skylines and custom-code

[Thomas Morley]

Hi,

please consider the code below.

\version "2.22.0"

#(ly:set-option 'debug-skylines #t)

{
  \override NoteHead.no-ledgers = ##t
  %\override NoteHead.stencil = #point-stencil
  \override Stem.stencil =
    #(lambda (grob)
      (for-each
        (lambda (nh) (ly:grob-translate-axis! nh -6 Y))
        (ly:grob-array->list
          (ly:grob-object (ly:grob-parent grob X) 'note-heads)))
      (ly:stem::print grob))
  b'''8
  b'''8.
}

For some graphical notation I need to move notes (i.e. at least
NoteHead, Stem, Flag) freely in Y-axis direction.
Using ly:grob-translate-axis! seemed to be nice for this pupose,
because while moving the NoteHead the mentioned other Grobs follow.

Alas, enabling 'debug-skylines shows a problem: the skyline obviously
still sees the old grob-positions.

How to avoid, circumvent, correct?

Furthermore, why there's no problem for dotted notes?


Thanks,
  Harm