NetHackWeb

This is a browser/mobile implementation of NetHack, based on NetHack 3.7's support for cross compilation to WebAssembly. Thank you in particular to apowers313 who did the ground work when it comes to cross compilation to WebAssembly (NetHack/NetHack#385).

If you just want to play, go to https://guillaumebrunerie.github.io/nethack.

If you are interested in the source code, keep reading.

File structure

• build contains NetHack compiled to WebAssembly (the nethack.js and nethack.wasm files). To compile it yourself, get NetHack's source code from git, install emscripten, and run:

  make fetch-lua
  ./sys/unix/setup.sh ./sys/unix/hints/linux.370
  make CROSS_TO_WASM=1
  

  Then you will find nethack.js and nethack.wasm in ./targets/wasm. You might need to tweak things to make it work on your system.

• lib contains a Typescript interface to NetHack's APIs for supporting different windowing systems. For documentation, check https://github.com/NetHack/NetHack/blob/NetHack-3.7/doc/window.txt.

  The main function it exports is startNethack which takes as first argument an object containing a function field (or method) for each method supported by NetHack (see above). So for instance you would use it like this:

  startNethack({
    rawprint(str) {
      [...]
    },
    ...
  })

  The Typescript interface is meant to be as close as possible to the official one, but with Typescript types and conventions. Note in particular:

  • All method names are converted from snake_case to camelCase. So print_glyph becomes printGlyph, etc.
  • Most enum-like data types are changed from integers to unions of literal strings.
  • Functions are made async whenever appropriate.
  • The status_update method is split in two different methodes: statusUpdate and statusUpdateConditions (read the documentation and you'll understand why).
  • Some functions pass pointers and expect you to use them as output values, this is here changed to regular output values (see for instance nh_poskey and select_menu). In particular, you should not have to deal with pointers at all when using this library.
  • player_selection is an async function that returns either null or an object containing the name/role/race/gender/alignment chosen. If you return null, it will fallback to the default tty player selection.

  A few other functions are exported, for instance

  • getExtCmdIndex: returns the index of a given extended command
  • getUniqueExtCmdAutocomplete: returns the extended command (with its description) corresponding to the given prefix (and taking autocomplete into account)
  • copyrightMessage: returns an array of strings containing the copyright messages
  • flags/iflags: returns the current flags/iflags, which are needed in some circumstances
  • getRoleData/getRaceData/getGenderData/getAlignData: returns data on which roles/races/genders/alignments are available, and how they relate to each other

• src is an actual implementation of a windowing system based on the lib interface above. It is written in React and is meant to work both in the browser and on mobile. There are a few restrictions for now:

  • It only supports IBMGraphics (no tiles).
  • The config file is hard coded (in src/nethackrc.txt).
  • Saving is supported, but it does not save automatically if you just quit the browser (or if your mobile OS decides to kill the tab).