/games

Small games, experiments, and notes on (Haskell) game development.

Primary LanguageHaskell

Small games, experiments and game dev notes.

Games and experiments

✅ = confirmed installable on target platforms as of release date 🕹 = a playable game 🔔 = sound
✅🕹 tiny-games-hs 2023 haskell
✅🕹🔔 caverunner 2021 haskell, ansi-terminal-game
🔔 breakout 2007, 2020 haskell, sdl
✅ metapong 2019 haskell, ansi-terminal-game
✅ symon 2016 haskell, ansi-terminal
✅🕹 guess-the-number 2013 haskell, cli
hssdl-osx-template 2013 haskell, sdl
hssdl-mac-example 2011 haskell, sdl
animtest-hs 2010 haskell, sdl, opengl
wallofdoom 2009 python, pygame
rocks 2005 IO
🔔 frozen-bubble-py 2002 python, pygame
✅🕹 FunGEn game engine & example games (maintenance) 2008-present haskell, opengl

Haskell game development

See also

How hard is it to make games in Haskell ?

Pretty hard to figure out a good setup; relatively easy and pleasant after that, for non-resource-intensive games at least. These notes and examples aim to help.

Some problems and solutions

(as of 2021-09)

Packaging/installation

Minimising packaging boilerplate and complex/unreliable install instructions
Use a stack script with script command.

Getting stack script header just right

  • Specify all extra packages (packages other than base that you import from) with --package options in the stack script header. If you forget any, the script may run for you but fail for others.

  • If they depend on packages not in stackage, you must also mention each of those (the error message will list them.)

  • Use a block comment ({- -}) so that you can write packages and options on multiple lines. (A line comment (--) will work only for one line.)

Avoiding apparent hang when ghc is installed on first run
Add --verbosity=info to stack options line to show ghc install progress (but this also shows unwanted "resolver" output on every run. --verbosity=warning hides that, but still shows package install progress. --verbosity=error hides that too.)

Avoiding recompilation delay on every run
Use script --compile in stack options line (or script --optimize, which might take longer and/or run faster).

Running stack script in threaded mode when using packages that require this
(ansi-terminal-game, etc.): add --ghc-options=-threaded to stack options line

Providing ready-to-run binaries that don't require the user to have stack or other haskell tools

  • set up Github CI workflows to build binary artifacts on the main platforms (and ideally, statically link the GNU/Linux binary); add those to a Github release for stable download url.

  • mac: get your app packaged in homebrew

  • etc.

Providing screenshots/screencasts
use a convenient screenshot tool on your platform (eg CMD-SHIFT-5 and friends on mac); or install and use asciinema to record .cast files, asciicast2gif or similar to convert those to animated GIF images; add the images to a README.md.

Tools

Getting haskell-language-server to see extra packages, eg for editing in VS Code
add this hie.yaml in the same directory:

cradle:
  stack:

and stack install each extra package in stack's global project.
(Still flaky..)

Configure GHC build options, eg to silence unwanted warnings
Add lines above your imports like
{-# OPTIONS_GHC -Wno-missing-signatures -Wno-unused-imports #-}

Enabling/disabling GHC's optional Haskell language extensions
Add lines above your imports like
{-# LANGUAGE MultiWayIf, RecordWildCards #-}

Terminal/console games

Drawing anywhere on the terminal, portably
use ansi-terminal

Getting non-blocking input, a ready-made event loop, and more powerful drawing, portably
use ansi-terminal-game

Getting more powerful input/drawing/event loop, if you don't care about Windows
use vty and brick

Getting arrow key and modifier key inputs
use vty