simonmichael / games

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

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

• #haskell-game matrix / IRC chat (also Discord, Telegram chats)
• https://haskell-game.dev
• http://www.reddit.com/r/haskellgamedev
• http://www.haskell.org/haskellwiki/Game_Development
• http://hackage.haskell.org/packages/#cat:Game
• https://github.com/haskell-game

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