Nanolathe

Nanolathe is an independent, open-source 2.5D real-time strategy engine in Go. Its current focus is a clean-room reimplementation of Total Annihilation for single-player skirmish and campaign play, with documented game formats and an experimental GPU renderer. It is under active development, with incomplete behavior and compatibility gaps.

Official website · Get started · Documentation · Contributors and AI agents

Engine footage captured offline with --film from films/announce.json. Opens on YouTube.

The engine reads content from your own local Total Annihilation installation. Nanolathe's original code is MIT licensed; the license does not grant rights to the original game or retail-derived artwork. Retail-derived remaster exports are excluded from this curated copy. See the publication review for the history policy and remaining provenance questions.

Run

The one-command installer downloads a private Go toolchain, builds the current tested source release, and creates a shortcut. It remembers one selected Total Annihilation installation and stores new saves separately. See the installer guide for updates, paths, and platform limitations.

To build manually, install Go 1.27.1 or newer and provide a local retail installation. Ebitengine 2.10 builds on desktop platforms with Go alone; macOS requires version 13 or newer. Linux still needs a graphical desktop and graphics/audio runtime libraries.

git clone https://github.com/nanolathe-gg/nanolathe.git
cd nanolathe
go build -o nanolathe ./cmd/nanolathe
./nanolathe

With no --root, Nanolathe searches registered and standard installation locations first, including GOG, Steam libraries, and Wine installations. It also checks nearby game folders and finally ~/TotalAnnihilation (a convenient location for manually placed data on macOS and Linux). It mounts only the first installation found in that order; detected installations are never overlaid. A build installed by the source installer and started directly uses the game folder its launcher remembered instead. A custom installation can be selected explicitly:

./nanolathe --root "/path/to/Total Annihilation"

The installed launcher selects one root explicitly and supplies its own --save-dir. Manual launches preserve the root policy above and save beside the game installation unless --save-dir "/path/to/saves" is supplied.

Skirmishes default to 1000 units per player under Strict 3.1 and to the gameplay feature table's limit otherwise (1500 in Modern and Community 3.9, or whatever a mod's table names). Override with ./nanolathe --unit-limit 2000, or set the top-level "unitLimit": 2000 value in ~/.config/nanolathe/settings.json (or $XDG_CONFIG_HOME/nanolathe/settings.json; NANOLATHE_SETTINGS overrides the full path). Accepted limits are 20..3276. Either override beats the feature table, and CLI takes precedence over the saved value. The CLI value is not saved, and the settings file only records a unitLimit you wrote yourself. Earlier builds wrote a unitLimit into the settings file on their own (usually 1000, sometimes a one-off --unit-limit or a loaded save's limit), and it now counts as your choice: remove that line to get the table's limit back. This also works with direct --map, --headless, and nanolathe-headless. Campaign missions retain their authored unit limits.

Downloaded mods live in $XDG_DATA_HOME/nanolathe/mods (default ~/.local/share/nanolathe/mods). Automatically remastered map tiles and feature sprites live in $XDG_CACHE_HOME/nanolathe/upscale/1 (default ~/.cache/nanolathe/upscale/1).

Mods can live in separate directories. Repeat --root in load order:

./nanolathe --root "$HOME/TotalAnnihilation" --root "$HOME/TA-Mods/MyMod"

For ProTA 4.8, see the ProTA setup and support notes. For Escalation Gold 10.2.0, see the Escalation support notes. For TA Zero Alpha 5, see the TA Zero setup and support notes.

Every later root overrides earlier roots, even when a later totala1.hpi provides a file already supplied by an earlier .ccx, .gp3, or loose file. Within each root, the existing loose-file and archive precedence is unchanged. This extra precedence layer is a deliberate departure from retail only when multiple roots are used. A mod root may contain only its overrides; it does not need its own base archives. Retail's content rules still apply, including packing unit and weapon definitions into archives.

Explicit roots replace automatic discovery. With no --root, NANOLATHE_TA_ROOT selects one root instead of discovery. Saves use the first root; --remaster overrides the entire root list. Both desktop and headless commands support these rules. See startup root policy for discovery details and limits.

The default launches the front end with the modern GPU renderer and a 60 FPS cap. Options → Nanolathe selects Classic / Modern and 30 / 60 / 120 FPS; OK saves the choices for future runs. F10 switches renderers during a match and saves that choice. Classic retains its 30 FPS presentation cadence. Use ./nanolathe --help for map, rendering, and diagnostic options. The separate cmd/nanolathe-headless command supports displayless simulation runs; see architecture and verification.

