taking-the-l/mode/main.fnl

; (local (speed ball-speed) (values 1 200))
(local (w h) (love.window.getMode))
; (local _state {:x 100 :y 100 :dx 2 :dy 1 :left (- (/ h 2) 50) :right (- (/ h 2) 50)})
; (global state {:x 100 :y 100 :dx 2 :dy 1 :left (- (/ h 2) 50) :right (- (/ h 2) 50)})
; (var pause false)

(local keys {:a [:left -1] :z [:left 1] :up [:right -1] :down [:right 1]})

;; (fn on-paddle? []
;;   (or (and (< state.x 20)
;;            (< state.left state.y) (< state.y (+ state.left 100)))
;;       (and (< (- w 20) state.x)
;;            (< state.right state.y) (< state.y (+ state.right 100)))))

(global Pong {})
(set Pong.__index Pong)

(fn Pong.new [cls]
  (let [t {:x 100 :y 100
           :dx 2 :dy 1
           :left (- (/ h 2) 50) :right (- (/ h 2) 50)
           :speed 1 :ball-speed 200
           :pause false}]
    (setmetatable t cls)))

(fn Pong.on-paddle? [self]
  (or (and (< self.x 20)
           (< self.left self.y) (< self.y (+ self.left 100)))
      (and (< (- w 20) self.x)
           (< self.right self.y) (< self.y (+ self.right 100)))))

(global pong nil)

{
 :name "pong"

 :init (fn init []
         (global pong (: Pong :new)))

 :update (fn update [dt set-mode]
           (when (not pong.pause)
             (set pong.x (+ pong.x (* pong.dx dt pong.ball-speed)))
             (set pong.y (+ pong.y (* pong.dy dt pong.ball-speed)))
             (each [key action (pairs keys)]
               (let [[player dir] action]
                 (when (love.keyboard.isDown key)
                   (tset pong player (+ (. pong player) (* dir pong.speed))))))

             (when (or
                     (< pong.y 0)
                     (> pong.y h))
               (set pong.dy (- 0 pong.dy)))

             (when (: pong :on-paddle?)
               (set pong.dx (- 0 pong.dx)))

             (when (< pong.x 0)
               (set-mode "mode.end" "2"))
             (when (> pong.x w)
               (set-mode "mode.end" "1"))))

 :keypressed (fn keypressed [key set-mode]
               (when (= "p" key)
                 (set pong.pause (not pong.pause))))

 :draw (fn draw [m]
         (when (not pong.pause)
           (love.graphics.rectangle "fill" 10 pong.left 10 100)
           (love.graphics.rectangle "fill" (- w 20) pong.right 10 100)
           (love.graphics.circle "fill" pong.x pong.y 10))
         (when pong.pause
           (love.graphics.printf "Press 'p' to unpause" 0 (/ h 3) w "center")))
 }