anchor.diff:        (compute-blit-info-dest-src nrows ncols from-array from-row from-col to-array to-row to-col)
       (assert (equal (array-element-type from) '(unsigned-byte 32)))
       (assert (equal (array-element-type to) '(unsigned-byte 32)))
  -    (mezzanine.supervisor:with-world-stopped
  +    (mezzanine.supervisor:with-pseudo-atomic
         (setf from (%simple-array-data-pointer from))
         (setf to (%simple-array-data-pointer to))
         (dotimes (y nrows)
  
positive.code: 
  (declaim (inline %bitset-mask-1-whole))
  (defun %bitset-mask-1-whole (setter nrows ncols colour mask mask-offset mask-stride to to-offset to-stride)
    (mezzanine.supervisor:with-world-stopped
      (setf to (%simple-array-data-pointer to))
      (setf mask (%simple-array-data-pointer mask))
      (dotimes (y nrows)
  
negative.code:     (assert (equal (array-element-type to) '(unsigned-byte 32)))
      ;; Stop early for 100% transparent colours.
      (unless (zerop (ldb (byte 8 24) colour))
        (mezzanine.supervisor:with-pseudo-atomic
          (setf to (%simple-array-data-pointer to))
          (setf mask (%simple-array-data-pointer mask))
          (dotimes (y nrows)
  