; LIBGL_ALWAYS_INDIRECT=1
(local fennel (require :fennel))
(import-macros {: def : q : ttype : static : eval : printform} :terra)
(local SDL (require :SDL))

(local CreateWindowAndRenderer (def [w int h int flags uint32]
  (var window [SDL.Window] nil)
  (var renderer [SDL.Renderer] nil)
  (var result (SDL.CreateWindowAndRenderer w h flags (& window) (& renderer)))
  (return result window renderer)))

(local clear (static (def [renderer [SDL.Renderer]]
    (SDL.SetRenderDrawColor renderer 0 0 0 255)
    (SDL.RenderClear renderer))))

(local hello (def [renderer [SDL.Renderer]]
  (clear renderer)
  (SDL.SetRenderDrawColor renderer 0 0 255 255)
  (var rect (SDL.Rect {x 100 y 100 w 50 h 30}))
  (SDL.RenderFillRect renderer (& rect))
  (SDL.RenderPresent renderer)))

(local last-event (printform (static (q (SDL.Event {type 0})))))
(fn event-loop [f]
  (while (not= (SDL.PollEvent (last-event:getpointer)) 0) (f (last-event:get))))

(local rect (def [x int y int w int h int]
  (return (SDL.Rect {x x y y w w h h}))))

(fn patch-clear [r g b]
  (let [new-clear (def [renderer [SDL.Renderer]]
                       (SDL.SetRenderDrawColor renderer r g b 255)
                       (SDL.RenderClear renderer))]
      ((def [] (set clear new-clear))))) ; no idea why (clear:set new-clear) doesn't work

(SDL.Init SDL.INIT_EVERYTHING)
(let [windowflags SDL.WINDOW_RESIZABLE
      (ok window renderer) (unpacktuple (CreateWindowAndRenderer 640 480 windowflags))]
  (event-loop #nil)
  (hello renderer)
  {: window : renderer : rect : event-loop : clear : hello : patch-clear})