Re: Centering bass figures on whole notes and longer (issue 325070043 by address@hidden)

[Richard Shann]

On Sat, 2017-07-15 at 02:09 -0700, address@hidden wrote:
> On 2017/07/15 08:55:43, richard_rshann.plus.com wrote:
> > On Sat, 2017-07-15 at 08:51 +0100, Richard Shann wrote:
> > > On Sat, 2017-07-15 at 00:40 -0700, mailto:address@hidden
> wrote:
> > > > On 2017/07/15 07:25:37, http://richard_rshann.plus.com wrote:
> > > > > On Sat, 2017-07-15 at 00:09 -0700,
> mailto:address@hidden
> > > > wrote:
> > > > > > I'm afraid this patch does not fix the problem as wished.
> > > >
> > > > > You give an example of multiple bass figures on a note, I'm not
> > > sure
> > > > > what you would wish to see for that case,
> > > >
> > > > In
> > > > <<
> > > >    \relative c' { c1 c1 }
> > > >    \figures { <6+>2 <6+>2 <6+>1 }
> > > >
> > > > I would expect same aligning for first and second BassFigure
> related
> > > to
> > > > the note.
> > > (understood: first and second *group* of bass figures)
> > >
> > > That would be ok, although when you have multiple figures on a note
> > > allowing a bit more space for them can be good sometimes. You could
> > > always move the whole group along by inserting a short duration note
> > > with no figure in the bass figures if there was a particular case
> > > where
> > > this seemed obtrusive (hacky of course).
> > >
> > > So I think you could validly object that you didn't like them being
> > > treated differently.
> > Ha! I think I was being over-generous to your case here :)
> > consider
> 
> > <<
> >     \relative c' { c1 c2 }
> >     \figures { <_+>2 <6+>2  <_+>4 <4>4}
> 
> >   >>
> 
> > In the current LilyPond the two groups of figures are aligned
> > differently.
> 
> As a debugging-helper I coded a visualization.tool:
> 
> \layout {
>    \context {
>      \FiguredBass
>      \override BassFigure.after-line-breaking =
>        #(lambda (grob)
>          (let ((line
>                  (ly:make-stencil
>                    (ly:stencil-expr (make-filled-box-stencil '(0 . 0) '(0
> . 10)))
>                    '(0 . 0)
>                    '(0 . 0))))
>          (format #t "\nX-extent:\t~a"
>            (interval-length (ly:grob-property grob 'X-extent)))
>          (ly:grob-set-property! grob 'stencil
>            (box-stencil
>              (ly:stencil-combine-at-edge
>                (ly:stencil-combine-at-edge
>                  line Y RIGHT (ly:text-interface::print grob) 0)
>                X RIGHT line 0)
>            0 0))))
>    }
> }
> 
> After applying it to your example I'm not sure what you mean. I don't
> see a significant difference.

Your visualization tool reveals the problem. They are aligned the same:
the left hand edge of the figure is aligned with the left hand edge of
the note. However, because the whole note is wider visual impression is
that the figure appears centered on the note for the shorter duration
notes but to the left for the whole note.
So the problem is perhaps that the choice of alignment point is
unfortunate.

Richard