[HarfBuzz] Overlap of vocal with thai text

[Vignesh Raman]

Hi Konstantin,

I will check the DejaVuSans font metrics.

The same font was used to render thai text by another application (It
does not use Qt). Here it is rendered correctly.
This application uses the harfbuzz 0.9.35 and freetype 2.5.3 calls to
render the thai font.
So it looks like harfbuzz code in Qt 4.7.4 is not able to handle the
incorrect metrics in DejaVuSans font.

Behdad said,
>You want to use Qt with harfbuzz-ng, not old-harfbuzz.  I'm not sure how to do
>that.  Search around for that perhaps.

So if I integrate harfbuzz-ng or harfbuzz 0.9.35 from
http://www.freedesktop.org/software/harfbuzz/release/ in Qt 4.7.4 will
it help?

Thanks.

Regards,
Vignesh.

On Mon, Mar 2, 2015 at 7:19 PM, Konstantin Ritt <ritt.ks at gmail.com> wrote:
> 2015-03-02 21:52 GMT+04:00 Vignesh Raman <rvignesh.raman at gmail.com>:
>>
>> I checked this thai font issue on a board with Qt 4.7.4 libs and this
>> happens with one particular font DejaVuSans.ttf.
>> When I tried DejaVuSansCondensed.ttf font the issue is not seen. I
>> wonder any of the harfbuzz-thai calls are not invoked for DejaVuSans
>> font?
>
>
> Might be a font issue. I already seen bugs related to an incorrect metrics
> in DejaVu fonts.
>
>>
>> Does font make a difference in harfbuzz bundled code
>> (src/3rdpart/hafbuzz) in Qt.
>
>
> Sure it does. Try inspecting the font's tables and metrics.
>
>>
>> Is there a way to trace harfbuzz-thai.c function calls for eg
>> thaiWordBreaks.
>
>
> I don't think so. You could build Qt with debug symbols and try to debug
> harfbuzz-thai.c, though I'd better inspect the problematic font prior to
> digging so deep.
>
>
> Konstantin
>



-- 
Regards,
Vignesh.