABLE OOB

CHAIN CLIPPING

PUSHABLE LAG OOB

PUSHABLE WEDGE OOB

PUSHABLE OOB OOB

PUSHABLE NARROW OOB

CLIMB OOB

FALL OOB

COLLISION OOB

PUSH CLIPPING/LIGHTWEIGHT CLIPPING

PRACTICAL TIPS/APPLIED

PRACTICAL TIPS/OPTIMIZATIONS

TIMING CERTAIN ACTIONS

THEORETICAL IN-BOUNDS/GLITCHLESS RUN

EXPERIMENTAL SPECULATION

MIGHT HELP IN AITD 2 OR 3

TAS-ONLY/GLITCHING/CRASHING/SOFTLOCKING/MEMORY CORRUPTION

GENERAL

THROWN OBJECTS SOFTLOCK

3D-WRAP-AROUND GLITCH

RENDER BUG/2D-WRAP-AROUND

POTENTIAL EXPLOITATION

MEDKIT RENDER BUG TRIALS

SOUND BUG

MISCELLANEOUS

MISCELLANEOUS/COMBINED TRICKS

TECHNICAL NOTES

(Probably) Pointless Trivia

UNANSWERED QUESTIONS

Alone in the Dark 2

Alone in the Dark 3

Jack in the Dark