Play and share your game in a browser

Open a game

One command builds, serves and opens the game:

lcom-ng web path/to/my-game

Inside the project folder:

lcom-ng web .

The project path defaults to the current folder. In this repository, prefix commands with devenv shell --:

devenv shell -- lcom-ng web examples/ninjix

Click the game to capture the mouse; the cursor moves past the browser edge.

Escape reaches the game. In fullscreen, browsers with Keyboard Lock keep capture. Windowed play and other browsers reserve Escape to release capture and also send it to the game once. Click again to recapture.

Shift+Escape releases a captured mouse; in a collection, press it again to return to the library. The top-right button toggles fullscreen.

Right Option on Mac and Right Ctrl release the mouse without sending Escape. Command stays available for app shortcuts. Sound starts on the first keypress or tap. Refresh restarts; press Enter after the game exits. If the browser cannot capture the pointer, the game reports it and keeps ordinary dragging.

On mobile, touch presses the left button at the game cursor; lift to click, drag to move with the button down. This is the default relative control. Projects can enable direct touch to tap at the finger.

• Mouse stick moves without clicking. Left click and Right click can be held with another finger; holding Right click makes a drag use that button.
• Esc, Space and Enter stay within reach. Keyboard shows the full keyboard, including latched Shift, Ctrl and Alt and Fn keys.
• Joystick starts in Mouse mode; push further to move faster. Arrow keys or WASD switch it to keyboard movement. Mouse + arrows or Mouse + WASD shows two sticks.
• Hide controls collapses the panel; Controls reopens it. Panels start closed. Landscape places panel controls beside the game; portrait moves them to the bottom.

Press Ctrl+C to stop. Re-run after source changes. --port 8080 chooses a port, --no-open prints the URL, and --host 0.0.0.0 lets a phone on the same network connect.

Play published games

• Plants vs. Zombies
• Ninjix
• Sushi Slash

Collection games with authored instructions open on Start game. Instructions reopens them during play.

Your project

Optional lcom.json sets title, icon, preview, mobile settings and theme; web and Android share it. For instruction screens and shortcut rows, see Instructions in the browser Arcade.

The exporter discovers:

• C files in the project root and under src/, with headers under include/;
• generated student workspaces, including proj/, lib/ and labs/;
• original Minix Makefiles and their source libraries.

assets/ is included automatically, preserving paths. For another layout, select files explicitly:

lcom-ng web . --source game/main.c --source shared/timer.c --include headers \
  --asset images --asset sounds

Explicit --asset replaces the automatic assets/. Use --arg value, or --arg=--option for values starting with a dash. Minix source libraries use --library name=file.c,other.c.

For legacy absolute paths, select the parent workspace:

lcom-ng web . --asset-root .. --asset proj/assets

Sources stay unchanged. The exporter rebuilds for WebAssembly; it does not convert a desktop or Minix binary.

Publish

lcom-ng export web path/to/my-game --output dist/my-game

Upload the complete folder to static hosting. Keep files together and serve .wasm as application/wasm. HTTPS is recommended. Players need only a browser; no special isolation headers are required.

Preview with python3 -m http.server 8080 --directory dist/my-game. Opening index.html from the filesystem is not supported.

Browser compatibility

The same export targets current Chrome, Edge, Firefox and Safari. Emscripten compiles to WebAssembly using Asyncify; no threads, SharedArrayBuffer or JavaScript Promise Integration are required.

Browser	Expected behavior	Verification
Chrome and Edge	Game, audio, keyboard and captured desktop mouse input	Chromium automated tests
Firefox on desktop	Same export, with desktop mouse capture	Automated collection startup and pause/resume checks
Safari on macOS	Same export, with desktop mouse capture	Not yet tested
Safari on iPhone and iPad	Game, audio and custom touch keyboard; no Pointer Lock	Physical devices not yet tested

Desktop capture uses Pointer Lock after a click. Touch keeps relative or direct controls. Embedded browsers may restrict capture. Mobile tests use touch emulation and do not certify every browser.

Tools and limits

Devenv supplies the compiler and build tools. Outside Devenv, install Emscripten, Python 3.11 or newer, CMake and Ninja. Minix exports also need the matching llvm-link next to Emscripten's Clang. Earlier archives may not include these commands.

• Single player and local UART loopback are supported. Paired instances and online multiplayer are not.
• Saved files disappear on reload. The clipboard is private to the game.
• Program output goes to the browser console. LCF output-file logging reports that it is unavailable.
• Inactive windows and hidden tabs pause virtual time and release held input.
• Native processes, threads, assembly and external libraries may need changes. Long computation without SDK calls cannot yield to the browser.