Building Names

One of Daggerfall’s long-running puzzles is how to generate the correct building name for any given building in a location. Daggerfall’s binary data exposes this information only as a seed value with no obvious correlation to the final name. From today, I’m happy to say this has been solved and I will be able to generate proper building names in the future. This article is a summary of the technical journey, minus all the dead ends and frustration.

The seed value used to generate building names has been known about for some time. This can be found in the BuildingData structure (link to UESP). The first step along the way was to generate some known values by changing a known seed value in MAPS.BSA. I started at the location Ashfield Hall in the Daggerfall province, which has a single tavern and some residences. Taverns are a great place to start as they have a very obvious PartA + PartB structure. For example The Bat And Skull. In Ashfield Hall, our single tavern is the The Howling Stag with a name seed value of 27748.

The first thing I did was change the name seed value for The Howling Stag in MAPS.BSA then start up Daggerfall to see how the name changes. Here’s a small sample of names generated from seeds 0-3. Keep this list in mind as we’ll return to it later.

0 = The Dancing Chasm
1 = The Knave and Scorpian
2 = The Pig and Ogre
3 = The Thirsty Fairy

Now I have somewhere to begin. I know the building is a tavern and have a sample group of seeds that result in specific names. The next trick is to work out how Daggerfall derives these names from the seed value.

I open up FALL.EXE in a hex viewer and search through for strings like “The Dancing” and “Chasm”. These strings are easy enough to locate, but these are just resources packed into the executable. What I need is the actual PartA and PartB tables Daggerfall is selecting from at runtime.

To get this information, I first have to use the DOSBox debugger to dump out memory from Daggerfall while it’s running. I can then search not just for strings, but for memory offsets pointing to those strings. I write a small bit of code to do the searches for me, and it doesn’t take long to find the correct offset tables for Part A and Part B of tavern names. Just think of this as a pair of arrays. In this case, both arrays are 36 elements long. Here they are as captured from the spreadsheet I dumped them out to.

TavernNamePartsAB

So how do we go from a seed of 0 to The Dancing Chasm? This is where most of the difficulty started. It was obvious Daggerfall used a random number generator to pick both parts, but the trick was to find the correct random number generator used by Daggerfall’s C compiler circa 1994-1996. Fortunately, I also needed this for correct texture table generation (still an open problem at time of writing) and had previously researched the correct random generator, known as a linear congruential generator, specific to Daggerfall. Here it is for completeness.

static ulong next;
public static void srand(int seed)
{
    next = (uint)seed;
}
public static uint rand()
{
    next = next * 1103515245 + 12345;
    return ((uint)((next >> 16) & 0x7FFF));
}

There are two methods here, one to set the seed (srand) and another to generate the next random number from that seed (rand). This is pretty much the standard ANSI LCG but specific to Daggerfall’s needs. Implementing this manually ensures that critical random number generation will always work just like Daggerfall, regardless of platform.

Now that I have the right random number generator, let’s feed it our test seeds from earlier and see what comes out. Starting with seed=0 and generating two numbers (indices into Part A and Part B name tables above), I get the following results.

PartA = 0
PartB = 12

First obvious thing is the spreadsheet starts from 1, not from 0. Just need to +1 each number to match the tables above (although zero-based arrays will be used in actual code). Matching these numbers to the above name table we get: Chasm The Dancing. OK, so Daggerfall obviously generates PartB first then PartA. Let’s try that again with the +1 and order swapped.

Seed = 0
  PartA = 13 (The Dancing)
  PartB = 1  (Chasm)
  Result: The Dancing Chasm

Using our handy table we can match row 13 with row 1 and we get The Dancing Chasm. Good! Let’s run some more tests and prove the concept.

