ludic/README.md

Ludic

Ludic is an ahead-of-time compiled language for 2D games with an entity-component core, a deterministic fixed-point runtime, and its graphics stack built into the language. ludicc lowers Ludic straight to LLVM IR and emits a native binary — and ludicc is itself written in Ludic, compiles its own source to a byte-exact fixpoint, and rebuilds from a checked-in IR seed with no C compiler in the loop.

  .ludic  ──►  ludicc  ──►  LLVM IR  ──►  object  ──►  native binary
             (in Ludic)

No C is generated, compiled or linked in a build. No interpreter, no transpiler, no C runtime: the framebuffer, sprites, PNG/DEFLATE decoding, TrueType text, the retained UI, the registers and the RNG are all written in Ludic (runtime/native/*.ludic); only the window seam — five win_* functions — is hand-written LLVM IR against the platform ABI (runtime/native/cocoa.ll), the same floor Rust and Swift stand on.

Backends

Backend	Status
Native 2D (macOS/Cocoa window; headless render for CI)	Shipping — the default bin/x app target.
Web / wasm32	In progress. The browser platform layer is in-tree and documented — runtime/web/ (the <canvas> window platform.js, the libc-free wasm.ll floor) and a Node harness that diffs native vs. wasm frame-for-frame (tools/ludic-web/run.mjs). Emitting wasm was a capability of the retired C compiler and is not yet re-wired on the self-hosted toolchain; see COMPILING.md.

The same is true of --target cross-compilation and --shared libraries: both are designed and documented, both lived in the old C compiler, and both are pending re-implementation on the self-hosted native toolchain.

Quick start

bin/x is the project's task runner — one native binary, written in Ludic and compiled by Ludic, that replaces every build/test/bootstrap shell script. Bootstrap it once from a clean checkout (the only step Ludic can't do for itself, since compiling Ludic needs a compiler) with clang alone:

clang selfhost/ludicc.seed.ll -o bin/ludicc && bin/ludicc tools/x/main.ludic -o bin/x

Then build the whole toolchain and run a game:

bin/x build                                  # -> bin/{ludicc,ludic,x,ludic-fmt,ludic-lsp}
bin/x app examples/games/snake.ludic         # compile + open a native window
./build/snake

Render a frame headlessly (what CI checks) — output lands in build/, never the repo root:

bin/x app examples/games/chronorift.ludic --headless
mkdir -p build && printf 'ddddwww' | ./build/chronorift_headless   # writes build/out.ppm
sips -s format png build/out.ppm --out frame.png

Run the suites:

bin/x test            # full regression: compiler builds from seed, every example, golden renders
bin/x selfhost-test   # correctness + the self-hosting / C-free bootstrap fixpoints
bin/x help            # every command

Layout

Path	What it is
selfhost/*.ludic	the compiler, written in Ludic — lexer, parser, and the LLVM-IR backend (ECS storage, queries, spawn, match/machine, UI, scenes, save/load, fixed-point). Built from selfhost/ludicc.seed.ll with clang alone.
selfhost/golden/renders.sha256	text baseline of render-output hashes (replaces binary .ppm fixtures); regenerate with bin/x golden.
tools/x/*.ludic	the task runner, written in Ludic — one binary (bin/x) that builds, tests, bootstraps and reseeds the project, replacing every shell script.
runtime/native/	the runtime in Ludic for the native path: core (framebuffer, input, RNG), image/inflate (PNG + DEFLATE, no zlib), truetype (glyph rasterizer), ui (retained widget tree); plus cocoa.ll, the macOS window seam in LLVM IR.
runtime/web/	the browser platform layer: platform.js (the <canvas> window), wasm.ll (the libc-free floor), index.html.
examples/	the example tour, grouped by intent — games/, rendering/, ecs/, events/, networking/, lang/, library/. See examples/README.md.
tools/ludic-tools/	the editor toolchain in Ludic: ludic-fmt (formatter) and ludic-lsp (language server) — one lexer, one vocabulary shared by both.
tools/editors/	plugins for VS Code and JetBrains, plus config for Neovim, Helix, Emacs, Sublime and Zed.
docs/	the per-symbol API reference, regenerated into the docs site.
COMPILING.md	the native pipeline: ludicc → LLVM IR → exe, the rt_* runtime protocol, and the (pending) wasm/cross-compile/shared-library paths.

