anchor.diff:  (defmethod glop:on-key (window state key)
     (format t "Key: ~S~%" key)
     (when (eql key #\Escape)
  -    (glop:push-close-event window))
  -  (when (and (eql key #\f) (eql state :press))
  -    (glop:toggle-fullscreen window)))
  +    (glop:push-close-event window)))
   
   (defmethod glop:on-button (window state button)
     (declare (ignore window state))
  
positive.code:          (glop:swap-buffers win))))
  
  (defun test-gl-hello-fullscreen ()
    (glop:with-window (win "Glop test window" 800 600 :fullscreen t)
      (format t "Created window: ~S~%" win)
      ;; GL init
  
negative.code:            (gl:vertex 0.25 0.75 0))
           (gl:flush)
           (glop:swap-buffers win))))
  
  (defun test-multiple-windows ()
    (let ((window-1 (glop:create-window "window 1" 800 600))
  	(window-2 (glop:create-window "window 2" 800 600)))
      (when (and window-1 window-2)
        (unwind-protect 
  	   (progn
  	     (glop:attach-gl-context window-1 (glop:window-gl-context window-1))
  	     (gl:clear-color 0.3 0.3 1.0 0)
  	     ;; setup view
  	     (gl:matrix-mode :projection)
  	     (gl:load-identity)
  	     (gl:ortho 0 1 0 1 -1 1)
  	     (glop:attach-gl-context window-2 (glop:window-gl-context window-2))
  	     (gl:clear-color 0.3 0.3 1.0 0)
  	     ;; setup view
  	     (gl:matrix-mode :projection)
  	     (gl:load-identity)
  	     (gl:ortho 0 1 0 1 -1 1)
  	     (loop 
  	       while (and (glop:dispatch-events window-1 :blocking nil)
  			 (glop:dispatch-events window-2 :blocking nil)) do
  			   (glop:attach-gl-context window-1 (glop:window-gl-context window-1))
  			   (gl:clear :color-buffer)
  			   (gl:color 1 1 1)
  			   (gl:with-primitive :polygon
  			     (gl:vertex 0.25 0.25 0)
  			     (gl:vertex 0.75 0.25 0)
  			     (gl:vertex 0.75 0.75 0)
  			     (gl:vertex 0.25 0.75 0))
  			   (gl:flush)
  			   (glop:swap-buffers window-1)
  			   (glop:attach-gl-context window-2 (glop:window-gl-context window-2))
  			   (gl:clear :color-buffer)
  			   (gl:color 1 1 1)
  			   (gl:with-primitive :polygon
  			     (gl:vertex 0.25 0.25 0)
  			     (gl:vertex 0.75 0.25 0)
  			     (gl:vertex 0.75 0.75 0)
  			     (gl:vertex 0.25 0.75 0))
  			   (gl:flush)
  			   (glop:swap-buffers window-2)))
  	(glop:destroy-window window-1)
  	(glop:destroy-window window-2)))))