Rework some letters using glyph references

[KrasnayaPloshchad]

Several letters such as Ѐ, Ё, Ѝ can be reconstructed by copy glyph references and paste them. The notable advantage is if you modified one glyph, other related glyphs can follow your change, thus giving conveniences for future maintances.

[typiconman]

Yes, this should be done.

[starover77]

This is definitely a good idea, but it has a much wider application with Latin and Greek fonts. I use glyph references in my Latin font designs, but I haven't seen enough need for it in Cyrillic fonts to consider it worth much time and effort. But if you can think of places in the Cyrillic ranges of Unicode where this would be applicable, it would be useful if we could establish a list of possible references for future design work.

[typiconman]

The problem is that the TTF format does not support characters with a mix of references and splines. So this limits the usefulness of this approach to only cases that consist of references entirely.

[KrasnayaPloshchad]

So which letters can be possibility composed by mix of references and splines?

[typiconman]

For example, think of ѿ. In principle, you could map all splines to glyphs in the PUA and have everything done via references. But is it worth it?

[KrasnayaPloshchad]

Now I have an idea for such letters. First, put an unencoded glyph into font to save a spline, second, copy a reference to encoded glyph. Is it possible?

[typiconman]

A decision to deprecate SIL Graphite would greatly simplify this issue. Please vote in #46

[KrasnayaPloshchad]

Maybe you can try to research FontForge documentation to see if there are any solution. I think this can be resolved by writing additional script to convert certain reference into spline for compiling TTF.

[typiconman]

This is not possible because TTF has been deprecated, together with SIL Graphite.
Pull requests are welcome.