anchor.diff:  ;(in-package #:cl-foo)
   
   (require :sdl2)
  -(require :cl-opengl)
  -(require :cl-glu)
   
   (defparameter *width* 1280)
   (defparameter *height* 720)
  
positive.code:     (gl:enable :cull-face :lighting :light0 :depth-test)
      (gl:matrix-mode :projection)
      (gl:load-identity)
  ;    (gl:frustum -2 2 -2 2 1 10)
      (gl:ortho 0 2 0 2 -2 10)
  ;    (glu:perspective 45.0 *ratio* 0.1 10)
      (gl:matrix-mode :modelview)
  
negative.code:            (:keysym keysym)
             (keyup-actions (sdl2:scancode-value keysym)))
  
            (:idle
             ())
  
            (:quit () t))))))
  