README.md

Wolfenstein 3D in Haskell

Wolfenstein 3D in Haskell. Inspired by John Carmack's Quakecon 2013 Talk and mentions of trying to implement games (and Wolf3D in particular) in functional programming/Haskell.

The implementation aims to use similar runtime data structures to the original source. I want to get a better understanding of how the original works and also reap the performance rewards (my naive attempts at a ray caster before performed badly). Also I hope this helps getting the same feel as the original.

This is a work in progress and is still in early stages.

Requirements

• Stack (tested with 1.9.1-1.9.3)
• SDL2 (tested with 2.0.8-2.0.9)
• SDL2 Image (tested with 2.0.4)
• SDL2 TTF (tested with 2.0.14)

Setting up Development Environment

stack setup
stack build --pedantic

Running

stack exec wolf3d

or

stack exec wolf3d-debug

Running REPL

stack repl

Running Tests

stack test --pedantic

Or continuous:

stack test --pedantic --file-watch

TODO

• have press m to toggle map for debug

• move sprites forward a bit. This was fudged in original:

  • https://github.com/id-Software/wolf3d/blob/05167784ef009d0d0daefe8d012b027f39dc8541/WOLFSRC/WL_DRAW.C#L227

• id system for items

• multi engine approach outlined in first 60 or so slides of https://www.slideshare.net/naughty_dog/multiprocessor-game-loops-lessons-from-uncharted-2-among-thieves

• static sprite targets that hero can shoot and kill

• SimItem infrastructure - Update each item to produce events, process those events which generate new events

• Split SDL dependency into own module

  • split Display into multiple modules
  • merge UI into display? - simplifies some things like disposing and setting up renderer

• rendering alternatives

  • https://github.com/bkaradzic/bgfx looks good for rendering
  • OpenGL renderer - https://hackage.haskell.org/package/OpenGL
  • See https://github.com/jxv/sdl2-fps
  • SoftwareRenderer provides much better performance (in createRenderer)
  • try using SDL.opengl ?
  • do some research on spritesheets, is it faster?
    • abstract textures into class - TextureSource, AnimatedTextureSource, etc.

• Hold multiple weapons and change between them with key presses

• read levels from shareware files (see https://devinsmith.net/backups/bruce/wolf3d.html)

• shoot Uzi

• animate Uzi

• difference for pistol and uzi - auto vs semi auto

• Structure cabal project in such a way that modules not exposed to main can still be exposed to test

  • Do general deeper research into cabal project and possibilities - multiple libraries?

• Dont render hidden sprites

  • only render within field of view bounds
  • only render in front of walls

• sprite items stop hero moving movement

• pickup items

• doors

• enemy

• secret doors

• All events together at the end of game loop passed to audio handler, which plays audio

• mouse look horizontal

• mouse look up/down (move projection plane up/down)

• SDL dispose textures at the end

• Example world that shows off diagonal walls, etc

• Console menu system at start

Nice to haves

• better index for weapon animation data
• Optimise render - a lot of calculations can be done once
• Try reading original data file? See carmackExpand in wolf3d-html. Or maybe just use the format from wolf3d-html