[HarfBuzz] COMING SOON: 2nd Annual Text Layout Summit at aKademy in July 2007

[Behdad Esfahbod]

CC'ing harfbuzz list.  Please join.

On Tue, 2007-06-12 at 21:41 +0900, Kenichi Handa wrote:
> > On Tue, 2007-06-12 at 15:18 +0900, Kenichi Handa wrote:
> 
> > > with m17n's pango module	with pango's original module
> > > ------------------------        -----------------------------
> > > real 9.80			real 9.91
> > > user 9.13			user 9.10
> > > sys 0.03			sys 0.08
> 
> Sorry, this test was not fair because m17n's pango module
> was the version that caches the result of CTL.  The version
> disabling caching was about 4 times slower.  I think we can
> make it twice or more faster by tuning various codes (we
> have not yet made any effort for such optimization), but it
> won't be as fast as native C codes.
> 
> > Another important data point is the per-process memory usage of FLT
> > versus more traditional shapers.
> 
> Sure.  Currently m17n's pango module is linked with all m17n
> libaries (libm17n-core.so, libm17n.so, libm17n-gui.so --
> total about 1M-byte), but they contain many modules
> unnecessary for FLT driving (e.g. code-conversion,
> input-method, text-property handling, etc).  It is possible
> to build a more slim library only for FLT.

Right, but per-process memory is more about malloc()s you do, and I
guess parsing FLT data at run-time does a lot of those.  Reducing this
per-process footprint is why I'm rewriting harfbuzz to use mmap()ed
fonts directly instead of parsing them into memory.


> > > By the way, m17n-lib currently uses our own libray for OTF
> > > handling (http://www.m17n.org/libotf).  I have a plan of
> > > replacing it with HarfBuzz.  Do you know how stable is it?
> 
> > I had a look at libotf, can't see how it handles GSUB/GPOS completely.
> > There's just not enough code there about it :).
> 
> Yes, I was lazy in implementing full version because it's
> just a stopgap until we get a better version, and it seems
> that we have HarfBuzz now.
> 
> > HarfBuzz is pretty stable by most definitions.  Please continue
> > discussion on harfbuzz list.
> 
> At first, I'd like to read the documentation of that
> library.

There's no documentation.  It was a big lump of code handed to us from
freetype 1 and we are just maintaining it for now, and working on an
improved version.


>   But,
> http://www.freedesktop.org/wiki/Software/HarfBuzz just says
> this:
> 
> ------------------------------------------------------------
> Download
> 
> There are no releases available for download yet, and
> currently there are no releases scheduled, as the main
> audience of the code is developers of text rendering engines
> and currently the recommended way to use the code is to copy
> it into your project. Use CVS to check out the latest
> version instead, but please keep a note of your checkout
> date in your project, that will help with tracking bugs
> later.
> ------------------------------------------------------------
> 
> Could you tell me what CVS command to use?
> 
> % cvs -d ???? co ???/HarfBuzz

Oops, we've moved to git now.  I don't have the details handy.  Simon,
can you please update the wiki, pointing out which branch is stable and
all...

Thanks,

-- 
behdad
http://behdad.org/

"Those who would give up Essential Liberty to purchase a little
 Temporary Safety, deserve neither Liberty nor Safety."
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