MeoWoW

The open source WoW client for cats.

An open-source reimplementation of the World of Warcraft 3.3.5a (build 12340) client, written from scratch in Rust.

This is a client only. It ships no game content: you point it at a copy of the 3.3.5a data files you already own, exactly as OpenMW does for Morrowind. It talks to existing 3.3.5a-compatible servers.

Status: it plays. Every data format reads, the world renders and streams, and the protocol reaches a live realm: log in, walk around, see other players move, cast spells, swing a sword. A native interface -- unit frames, chat, a spellbook, action bars -- draws over it, with no FrameXML and no addons. Roughly 58% of the way to something a person could sit down and play. See docs/ROADMAP.md for the milestone ladder and what's still missing (inventory, quests, most spell effects).

What works today

• MPQ archives — format versions 0 and 1, zlib and bzip2 sectors, encrypted files, single-unit and sectored storage, sparse decoding.

• Patch chains — resolves a path across all 17 archives of a stock installation in the client's load order, including delete markers, so patches correctly shadow and remove base content.

• DBC tables — the client's database files. 18 tables have typed schemas (Map, Spell and its duration/radius siblings, the creature and character-customisation tables, Item/ItemDisplayInfo, the lighting tables, and more), verified with wow-cli dbc check; column-type inference transcribes the rest of the 245 tables in the install on demand.

• BLP textures — DXT1/3/5, palettized at every alpha depth, and raw BGRA, with PNG export. Compressed blocks are also exposed unmodified, so the renderer can hand them to the GPU without a CPU decode.

• M2 models — header, vertex pool, bone hierarchy, materials, and the .skin files holding the actual triangles, plus the DBC walk that turns a creature display id into a model on disk.

• Animation — keyframe tracks, the external .anim files most sequences actually live in, alias resolution, and GPU skinning.

• WMO objects — buildings and dungeon interiors: root plus group files, materials, render batches, collision separation, and doodad sets.

• ADT terrain — WDT tile maps, height fields, texture layers with their alpha maps, and the doodad and world-object placements that fill the world.

• Protocol — SRP6 login against the auth server, the realm list, the world handshake and its RC4 header cipher, movement (walk, strafe, jump, fall), chat, spellcasting, melee combat, and a replicated WorldState that folds every packet into the world other players and creatures actually see: creatures slide along their real path and play the model's own walk/stand cycles. Confirmed against a live realm with two clients at once, including one watching the other move.

• Interface — a native, from-scratch UI with no addon support: player and target unit frames, click-to-target, a chat window, three action bars with real spell icons, hover tooltips, a cooldown sweep, and a spellbook you build the bars from. Every position, size and colour is a plain number in ui.toml, editable by hand or by dragging frames in-game. See docs/UI.md.

• Game — auto-attack and swing-timer melee with a named combat log, spell casting off real Spell.dbc data (82% of its description templates resolve), and a player character drawn in third person with its own chosen face, skin, hair and gear -- weapon included, drawn on the correct attachment bone and sheathed to the position Item.dbc names for it.

Verified against a stock build 12340 install: 203,949 paths, of which 198,827 read and decompress cleanly (21.4 GiB) and 5,121 are correctly masked by patch tombstones. The one remaining unresolved path is a stale entry in Blizzard's own listfile. All 245 DBC tables present in the install parse, as do all 107,927 readable textures, all 22,779 models with their 24,626 skins (9.9M vertices, 15.9M triangles), and all 1,985 world objects with their 9,346 groups (29.4M vertices, 31.6M triangles). All 5,744 terrain tiles across 106 maps parse with every chunk edge meeting its neighbour, carrying 1,023,338 doodad and 11,182 world-object placements.

