Bezier Curve Subdivision Functions

curve.clj

(defn edges [listing]
  (loop [accum (list (take 2 listing))
         queue (rest listing)]
    (if (> (count queue) 1)
      (recur
        (concat accum
                (list (take 2 queue)))
        (rest queue))
      accum)))



(defn at_step [n0 n1 steps t]
  (let [step_size (/ (- n1 n0) steps)]
    (+ n0 (* step_size t) )))

(defn n_step [items steps t]
  (loop [reduction items]
    (if (> (count reduction) 2)
      (let [lines (edges reduction)]
        (recur (map
          (fn [[p1 p2]]
            (at_step p1 p2 steps t))
          lines)))
      (let [[p1 p2] reduction]
        (at_step p1 p2 steps t))
      )))

(defn n_2d [coords steps t]
  (let [dimen #(n_step (map % coords)
                       steps t)
        xx (dimen first)
        yy (dimen second)]
    (list xx yy)))

(defn n_to [coords steps] 
  (map 
    #(n_2d coords steps %)
    (range steps)))

(defn n_to_including [coords steps]
  (map 
    #(n_2d coords steps %)
    (range (+ steps 1))))