Seed = 1
  PartA = 35 (The Knave and)
  PartB = 27 (Scorpion)
  Result: The Knave and Scorpion

Seed = 2
  PartA = 30 (The Pig and)
  PartB = 9  (Ogre)
  Result: The Pig and Ogre

Seed = 3
  PartA = 16 (The Thirsty)
  PartB = 36 (Fairy)
  Result: The Thirsty Fairy

So far, so good! Building names are output just like Daggerfall given the same inputs. Let’s try the original, unmodified seed value of 27748 which should give us The Howling Stag.

Seed = 27748
  PartA = 21 (The Howling)
  PartB = 33 (Stag)
  Result: The Howling Stag

And there we have it! Building name generation from initial seed value resulting in a string exactly matching Daggerfall.

From here, I still need to extract hard-coded name tables for other building types like armorers and weapon-smiths. This isn’t hard though, I just need to find the tables using the same methods as taverns. I also need to assign full building data from MAPS.BSA to the correct models in Unity scene and wire up API methods to query this data when inspecting or entering a building. One challenge at a time though.

For regular small updates on Daggerfall Unity, I can be found on Twitter @gav_clayton.

Daggerfall Unity 0.2.9 (Updated)

I’ve released a small patch to version 0.2.9. Latest download is on the standalone download page.

Patch notes for recent versions below:

0.2.7
  • Reverted minor change to terrain tilemap shader. This might fix black ground issue on older DX9 systems.
  • Implemented floating origin for Y axis to correct flickering shadows at high elevations. This still requires full testing.
  • Items imported from classic saves will have dye synced to material type at import time.
  • Settings INI now saves floats with invariant culture.
  • Update to Uncanny_Valley’s grass mod.
  • Added restart button to options UI.
  • Nystul fixed white interior textures when reflections mod enabled. Also fixes stalled fireplace animation.
  • Arrows should now always display correct inventory icon.
  • Can no longer equip arrows to hands.
  • Disabled bows until archery is implemented.
  • Can now open inventory from character window.
  • Weapon manager now resets sheathe state and equipped hand on new game / load.
0.2.8
  • Fixed floating origin issue that would start player high in the air when exiting a building at higher altitudes.
  • Nystul fix for resetting dungeon map on new game.
0.2.9
  • Disabled floating origin Y implementation for now. This means lighting and shadow issues at high elevations will return, particularly when using distant enhanced mod (which has a much higher vertical scale than default terrain).
  • Camera now clears background when inside a dungeon allowing you better see within the void.
  • Lypyl: Fix for white film on travel map. New console commands to display FPS and trigger action objects.
  • Nystul: Automap camera settings now preserved when opening automap.

For regular small updates on Daggerfall Unity, I can be found on Twitter @gav_clayton.

Daggerfall Unity 0.2 Release

This post is a mirror of the new standalone download page. Please refer to this page for the latest version.

Daggerfall Unity 0.2

Daggerfall Unity 0.2 is now available for general download. Key features of this build are:

  • Nearly complete item back-end. Monster loot and treasure piles coming soon.
  • Inventory UI.
  • Setup helper UI.
  • Persistent data for settings, keybinds, and saves.
  • Hundreds of small bug fixes and enhancements.
  • Travel map (Lypyl).
  • Almost complete support of dungeon actions (Lypyl).
  • Updates to enhanced sky (Lypyl)
  • Dungeon and interior auto-map (Nystul).
  • Realtime reflections (Nystul).
  • Animated grass and birds (Uncanny_Valley).

 

Download

Current version: 0.2.9 (9 April 2016)

Windows
Download Daggerfall Unity Test (Windows)
Linux
Download Daggerfall Unity Test (Linux)
Mac
Download Daggerfall Unity Test (Mac)

Note: Mac build is experimental as I don’t own a Mac to test on. Please let me know how you go with it on forums (see below).

 

Game Files

For convenience, here is a universal archive of compatible Daggerfall game files. This is primarily for platforms where installing Daggerfall is more difficult (e.g. Linux) but can be used on any supported desktop platform.

Note: This download contains game data only for Daggerfall Unity. It is not a standalone version of Daggerfall.

