Re: Kievan square notation in LilyPond

[Jan Warchoł]

Hi,

2011/8/8 Aleksandr Andreev <address@hidden>:
> Hi everybody,
>
> Back to the topic of adding support for East Slavic (aka Kievan) music 
> notation.

Great to see you working on this!

> I've rewritten our font for Kievan notation (called Suprasl) in
> Metafont. Now, I am trying to figure out how to incorporate the new
> glyphs into the Feta files.

Our contributor's guide contains a very brief introduction to
modifying metafont files, it may be useful if you haven't seen it yet:
http://lilypond.org/doc/v2.15/Documentation/contributor/modifying-the-feta-font
If during your work you'll have anything to add there, contributions
to CG will be most welcome!

> I've created a new file, feta-kievan.mf in the mf directory.
>
> Now I'd like to make sure I'm doing this right before I proceed ..
> this is the first time I've worked with Metafont, so please bear with
> me.
>
> In our file (suprasl.mf), the glyphs are defined with beginchar(name,
> width, height, depth). Next, I define a series of points in terms of
> the quantity u, which is derived from a sharped quantity u#.
> Basically, u# tells us what the size of the character should be given
> the font's design size. Finally, I draw the character with fill.

can you send these files (in the patch format if possible)?  It's
easier to say something when you see the code (at least in my case).

> The question I have is this: what is the appropriate coordinate system
> to use for feta-kievan?
>
> What I've gleaned from reading the source of feta-notehead.mf is that
> things are somehow defined in terms of stafflinethickness# and
> staff_space.

Yes, and also there is design_size used to encode differencies between
particular versions of the font (see
http://lilypond.org/doc/v2.15/Documentation/essay/engraving-details#optical-sizing).

> Am I right to understand that stafflinethickness is the thickness of a
> line in the five line staff? And staff_space is the amount of space
> between lines?

stafflinethickness is the thickness of one line in the staff.
staff_space is the distance between middle of one line to the middle
of a next line (in other words, it's the amount of whitespace between
lines + stafflinethickness)

> Would it be appropriate to define a basis unit u in terms of
> stafflinethickness and then specify the points in terms of u?

In case of noteheads, i suppose that everything would be best defined
in staff_space.  For stems (as i understand there are special
characters for stems) stafflinethickness will be more appropriate.
However, i may be mistaken since i don't see the code.

> Where is the origin?

origin of what? (sorry, i didn't understand)

HTH,
Janek