Re: [ft-devel] Open Type Font Support on Mobile Devices?

[Behdad Esfahbod]

Hi Maggy,

First, you would need FriBidi or another bidi implementation even if you use
HarfBuzz.

Next, for Arabic shaping, FriBidi does a very basic job of that, with no
advanced substitution/positioning involved and hence no need for GSUB/GPOS
tables.  For anything more than basic Arabic you need HarfBuzz.

behdad

On 01/24/2010 10:30 PM, Maggy Anastasia wrote:
> Hi Behdad,
> 
> 
> At the moment I am trying to use HarfBuzz (and FreeType) to deal with these 
> tables. The only reason for me to do so (at least at current moment) is to 
> render Arabic font correctlly.
> 
> you mentioned that if the primary use is to get Arabic rendering, I can use 
> FriBidi only to do so.
> Does FriBidi2 needs advance typography tables (GPOS, GSUB, etc) as input? I 
> looked at the interface of fribidi, it seems to me that freebidi output is 
> independent from
> 
>  font files (ttf or otf) and  that the information regarding glyph 
> substitution, joining, etc is already defined in a built in lookup table 
> (please correct me if I am wrong).
> If this is the case, if I want to render the arabic text using certain font, 
> is it true that for glyph positioning, i would still need to use the 
> information in GPOS table, thus requiring me to use 
> 
> HarfBuzz and FreeType?
> 
> I am so sorry if my question is too basic, I have no prior knowledge on 
> Arabic typography. I am basically in need of enlightenment on when to use 
> fribidi, 
> harfbuzz and freetype and whether I should combine any of these in this 
> situation.
> 
> 
> best regards
> 
> Maggy Anastasia Suryanto
> 
> 
> 
> Hi,
> 
> 
> For OpenType complex shaping you need HarfBuzz [1]. Google engineers are
> working on using it for the Chromium port on Linux [2]. Using Pango with
> the FreeType backend is a simpler solution (Pango+FreeType uses HarfBuzz
> internally).
> 
> If your primary use is to get Arabic rendering done, you can get away
> with using FriBidi2 [3] only.
> 
> behdad
> 
> 
> [1] http://freedesktop.org/wiki/Software/HarfBuzz
> [2] http://lists.freedesktop.org/archives/harfbuzz/2009-March/000312.html
> 
> [3] http://fribidi.freedesktop.org/
> 
> 
> 
> On 04/09/2009 05:19 AM, Waqar Ahmad wrote:
> 
>     Hi,
> 
> 
>     Is there anybody who has been working on font related stuff on mobile
>     devices? I am interested in getting Open Type Font (OTF) support on
>     symbian, windows mobile devices and most likely on Android in future
> 
>     as well. As far as I know, Open Type Fonts (Arabic, Urdu etc.) are not
>     supported on Symbian and Windows Mobile devices. FreeType does not
>     support GSUB and GPOS.
> 
> 
>     I am thinking about porting an existing open source OTF solution to
>     mobile devices. A few possibilities that come in my mind are mentioned
>     below and suggestions from members of this list are solicited.
> 
> 
>     -Is there any good port of FreeType for Symbian and Windows Mobile
>     available in open source? If it is there, I can try to further extend
>     it to add required support for OTF.
> 
> 
>     -If somebody has experience of working with Pango and consider it good
>     for porting to mobile devices, this can be another option to explore.
> 
> 
>     -Google Adroid is using FreeType, however, I don't know if they have
>     added any support for OTF. One way could be to take FreeType from
>     Android (assuming it would have been optimized for constrained mobile
> 
>     devices) and add support for OTF.
> 
> 
>     I would highly appreciate suggestions and guidelines from this list on
>     above matters.
> 
> 
>     Best Regards,
>     Waqar
> 
> 
> 
> 
>     However, I am not sure if Open Type Font are completely supported or
>     not in FreeType library.
> 
> 
>     Specifically, I am interested in Urdu and Arabic languages support
>     which require a number of rules for appropriate text rendering like
>     glyph positioning and substitution. I want to know if such features
> 
>     are supported in FreeType library? If not, is there any other project
>     in your knowledge that is working on something similar to what I am
>     interested in?
> 
> 
>     I will highly appreciate your guidance in this regard.
> 
> 
> 
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> 
> 
> 
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