abrian.clj

;; vector of arrays version
(import '(javax.swing JFrame JPanel) 
        '(java.awt Color Graphics2D))

(defn neighbours-count [[above current below] i w]
  (let [j (mod (inc i) w)
        k (mod (dec i) w)
        s #(if (= (aget #^objects %1 (int %2)) :on) 1 0)]
    (+ (+ (+ (s above j) (s above i))
         (+ (s above k) (s current j)))
      (+ (+ (s current k) (s below j))
        (+ (s below i) (s below k))))))

(defn step1 [rows]
  (let [#^objects current (second rows)
        w (count current)]
    (loop [i (int (dec w)), #^objects row (aclone current)]
      (if (neg? i)
        row
        (let [c (aget current i)]
          (cond
            (= c :on) 
              (recur (dec i) (doto row (aset i :dying)))
            (= c :dying) 
              (recur (dec i) (doto row (aset i :off)))
            (= 2 (neighbours-count rows i w))
              (recur (dec i) (doto row (aset i :on)))
            :else
              (recur (dec i) row)))))))

;; non parallel step
(defn step [board]
  (vec (map step1 
         (partition 3 1 (concat [(peek board)] board [(first board)])))))

(defn step [board]
  (let [n (.availableProcessors (Runtime/getRuntime))
        l (count board)
        bounds (map int (range 0 (inc l) (/ l n)))]
    (apply into
      (pmap #(vec (map step1 (partition 3 1 
               (concat [(board (mod (dec %1) l))] 
                 (subvec board %1 %2) 
                 [(board (mod %2 l))]))))
        bounds (rest bounds)))))

;; utilities and frontend
(defn rand-board [w h]
  (vec (map #(into-array Object %) (partition w (take (* w h) (repeatedly #(if (zero? (rand-int 3)) :on :off)))))))

(defn dims [[row :as board]] [(count row) (count board)])

(defn render-board [board #^Graphics2D g cell-size]
  (let [[w h] (dims board)]
    (doto g
      (.setColor Color/BLACK)
      (.scale cell-size cell-size)
      (.fillRect 0 0 w h))
    (doseq [i (range h) j (range w)]
      (when-let [color ({:on Color/WHITE :dying Color/GRAY} (aget #^objects (board i) (int j)))]
        (doto g
          (.setColor color)
          (.fillRect j i 1 1))))))

(defn start-brian [board cell-size]
  (let [[w h] (dims board)
        switch (atom true)
        board (atom board)
        panel (doto (proxy [JPanel] []
                      (paint [g] (render-board @board g cell-size)))
                (.setDoubleBuffered true))]
    (doto (JFrame.) 
      (.addWindowListener (proxy [java.awt.event.WindowAdapter] []
                            (windowClosing [_] (reset! switch false))))
      (.setSize (* w cell-size) (* h cell-size))
      (.add panel)
      .show)
    (future (while @switch (swap! board step)))
    (future (while @switch (.repaint panel) (Thread/sleep 40)))))

(start-brian (rand-board 200 200) 5)

brian.clj

;; vector of vector version
(import '(javax.swing JFrame JPanel) 
        '(java.awt Color Graphics2D))

;; non unrolled version
(defn neighbours-count [rows i w]
  (count (for [j [(mod (inc i) w) i (mod (dec i) w)]
               r rows :when (= :on (r j))] r)))

(defn neighbours-count [[above current below] i w]
  (let [j (mod (inc i) w)
        k (mod (dec i) w)
        s #(if (= (%1 %2) :on) 1 0)]
    (+ (+ (+ (s above j) (s above i))
         (+ (s above k) (s current j)))
      (+ (+ (s current k) (s below j))
        (+ (s below i) (s below k))))))

(defn step1 [rows]
  (let [current (second rows)
        w (count current)]
    (loop [i (dec w), row (transient current)]
      (if (neg? i)
        (persistent! row)
        (let [c (current i)]
          (cond
            (= c :on) 
              (recur (dec i) (assoc! row i :dying))
            (= c :dying) 
              (recur (dec i) (assoc! row i :off))
            (= 2 (neighbours-count rows i w))
              (recur (dec i) (assoc! row i :on))
            :else
              (recur (dec i) row)))))))

;; non parallel step
(defn step [board]
  (vec (map step1 
         (partition 3 1 (concat [(peek board)] board [(first board)])))))

(defn step [board]
  (let [n (.availableProcessors (Runtime/getRuntime))
        l (count board)
        bounds (map int (range 0 (inc l) (/ l n)))]
    (apply into
      (pmap #(vec (map step1 (partition 3 1 
               (concat [(board (mod (dec %1) l))] 
                 (subvec board %1 %2) 
                 [(board (mod %2 l))]))))
        bounds (rest bounds)))))

;; utilities and frontend
(defn rand-board [w h]
  (vec (map vec (partition w (take (* w h) (repeatedly #(if (zero? (rand-int 3)) :on :off)))))))

(defn dims [[row :as board]] [(count row) (count board)])

(defn render-board [board #^Graphics2D g cell-size]
  (let [[w h] (dims board)]
    (doto g
      (.setColor Color/BLACK)
      (.scale cell-size cell-size)
      (.fillRect 0 0 w h))
    (doseq [i (range h) j (range w)]
      (when-let [color ({:on Color/WHITE :dying Color/GRAY} ((board i) j))]
        (doto g
          (.setColor color)
          (.fillRect j i 1 1))))))

(defn start-brian [board cell-size]
  (let [[w h] (dims board)
        switch (atom true)
        board (atom board)
        panel (doto (proxy [JPanel] []
                      (paint [g] (render-board @board g cell-size)))
                (.setDoubleBuffered true))]
    (doto (JFrame.) 
      (.addWindowListener (proxy [java.awt.event.WindowAdapter] []
                            (windowClosing [_] (reset! switch false))))
      (.setSize (* w cell-size) (* h cell-size))
      (.add panel)
      .show)
    (future (while @switch (swap! board step)))
    (future (while @switch (.repaint panel) (Thread/sleep 40)))))

(start-brian (rand-board 200 200) 5)