$ wow-cli --data "D:/Games/World of Warcraft 3.3.5a/Data" info
17 archives, in load order (last wins):
   1. common.MPQ           2723.8 MiB    83670 listed
   ...
total unique paths: 203949

$ wow-cli --data ... which 'DBFilesClient\Map.dbc'
DBFilesClient\Map.dbc
  -> .../enUS/patch-enUS-3.MPQ
     43226 bytes (7746 packed), compressed

$ wow-cli dbc rows Map --limit 1
MapRow { id: 0, directory: "Azeroth", instance_type: 0, name: "Eastern Kingdoms", ... }

Viewer

apps/viewer puts assets on screen. It also renders headless, which is how the GPU path is checked without a display:

cargo run -p wow-viewer -- --creature 1216            # a gnoll, skinned and animated
cargo run -p wow-viewer -- --map Azeroth --tile 31,48 --stream --radius 2  # fly over Stormwind
cargo run -p wow-viewer -- --map Azeroth --tile 32,48 --world  # one tile, populated
cargo run -p wow-viewer -- --wmo 'World\wmo\Azeroth\Buildings\Human_Farm\Farm.wmo'
cargo run -p wow-viewer -- --model 'World\...\HumanGuardTower.m2'
cargo run -p wow-viewer -- --texture 'Interface\Icons\Spell_Fire_Fireball02.blp'
cargo run -p wow-viewer -- --screenshot frame.png --creature 1216 --yaw 0

Drag to orbit, scroll to zoom. DXT textures are handed to the GPU as Bc1/2/3 blocks with no CPU decode, and the overlay reports which path each texture took and why. See docs/RENDERING.md.

Playing on a realm

Run wow-viewer with no arguments -- double-clicking it counts -- and it opens a sign-in screen: account, password, realm server, and a cat-headed button that asks where your Data folder is. Sign in and it lists the characters on the account for you to pick one. It remembers everything but the password, which it never writes anywhere.

It does not create characters. Make those in the original client; this one plays them.

The command line still says the whole thing, which is what every probe and screenshot in docs/ relies on:

cargo run -p wow-viewer -- --realm-host <host> --user <account> --character <name>

Given all three it connects straight away and never shows the screen. Given some of them it shows the screen with those parts filled in.

W/S walk, A/D turn, Q/E strafe, Space jumps, right-drag steers while left-drag swings the camera, left-click selects and right-click attacks. Enter opens a chat line, P opens the spellbook, F1 unlocks the interface for dragging. wow-cli world and wow-cli auth do the login half headlessly, for scripting or for checking a capture without a window. See docs/PROTOCOL.md.

The interface comes in four palettes -- slate, neko, void and calico -- picked from the sign-in screen's settings. Choosing one writes the colours into ui.toml, so a theme is a starting point you then edit rather than a layer hiding under the file. See docs/UI.md.

Getting started

You need a 3.3.5a installation (verify Wow.exe reports file version 3, 3, 5, 12340) and a recent stable Rust toolchain.

cargo build --release
cargo run -p wow-cli -- --data "<path>/Data" info

Set WOW_DATA to avoid passing --data every time. If your source tree lives on a network share, see docs/BUILDING.md.

Releases

Prebuilt Windows binaries (wow-viewer.exe, wow-cli.exe) are attached to each GitHub Release as a zip -- no build toolchain required, and, per the design commitments above, no game assets inside it either. Unzip it, point wow-viewer.exe at your own Data folder from its sign-in screen (or pass --data), and go.

Cutting a new release (maintainers): push a tag matching v*.*.*, e.g.

git tag v0.1.0
git push origin v0.1.0

.github/workflows/release.yml picks that up, runs the same zero-warning build and full test suite this project holds itself to, packages both binaries plus the README into a zip, and publishes it as a GitHub Release with auto-generated notes. A tag is the only trigger that publishes; the workflow can also be run by hand from the Actions tab (workflow_dispatch) to sanity check the build without cutting a real release.

Design commitments

These are the constraints the project holds itself to; they are the reason it is structured the way it is.

1. No game assets, ever. Not in the repo, not in releases, not in test fixtures. Tests that need real data are gated behind WOW_DATA and skip when it is unset.
2. Formats are implemented in-tree from public documentation. Every WoW format parser is ours. Generic plumbing (GPU, windowing, zlib) comes from the ecosystem. See docs/REUSE-POLICY.md.
3. No GPL code in the tree. The reference server implementations are GPL; we read the public protocol documentation instead, so this project can stay MIT/Apache-2.0.
4. Every layer is inspectable from the CLI before it is wired into the engine. A format is not done until wow-cli can dump it.

License

Dual-licensed under MIT or Apache-2.0, at your option.

World of Warcraft is a trademark of Blizzard Entertainment, Inc. This project is not affiliated with or endorsed by Blizzard Entertainment.