[cells-devel] Cello fixes for FTGL <whew!>

[Kenny Tilton]

CVS willing (I have my doubts), Cells and Cello have now been updated 
with changes to resolve some deadly problems with FTGL when combined 
with display lists.

The Cells change had to do with enhancing the "lazy" option to be more 
of a code than a flag: one now has options :once-asked, :until-asked, 
and :always (alias t). Aside: I was surprised to see I had done this 
originally as an option on a formula for a slot. Seems to me it should 
be a slot option. ie, that when one needs lazy it will because the slot 
itself needs that behavior, no matter what the formula. So we'll put a 
"watch" on this design decision,which I left as is for now.

making display list calculation lazy (until asked) solved the problem 
with extruded fonts. Texture fonts were fixed by hacking FTGL in ways 
which turned out to be in testing already for FTGL v2.1 -- ie, I ran 
into this at the same time as others and happened to come up with the 
same fix. The problem was pretty subtle, so I will spare you all unless 
someone asks for the deets. Pretty much just a deep issue with display 
list generation.

Anyway, it now seems as if FTGL is back under control. Note that all 
this started when I went for the big performance enhancement of using 
nested display lists for all imaging. That interacted badly with some 
FTGL design decisions which have now been fixed or worked around.

kenny