anchor.diff:                     :max-list-nesting
                      :max-eval-order
                      :max-viewport-dims
  +                   :max-viewports
  +                   :viewport-subpixel-bits
  +                   :viewport-bounds-range
                      :max-attrib-stack-depth
                      :max-client-attrib-stack-depth
                      :aliased-point-size-range
  
positive.code:                    :max-texture-units
                     :max-vertex-attribs
                     :max-vertex-uniform-components
                     :max-varying-components
                     :max-combined-texture-image-units
                     :max-vertex-texture-image-units
                     :max-texture-image-units
                     :max-texture-coords
                     :max-fragment-uniform-components
                     :min-program-texel-offset
                     :max-program-texel-offset
                     :aux-buffers
                     :max-draw-buffers
                     :max-color-attachments
                     :max-samples)
       do (format t "~s: ~s~%" i (gl:get* i))))
  
  (defmethod glut:display ((w gl-info-window))
    (glut:destroy-current-window))
  
negative.code:   (format t "GL renderer: ~a~%" (gl:get* :renderer))
    (format t "GL extensions: ~a~%" (gl:get* :extensions))
  
    (loop for i in '(:max-clip-planes
                     :max-clip-distances
                     :max-3d-texture-size
                     :max-texture-size
                     :max-array-texture-layers
                     :max-texture-lod-bias
  