Re: bug in lyric syllable magnetic snap

[Thomas Morley]

Am Do., 16. Mai 2019 um 13:25 Uhr schrieb Alexander Kobel <address@hidden>:
>
> Hi David, hi Mike, hi all,
>
> I sometimes (still use Lilypond, and when I do, I typically use) your
> wonderful snippet for snapping "close" syllables into a single token.
>
> (For those who don't know this contribution: it's meant to get rid of
> unpleasant thin-space gaps between syllables in cramped conditions, when
> LyricHyphens are not shown, but there's a "kerning" problem due to the
> fact that syllables are engraved as separate entities.)
>
> Now I stumbled across an issue with that: two syllables are combined
> which are clearly far apart; see the attached screenshot and reduced
> working example from an actual engraving. It's not exactly minimal, but
> at least it's reasonably short and shows the problem. And the exact
> circumstances when the bug occurs are not clear to me, and it's somewhat
> sensitive to reduction.
>
> According to my tests, it's related to the facts that there is
>
> (1) a hyphen *before* the syllable "bor" in "ver -- bor -- gen" in the
> alto part;
>
> (2) a line break exactly there (moving the break "remedies" the
> problem); and
>
> (3) another voice/staff simultaneously (commenting out the soprano
> mitigates the issue as well).
>
> It's not, however, related to the accidental in the soprano, or the fact
> that the whole note in the lower voice is wider than the quarter in the
> upper voice (replacing d'1 by d'4*4 doesn't help).
>
>
> Any thoughts on what goes wrong here, and about a possible fix or
> workarounds?
>
>
> [ In case you wonder: it's an excerpt of Heinrich Schütz' "Die Himmel
> erzählen", converted from James Gibb's contribution 46745 to CPDL
> (engraved in Capella) via musicxml2ly. I mainly want to fix a couple of
> minor spelling errors; the conversion worked fairly pleasant in general. ]
>
>
> Cheers,
> Alex

Hi,

I tried to have a look at it ...

Though, I'm too tired to be verbose, please refer to the pdf.
First a minimal, then some debugging output with a probably
significant difference.

Currently I've no idea for a fix, though.

\version "2.19.82"

\include "lyric-syllable-magnetic-snap-orig.ily"

\markup
  \box \fill-line { minimal }

\new Lyrics
  \lyricmode {
    \override LyricWord.after-line-breaking = #(lyric-word-compressor 0.5)

    foo8 -- bar
    _4
    one2 --
    \break
    two1 -- three
  }


good =
  \lyricmode {
    _4
    foo8 -- bar
    one2 --
    \break
    two1 -- three
  }

bad =
  \lyricmode {
      %% !!!!!!!!!!!!!!!!
    foo8 -- bar
    _4
    one2 --
    \break
    two1 -- three
  }

tst =
  \override LyricWord.after-line-breaking =
    #(lambda (grob)
      (newline)
      (pretty-print
        (map
          (lambda (elt)
            (cons
              elt
              (ly:grob-property elt 'text)))
          (ly:grob-array->list (ly:grob-object grob 'text-items))))
      ((lyric-word-compressor 0.5) grob))

\markup
  \box \fill-line {
        \column {
        BAD-OUTPUT
        "terminal:"
        "[...]"
      \with-color #red "((#<Grob LyricHyphen >)"
      "(#<Grob LyricText > . \"two\")"
      "(#<Grob LyricHyphen >"
      "(#<Grob LyricText > . \"three\")))"
      }

  }

\new Lyrics \lyricmode { \tst \bad }

\markup
  \box \fill-line {
        \column {
        GOOD-OUTPUT
        "terminal:"
        "[...]"
      \with-color #red "((#<Grob Spanner >)"
      "(#<Grob LyricText > . \"two\")"
      "(#<Grob LyricHyphen >"
      "(#<Grob LyricText > . \"three\")))"
      }

  }

\new Lyrics \lyricmode { \tst \good } }

Cheers,
  Harm