DaggerfallGameFiles.zip (Google Drive link)

 

Controls

General

  • Mouse to look.
  • W, S, A, D to move.
  • C to toggle crouch.
  • SHIFT (hold) to run.
  • SPACE to jump.
  • LEFT-CLICK mouse to open doors, enter dungeons, operate switches, etc.
  • ESC to pause game or go back to previous window.
  • F5 to open Character Sheet.
  • F6 to open inventory.
  • M to open interior automap (indoors only).
  • V to open travel map (outdoors only).
  • ` (backquote) to open console. Enter help to list console commands.

Weapons

  • Z to unsheathe / sheathe weapon.
  • H to switch equipped hands.
  • RIGHT-CLICK and drag mouse to swing weapon.

Save/Load

  • F9 to quick-save.
  • F12 to quick-load.

Note: Keys can be rebound by editing keybinds.txt. See manual for more details. A full key-binding UI will be implemented in a future release.

 

Manual

A PDF manual is included with the download, but you can also download a standalone copy.

 

Feedback

If you would like to offer feedback and bug reports, please use this thread on the forums or contact me directly.

First Look At Setup UI

The first time you run Daggerfall Unity 0.2 and later, a simple setup wizard helps you configure the game. This replaces the Unity resolution dialog, and for many users will entirely remove the need to edit an INI file to get up and running.

As discussed in my previous post the INI file and KeyBinds files are now stored in a persistent data path. This means you only need to setup Daggerfall Unity once and future updates will continue to use your custom settings. This should make things more convenient when downloading incremental releases in future.

For regular micro-updates on Daggerfall Unity, I can be found on Twitter @gav_clayton.

Setup Enhancements In 0.2

There are a few areas where setting up Daggerfall Unity could be a lot easier:

  • Obtaining Daggerfall’s game files. There is no easy way of obtaining Daggerfall’s game files for non-Windows users. You basically need to install the game on a Windows PC then copy game files to your platform of choice.
  • Using the right game files. Most setup issues boil down to the game files being a CD-based version (movies not copied into arena2), not patched to .213, or game files have been modified over the years and don’t work as expected.
  • Settings not persistent. Every time you download a new version of Daggerfall Unity, you need to configure your settings.ini and keybinds all over again. There is no way of pushing out new settings without giving you whole new files each time with all default values.
  • Unclear when something goes wrong. If you start the game without setting your Daggerfall path, or if files are missing, you just see an unhelpful black screen or an obscure message.

Starting from 0.2, I will try to address the above problems with the following changes:

  • Providing game files download. Starting from Daggerfall Unity 0.2, I will provide a download archive for a known-good set of game files. This archive can be unzipped and used on Windows/Linux/Mac. You can still point to your own installation as before, so this download is completely optional, but it will be the recommended source of Daggerfall’s game files moving forwards. As Daggerfall’s game files are static, you will generally only need to download this archive once and it can be used for all future versions of Daggerfall Unity.
  • Settings will be persistent. The settings.ini and keybinds files are now deployed to Application.persistentDataPath, so you will keep your settings whenever upgrading Daggerfall Unity. New settings will be automatically synced without changing your other settings.
  • Setup UI. The new Daggerfall Unity game setup UI will be a friendly starting point guiding you through first-time configuration. If there are problems with your game files, the setup UI will try to point you in the right direction. This will evolve over time based on user feedback.
  • Options UI. Coming later in 0.2 cycle will be a Daggerfall Unity options UI. Most settings can be configured without opening settings.ini or keybinds files at all.

More news on the 0.2 release will be posted soon.

Items Part 3 – Paper Doll

With item bitmaps and dyes out of the way, it’s finally time to begin work on paper dolls. The concept of layering cutouts of clothing and other accessories over a figure is centuries old, and a perfect solution for early video games where memory was at a premium. Daggerfall’s paper doll system is easily one of the most extensive to be found in video games of the time.

Before equipping anything to the paper doll, a few key pieces had to be researched.

