[HarfBuzz] Accent positioning with greek smallcaps

[Georg Duffner]

Thank you, Behdad!

I’ve found the problematic parts and fixed them in the font. In fact, 
Fontforge did warn about it, but I didn’t see the warning due to script 
based font generation.

Am 2013-01-08 23:18, schrieb Behdad Esfahbod:
> Figured it out:
>
> If you check with ttx for example, indeed Lookup 34, MarkBasePos subtable 1
> covers that mark and base sequence but has no anchor for it.  However,
> subtable 2 has.  Just fixed HarfBuzz to keep looking if an anchor is missing.
>   Renders fine now.
>
> Thanks,
>
> behdad
>
> On 13-01-08 01:14 AM, Georg Duffner wrote:
>> Hi Behdad,
>>
>> which tool did you use for debugging? With Fontforge I can’t find the null
>> anchor you found. The source featurefile as well as the featurefile extracted
>> from the font both show correct values for the anchors and inn Fontforge’s
>> metrics view, the results look as expected. What’s more, XeTeX and LuaTeX
>> position the accents correctly (they fail at other places though).
>>
>> Georg
>>
>> Am 2013-01-07 10:25, schrieb Behdad Esfahbod:
>>> Hi Georg,
>>>
>>> I debugged the font.  It does look like a font issue to me.  The MarkBase
>>> table for those accents and those bases has a null anchor for the base.
>>> That's all I know.
>>>
>>> behdad
>>>
>>> On 13-01-07 02:06 AM, Georg Duffner wrote:
>>>> Hello,
>>>>
>>>> There seems to be something wrong with accent positioning in greek smallcaps
>>>> with a ccmp feature enabled. In EB Garamond I’ve put together a feature (as
>>>> stylistic set ss20) that decomposes all composed characters and mark and mkmk
>>>> anchors are in place where needed. This all works nicely with Harfbuzz except
>>>> for greek smallcaps as you can see at
>>>> http://georgduffner.at/ebgaramond/greektests.html (with Firefox of course).
>>>> Accents are placed in front of the letters at the bottom instead of atop of
>>>> the letters. The last row of “Smallcaps” shows that latin smallcaps are fine,
>>>> simple ones as well as stacked ones. I got the same results with hb-view
>>>> (harfbuzz 0.9.9 on Arch Linux).
>>>>
>>>> Results from hb-shape are:
>>>>
>>>> 1: (ἂἅἇ)
>>>> 1: <U+1F02,U+1F05,U+1F07>
>>>> 1:
>>>> [alpha.sc=0+549|uni0313.grksc=0 at -751,-630+0|gravecomb.grkstacksc=0 at -626,-630+0|alpha.sc=1+549|uni0314.grksc=1 at -751,-630+0|acutecomb.grkstacksc=1 at -626,-630+0|alpha.sc=2+549|uni0314.grkstacksc=2 at -684,-665+0|uni0342.sc=2 at -771,-489+0]
>>>>
>>>>
>>>>
>>>> and
>>>>
>>>> 1: (áäấÄÖÜ)
>>>> 1: <U+00E1,U+00E4,U+1EA5,U+00C4,U+00D6,U+00DC>
>>>> 1:
>>>> [a.sc=0+549|acutecomb.sc=0 at -319,65+0|a.sc=1+549|uni0308.sc=1 at -421,84+0|a.sc=2+549|uni0302.stacksc=2 at -389,65+0|acutecomb.stacksc=2 at -197,167+0|Adieresis.deu=3+684|Odieresis.deu=4+763|Udieresis.deu=5+738]
>>>>
>>>>
>>>>
>>>> I attach the results from hb-view.
>>>> The options used are:
>>>> --features="ss20","smcp"
>>>>
>>>> You can find the font used in the tests at
>>>> http://georgduffner.at/ebgaramond/tests/EBGaramond12-Regular.otf (it is too
>>>> big for the limit of this list, even when compressed).
>>>>
>>>> Please note that the testpage on the web uses a version of the font where the
>>>> decomposition table is included in ccmp which I don’t want to because this
>>>> should only be enabled when really necessary. But it doesn’t make a
>>>> difference.
>>>>
>>>> Best regards,
>>>> Georg
>>>>
>>>>
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>>>> HarfBuzz at lists.freedesktop.org
>>>> http://lists.freedesktop.org/mailman/listinfo/harfbuzz
>>>>
>>>
>>
>>
>


-- 
EB Garamond: http://www.georgduffner.at/ebgaramond