[gsharp-devel] my current development directions and issues

[Christophe Rhodes]

Hi,

I thought it might interest people who read this list but don't
perpetually idle on IRC to know some of what I'm doing at the moment.
I'm looking, based partly on a late-night conversation in a bar in
Berlin, at implementing support for Mensural (black) notation, with a
view to allowing editing and typesetting of chant (as in the Liber
Usualis and similar collections).  I'm also simultaneously attempting
to learn how to use the git distributed version control system, which
is why you can see a mirror of my development tree (and even play
along, should you so wish) at
<http://www-jcsu.jesus.cam.ac.uk/~csr21/cgi-bin/gitweb.cgi?p=gsharp/.git;a=summary>.

The neumes and ligatures which are currently implemented can be seen
at <http://www-jcsu.jesus.cam.ac.uk/~csr21/tmp/foo.html>; at present,
there's no support for stems, accidentals; I've drawn glyphs for the
F-clef and the diamond punctum, but there's no UI for them yet.
(There are other slightly broken bits of the UI and display code, and
it's as yet completely uncoupled to the MIDI output, and and...).  I
hope the lurking mediaeval music experts will pitch in!

Bugs that I've found or remembered in the course of this development
include:

* Issues with non-6 staff sizes:
  ** beams are drawn wrong at size 8 or 12 (and possibly others) using
     the CLX backend: an example of what I get is at
     <http://www-jcsu.jesus.cam.ac.uk/~csr21/tmp/bad-beams.png>; there
     are two different problems shown there: the vertical misalignment
     of some of the beam components, and the apparent miscalculation
     of the horizontal extent
  ** miscalculation of the position for the first note on a staff;
     with large sizes (towards the top of the range), the first note
     is almost completely obscured by a treble clef.
  ** the space allowed for multiple staves in a system is inadequate
     with large staff sizes.
  (Larger staff sizes are potentially important in the context of
  mensural notation because the neume glyphs are small; in fact, for
  printing it might be worth making the staff lines thinner so that
  the neumes are more clearly distinguishable.)

* Data structure badness
  ** M-x Insert Segment After RET followed by M-x Delete Segment gives
     some kind of data structure corruption.  This might be simple to
     fix.

* ESA? issues
  ** C-h b lists a non-helpful set of commands; I /think/ that the
     commands it lists are those in the `gsharp' command table, rather
     than those which are in the currently applicable command table.

Cheers,

Christophe