Re: [ft-devel] A question about freetype and harfbuzz

[Werner LEMBERG]

> I have a question about freetype and harfbuzz.  FreeType1 includes
> an extension to support OpenType text layout processing.  But this
> support hasn't become part of FreeType2.  Why?  Why does FreeType2
> not use the codes of harfbuzz to support OpenType text layout
> processing?

We have decided to let FreeType 2 do one job: Rendering glyphs.
Producing correct text layout for more complicated scripts like Arabic
or Indic requires the interpretation of the input text strings, in
close connection with font data like OpenType or Apple's AAT.  With
other words, you need three levels to do this, for example


             pango   ->   handling of layout

             ^  |
             |  v

           harfbuzz  ->   handling of OpenType features

             ^  |
             |  V

           freetype  ->   handling of glyph rendering


Both harfbuzz and pango could be replaced with ICU (which also can use
FreeType).

However, there must be some reason for your question -- you are
actively working on both harfbuzz and pagno, AFAIK, and you know these
things very well, I believe, so please tell us why you think that
unifying harfbuzz and freetype would be a good thing.


    Werner