[HarfBuzz] Post Base Substitution fails with Malayalam repha

[Rajeesh K Nambiar]

On Fri, Sep 13, 2013 at 11:28 AM, Suresh P <sureshp at gmx.com> wrote:
> Jonathan Kew wrote:
>>
>> Hi Suresh,
>>
>> Please specify the exact font (version? link?) being used, to ensure we
>> can reliably reproduce the problem. Thanks.
>>
> As Rejeesh pointed out this happens with any traditional lipi font. I am not
> aware of what Uniscribe does with it. Meanwhile, if the reph postion flag
> for Malayalam changed to REPH_POS_AFTER_POST from REPH_POS_AFTER_MAIN ( in
> hb-ot-shape-complex-indic.cc ) the problem disappears!. But then it is moved
> even after the post base matra which is undesirable, too.

Here's a font: http://rajeeshknambiar.fedorapeople.org/smc-fonts-6.0/Meera-6.0.ttf
It has GPOS abvm rule for dotreph.
"hb-view Meera.ttf  ൎക്കു " gives the following rendering -
http://i.imgur.com/Ln9AmKv.png (postbase Matra u1 is separate)
hb-shape shows that Dotreph is reordered after base -
[k1k1=0+2018|dotreph=0 at -234,-64+0|u1=0+639]
Correct rendering is - http://i.imgur.com/OsTdcVH.png (postbase Matra
forms k1k1u1 glyph correctly)

I guess it would be easiest for us to update the fonts if Dotreph is
not reordered at all.
Also see an earlier discussion -
http://lists.freedesktop.org/archives/harfbuzz/2013-July/003433.html


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Cheers,
Rajeesh
http://rajeeshknambiar.wordpress.com