Re: [AC21.5] internals.texi: document some issues raised by Xft

>>>>> "Ben" == Ben Wing <[email protected]> writes:

    Ben> I now really consider the exposure of consoles to be a
    Ben> mistake.

    Ben> I'm interested in seeing if we can "de-expose" them and use
    Ben> devices in all cases instead.  What do you think?

That kind of abstraction is your pidgen; I'm willing to bet my time on
your judgment.

However, it's not obvious to me that "device" is the right
abstraction, in that Xft and X11 text rendering will share the same
screen (and associated graphics will be done by core X protocol), but
at least at present need somewhat different APIs (because the fonts
are specified differently).

At least in X.org X11R6.8, fonts have their own drawing methods
internally (this isn't exposed to Xlib AFAICS, but rather is used
internally in the generic wrappers used to handle the Xmb/Xwc/Xutf8
variants of text-handling routines).  I'm wondering if we shouldn't go
in that direction.  Then devices themselves might very well disappear,
or at least end up in a very different position in this hierarchy.

    Ben> Note also another issue under Windows, if we want to support
    Ben> glyph shaping, as required for Arabic, Devanagari, etc.
    Ben> Windows has built-in routines to take care of this but you
    Ben> need to pass the whole string of text and do text-width
    Ben> calculations similarly on the whole string rather than
    Ben> char-by-char.

Don't we already semi-abstract to this?  AFAIK we do geometry
calculations on runs of text, defined more or less by "all these
characters will be represented by the same font."  The Xft code that I
borrowed from Knauel and Neuebaur does this (although come to think of
it that routine was scammed from the MS Windows code).





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