#3106 wrong accidental positions in polyphonic voices

[Anonymous]

Originally created by: *anonymous

Originally created by: lemzw...@googlemail.com

\version "2.17.10"

\header { texidoc = "
In polyphonic situations, where one voice has tied chords and the other one
doesn't contain a tie, the accidental positions after the bar lines must be
recomputed to take care of the visible accidentals only.

Here is a counterexample.
" }

\relative c''' {
  << { <gis cis eis gis>1 ~ q   } \\      { eis,1                eis } >>
}

... For this bug I suggest a new category: `very ugly' :-)

[Google Importer]

Originally posted by: lemzw...@googlemail.com

Just curious: Will the fix of #3108 also fix this issue?

[Google Importer]

Originally posted by: m...@mikesolomon.org

It doesn't fix this by default, but it does if you set the accidentalGrouping property to #'voice. So it's still a bug, but it'll soon has a workaround.

[Google Importer]

Originally posted by: dak@gnu.org

I don't think that there will be a useful workaround easily.  The main issue is likely that tied accidentals _do_ have to appear after a line break.  Check out
\repeat unfold 10
\relative c''' {
  << { <gis cis eis gis>1 ~ q   } \\      { eis,1                eis } >>
}
and it is clear where the reserved space is coming from.  Basically, one would have to do two completely independent versions, one for use in the same line, one for use after a line break.

However, we also have a problem with reminder accidentals and line breaks independent from the tie problem, and it is likely that this would need to get addressed with a similar mechanism leading to two different versions of accidental columns depending on whether we have a line break or not.

[Google Importer]

Originally posted by: k-ohara5...@oco.net

The workaround from comment 2 avoids the problem, when some voices are tied and some not:

\new Staff \with { accidentalGrouping = #'voice }
\repeat unfold 10 \relative c''' {
  << { <gis cis eis gis>1 ~ q   } \\      { eis,1                eis } >> }

In the less-common case where, within one voice, some notes are tied and some not, we still need to figure the accidental configuration for both cases.

[Google Importer]

Originally posted by: lemzw...@googlemail.com

Responding to #3:

> Basically, one would have to do two completely independent
> versions, one for use in the same line, one for use after
> a line break.

I think we are doing this already for various other grobs, right?  It seems natural to me to extend this accordingly.  However, given that a nice workaround is available now, this problem is no longer urgent (at least for me :-)

[Google Importer]

Originally posted by: Elu...@gmail.com

the workaround is good for voices with enough vertical separation: if the 2nd voice climbs up to bis the accidentals will collide directly and LilyPond will avoid this.

another - cumbersome and limited  - workaround then is given with

      \once {
        \override Accidental.stencil = #point-stencil
        \override Accidental.font-size = #-20
      }