[9front] qball(2) bounced back

[rgl@antares-labs.eu]

hello everyone,

i recently fixed the qball, after almost a year and a half of me saying i would:

	http://git.antares-labs.eu/3dee/plain/qball.c

it is consistent with the conventions used in libgeometry, and it works by
default when looking at a model from the positive z-axis (just like Shoemake's).

the thing is, i've been thinking about it, and it doesn't make sense to
put it in there. it is actually a perfect fit for mouse.h with its menuhit(2)
and enter(2) routines; the problem is that this would make libdraw depend on
libgeometry, or require to keep a copy of the Quaternion procedures used for
the qball—and make sure they are in sync with libgeometry.

i don't know how many users of libgeometry are out there, even less so that
would be interested in a contraption like this, but if you have better ideas,
now is the time to speak up. :)

you can try it out with the visualizer from 3dee:

	% git/clone git://shithub.us/rodri/3dee
	% cd 3dee && mk pulldeps && mk all
	% 6.vis mdl/tribasis.obj
	# or better yet
	% 6.vis -t <{ <mdl/diablo3_diffuse.tga tga -9t} mdl/diablo3.obj

then use LMB to rotate the model.

if there's no interest in adding this to the system at the moment, i will
probably end up putting it on libgraphics, in a control.c file along with
other 3d control devices i might need over time.

also feel free to grab it and use it for your own projects.


thank you for your time, and have a good weekend!

-rodri