[HarfBuzz] Ligatures and color changes

[Behdad Esfahbod]

On 13-02-20 08:03 AM, Jonathan Kew wrote:
> On 20/2/13 12:24, Lóránt Pintér wrote:
>> I'm trying this with a font that has the kerning data in the "kern"
>> table as well as in the "GPOS" table. (Is that possible?)
>>
>> Can you show me a font that this feature works with?
>>
> 
> I thought we'd seen it work last week, but now it doesn't seem to. :( Behdad,
> did we miss something here? It seems to me like the skippy_iter in
> PairPosFormat1::apply doesn't know what it's looking for...

Ouched.  Fixed in master.

b


> JK
> 
>> -- 
>>
>> *Lóránt Pintér*
>>
>> Developer at Prezi <http://prezi.com>
>>
>> On Wednesday, February 20, 2013 at 10:26 AM, Jonathan Kew wrote:
>>
>>> On 19/2/13 23:35, Lóránt Pintér wrote:
>>>> Using ZWNJ would be a great way of fixing it. And indeed it splits the
>>>> ligature all right, but it also destroys the kerning. Here's a little
>>>> test I did with HarfBuzz @ e0486fc1affd3796fb8f664e2e7fc208f1d2106c:
>>>> (the font has an "fi" ligature, and has some kerning between "F" and ",")
>>>>
>>>> Splitting the ligature with the ZWNJ works:
>>>>
>>>> Shaped "fif\u200Ci" with features: [ ]
>>>> Glyph: #682, x_advance: 652
>>>> Glyph: #71, x_advance: 380
>>>> Glyph: #3, x_advance: 0
>>>> Glyph: #74, x_advance: 292
>>>>
>>>> Kerning across the ZWNJ does not:
>>>>
>>>> Shaped "F,F\u200C," with features: [ ]
>>>> Glyph: #39, x_advance: 483
>>>> Glyph: #13, x_advance: 242
>>>> Glyph: #39, x_advance: 563
>>>> Glyph: #3, x_advance: 0
>>>> Glyph: #13, x_advance: 242
>>>>
>>>> Is it possible that doing this will be supported later in HarfBuzz?
>>>
>>> Hmm - is that font using a legacy 'kern' table, or a GPOS 'kern'
>>> feature? For the former, I can understand that kerning would break, as
>>> it's a naïve glyph-pair lookup, but for the latter, I thought we should
>>> now ignore the ZWNJ.
>>>
>>> JK
>>
> 
> 

-- 
behdad
http://behdad.org/