Desktop fullscreen is available with --fullscreen; Alt+Enter toggles it from menus or battle and saves the preference. Use --fullscreen=false to start windowed regardless of the saved preference. The selected display size applies to the window throughout menus, loading, battle and results; menu art scales proportionally from its authored 640×480 canvas. The resolution slider also offers 1280×720, 1600×900, and 1920×1080. Resolution changes apply when you confirm Options with OK; dragging the slider leaves the window stable. Fullscreen scales to the desktop without changing the monitor resolution. On macOS, fullscreen entered through the green window button must be exited through that native control.

For music, copy the GOG installation's music folder into the same retail root. Nanolathe plays its MP3 soundtrack on Windows, Linux and macOS; no conversion is needed. Music starts when a battle begins. Options → Music controls volume, playback mode and track selection. The main menu retains its retail ambient loop.

Multiplayer is designed and not yet built: see docs/DESIGN_MULTIPLAYER.md. For implemented contracts and known gaps, read the design document for the relevant engine area.

Contributors and AI agents

Read AGENTS.md before making changes; it is the authoritative contribution guide for people and coding agents. Work in an isolated worktree, preserve concurrent work, and follow its verification and landing rules.

Start with the architecture, invariants, and the design document for the area you are changing. Follow their research citations before implementing behavior; record unanswered questions explicitly instead of guessing.

The repository keeps each kind of guidance in one place:

• AGENTS.md — contribution rules, clean-room discipline, worktrees, dispatch, review, and landing.
• docs/ARCHITECTURE.md — package map, dependency graph, the authoritative tick, what runs today, verification, and the citation routing every token in the tree resolves through.
• The eleven design documents, one per engine area — how it is built in Go, its contracts, and which research owns each behavior: DESIGN_RUNTIME_DETERMINISM, DESIGN_CONTENT_VFS, DESIGN_WORLD_VISIBILITY, DESIGN_UNITS_ORDERS_COB, DESIGN_MOVEMENT_PATH, DESIGN_ECONOMY_CONSTRUCTION, DESIGN_WEAPONS_PROJECTILES, DESIGN_INTERFACE_HUD_INPUT, DESIGN_SESSIONS_AI_SAVE, DESIGN_PRESENTATION_CLIENT, DESIGN_GPU_RENDERER.
• docs/INVARIANTS.md — cross-cutting implementation rules every change must preserve.
• docs/SPEC_CONFLICTS.md — audited cases where a retail install corrected an older written contract.
• research/retail-executable-spec/README.md — research reading order, category index, evidence language, deciders, writing rules, citation convention, and gap disposition.
• research/formats/README.md — file-format reference. Format documents own byte layout; the executable specification owns runtime behavior.

A design document is a description of the build, not a checklist: it states the contracts the packages implement and, in its last section, what is not implemented and what is still open. Research states what retail does; the design documents state how this tree does it.

Current boundary

The runtime has one Ebitengine window path. internal/session owns the authoritative tick and publishes bounded unit/order, projectile, effect, economy, construction, HUD, and fog state directly into the committed internal/frame.Buffer; internal/client reads that current committed frame and never writes simulation state. Classic presentation samples the committed tick as published, with no interpolation [03 §2.4] [I6]. The experimental modern renderer has its own presentation policy, including interpolation that leaves authoritative simulation unchanged.

Save/load uses the retail HAPIBANK account format, including in-battle restoration. This is still a compatibility work in progress; the session design describes the implemented accounts and remaining gaps.

Exact-retail gaps remain explicit as TODO(T23), TODO(T25), or TODO(question) at their implementation site and under the relevant research document's Unknown section. Do not replace them with plausible defaults.

Build and check

With neither NANOLATHE_RETAIL_ASSETS nor NANOLATHE_TA_ROOT set, these checks use authored fixtures and skip tests that require retail assets. Desktop packages require the native build prerequisites above.

go build ./...
go vet ./...
go test ./...

./tools/check runs the same checks plus formatting and explicitly disables retail tests, even if your shell has asset variables set.

For the separate asset-backed integration gate, including retail-tagged tests:

NANOLATHE_RETAIL_ASSETS="$HOME/TotalAnnihilation" ./tools/check-retail

Use an isolated writable GOCACHE when the host environment requires it. Report whether an asset-backed run actually executed when sharing test results.

Clean-room contribution rule

Committed prose describes what retail does in plain technical language with a confidence level and a document/section citation. Executable addresses, decompiler output, generated names, register narration, and raw analysis stay outside the repository in $HOME/ta-decompile. See AGENTS.md before changing research or authoritative behavior.

About this history

This repository presents curated integration snapshots of the original private development history. Adjacent changes have been combined in ancestry order; development-only artifacts and raw-analysis material were removed. Intermediate snapshots represent work in progress, not individually verified releases. The final source was checked separately. See the publication review for scope and limitations.