Re: NoteColumn shift in one voice affects dot position in another voice

[Nick Payne]

On 26/12/09 20:46, David Kastrup wrote:
> Nick Payne<address@hidden>  writes:
>
>    
> > See below. When I shift the first note in voiceTwo to avoid a
> > collision with the note in voiceFour, the dot on the rest that begins
> > voiceOne gets separated from the rest and pretty much disappears under
> > the following accidental. It looks to me as though Lilypond is trying
> > to keep the dots for the rest in voiceOne and the A in voiceFour
> > vertically aligned, regardless of whether the rest and the A are
> > vertically aligned. You can see this quite clearly by setting the
> > hshift value to something larger such as #2.
> >      
> I guess that this sort of thing needs some accounting and/or linear
> programming in order to arrive at a good solution.  You go down the note
> column and put all "natural" dot columns in one list.  Then you assign
> the best columns overall.  Opening a new column in the total is
> expensive (but less so if the vertical distance to the last column is
> large), displacing a dot from its note costs corresponding to the
> displacement, least total cost is taken.  Something like that.
>    
In a similar vein, having a chord of dotted notes across voices, with a 
second in one voice, results in the dot in the other voice asking for a 
divorce. Though in this case I don't know what the convention for 
engraving is. The example I have in a 19th century score (Mertz's 
transcription of Schuberts Ständchen for guitar) corresponds to the 2nd 
chord in the example below, where the dot has been moved back to where 
it would normally be with a single note.

\version "2.13.9"

\relative c'' {
    \new Staff
<<
    \new Voice { \voiceOne <e d>4. <e d>4. }
    \new Voice { \voiceTwo e,4. \once \override Dots #'extra-offset = 
#'(-1 . 0) e4. }
>>
}

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