[HarfBuzz] ICU?

[Ed Trager]

Hi, Sharon,

OpenOffice.org, represented by "OOo" on the diagram, uses ICU's layout
classes.  So that's the one place where ICU was understood to exist in
the diagram --but this is of course entirely non-obvious unless one
already knows about it.

In the future world of a unified text layout engine (UTLE), presumably
OpenOffice would just use the new UTLE with HarfBuzz in there
directly.  Currently OOo uses Uniscribe on Windows, ICU on Linux, and
I don't know what it does on OS X.

Assuming the new UTLE is superior --which we can safely assume is
everyone's goal-- then in the future authors of FLOSS software will
perhaps choose to use UTLE exclusively and perhaps not even bother
with conditional compilation to use Uniscribe on Win32 or ATSUI on
OSX.

As Eric Mader recently noted on this list, ICU's LayoutEngine uses the
interesting idea of having a "canned" GSUB table to do
presentation-forms-based shaping of Arabic if a font shows up with no
'GSUB' table in the font.  Behdad has already noted that he plans to
incorporate this kind of thing into HarfBuzz, and it might be
something that can be extended and used for some other scripts besides
Arabic too.  In conclusion, it seems likely that the best ideas from
all existing layout engines --including of course ICU-- will be vetted
for inclusion in the UTLE.  That is certainly my hope.

Best - Ed

x> Hi, I've just joined this list and I have various questions. Hope this one
> is appropriate, let me know if not.
>
> I was looking at the diagram put together as a result of the Boston Text
> Layout Summit:
>
> http://eyegene.ophthy.med.umich.edu/interview/boston.php
>
> So, where does ICU fit in to that diagram?
>
> Sharon Correll,
> SIL International