Play and share your game in a browser

Open a game

One command builds the game, starts a local server and opens your browser:

lcom-ng web path/to/my-game

Inside the project folder, run:

lcom-ng web .

The project defaults to the current folder. In this repository, prefix commands with devenv shell --. Examples use the same project-folder command:

devenv shell -- lcom-ng web examples/ninjix

The game starts automatically. Desktop players see the game with black bars where needed. Click the game to capture and hide the system mouse. Right Ctrl releases capture. Escape reaches the game and also releases capture, so going back or pausing takes one press. Sound starts on the first keypress or tap. Refresh the page to restart, or press Enter after the game exits. Mouse capture requires Pointer Lock support. Embedded browsers without it hide the system cursor over the game but cannot keep it inside the window.

On mobile, touch the area above the controls to press the left mouse button at the game cursor. Lift to finish the click, or hold and drag to move the cursor with the button down. A new touch never jumps the cursor to your finger. Use the Mouse joystick to move without clicking. The separate Left click and Right click buttons can be held while using a stick. Holding Right click also makes a screen drag use that button instead of adding a left click.

Esc, Space and Enter stay within reach. Tap Keyboard to show or hide the full keyboard. Hold keys, combine touches, or tap Shift, Ctrl and Alt to latch modifiers. Fn switches to function keys, navigation and punctuation. The optional Joystick starts in Mouse mode: hold the stick to move the cursor, and push further to move faster. Arrow keys and WASD control keyboard movement instead. Mouse + arrows or Mouse + WASD shows two independent sticks, so you can move and aim together while holding a click button. Both panels start closed to leave more room for the game. Desktop stays game-only. Rotate to landscape to put the mobile controls beside the game on the right. Hide controls collapses that panel; tap Controls to bring it back. In portrait, the controls return to the bottom.

Press Ctrl+C in the terminal to stop the preview. Re-run the command after source changes. Use --port 8080 to choose a port or --no-open to copy the printed URL into another browser. To try a phone on the same network, add --host 0.0.0.0 and open your computer's network address with the printed port.

Play published games

• Plants vs. Zombies, built from the unchanged original student archive.
• Ninjix.
• Sushi Slash, built from the original upstream project.

Your project

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.

An assets/ folder is included automatically, preserving paths such as assets/background.bmp. 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 options replace the automatic assets/ selection. Use --arg value for each game argument; use --arg=--option for values beginning with a dash. Minix source-library overrides use --library name=file.c,other.c.

For legacy absolute paths such as /home/lcom/labs/proj/assets, select the parent workspace as the asset root:

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

Source files stay unchanged. The exporter rebuilds for WebAssembly rather than converting a desktop or Minix executable.

Publish

Create a standalone export without starting a preview server:

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

Upload the complete output folder to static hosting. Keep the files together and serve .wasm as application/wasm. HTTPS is recommended. Players need a browser, without installing lcom-ng or connecting to a game server. No special isolation headers are required.

Exports can also be previewed with python3 -m http.server 8080 --directory dist/my-game. Opening index.html directly from the filesystem is not supported.

Browser compatibility

The same export targets current Chrome, Edge, Firefox and Safari. Emscripten compiles the game and device core to WebAssembly. The build uses Asyncify and does not require threads, SharedArrayBuffer or JavaScript Promise Integration.

Browser	Expected behavior	Verification
Chrome and Edge	Game, audio, keyboard and desktop mouse capture	Chromium automated tests; native Chrome Escape checked
Firefox on desktop	Same export, including mouse capture	Not yet tested
Safari on macOS	Same export, including 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 Firefox and Safari support mouse capture. Safari on iOS does not expose Pointer Lock. Embedded browsers may also omit it. See the Pointer Lock compatibility data. Browser API availability is separate from testing this player on each device.

Chromium tests cover Flappy, Ninjix, native and Minix fixtures, installed SDK relocation, student workspaces, mouse capture, a single Escape after capture, multi-touch keyboard input, relative touch dragging, separate mouse buttons, and the optional joystick. Mobile tests use touch emulation. This does not certify every Minix project or every mobile browser.

Tools and limits

The repository's Devenv shell 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. Current source builds include these commands; earlier published archives do not.

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