anchor.diff:  (require :cl-opengl)
   
   (defun basic-test ()
  -  (sdl2:with-init (:video)
  +  (sdl2:with-init (:everything)
       (let* ((win (sdl2:create-window :flags '(:shown :opengl)))
  -           (gl-context (sdl2:gl-create-context win)))
  +           (gl-context (sdl2:gl-create-context win))
  +           (controllers ()))
  +
  +      ;; basic window/gl setup
         (sdl2:gl-make-current win gl-context)
         (gl:viewport 0 0 800 600)
         (gl:matrix-mode :projection)
  
positive.code:       (gl:load-identity)
        (gl:clear-color 0.0 0.0 1.0 1.0)
        (gl:clear :color-buffer)
        (sdl2:with-event-loop (:method :poll)
          (:keydown (:keysym keysym)
            (let ((scancode (sdl2:scancode-value keysym))
  
negative.code:           (gl:flush)
            (sdl2:gl-swap-window win))
          (:quit () t))
  
        ;; close any game controllers that were opened
        (loop for (_ . controller) in controllers
           do (sdl2:game-controller-close controller))
        
        (sdl2:gl-delete-context gl-context)
        (sdl2:destroy-window win))))
  