[ call -> stop ]
update-ui-loop
update-ui
redraw-worlds
draw-world
M\ world draw-world*
(draw-gadget)
M\ gadget draw-children
(draw-gadget)
draw-background
M\ nehe2-gadget draw-gadget*
gluPerspective
[
    63 getenv error-thread set-global
    continuation -> error-continuation set-global rethrow
]