AI-1000 hat demonstration

HAT.L

(defun hat ()
  (angle 0) ; degree
  (clear-screen)
  (setq d (make-array 192))
  (do ((i 0 (1+ i))) ((= i 191) i) (setf (aref d i) 100))
  ; (setq rd (/ 3.14 180))
  (draw 0 0)
  (do ((y -180 (+ y 18))) ((<= 180 y) t) ; step 6
      (do ((x -180 (+ x 12))) ((<= 180 x) t) ; step 4
          (setf r (sqrt (+ (* x x)(* y y))))
          (setf z (- (* 100 (cos r)) (* 30 (cos (* 3 r)))))
          (setf sx (truncate (+ 96 (/ x 3) (/ y -6))))
          (setf sy (truncate (+ 40 (/ y -6) (/ z -4))))
          (when (> (aref d sx) sy)
                (setf (aref d sx) sy)
                ; (set-cursor 0 0)(princ sx)(print sy)
                (draw sx (/ sy 3))) ; 192x64dot
      )
  )
  (drawc 0 0)
  (loop)
)