[HarfBuzz] HarfBuzz API design

Adam Twardoch list.adam at twardoch.com
Wed Aug 19 13:04:51 PDT 2009

But surely there needs to be a way to trace which glyphs relate to which
character codes, which can of course be an n:m relationship. When the
user moves around the rendered text with a text cursor and decides to
delete some glyphs, select them or change them, the client needs to make
sure to sync the operations that it does in its own text buffer with the
rendering -- especially regarding the size of the selection and/or
position of the cursor?

Does HarfBuzz provide access to the cursor position information that can
optionally be stored in the GDEF table?


Behdad Esfahbod wrote:
> On 08/19/2009 03:16 PM, Ed Trager wrote:
>> Hi, everyone,
>>> I don't have much to say about the actual font-related parts of the
>>> proposal. But I do think it's perhaps a bad idea to reuse the same
>>> buffer for text input and glyph output. Is memory that tight? Might a
>>> user not want to be able to query the text back out even after
>>> shaping?
>> I was wondering about this too : When selecting or highlighting shaped
>> text (to copy/paste/do something else to it) surely a shaper like
>> HarfBuzz needs to provide convenient access / mapping back to the
>> underlying Unicode text ?
> A shaper just converts text to glyphs, giving back the cluster mapping too. 
> The rest is done by the client.  The client sure has the text somewhere 
> already.  there's no point in keeping a separate copy by HarfBuzz.
> behdad
>> - Ed
> _______________________________________________
> HarfBuzz mailing list
> HarfBuzz at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/harfbuzz


Adam Twardoch
| Language Typography Unicode Fonts OpenType
| twardoch.com | silesian.com | fontlab.net

The illegal we do immediately.
The unconstitutional takes a little longer.
(Henry Kissinger)

More information about the HarfBuzz mailing list