JEP Proposal update, and JavaOne

[Doug Felt]

On Tue, Sep 30, 2014 at 10:38 AM, Steven R. Loomis <srl at icu-project.org>
wrote:

> On 09/30/2014 09:19 AM, Doug Felt wrote:
> > For the JEP, I'd just like to state that
> >
> > 1) even when both engines support a language, the GlyphVectors output by
> > ICU LayoutEngine and HarfBuzz will not always be the same.  In
> particular,
> > ICU uses 'filler glyphs' and tries to arrange the glyph to char mapping
> to
> > be as exact as possible.  HarfBuzz does not natively use filler glyphs or
> > generate a close mapping, so the icu-le-hb compatibility shim generates
> an
> > emulation of this.  Anyone who depends in detail on the placement of
> filler
> > glyphs or the glyph-to-char mapping will see changes. We expect there to
> be
> > very few such clients, but they should be aware of this possibility.
>
> Yes, we should note that the compatibility is not bit for bit.
>
> >
> > 2) Given that we expect few such clients, and some of them will possibly
> > break anyway, another option is to not generate the filler glyphs at all,
> > but instead generate HarfBuzz's native output and adjust the layers
> inside
> > the JDK (not API) that consume them to use the HarfBuzz native output
> > instead.
> I will add that to the JEP.   Would you be able to file a ticket on
> this? (tag it 'harfbuzz')
> >
> > 3) Third party clients are unable to effectively use the current
> > glyphvector data (all that is exposed in the API) to determine the
> > boundaries of glyph clusters, which is necessary for client layout of
> text
> > on a path. If we change the GlyphVector data, we might consider reworking
> > it so that it is useful for this purpose.
>
> I will probably put something in like "address limitations in the
> GlyphVector API"
>
> Can you file a ticket on this one as well?
>

Sure.  How do I file tickets again?

>
> >
> > On Mon, Sep 29, 2014 at 10:30 PM, Steven R. Loomis <
> steven.loomis at oracle.com
> >> wrote:
> >> On 08/01/2014 10:44 PM, Steven R. Loomis wrote:
> >>> Forgot to mention!
> >>> We'll be talking about HarfBuzz at this session - if you are at JavaOne
> >>> come by!
> >>>
> >>>
> >>>
> >>
> https://oracleus.activeevents.com/2014/connect/sessionDetail.ww?SESSION_ID=2890
> >> Hello.
> >> I've updated the JEP here: http://goo.gl/n5SSMV
> >>
> >> See some of you at 9pm tomorrow in SF hopefully!
> >>
> >> Steven
> >>
> >>
> >
>
>
> --
>
> IBMer but all opinions are mine.
> https://www.ohloh.net/accounts/srl295 // fingerprint @
> https://ssl.icu-project.org/trac/wiki/Srl
>
>
>


-- 

Doug Felt | Software Engineer | dougfelt at google.com
<https://mail.google.com/mail/?view=cm&fs=1&tf=1&to=dougfelt@google.com> |
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