问使用SDL2和Lisp的多个图形窗口？

EN

(ql:quickload "sdl2")
(require :sdl2)

(defun make-two-SDL-2-windows ()
  (let* ((win1 (sdl2:create-window :title "Win 1" :w 400 :h 400))
         (ren1 (sdl2:create-renderer win1))
         (win2 (sdl2:create-window :title "Win 2" :w 300 :h 300))
         (ren2 (sdl2:create-renderer win2)))
    (sdl2:with-event-loop (:method :poll)
      (:keyup
        (:keysym keysym)
        (when (sdl2:scancode= (sdl2:scancode-value keysym) :scancode-escape)
           (sdl2:push-event :quit)))
      (:idle ()
        (progn
          (sdl2:render-present ren1)
          (sdl2:render-present ren2)))
      (:quit () 
        (progn 
          (sdl2:destroy-renderer ren1)
          (sdl2:destroy-renderer ren2)
          (sdl2:destroy-window win1)
          (sdl2:destroy-window win2)
          t)))))

(defun main ()
  (sdl2:init :everything)
  ;;;Clozure...
  (process-run-function "window" #'make-two-SDL-2-windows))

(main)

(defun make-two-SDL-2-windows ()
  (sdl2:with-init (:everything)
    (sdl2:with-window (win1 :title "Win1" :flags '(:shown))
      (sdl2:with-window (win2 :title "Win2" :flags '(:shown))
        (sdl2:with-renderer (ren1 win1 :flags '(:renderer-accelerated))
          (sdl2:with-renderer (ren2 win2 :flags '(:renderer-accelerated))
             (sdl2:with-event-loop (:method :poll)
               (:keyup
                 (:keysym keysym)
                   (when (sdl2:scancode= (sdl2:scancode-value keysym)  :scancode-escape)
                      (sdl2:push-event :quit)))
                 (:idle
                   ()
                   (progn
                     (sdl2:set-render-draw-color ren1 0 0 255 255)
                     (sdl2:set-render-draw-color ren2 0 255 0 255)
                     (sdl2:render-draw-line ren1 150 20 100 300)
                     (sdl2:render-draw-line ren2 20 20 150 150)
                     (sdl2:render-present ren1)
                     (sdl2:render-present ren2)))
                 (:quit () t))))))))