PATCH: Arrowed accidentals for microtone notation

[Maximilian Albert]

Hi all,

for various reasons I've been inactive on this list for quite a long 
time. My last post was concerning a possible contribution, namely 
arrowed microtonal accidentals, which have been requested on this list 
quite a few times.

IIRC, I had already sent a pdf file showing off the new accidentals but 
haven't provided a patch yet. The reason for this is that 1) out of some 
amazing stupidness I hadn't properly put my attempts under version 
control and thus needed to re-write a couple of things and 2) the 
original design was very generic (to allow for easy tweaking), but once 
the design was settled I needed to eliminate a lot of variables, which 
turned out much more time-consuming than expected. So alas I didn't get 
to do it before now. My sincere apologies to everyone who has been 
waiting for me to follow up.

Anyway, here finally is a series of patches implementing these 
accidentals. The first one adds a function to draw the arrow, while the 
other ones add sharp/flat/natural signs with up- and downward pointing 
arrows attached. I made it so that the plain accidentals (i.e., without 
arrows) are created using the exact same operations as before, so that 
their shape isn't changed. Nnote that for natural and flat signs *with* 
arrows attached the brushing of the stems needed to be slightly reduced, 
or else they would look very awkward; but this only applies to the new 
accidentals. Patch No. #5 is optional because it adds accidentals with 
arrows in *both* directions (which is probably not needed, but you 
never know what people want to use in their scores :-). As for No. #6, 
see below.

A sample .pdf showing the accidentals in various positions is attached, 
together with its .ly file (the latter is basically a slight variation 
of the maqam example). I guess that the file could be stripped down but 
I was too lazy for that. :-) In any case, it should be easy to adapt it 
so that you can inspect the accidentals in all positions and combinations.

Anyone up for a review?

Cheers,
Max

P.S.: I took care to make the charboxes precisely enclose the glyphs 
(which metafont confirms). However, the result looks rather clamped, and 
there are even occasional collisions with the arrowheads. Is this a bug 
in lilypond's spacing algorithm? I seem to remember that there have been 
problems with accidentals being placed too close to other symbols. Could 
this be the same issue? If for some reason there really needs to be more 
space around the glyphs, you can also apply patch #6 (and tweak the 
numbers if you wish).

micro_accs_patches.tgz
Description: GNU Unix tar archive

microtone_accs.pdf
Description: Adobe PDF document

\include "deutsch.ly"

#(define-public KOMA 1/9)
#(define-public BAKIYE 4/9)
#(define-public KUCUK 5/9)
#(define-public BUYUKMUCENNEB 8/9)

makamPitchNames = #`(
  (c . ,(ly:make-pitch -1 0 NATURAL))
  (d . ,(ly:make-pitch -1 1 NATURAL))
  (e . ,(ly:make-pitch -1 2 NATURAL))
  (f . ,(ly:make-pitch -1 3 NATURAL))
  (g . ,(ly:make-pitch -1 4 NATURAL))
  (a . ,(ly:make-pitch -1 5 NATURAL))
  (b . ,(ly:make-pitch -1 6 NATURAL))
  
  (cc . ,(ly:make-pitch -1 0 KOMA))
  (dc . ,(ly:make-pitch -1 1 KOMA))
  (ec . ,(ly:make-pitch -1 2 KOMA))
  (fc . ,(ly:make-pitch -1 3 KOMA))
  (gc . ,(ly:make-pitch -1 4 KOMA))
  (ac . ,(ly:make-pitch -1 5 KOMA))
  (bc . ,(ly:make-pitch -1 6 KOMA))

  (cb . ,(ly:make-pitch -1 0 BAKIYE))
  (db . ,(ly:make-pitch -1 1 BAKIYE))
  (eb . ,(ly:make-pitch -1 2 BAKIYE))
  (fb . ,(ly:make-pitch -1 3 BAKIYE))
  (gb . ,(ly:make-pitch -1 4 BAKIYE))
  (ab . ,(ly:make-pitch -1 5 BAKIYE))
  (bb . ,(ly:make-pitch -1 6 BAKIYE))

  (ck . ,(ly:make-pitch -1 0 KUCUK))
  (dk . ,(ly:make-pitch -1 1 KUCUK))
  (ek . ,(ly:make-pitch -1 2 KUCUK))
  (fk . ,(ly:make-pitch -1 3 KUCUK))
  (gk . ,(ly:make-pitch -1 4 KUCUK))
  (ak . ,(ly:make-pitch -1 5 KUCUK))
  (bk . ,(ly:make-pitch -1 6 KUCUK))

