anchor.diff:             (array-dimension input-array 0)
              x0 y0))
     
  +;;;;;
  +
  +(defmethod compose-pixel ((pixel-format pixel-format) red green blue opacity x y)
  +  (funcall (or (slot-value pixel-format 'composer)
  +               (setf (slot-value pixel-format 'composer)
  +                 (compile nil (pixel-composing-code pixel-format))))
  +           nil red green blue opacity x y))
positive.code:                             nil nil sample x y)) ))))
  
  (defmethod pixels-translator (input-pixel-format output-pixel-format)
    (or ;; (gethash (list input-pixel-format output-pixel-format) *pixels-translator-cache*)
        (setf (gethash (list input-pixel-format output-pixel-format) *pixels-translator-cache*)
              (compile
               nil
  
negative.code: ;; OUTPUT-PIXEL-FORMAT                                          [class]
  ;; IO-PIXEL-FORMAT                                              [class]
  
  (define-protocol-class pixel-format ()
    ((composer :initform nil)))
  
  (define-protocol-class input-pixel-format (pixel-format) 
    ())
  
  (define-protocol-class output-pixel-format (pixel-format)
    ())
  
  (define-protocol-class io-pixel-format (input-pixel-format output-pixel-format) ())
  
  (define-protocol-class uniform-pixel-format () ()
    ;; Mixin class for uniform pixel formats
    )
  
  (define-protocol-class non-uniform-pixel-format () ()
    ;; Mixin class for non-uniform pixel formats
    )
  
  ;; and their predicates
  
  ;; The protocol
  
  