On Sat, May 11, 2013 at 03:22:27PM -0600, Idris Samawi Hamid ادريس سماوي حامد wrote:

Salaam, Huseyin,

I missed this and other threads, it's been busy here...

On Tue, 07 May 2013 23:35:25 -0600, H. Özoguz wrote:

...

But with traditionalarabic it is worse than with arabtype. What could be a way to fix this?

Traditional Arabic is a uniscribe-compliant font, but not a fully opentype font. Uniscribe also supports older, pre-unicode protocols. In other words, TraditionalArabic is platform-dependent. So unless M$ has updated it in a recent OS, it will not work in ConTeXt MkIV.

It did (all its fonts actually), it now uses GPOS for mark placement.

Since XeTeX uses the local libraries, then mkii/xetex on windows might work.

XeTeX does not use any system libraries for its OpenType layout, in the past is was using ICU LayoutEngine and now it is using HarfBuzz, in all platforms (i.e. a third party library, but not a system one). However, HarfBuzz has heuristics to place marks based on glyph bounding boxes in the case of GPOS absence (a bit similar to TeX's \accent but knows which marks goes above or below or off the center). Regards, Khaled