Unity Tutorial Project in Haskell with Apecs and SDL2

This is a project based on the Unity 2D Roguelike tutorial. It doesn't follow the tutorial by the letter, but is very similar. Assets are from https://learn.unity.com/project/2d-roguelike-tutorial. It is built upon the ECS apecs for game logic and sdl2 for window management, images, audio and fonts.

Issues during development

• Some .aif files wouldn't work so converted them to ogg
• Some documentation about SDL2 bindings that I had a hard time finding, but managed to find what I needed from the respective Github projects of the different bindings.

Inspiration

https://hackage.haskell.org/package/apecs

• apecs is an ECS I always wanted to try out

http://jxv.io/blog/2018-02-28-A-Game-in-Haskell.html

• Non-apecs example with SDL2

https://nmaehlmann.itch.io/mallrl

• Main inspiration of how to use apecs and SDL2 in a game

https://lazyfoo.net/tutorials/SDL/

• Tutorials on how to use SDL2

https://github.com/haskell-game/sdl2
https://hackage.haskell.org/package/sdl2-image
https://hackage.haskell.org/package/sdl2-mixer
https://hackage.haskell.org/package/sdl2-ttf

• Couldn't have done it without the SDL2 bindings

https://hackage.haskell.org/package/rapid-0.1.4/docs/Rapid.html
https://github.com/ndmitchell/ghcid

• For hot reloading

Building on Linux

1. Install SDL2 via apt

sudo apt install libsdl2-dev libsdl2-ttf-dev libsdl2-image-dev libsdl2-mixer-dev libsdl2-gfx-dev libsdl2-net-dev

2. Build and run

stack run

Building on Windows

1. Install SDL2 via stack & pacman:

stack exec -- pacman -Syu

stack exec -- pacman -S mingw-w64-x86_64-pkg-config mingw-w64-x86_64-SDL2

2. Build and run

I couldn't make stack run work, so the easiest way to play it is to do either

• Execute stack ghci and run main
• Execute stack build --copy-bins --local-bin-path . and run the built binary (game-exe)

Development

For development use rapid and ghcid for some kind of "hot reloading". Rapid allows one to persist state (eg. window, renderer and game state) across ghci reloads and ghcid a simple way of recompiling changed code and running the Rapid entrypoint.

• Install ghcid by executing stack install ghcid
• Execute ghcid
  • Passed flags can be found in .ghcid
  • Window should appear and update whenever there is a code change

Input

• Main Menu
  • ArrowUp, ArrowDown, Enter, Esc (Return to game)
• Game
  • ArrowUp, ArrowRight, ArrowDown, ArrowLeft, Esc (Return to menu)

Related projects

Check out https://github.com/Simre1/hero, it's an ECS like APECS and seems like a really cool project! I hope to make this unity tutorial project for it as well.

Check out https://github.com/matthunz/aztecs, it's also an ECS!

Thanks

If I forgot something or you think something should be added just open an issue! Free to do whatever with my code, but the assets aren't mine.