[Devel] OpenType layout as a many-to-many CMAP

[Vinod Kumar]

On Thu, 24 Jul 2003, Werner LEMBERG wrote:

>   . We've decided that OpenType support must be implemented one level
>     higher than FreeType, since FreeType is basically a rendering
>     engine which converts an outline to a bitmap.

The IndiX project has viewed the OpenType layout tables as a
many-to-many CMAP table implemented not as an table lookup
but as a complicated function implemented by the sequence of
OpenType layout tables lookup and processing. Even GPOS information
can be subsumed into Spacer and Unspacer glyphs. This approach works
for Indic scripts. Can I please influence freetype.org to reconsider
the decision to provide OpenType support at one level higher?
A one-to-one CMAP support can have as its brother, a many-to-many
CMAP support.

>
> > It appears that OpenType layout (v1.3) is fully supported by
> > FreeType2.
>
> How did you get this impression?

Oops. Devel archive message no 006672 and the presence of src/otlayout
and ftlayout made me jump at this fond (font?) hope, overlooking
the prominent FT 1.x in the title.

> We would be glad if someone (you?) can work on OpenType support,
> making the stuff in src/otlayout actually work together with writing
> the high-level API equivalent to the FreeType 1 functions
> TT_GSUB/GPOS_Apply_String, either as a new library on top of FT2 or as
> a module for FT2.  Discussion is highly welcome.

Yes I would love to work on this. I prefer it to be a OTCMAP module
for FT2.

>
> BTW, it would be nice if any bugs your team has found in FT1's
> OpenType code could be incorporated back into the FT1 distribution

I shall compare the CVS diff between our working FT1.4 and the
one in the distribution and help in the incorporation.

Vinod Kumar
The IndiX project