anchor.diff:                           :color color
                            :x x :y y :width width :height height
                            :bbox bbox :flip flip
  -                         :shape (create-rectangle-shape (- x (* width 0.5))
  -                                                        (- y (* height 0.5))
  -                                                        (+ x (* width 0.5))
  -                                                        (+ y (* height 0.5))))))
  +                         :shape (create-rectangle-shape x y (+ x width) (+ y height)))))
       (setf (sprite-flip sp) flip)
       (rotate-sprite sp angle)
       (when bbox (bbox-overwrite/shape (sprite-bbox sp) (sprite-shape sp)))
  
positive.code:   color
    (flip :none))
  
  (defun sprite-set-flip (it value)
    (case value
      (:vertical (setf (shape-tex-coords (sprite-shape it)) #(0.0 1.0 1.0 1.0 1.0 0.0 0.0 0.0)))
  
negative.code:     (translate-sprite sp dx dy)))
  
  (defun rotate-sprite (sp dangle)
    (rotate-shape-2d (sprite-shape sp) dangle (sprite-center-x sp) (sprite-center-y sp))
    (when (sprite-bbox sp) (bbox-overwrite/shape (sprite-bbox sp) (sprite-shape sp))))
  
  
  