A port of the tutorial from lodev.org/cgtutor/raycasting.html into SDL2
All credit for quickcp and this raycasting code goes to Lode Vandevenne!
The tutorial was designed to be used with quickcg http://lodev.org/quickcg/ but sadly that hasn't been updated to SDL2 as far as i know. Despite this it's still possible to follow along with Lode's tutorials if you know a little about SDL2.
To get up to speed with SDL2 I suggest checking out:
http://lazyfoo.net/tutorials/SDL/
http://www.willusher.io/pages/sdl2/
This example only actually uses a small set of the functions from quickcg which i've included in main.