anchor.diff:  (define-constant +expected-dpi+ 96)
   
   (defclass host-application (bodge-host:window)
  -  ((init-continuation :initarg :continuation)))
  +  ((init-continuation :initarg :init-continuation)
  +   (destroy-continuation :initarg :destroy-continuation)))
  +
  +
  +(defun set-destroy-continuation (host-application cont)
  +  (with-slots (destroy-continuation) host-application
  +    (setf destroy-continuation cont)))
  +
   
   (defclass host-system (enableable dispatching generic-system)
     ((host-application :initform nil)
  
positive.code: 
  (defmethod bodge-host:on-init ((this host-application))
    (with-slots (init-continuation) this
      (funcall init-continuation)))
  
  
  (defmethod bodge-host:on-hide ((this host-application))
  
negative.code: 
  (defun make-host-application (cont)
    (make-instance 'host-application
                   :init-continuation cont
                   :opengl-version (property '(:host :opengl-version) '(3 3))
                   :resizable (property '(:host :viewport-resizable) nil)
                   :decorated (property '(:host :viewport-decorated) t)
  