Re: Ligatures and Pango?

[Behdad Esfahbod <behdad cs toronto edu>]

On Sun, 27 Nov 2005, Han-Wen Nienhuys wrote:

> I just installed CVS Pango, to test ligatures. It turns that out of my
> 180 ttf files (including the ones that Apple ships with MacOS 10.3) none
> have GSUB tables. However, loading the font into Fontforge, and saving
> as TTF (and OTF/CFF I guess) adds a GSUB table. Wonderful!

If you are talking about Pango from CVS HEAD, that may not be the
best version to test these things with.  Right now on HEAD, we
only handle OpenType fonts in the basic module.  Previously it
was the other way, OpenType was not handled.  Ultimately a
combination of the two will work, but I'm still figuring out how
to make that work.  As a result, if you have a TrueType font with
no OpenType kern table, the TrueType kerning information is used
to kern in older Pango versions (including pango-1-10 branch),
but not on HEAD.  OTOH, if you have a font with OpenType kern
feature, that's respected only with Pango HEAD.


> I noticed that LilyPond doesn't do kerning automatically; for a
> PangoGlyphString,  we just do
>
>    PGIX PGIY rmoveto GLYPHNAME glyphshow
>
> for each glyph (PGIX = PangoGlyphInfo->PangoGlyphGeometry.x) I thought
> kerning would be put into PGIX. I tried doing

Yeah, that's the plan.  The shaper adjusts PGIX to do kerning.

--behdad
http://behdad.org/

"Commandment Three says Do Not Kill, Amendment Two says Blood Will Spill"
	-- Dan Bern, "New American Language"