anchor.diff:    (%with-cepl-context-slots (default-framebuffer) (cepl-context)
       (%bind-fbo default-framebuffer :framebuffer)))
   
  -(defn-inline %color-attachments ((processed (simple-array gl-enum-value (*)))
  -                                  (unprocessed list)
  -                                  (total-len gl-sizei))
  -    (simple-array gl-enum-value (*))
  -  (declare (optimize (speed 3) (safety 1) (debug 1)))
  -  (let* ((arr (make-array total-len :element-type 'gl-enum-value))
  -         (proc-len (length processed)))
  -    (loop
  -       :for i :below proc-len
  -       :do (setf (aref arr i) (aref processed i)))
  -    (loop
  -       :for v :in unprocessed
  -       :for i :from proc-len
  -       :do (setf (aref arr i) (color-attachment-enum v)))
  -    arr))
  -
   (defn-inline color-attachments (&rest (vals extended-attachment-num))
       (simple-array gl-enum-value (*))
     (declare (optimize (speed 3) (safety 1) (debug 1)))
  
positive.code:                      (loop
                          :for c :across ,l-arr
                          :for index := (- c base)
                          :unless (and (< index fp)
                                       (att-array (aref arrs index)))
                          :do (throw-missing-col-attrs
                               ,l-arr current-fbo arrs fp))))))
             (release-unwind-protect
  
negative.code:     arr))
  
  (define-compiler-macro color-attachments (&rest vals)
    (if (every #'constantp vals)
        (make-array
         (length vals) :element-type 'gl-enum-value
         :initial-contents
         (loop
            :for v :in vals
            :if (symbolp v) :collect (color-attachment-enum (symbol-value v))
            :else :collect (color-attachment-enum v)))
        `(make-array
          ,(length vals) :element-type 'gl-enum-value
          :initial-contents
          (list
           ,@(loop
                :for v :in vals
                :collect
                  (if (constantp v)
                      (if (symbolp v)
                          (color-attachment-enum (symbol-value v))
                          (color-attachment-enum v))
                      `(color-attachment-enum ,v)))))))
  
  (defn attachment-pattern (&rest (vals extended-attachment-num))
      (simple-array gl-enum-value (*))
  