[Devel] Re: [Fonts] Re: [Render] Font name matching (urg)

[Werner LEMBERG]

> I'm still exploring FreeType, but as I understand it, it provides
> for access to glyphs through several pre-defined encodings, unicode
> among them.  I don't know how to access glyphs using the raw font
> glyph values.

Just use FT_Load_Glyph() :-) To be serious, it makes no sense to
access the raw font glyph values directly.  It only makes sense to
access glyphs with glyph names, but not all TT fonts provide this
information reliably.

> > Pango currently seems to be taking care of this character -> glyph
> > mapping for old-style X fonts, while FreeType appears to intend to
> > support OpenType "layout" features (that include reordering, I
> > think).
> 
> I don't quite understand exactly where FreeType is going; at this
> point it's providing pretty good rasterization but not much else.

Exactly.  Higher-level features have been intentionally removed in
FreeType 2 (except some core functions to make the use of library
easier right now).

We have already discussed how to proceed (writing a text layout engine
on top of FT2); some experimental (non-working) code how to parse OT
tables can be found in the `ftlayout' CVS model; a replacement for
glib is in the `mlib' module (which satifies the needs of FT2), etc.
It will take some time...

> > Will the Render libraries call FreeType and/or Pango APIs? Or will
> > the app be expected to call those libraries separately? Where do
> > the Render libraries fit into this big picture?
> 
> The library I'm developing is called 'Xft' and is designed to
> support FreeType font access using the Render extension.  This
> should be below Pango.  The fact that FreeType is providing both the
> low-level rasterization along with high-level character->glyph
> mapping stuff makes things more confusing.  My original intent was
> to use FreeType as a rasterization engine to replace the existing
> core glyphs.

The only `high-level' stuff is synthesizing a Unicode character->glyph
map.  Or do you mean something different.


    Werner