[HarfBuzz] arabic positioning without gpos
behdad at behdad.org
Thu Jan 14 16:39:56 PST 2010
On 01/14/2010 05:17 PM, Evan Martin wrote:
> On Thu, Jan 14, 2010 at 12:32 PM, Khaled Hosny <khaledhosny at eglug.org> wrote:
>> On Thu, Jan 14, 2010 at 11:53:56AM -0800, Evan Martin wrote:
>>> This code obviously works for the other users of Harfbuzz, so I must
>>> be missing something in my understanding. (Maybe the glyph advances
>>> for Arabic vowels should always be zero?
>> AFAIK, yes, actually I think this is true for any glyph of combining
>> marks class.
> I found this function in Pango:
> * pango_ot_buffer_set_zero_width_marks
> * @buffer: a #PangoOTBuffer
> * @zero_width_marks: %TRUE if characters with a mark class should
> * be forced to zero width.
> * Sets whether characters with a mark class should be forced to zero width.
> * This setting is needed for proper positioning of Arabic accents,
> * but will produce incorrect results with standard OpenType Indic
> * fonts.
> * Since: 1.6
> Pango calls this from the Arabic shaper. Perhaps such a hack belongs
> in Harfbuzz?
It will be in the new harfbuzz. I'm not familiar enough with the old harfbuzz
shaping code to comment.
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