mempcy-slow-2.lisp

(defun cocoa-build-sprite (sprite image mask size)
  (declare #.*optimize*
           (type fixnum size))
  (fli:with-coerced-pointer
      (sp :type '(:foreign-array :byte (10000000))) sprite
      (fli:with-coerced-pointer
          (ip :type '(:foreign-array :byte (10000000))) image
          (loop for i fixnum from 0 below (* size 3) by 3
             for j from 3 by 3
             for alpha from 3 by 4 do
             (fli:replace-foreign-array sp ip
                                        :start1 i :end1 j
                                        :start2 i :end2 j)
             (setf (fli:dereference sprite :index alpha)
                   (fli:dereference mask :index i))))))