DOOM in Whitespace

The original DOOM — id Software's linuxdoom-1.10 C source, unmodified — compiled to Whitespace, a language whose only characters are space, tab and newline. doom.ws is the whole game, engine and shareware episode: 36 MB of whitespace.

Play it: https://overstruck.github.io/whitespace-doom/

Arrows move, Ctrl fires, Space opens, Shift runs, Alt strafes, 1–7 pick weapons, Tab shows the map, Esc opens the menu.

How it works

The Rust workspace is a C compiler and a Whitespace interpreter:

• crates/ccfront preprocesses and parses the C89 source; crates/ccback compiles it to Whitespace. Memory is one heap cell per C scalar (sizeof counts cells).
• crates/runtime (libc, game data access, savegames) and crates/platform (DOOM's i_*.c: video, keyboard, timer) are written in a Rust DSL that emits Whitespace (src/dsl.rs).
• The levels, graphics and demos become heap cells that the program stores at start-up.
• crates/doomgen links everything into doom.ws.

Whitespace programs can only read and print characters, so that is how DOOM talks to its host:

• Time: when no key is waiting, the host sends byte 0x80+N for N elapsed tics of 1/35 s. Without it (any standard interpreter) DOOM runs turn by turn: 4 tics per key.
• Screen: in a terminal DOOM prints each frame as ▀ characters in 256 colours. The web page answers DOOM's screen-size query with 0;0, then gets raw 320×200 frames and palettes and sends real key presses and releases.

The web page runs doom.ws in the interpreter (src/vm.rs) compiled to WebAssembly (crates/web).

Run it locally

cargo build --release
./target/release/doom             # serves the page and opens it in a browser window
./target/release/doom --terminal  # plays in the terminal (z fires, always runs)
./target/release/doom other.ws    # runs any Whitespace program

Rebuild

cargo run --release -p doomgen    # writes doom.ws
cargo test --release --workspace

The page's pkg/ needs the wasm32-unknown-unknown target and wasm-bindgen-cli 0.2.129:

cargo build --release -p doom-web --target wasm32-unknown-unknown
wasm-bindgen --target web --no-typescript --out-dir pkg target/wasm32-unknown-unknown/release/doom_web.wasm

Differences from DOS DOOM

No sound; saved games last until you quit or reload; the three demos' version byte says 1.10 so linuxdoom plays them.

License

GPL-2.0 (LICENSE). DOOM's source in vendor/ is id Software's, released under the GPL in 1999 (the files keep their 1997 headers). The game data inside doom.ws is id Software's freely distributable shareware.