Mandelbrot

(scl 5)

(de dist (X)
   (sqrt (*/ (car X) (car X) 1.) (*/ (cdr X) (cdr X) 1.)))

(de rlerp (n a b x y)
   (+ x (*/ (*/ (- n a) 1.0 (- b a)) (- y x) 1.0 ) ))

(de imgAdd (X Y)
   (cons (+ (car X) (car Y)) (+ (cdr X) (cdr Y))))

(de imgSq (X)
   (let (a (car X) b (cdr X))
      (cons (- (*/ a a 1.0) (*/ b b 1.0))  (/ (* 2. a b) 1.0 1.0) ) ))

(setq colors (apply circ (chop " 8$#%&/")))

(for j 45
   (for i 120
      (let c (cons (rlerp (* i 1.) 0 120. -2. 1.) (rlerp (* j 1.) 0 45. -1.2 1.2))
         (let z (0.0 . 0.0)
            (let it (for it 100
                     (setq z (imgAdd (imgSq z) c))
                     (T (or (>= it 100) (> (abs (dist z)) 2.0)) it))
                  (if (= it 100)
                     (prin " ")
                     (prin  (car (nth colors it)) ))))))
         (prinl))

(bye)