(def canvas (js/document.getElementById "canvas-1"))
(def ctx (.getContext canvas "2d"))
(def width (.-width canvas))
(def height (.-height canvas))

(defn fill [color] (set! (.-fillStyle ctx) color))
(defn rect [x y w h] (.fillRect ctx x y w h))
(defn clear [] (.clearRect ctx 0 0 width height))

(clear)
(fill "red")
(for [x (range 20) y (range 20)] (rect (* x 11) (* y 11) 10 10))