One of the high-priority VPython bugs is that the "label" object for
displaying text does not exist in the Linux version. Among other things,
this makes the autoscaled graphing be unusable. Is it possible that there
is someone in the VPython user community who is sufficiently knowledgeable
in Linux to be able to help with this? We are short of this resource at the
moment.
A main component of the problem is simply choosing a font. Here are some
notes from students who looked at the problem earlier in the semester but
ran out of time to devote to it.
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On Unix, an analogous function glXUseXFont() is available. However, we
have been using the (higher level) GTK-GLArea widget instead of writing
directly to glX. GTK-GLArea seems to only provide a draw_text() function,
not a way to obtain fonts.
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From Ari: unfortunately, i can't even compile, due to an evil name
conflict: X uses the name 'Display' to refer to an X display; we use
Display internally as well. I played with trying to #define one away from
the other, but the modules are too interlinked -- i always end up hitting
both of them. short of massively reordering the include structure, i'm not
sure it's practical.
Xlib.h typedef's struct _XDisplay to Display. Xlib is pulled in by glx.h
which is needed by our xgl.h. But you can't move xgl.h ahead of the stuff
that pulls in our display.h (i.e. say from the first to the 2nd line of
arrow.cpp) because we need the other core Visual headers so we know what a
glcontext is and stuff .... yuck.
before i go doing anything drastic (like renaming everyplace we use
Display, or putting it in the namespace Visual or something like that) i
wanted to consult with Scherer. Do you want me to check my stuff in, even
tho it's broken?
it's likely also to have font-naming errors, since X will probably want an
evil X long named font
('adobe-courier-bitstream-foundry-10-*-1-1-2-3-5-*-=|:-)}-abe-lincoln'). i
*think* it might work where i just try to load 'fixed' (since X seems to
like to do that in other cases where i specify names that don't exist) but
we'll see. i don't have any real docs on glX calls, except Sun's online
manpages (which are pretty thin at best). Mesa doesn't bother with
documentation :) and the only statement in the red book about glXUseXFont
is that it exists (i could *really* use a working example). the Linux X
call docs aren't bad tho ... i think everything else in there will work
right.
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