  (cbm . ,(ly:make-pitch -1 0 BUYUKMUCENNEB))
  (dbm . ,(ly:make-pitch -1 1 BUYUKMUCENNEB))
  (ebm . ,(ly:make-pitch -1 2 BUYUKMUCENNEB))
  (fbm . ,(ly:make-pitch -1 3 BUYUKMUCENNEB))
  (gbm . ,(ly:make-pitch -1 4 BUYUKMUCENNEB))
  (abm . ,(ly:make-pitch -1 5 BUYUKMUCENNEB))
  (bbm . ,(ly:make-pitch -1 6 BUYUKMUCENNEB))

  ;; f for flat.
  (cfc . ,(ly:make-pitch -1 0 (- KOMA)))
  (dfc . ,(ly:make-pitch -1 1 (- KOMA)))
  (efc . ,(ly:make-pitch -1 2 (- KOMA)))
  (ffc . ,(ly:make-pitch -1 3 (- KOMA)))
  (gfc . ,(ly:make-pitch -1 4 (- KOMA)))
  (afc . ,(ly:make-pitch -1 5 (- KOMA)))
  (bfc . ,(ly:make-pitch -1 6 (- KOMA)))
  
  (cfb . ,(ly:make-pitch -1 0 (- BAKIYE)))
  (dfb . ,(ly:make-pitch -1 1 (- BAKIYE)))
  (efb . ,(ly:make-pitch -1 2 (- BAKIYE)))
  (ffb . ,(ly:make-pitch -1 3 (- BAKIYE)))
  (gfb . ,(ly:make-pitch -1 4 (- BAKIYE)))
  (afb . ,(ly:make-pitch -1 5 (- BAKIYE)))
  (bfb . ,(ly:make-pitch -1 6 (- BAKIYE)))

  (cfk . ,(ly:make-pitch -1 0 (- KUCUK)))
  (dfk . ,(ly:make-pitch -1 1 (- KUCUK)))
  (efk . ,(ly:make-pitch -1 2 (- KUCUK)))
  (ffk . ,(ly:make-pitch -1 3 (- KUCUK)))
  (gfk . ,(ly:make-pitch -1 4 (- KUCUK)))
  (afk . ,(ly:make-pitch -1 5 (- KUCUK)))
  (bfk . ,(ly:make-pitch -1 6 (- KUCUK)))

  (cfbm . ,(ly:make-pitch -1 0 (- BUYUKMUCENNEB)))
  (dfbm . ,(ly:make-pitch -1 1 (- BUYUKMUCENNEB)))
  (efbm . ,(ly:make-pitch -1 2 (- BUYUKMUCENNEB)))
  (ffbm . ,(ly:make-pitch -1 3 (- BUYUKMUCENNEB)))
  (gfbm . ,(ly:make-pitch -1 4 (- BUYUKMUCENNEB)))
  (afbm . ,(ly:make-pitch -1 5 (- BUYUKMUCENNEB)))
  (bfbm . ,(ly:make-pitch -1 6 (- BUYUKMUCENNEB)))

)

pitchnames = \makamPitchNames 
#(ly:parser-set-note-names parser makamPitchNames)

microGlyphs = #'((1    . "accidentals.sharpsharp")
                 (8/9  . "accidentals.sharp.arrowup")
                 (5/9  . "accidentals.sharp")
                 (4/9  . "accidentals.sharp.arrowdown")
                 (1/9  . "accidentals.natural.arrowup")
                 (0    . "accidentals.natural")
                 (-1/9 . "accidentals.natural.arrowdown")
                 (-4/9 . "accidentals.flat.arrowup")
                 (-5/9 . "accidentals.flat")
                 (-8/9 . "accidentals.flat.arrowdown")
                 (-1   . "accidentals.flatflat"))

\relative c'' {
  \override Staff.KeySignature #'glyph-name-alist = #microGlyphs
  \set Staff.keySignature =  #'(
        (1 .  1)
        (2 .  8/9)
        (3 .  5/9)
        (4 .  4/9)
        (5 .  1/9)
        (6 .  0))
  \override Accidental #'glyph-name-alist = #microGlyphs

  c cc db fk, gbm gfc gfb efk dfbm
}