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kohyama/barnsleys_fern.clj

Created November 15, 2015 17:23
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Revisions

  1. kohyama revised this gist Nov 15, 2015. 1 changed file with 38 additions and 0 deletions.
    38 changes: 38 additions & 0 deletions minimal_canvas.clj
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,38 @@
    (ns minimal-canvas)

    (def ^:private fpg (atom nil))

    (defn open! [title width height]
    (let [f (javax.swing.JFrame. title)
    p (.getContentPane f)]
    (.setPreferredSize p (java.awt.Dimension. width height))
    (.setBackground p java.awt.Color/white)
    (.pack f)
    (.setVisible f true)
    (reset! fpg {:frame f :panel p :graphics (.getGraphics p)})))

    (defmacro gdo [& body]
    `(if @@#'minimal-canvas/fpg
    (doto (:graphics @@#'minimal-canvas/fpg) ~@body)))

    (defn clear! []
    (if-let [p (:panel @fpg)]
    (gdo (.setBackground (.getBackground p))
    (.clearRect 0 0 (.getWidth p) (.getHeight p)))))

    (defn close! []
    (when-let [f (:frame @fpg)]
    (.setVisible f false)
    (.dispose f)
    (reset! fpg nil)))

    (comment
    ;; example of use
    (require '[minimal-canvas :refer (open! gdo clear! close!)])
    (open! "foo" 640 480)
    (gdo (.drawLine 0 0 640 480))
    (clear!)
    (gdo (.setColor java.awt.Color/RED)
    (.fillOval 176 96 288 288))
    (close!)
    )
  2. kohyama created this gist Nov 15, 2015.
    38 changes: 38 additions & 0 deletions barnsleys_fern.clj
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,38 @@
    (ns barnsleys-fern)

    (defn- affine [a b]
    (fn [x] (map #(apply + (conj (map * %1 x) %2)) a b)))

    (defn- move [x]
    (let [afs (mapv (partial apply affine)
    [[[[ 0.0 0.0 ] [ 0.0 0.16]] [0.0 0.0 ]]
    [[[ 0.85 0.04] [-0.04 0.85]] [0.0 1.6 ]]
    [[[ 0.2 -0.26] [ 0.23 0.22]] [0.0 1.6 ]]
    [[[-0.15 0.28] [ 0.26 0.24]] [0.0 0.44]]])
    p (rand-int 100)]
    (condp > p
    1 ((afs 0) x)
    86 ((afs 1) x)
    93 ((afs 2) x)
    ((afs 3) x))))

    (def points (iterate move [0.0 0.0]))

    (comment
    ;; example of use with minimal-canvas
    (require '[minimal-canvas :refer (open! close! clear! gdo)])
    (require 'barnsleys-fern)
    (open! "Barnsley's fern" 480 480)
    (defn draw-fern [n color]
    (gdo (.setColor color))
    (doseq [[x y] (take n barnsleys-fern/points)]
    (let [ex (+ 240 (* 40 x))
    ey (- 440 (* 40 y))]
    (gdo (.drawLine ex ey ex ey)))))
    (draw-fern 10000 java.awt.Color/black)
    (clear!)
    (draw-fern 100000 java.awt.Color/black)
    (clear!)
    (draw-fern 200000 (java.awt.Color. 0 128 0))
    (close!)
    )