How to make a new greek font to work with babel

Question

I have an OpenType font (.otf) and I need to use it from pdftex. I use an 8 bit input encoding. I am stuck on the greek part with babel. The input I use is the following:

\selectlanguage{polutonikogreek}>~h

Which should output ἦ (U+1F26, GREEK SMALL LETTER ETA WITH PSILI AND PERISPOMENI).

The glyph ἦ is not in the font, but there is ῏ (U+1FCF, GREEK PSILI AND PERISPOMENI) and η (U+03B7, GREEK SMALL LETTER ETA), so combining these would be fine:

\selectlanguage{polutonikogreek}{\accent92\char104}

looks ok.

The question is now: how to get >~h to make {\accent92\char104}?

Note: the greek fonts that I know make a ligature of >~h to get the desired output.

Answer 1

I use otftotfm to generate the tfm files from the OpenType font. I have created a custom encoding file that includes lines like these:

% LIGKERN uni0313 uni1FC0 =: uni1FCF
% LIGKERN uni0313 tonos =: uni1FCE
% LIGKERN uni0313 uni1FEF =: uni1FCD
% LIGKERN uni0313 alpha =: uni1F00
% LIGKERN uni0313 epsilon =: uni1F10
% LIGKERN uni0313 eta =: uni1F20
% LIGKERN uni0313 rho =: uni1FE4
% LIGKERN uni0313 omicron =: uni1F40
% LIGKERN uni0313 omega =: uni1F60
% LIGKERN uni0313 iota =: uni1F30
% LIGKERN uni0313 upsilon =: uni1F50

and

% POSITION uni1FCF 180 00 -300
% POSITION uni1FCE 200 00 -300
% POSITION uni1FCD 200 00 -300

These are instructions to otftotfm to add virtual fonts with ligatures and MOVERIGHT commands.

This is not perfect yet, but the best way in terms of reproducibility (I am scripting the font conversion process). There are still some issues with accent placement. More will follow here.