viewing and projection in OpenGL. It allows user to see effects
of changing viewing and projection parameters on seeing a scene.
Additionally it is possible to dump a C file which specifies viewing
and projection of the current principal view in one routine. It could
be incorporated into another program that wants to define a specific
view and projection. VVV can therefore be used as a preview tool.
PR: ports/85948
Submitted by: Igor Pokrovsky <ip@doom.homeunix.org>