anchor.diff:    (defun set-register-event-callback-func (func)
       "Call this and pass the function that will be called when the cepl needs to
        query the window size"
  -    (setf reg-event-callback-func func))
  +    (setf reg-event-callback-func func)
  +	(map nil #'register-event-listener event-callbacks-cache)
  +	func)
   
     (defun set-make-gl-context-current-on-surface (func)
       "Call this and pass the function that will be called when the cepl needs to
  
positive.code: (let (step-func
        swap-func
        win-size-func
        (reg-event-callback-func (lambda (x) x))
        (make-current-func (lambda (c s) c s)))
  
    (defun set-step-func (func)
  
negative.code: 
    (defun register-event-listener (function)
      "not external"
  	(if reg-event-callback-func
  		(funcall reg-event-callback-func function)
  		(push function event-callbacks-cache))))
  
  ;;----------------------------------------------------------------------
  
  