Re: X fonts

[Mouse <mouse%Rodents-Montreal.ORG@localhost>]

> I'm just trying to run xclock remotely (over SSH).  However, this
> doesn't work:

> $ /usr/X11R6/bin/xclock -digital -update 1 -bg black -fg green -title 
> tick:xclock -fn -*-helvetica-*-r-*-*-22-*-*-*-*-*-*-* -strftime "%a, %b %e, 
> %Y %H:%M:%S %Z" -geometry 400x40

Depending on your shell, the -*-helvetica-*-r-*-*-22-*-*-*-*-*-*-*
glob pattern may not turn into what you want.  I'm going to assume your
shell turns it into a single argument identical to what you specified.

> Warning: Cannot convert string "" to type XftFont
> Segmentation fault (core dumped)

> It does work if I add -norender to the command.

Based on trying that command with and without -norender using my 4.0.1
system's /usr/X11R6/bin/xclock, I'm fairly sure the version without
-norender is not using X fonts, or at least not fonts as provided by
the core X protcol.  It's doing some kind of antialiased font
rendering, which is beyond what core X font support provides.

> It seems X fonts are mystical magic.  If they work you're lucky, if
> they don't you're lost.

They're pretty straightforward, if you stick to core X.

My guess - and a guess is all it is - is that when you use -norender,
it's using core X font support, with the -fn argument being turned into
a font, and rendered, on the server, whereas with -norender, all the
rendering is happening client-side and sent as bitmaps.  Running it
under xscope reveals that the no--norender version heavily uses an
extension called RENDER; I have so far been unable to find
documentation on this, so I don't know what it's doing with it.

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