Re: Fermatas with tremolos

[Thomas Morley]

2018-02-19 21:08 GMT+01:00 Simon Albrecht <address@hidden>:
> I think the best way to do it would be essentially an override to the beam,
> adding the fermata to its stencils. However I have to call on the expect
> Schemers around here (Harm, David N.?) for finishing it, since I haven’t
> been able to align the fermata to the horizontal center of the beam.

Hi Simon,

you need to go for the grob's left/right-bounds in order to get their
coordinates and move the fermata accordingly.

Leads to:

#(define (beam-with-fermata grob)
  (let* ((beam-stil (ly:beam::print grob))
         (left-stem (ly:spanner-bound grob LEFT))
         (right-stem (ly:spanner-bound grob RIGHT))
         (all-stems?
           (every
             (lambda (g)
               (grob::has-interface g 'stem-interface))
             (list left-stem right-stem))))
    (if all-stems?
        (let ((sys (ly:grob-system grob)))
          (ly:stencil-combine-at-edge
            beam-stil
            Y
            UP
            (ly:stencil-translate-axis
              (ly:stencil-aligned-to
                (grob-interpret-markup
                  grob
                  (markup #:musicglyph "scripts.ufermata"))
                X
                CENTER)
              (/
                (-
                  (ly:grob-relative-coordinate right-stem sys X)
                  (ly:grob-relative-coordinate left-stem sys X))
                2)
              X)
            0.5))
        beam-stil)))

{
  \override Beam.stencil = #beam-with-fermata
  \repeat tremolo 16 { c'32 c''}
}

Or use the method with tuplets, at least less invasive.

Also, following links may be of interest. They provide excerpts of an
old and new edition of Janacek, Glagolitic Mass.
http://notovodstvo.ru/forum/fermata/tremolo_fermata_old.gif
http://notovodstvo.ru/forum/fermata/tremolo_fermata_new.gif
Taken from:
https://forums.makemusic.com/viewtopic.php?f=12&t=2065&sid=70206c7b17c9cd8107c4ad1250073f0c
But not discussing how it _should_ be done.
I don't have Gould at hand, does she says anything about it?

Cheers,
  Harm