Re: \textLengthOn in polyphony and over MultiMeasureRests

[Urs Liska]

Am 30.07.2018 um 11:36 schrieb Urs Liska:
> Hi Torsten,
>
> thanks for these explanations.
>
>
> Am 29.07.2018 um 19:22 schrieb Torsten Hämmerle:
> > Trevor Bača-2 wrote
> > > Torsten, how are you achieving the text centered above the pair of half
> > > notes in the original example (ie, in the measure top-headed with
> > > "Minima")? Try as I might, I can't get it!
> >
> > Hi Trevor,
> >
> > You've got me there! ;)
> >
> > Standard \textLengthOn will push away neighbouring notes and you 
> > won't get
> > the markup text to neatly and symmetrically align with the barlines 
> > without
> > some tweaking.
> >
> > \textLengthOn just sets the following two properties:
> >
> >    \override TextScript.extra-spacing-width = #'(-0.0 . 0.4)
> >    \override TextScript.extra-spacing-height = #'(-inf.0 . +inf.0)
> >
> > By adapting extra-spacing-width, we can actually set the left and right
> > "margins" of the text. This way, we can attach the TextScript to the 
> > second
> > note and make it overlap the first note.
> >
> > Finally (this is not necessary, though) I've shifted both notes to 
> > the right
> > by using extra-offset to better match the original.
> >
> > <http://lilypond.1069038.n5.nabble.com/file/t3887/textlength-modified.png> 
> >
> >
> > %%%%%%%
> > {
> >    \override TextScript.self-alignment-X = #CENTER
> >
> > % custom version of \textLengthOn:
> >    \override TextScript.extra-spacing-width = #'(2.6 . 0.4)    % 
> > default:
> > #'(-0.0 . 0.4)
> >    \override TextScript.extra-spacing-height = #'(-inf.0 . +inf.0)
> >
> > % Shift NoteHead and Stem to the right
> >    \override NoteHead.extra-offset = #'(5 . 0)
> >    \override Stem.extra-offset = #'(5 . 0)
> >
> >    R1
> >    \bar "||"
> >    c''2 c''^\markup \line { \typewriter "#'extra-offset" "trickery" }
> >    \bar "||"
> > }
> > %%%%%%
> >
> > HTH,
> > Torsten
>
> So if I see correctly this means your essentially doing a regular 
> \textLengthOn that would push the neighboring notes away but prevent 
> that by manually setting a "negative padding". And this has to be 
> adjusted to the content around the element with the markup on it. 
> Which makes it even less likely to get a decently working solution as 
> a *function* that automatically determines the widths to set. I can 
> imagine going through the note columns of the current system/measure 
> and do some calculations, but earlier intense experiments with this 
> area (I had to create manually drawn slur replacments) make be doubt 
> that the width values needed for this are available at the point where 
> I still can change the extra-spacing-width.
>
> Plus: it seems this approach is problematic when more than one other 
> note is in the area covered by the text (see attached PNG):
>
> %%%%%%%
> {
>   \override TextScript.self-alignment-X = #CENTER
>   \override TextScript.extra-spacing-width = #'(5 . 0.4)
>   \override TextScript.extra-spacing-height = #'(-inf.0 . +inf.0)
>
>   R1
>   \bar "||"
>   c''4 c'' c''2^\markup \line { \typewriter "#'extra-offset" "trickery" }
>   \bar "||"
> }
> %%%%%%
>
> Best
> Urs, who is trying further ...

Hm, I thought I finally had the solution, based on ideas from an earlier 
post by you and the one by Trevor:

%%%%%%%%%%%%%%%%
\new Staff \relative {
  <<
    {
      \override Staff.NoteColumn.X-offset = 10
      c''2 c
    }
    \new Voice {
      <>^\markup " A pretty long text that should extend the measure  "
    }
  >>
% uncomment to make things break ...
%{
  <<
    {
      c8 c c c c2
    }
    \new Voice {
      <>^\markup " A pretty long text that should extend the measure  "
    }
  >>
%}
}
%%%%%%%%%%%%%%%%

This works perfectly for one measure (and is totally agnostic of what 
happens in the "music" voice), but as soon as you add (uncomment) the 
second measure, things overlap again. Inserting \textLengthOn again 
makes the markup push notes around. So I'm still not moving forward here ...

Urs