gistfile1.clj

(defstruct transform :coefficients :prob)

(defn mk-transform
  [[a b c d e f] prob]
  (struct transform [a b c d e f] prob))
  
(defn calculate-point
  "Calculate the next point to render based on the previous"
  [transform [x y]]
  (let [r (rand)
        t (:coefficients (first (filter (fn [x] (< r (:prob x))) transform)))]
    [(+ (* (t 0) x) (* (t 1) y) (t 4))
     (+ (* (t 2) x) (* (t 3) y) (t 5))]))

(defvar fern-leaf-transform
  (list
   (mk-transform [0.85 0.04 -0.04 0.85 0.0 1.6] 0.85)
   (mk-transform [0.2 -0.26 0.23 0.22 0 1.6] 0.92)
   (mk-transform [-0.15 0.28 0.26 0.24 0 0.04] 0.99)
   (mk-transform [0 0 0 0.16 0 0] 1.00))
  "List of attractors for the fern leaf [-2.1818 <= x <= 2.6556 0 <= y <= 9.95851]")

(defvar sierpinski-transform
  (list
   (mk-transform [0.5 0.0 0 0.5 0 0] 0.33)
   (mk-transform [0.5 0.0 0 0.5  0.25 (* 0.5 (/ (Math/sqrt 3) 2))] 0.66)
   (mk-transform [0.5 0.0 0 0.5 0 0.5 0 ] 1.00))
  "The sierpinski transform")