anim_using_fiber.janet

(use ./build/jaylib)

(set-config-flags
  :msaa-4x-hint)

(init-window 800 600 "Chart")
(init-audio-device)
(set-target-fps 60)

(def current-animations @{})

(def big 50)
(def small 30)
(def frames 30)

(def rects
  (seq [x :range [20 (+ 40 (get-screen-width)) 40] 
        y :range [20 (+ 40 (get-screen-height)) 40] 
        :let [r @[x y small small]]]
    r))

(defn bigger-anim
  [r]
  (def w 2)
  (def h 3)
  (loop [i :range [0 frames]
         :let [p (/ i frames)
               v (+ small (* (- big small) p))]] # here's the tweening
    (put r w v)
    (put r h v)
    (yield))
  (put current-animations r nil))

(defn smaller-anim
  [r]
  (def w 2)
  (def h 3)
  (loop [i :range [0 frames]
         :let [p (/ i frames)
               v (- big (* (- big small) p))]] # here's the tweening
    (put r w v)
    (put r h v)
    (yield))
  (put current-animations r nil))

(defn make-bigger
  [r]
  (when (and (not (current-animations r))
             (< (r 2) (inc small)))
    (def anim (fiber/new |(bigger-anim r)))
    (put current-animations r anim)))

(defn make-smaller
  [r]
  (when (and (not (current-animations r))
             (> (r 2) (dec big)))
    (def anim (fiber/new |(smaller-anim r)))
    (put current-animations r anim)))

(while (not (window-should-close))
  (begin-drawing)
  
  (clear-background [0 0 0])
  
  (def [mx my] (get-mouse-position))  
  (def mr [(- mx 15) (- my 15) small small])
  (draw-rectangle-rec mr :blue)  
  
  (loop [a :in current-animations]
    (resume a))
  
  (loop [r :in rects
         :let [coll (check-collision-recs
                      r
                      mr)]]
    (when coll
      (make-bigger r))
    
    (when (not coll)
      (make-smaller r))
    
    (draw-rectangle-rec r (if coll :yellow :green)))
  
  (end-drawing))

(close-window)