anchor.diff:      (gl:vertex 0.0 0.0 scale)))
   
   (defun reshape (width height)
  -  ;; set viewport to full window
  +  ;; set viewport to full screen
     (gl:viewport 0 0 width height)
     (setf *display-width* width)
     (setf *display-height* height))
  
positive.code:   (gl:matrix-mode :modelview)
    (gl:load-identity)
    (gl:light :light0 :position #(0.0 0.0 0.0 1.0))
    (gl:light :light0 :diffuse #(1.0 1.0 1.0 1.0))
    (gl:light :light0 :specular #(1.0 1.0 1.0 1.0))
    (gl:light :light0 :ambient #(1.0 1.0 1.0 1.0)))
  
  (defun setup-2d-defaults ()
    (gl:clear-color 0.3 0.3 0.3 0)
  
negative.code:   (gl:enable :depth-test)
    (gl:depth-func :lequal)
    (gl:depth-mask :enable)
    (gl:enable :cull-face)
    (gl:cull-face :back)
    (gl:enable :lighting)
    (gl:enable :light0)
  