sketch_dec-31-2020_18-20-11.glisp.glisp

;; grid specification
(def interval 40)
(def nlines 10)

(transform [1 0 0 1
            (* nlines interval -0.5) 
            (* nlines interval -0.5)]

;; circles as controller
(def cs [
         (circle [108 31.7872] 114.1578)
         (circle [279 236.7872] 133.0601)
         (circle [63 290.7872] 103.0194)
         ])
)
        
;; expansion rate (-1 <= x <= 1)
(def expan_rate 1)

;;- - - - - - - - - - - - 
;; circle's center
(defn cc [c] (vec2/scale (vec2/+ (nth c 2) (nth c 10)) 0.5))
;; circle's radius
(defn cr [c] (/ (vec2/dist (nth c 2) (nth c 10)) 2))
;; magnitude of vector
(defn mag [v] (vec2/dist [0 0] v))
;; closest circle(center) from vector p
;; returns: [distance, vector from center to p, circle instance]
(defn closestCircle [p]
    (let [ds (for [c cs]
               (let [v (vec2/- p (cc c))]
                   [(mag v) v c]))]
    (reduce #(if (< (first %1) (first %2)) %1 %2) (first ds) ds)
    ))

(def range1 (range 0,(* nlines interval), interval))
(def range2 (range 0,(* nlines nlines), nlines))

;; generates points for grid
(def points
	(for [x range1, y range1]
     (let [o [x y]
           circle_spec (closestCircle o)
           d (first circle_spec)
           v (second circle_spec)
           r (cr (nth circle_spec 2))]
            (if (< d r)
                (vec2/+ o (vec2/scale v 
                (* expan_rate (pow (fit 0 r 1 0 d) 2))))
                o)
)))

:start-sketch
(background "#fff")

(transform [1 0 0 1
            (* nlines interval -0.5) 
            (* nlines interval -0.5)] 
(style (stroke "black" 2)
	(let [ps points]
	    (conj
            (for [x range2] (apply polyline (for [y (range nlines)] (nth ps (+ x y)))))
            (for [x (range nlines)] (apply polyline (for [y range2] (nth ps (+ x y)))))
))))