anchor.diff:     (transformed-image :accessor transformed-image :initarg :transformed-image)
      (image-pattern :accessor image-pattern :initarg :image-pattern))
     (:default-initargs :value nil
  -    :transform-parameters (list 1d0 1d0 0d0 0d0 0d0 0d0 0d0)
  +    :transform-parameters #(1d0 1d0 0d0 0d0 0d0 0d0 0d0)
       :transform nil
       :transformed-image nil
       :image-pattern nil))
  
positive.code:     (when image
        (unless transform
          (destructuring-bind (y-scale x-scale y-shift x-shift y-shear x-shear rotate)
              transform-parameters
            (setf transform
                  (make-affine-transformation :y-scale y-scale
                                              :x-scale x-scale
  
negative.code:                                         (list (/ bounding-rectangle-width oldx))))))
                (setf (gadget-value y-scale-slider) scale
                      (gadget-value x-scale-slider) scale)
                (setf (elt transform-parameters 0) scale
                      (elt transform-parameters 1) scale
                      transform nil)))
            (setf image image))))))
  
  