random-bars.clj

(ns fun-mode-sketch
  (:require [quil.core :as q]
            [quil.middleware :as m]))

(def win-width 400)
(def win-height 200)
(def bar-width 1)
(def bar-height 10)
(def bar-count (/ win-width bar-width))
(def grow-bar (partial + bar-height))

(defn setup []
  (q/frame-rate 60)
  {:bars (vec (repeat bar-count 0))})

(defn update [state]
  (let [bar-to-grow (int (rand bar-count))
        new-bars (update-in (:bars state) [bar-to-grow] grow-bar)] 
    (assoc state :bars new-bars)))
 
(defn draw [state]
  (q/background 255) 
  (q/fill 0)
  (doall
    (map-indexed 
      (fn [i height] 
        (q/rect (* i bar-width) (- win-height height) bar-width height)) 
      (:bars state))))

(q/defsketch example
  :size [win-width win-height]
  :setup setup
  :draw draw
  :update update
  :middleware [m/fun-mode])