anchor.diff:    (let ((wrap (if (keywordp wrap)
                     (vector wrap wrap wrap)
                     wrap)))
  -    (if (and (= lod-bias 0.0) (= min-lod -1000.0) (= max-lod 1000.0)
  -             (eq minify-filter :linear) (eq magnify-filter :linear)
  +    (if (and (= lod-bias 0.0)
  +             (= min-lod -1000.0)
  +             (= max-lod 1000.0)
  +             (eq minify-filter :linear)
  +             (eq magnify-filter :linear)
                (wrap-eq wrap #(:repeat :repeat :repeat))
                (eq compare :none))
           *default-sampler-id-box*
  
positive.code:       (format stream "#<SAMPLER :UNINITIALIZED>")))
  
  (defun+ free-sampler (sampler)
    (unless (sampler-shared-p sampler)
      ;; Be sure to add this back in when you implement freeing
      ;; samplers.
      (warn "CEPL: free-sampler not yet implemented~%leaking ~s"
            sampler)))
  
  (defmethod free ((sampler sampler))
    (free-sampler sampler))
  
negative.code:     ;; change box
      ;; (in future we can look up based on some hash)
      (setf (%sampler-id-box sampler)
            (make-sampler-id-box :id (%get-id) :shared-p nil)))
    sampler)
  
  
  