anchor.diff:  (defparameter *scale* 500)
   (defparameter *border* (round (/ *scale* 100)))
   (defparameter *steps* 5)
  +
  +(defun get-x (x)
  +  (round (* x *scale*)))
  +
  +(defun get-y (y)
  +  (round (- *scale* (* y *scale*))))
   
   (defun draw-field (scene)
     (let ((a1 *border*)
  
positive.code: (defpackage :src/drawer
    (:nicknames :drawer)
    (:use :common-lisp :src/field :src/utils :cl-svg)
    ;;(:import-from :mcts)
    (:import-from :spatial-trees)
    (:import-from :rectangles))
  
negative.code:             (draw group (:line :x1 (+ *scale* (- *border* a3)) :y1 cur-a :x2 (+ *scale* (+ *border* a3)) :y2 cur-a))
              ))))
  
  (defun draw-text (scene text point)
    (text scene (:x (get-x (x point)) :y (get-y (y point))) text))
  
  (defun draw-point (scene point)
    (draw scene (:circle :cx (get-x (x point)) :cy (get-y (y point)) :r 2)))
  
  (defun draw-polygon (scene polygon)
    (let* ((points (point-list polygon))
           (string-points (format nil "~{~A~^ ~}" (mapcar (lambda (point)
                                                            (format nil "~A,~A"
                                                                    (get-x (x point))
                                                                    (get-y (y point))))
                                                          points))))
      (draw scene (:polygon :points string-points :fill "orange"))))
  
  (defun draw-line-segment (scene line-segment)
    (let ((group
           (make-group scene (:stroke "darkorange"
                                      ;;:fill color :opacity alpha
                                      :stroke-width 1
                                      ;;:fill-opacity (* alpha 0.6)
                                      ;;:stroke-linecap "round"
                                      ))))
      (draw group (:line :x1 (get-x (x (start line-segment)))
                         :y1 (get-y (y (start line-segment)))
                         :x2 (get-x (x (end line-segment)))
                         :y2 (get-y (y (end line-segment)))))))
  
  (defun draw-state (field &key (filename #p"~/field.svg"))
    (declare (ignore field))
    (let ((size (+ *scale* (* 2 *border*))))
  