Design and roadmap documents — LANGUAGE.md, EVENTS-DESIGN.md, NETWORKING-DESIGN.md, SCENES-DESIGN.md, LIFECYCLE-DESIGN.md, SYNTAX-REDESIGN.md, MOBILE-DESIGN.md, LUANTI-ROADMAP.md, BOOTSTRAP.md — live at the repository root today and are being migrated to the wiki.

Language at a glance

• program / property (typed fields + defaults) / model (named entity kinds) / system (phase, @annotations, reads/writes).
• ECS queries for (a, b) in query [A, B, {Tag}] where <expr> { … }, spawn/despawn with slot reuse, @-driven lifecycle hooks.
• An event bus (event / emit / @On, cancellable, @Public promotion) and networking primitives (@Sync, ownership, RPCs) over a built-in loopback transport — all deterministic, all pure Ludic.
• scene / layer / become, match / machine + state.
• Types int, fixed (Q16.16), bool, entity, str, byte, typed buffers; a growing namespaced standard library (Math, Vector, Time/Date/ Duration/Clock, Random, Hash, Crypto, sorting, …).
• Deterministic seeded RNG and save()/load() snapshot of the whole World.
• Built-in 2D: framebuffer primitives, PNG sprites, TrueType text, 9-slice, and a retained ui widget tree declared as data.

See LANGUAGE.md for the full reference, and examples/README.md for runnable demos of each feature.

Editor support

bin/x tools                     # -> bin/ludic-fmt, bin/ludic-lsp

ludic-lsp speaks LSP 3.17 over stdio, so one binary serves every editor: context-aware completion, diagnostics from the compiler itself, go-to-definition and rename across imported files, and comment-preserving formatting. ludic-fmt is the same formatter as a CLI, for pre-commit hooks and CI. Both also understand ```ludic fences in Markdown. Plugins and drop-in config are in tools/editors/.

Chrono Rift — the flagship game

examples/games/chronorift.ludic is a playable co-op JRPG — overworld, dungeon, random encounters, a turn-based co-op battle, a boss, an item shop and snapshot save/load — split across modules under games/chronorift/. Its art is CC0 Kenney sprites, decoded from PNG at runtime by the Ludic-written PNG/DEFLATE decoder — no zlib, no external dependency.

• Overworld: WASD move, K save, L load.
• Battle (local co-op): P1/Knight W/S select, Space confirm; P2/Mage I/K select, J confirm.

Status & roadmap

The compiler self-hosts to a byte-exact fixpoint and rebuilds from its IR seed with no C compiler; the ECS runtime, windowed + headless 2D rendering, the event bus, the deterministic networking stack, scenes, and save/load are all in place and covered by bin/x test. CI gates every push and PR on the build, the test suites, and that C-free fixpoint. The toolchain is versioned with SemVer (ludicc --version); releases and the CHANGELOG.md are cut from changesets by x release.

Active work and proposals — the standard library, a fuller type system, rendering/animation/lighting extras, input, filesystem/IO, testing, and re-wiring the web/wasm and cross-compile backends — are tracked as issues, not inlined here:

• Issues & proposals: https://git.workshopsoft.io/workshopsoft/ludic/issues
• Docs site (API reference): https://workshopsoft.pages.workshopsoft.io/ludic/
• Wiki (design & roadmap): https://git.workshopsoft.io/workshopsoft/ludic/wiki

Contributing

See CONTRIBUTING.md for the development loop (bin/x reseed → bin/x bootstrap-cfree → bin/x test), the code and commit conventions, and how the bootstrap fixpoint works. Issue and pull-request templates live under .forgejo/.

License

The Ludic compiler and runtime source are licensed under the Apache License 2.0 (SPDX-License-Identifier: Apache-2.0) — a permissive license with an explicit patent grant.

The bundled Kenney art under assets/kenney/ is third-party and released under CC0 1.0 (public domain); each pack keeps its own License.txt. Code and assets are licensed separately: Apache-2.0 covers the source, not the art.