  • Body Morphology. Every bit of armour and clothing has 8 variations to suit the male and female body shapes of Argonians, Elves, Humans, and Khajiit. The correct texture set must be mapped to the correct race and gender.
  • Position. The X, Y coordinates of each item on paper doll is coded into their texture files. This is tightly coupled to morphology.
  • Draw Order. Every item template has a value to determine the correct item rendering order on paper doll.
  • Equip Table. The equipment slots available to player and rules for what is equipped where.

I won’t go into detail about the first three, that information is just managed by the API as part of importing or generating items. The equip table is a little interesting however with a total of 27 slots available. I use the same index setup as Daggerfall itself.

  • 00 Amulet0 (amulets, torcs, etc.)
  • 01 Amulet1
  • 02 Bracelet0
  • 03 Bracelet1
  • 04 Ring0
  • 05 Ring1
  • 06 Bracer0
  • 07 Bracer1
  • 08 Mark0
  • 09 Mark1
  • 10 Crystal0
  • 11 Crystal1
  • 12 Head (helms)
  • 13 RightArm (right pauldron)
  • 14 Cloak1 (casual cloak, formal cloak)
  • 15 LeftArm (left pauldron)
  • 16 Cloak2
  • 17 ChestClothes (shirt, straps, armbands, eodorics, tunics, surcoats, robes, etc.)
  • 18 ChestArmor (cuirass)
  • 19 RightHand (right-hand weapon, two-hand weapon)
  • 20 Gloves (gauntlets)
  • 21 LeftHand (left-hand weapon, shield)
  • 22 Unknown1
  • 23 LegsArmor (greaves)
  • 24 LegsClothes (khajiit suits, loincloths, skirts, etc.)
  • 25 Unknown2
  • 26 Boots (boots, shoes, sandals, etc.)

The two unknowns could just be reserved indices as I was unable to find any equipment Daggerfall mapped to these slots. If there’s more to this, I’m confident it will be found in future testing.

As usual the API handles equipping items for developer, it’s easy as calling EquipItem(item) on the entity’s equip table. If an item of that type is already equipped, it will be dropped in the next compatible slot (if one is free) or swap out an existing item based on swap rules for that item template.

Now that we know which items the player has equipped, the textures to use, and their position and draw order, it’s fairly trivial to start layering down bitmaps onto the paper doll. But as usual, a couple of additional problems must be solved.

First up are cloaks, which have both interior and exterior parts drawn at different stages of the build. The below image shows how the two parts work together.

 

Cloak Components

 

The interior is drawn first, then the avatar, then the cloak exteriors. It’s actually possible to wear two formal or casual cloaks in Dagerfall (slots 14 and 16). Note: the above image was taken prior to order being fixed which is why the loincloth is slightly eroded in first and third images.

Our next problem is masking. Daggerfall has a special mask index allocated to hide hair that would otherwise be drawn outside of helmets. During the build process, the mask becomes transparent and overwrites anything else in that position. Masking is used for both helmets and hooded robes/cloaks.

 

Mask Components

 

Other items can then be drawn based on their draw order. The below animation shows a step-by-step paper doll build after sorting items by draw order.

 

 

Now that items are equipped, we need a way of removing them again. Daggerfall allows you to click directly on paper doll itself to remove an item from your avatar. This is accomplished by creating a special selection mask where each pixel is an index mapping to 0-26 on the equip table above. This isn’t actually visible, it’s just an array sampled when player clicks on paper doll. Following is how the selection mask looks when rendered out to an image using grey values to represent indices. Each grey value maps to an item slot on paper doll.

 

 

AvatarAndMask

 

I’m finally nearing the end of initial item support in Daggerfall Unity. There is still much to do (loot tables, shops, dropping items, repairing, storing items, effects, and so on) but those problems can each be tackled in turn. What I want to do now is clean up some code and begin a new test release cycle. This will allow me to fix any early bugs before moving onto the next stage of item support. I will post more news on this soon.