Re: [ft] Rendering Arabic

[Simon Cozens]

On 05/08/2019 10:39, Tim Orton wrote:
> Can anyone tell me how to render Arabic text using FreeType2?
> The main issue is that with Arabic, characters have different forms
> depending on whether they are at the start, middle or end of a word. (I
> think this is called "glyph joining", is that correct?)

More generally, selecting the right glyph from the font according to 
text-level considerations is called "shaping", but we know what you 
mean. :-)

> FreeType doesn't seem to handle this natively, so I think I need to use
> another library to handle it, such as Pango or FriBidi

Right, you will need a shaping engine. The open source shaping engine is 
Harfbuzz, and it is available under the MIT license so you will be able 
to use it in commercial projects. Fribidi is available under the LGPL, 
so using it as a library does not require you to disclose your source.

You might also find libraqm (also MIT licensed) a more helpful 
high-level library for laying out Arabic; it interfaces between 
freetype, harfbuzz and fribidi.