raindrops

I've used this game in several talks to demonstrate that game programming in Haskell is very, very easy. If you attended any of those talks and listened to this boring fellow, thank you all for attending the talk :)

The slides for one of those talks are here: http://ivanperez-keera.github.io/slides/2015-04-upm-iperez/#/

I would recommend going through them again, in particular, to see the videos from youtube. These also explain why your game does not have to be 3D or complex to be good or successful. The last few videos are from games that became (at least for a few weeks) hits on Google Play.

A few pointers to help you on your way:

Haskell programming

• Learn you a Haskell for great good (Miran Lipovaca) (http://learnyouahaskell.com/chapters)
• Introduction to Functional Programming (Bird & Wadler) (old edition).

Functional Reactive Programming

• Functional Reactive Animation (Elliott & Hudak, 1997). I would recommend reading the Intro, and section 3 for larger examples. In section 2, I would skip the first part of section 2.1 if it becomes too hard to understand.
• http://conal.net/fran/tutorial.htm Contains multiple examples with animations.
• The Yampa Arcade (Courtney, Nilsson & Peterson, 2003) describes FRP based on Signal Functions in a very clear and concised way. It then uses it to create a small asteroids game.
• Yampa (Functional Reactive Programming implementation): https://github.com/ivanperez-keera/Yampa
• Elm (try FRP on your browser): http://elm-lang.org/try, http://elm-lang.org/Examples.elm

Game Programming

• Game Engine Architecture (Jason Gregory). (This book does not contain code. Instead, it tries to give you a good understanding of what game programming entails, the problems you will find, and good solutions. I personally think it's extremely good.)

Game Design

• The Art of Game Design: A book of lenses (Jesse Schell, ex-Disney, ex-Bell Labs, currently Carneige Mellon and CEO of Schell Games, a game development company with more than 100 employees).

Examples of games written in Haskell

• Nikki and the Robots. https://github.com/nikki-and-the-robots/nikki
• Haskanoid: http://github.com/ivanperez-keera/haskanoid (This game uses wiimotes, kinect and mouse.)
• Raincat: https://github.com/styx/Raincat
• Nario bros: https://github.com/keera-studios/monao
• Frag (3D, OpenGL): https://github.com/snowmantw/Frag (Note: this game is written in Yampa, a Functional Reactive Programmming framework)
• Falling Blocks (SDL): https://github.com/ivanperez-keera/fallingblocks (Note: this game is a good example of what one could do in 700 lines of Haskell. I would change a few things about the architecture, for instance, I would include an abstract Controller/Input, and separate rendering and logic game state, but the code is still quite clear.)
• Voldemort: an addictive, quick-paced arcade game https://github.com/ivanperez-keera/zurihac2015

Writing Haskell games for Android

On linux, just run the steps described here: https://github.com/neurocyte/ghc-android

It will create a chroot within which you will have a haskell compiler ready to create Android code. It takes some time to compile, but it should work perfectly. From that, creating your first hello world and running it on your phones should be trivial.

When you have your Haskell game running on desktop and want to distribute it for Android, drop me an email and I'll help you get it running. You'll need to create an Android project, a Java class and a small C program, but I can send you mine.

Recommendation: In your games, do not use print/putStrLn, or your code won't work well on Android.

Libraries

SDL (Simple DirectMedia Layer) is a collection of libraries that provides basic operations to do multimedia, networking, threading, etc. I recommend that you use it for your games, unless you need 3D.

SDL 1.2 and OpenGL are available on hackage. To install them, just: $ cabal install OpenGL and $ cabal install sdl sdl-image sdl-mixer sdl-ttf

For SDL2, I use the following repositories instead of what is available by default:

• https://github.com/keera-studios/hsSDL2.git
• https://github.com/jdeseno/hs-sdl2-image
• https://github.com/jdeseno/hs-sdl2-mixer
• https://github.com/osa1/hsSDL2-ttf/
• https://github.com/keera-studios/hssdl2-gfx

Assets

• OpenGameArt: http://opengameart.org/
• DaFont (only for fonts): http://www.dafont.com/

Online communities

• Facebook: https://www.facebook.com/groups/programming.haskell/

Other notes

Whenever you try new things using cabal, use sandboxes. Sandboxes help you keep your environment clean, by installing packages only in one directory instead of making them available for every user/haskell project.

It's simple:

mkdir myproject
cd myproject
cabal sandbox init
cabal install ...<whatever>...