notes

Floor casting -> DONE!!!
	get pixel y in projection plane
	
	(tan(field of view/2) * focal length) * 2 = actual length of projection plane (ppl)
	
	ppl/w = converstion factor between pixels and actual distance (cf)
	
	(y - h/2) * cf = distance between projection plane center row and y (dcpp)
	
	sqrt(((w/2 - x) * cf)^2 + focal length^2)) = distance between player and pixel on projection plane (dppp) 
	
	dppp/dcpp = tangent of angle from player to floor point (ta)
	
	player height * ta = distance along floor to floor point (df)
	
	player x + df * cos(original angle) = texture x coordinate
	
	player y + df * sin(original angle) = texture y coordinate

Focus to window when starting in fullscreen -> DONE!!!
  - investigate
    - SDL arg??? -> correct - `WINDOW_FULLSCREEN_DESKTOP`

Scale to fullscreen -> DONE!!!
    - investigate why it doesn't scale atm -> solved through use of `WINDOW_FULLSCREEN_DESKTOP`
      - hardcoded values?

Make less jarring
  - investigate
    - is jarring movement related to performance or input handling?
      - at a modest resolution (640*480) it's fine so input handling should be improved. <- IMPROVED - runs at a decent (1280*960) resolution now.
      - performance can *definitely* be improved though...
        - stop drawing pixels individually! <- DONE (for walls)
        - utilise harware acceleration via *Sdl.Texture <- DONE (for walls)
        - figure out how to draw floor and ceiling using this method...

Fix slowdown when close to wall -> DONE!!! render stripes instead of pixels
  - investigate
    - may be related to rays cast not stopping at the wall???