Re: Figured Bass support

[Richard Shann]

 Han-Wen Nienhuys wrote:

> address@hidden writes:
>  
>
> > The last problem is easily fixed:
> >
> > \property FiguredBass.BassFigure \override #'font-relative-size = #-3
> >
> > just before the figures does the trick.
> >    
>
> I've added this to scm/grob-description.scm
>
>  
This change seems to have got lost  - in 1.8.0 in scm/define-grobs.scm 
there is (font-relative-size . -1)

I sent a sample output from 1.8.0 to a composer (who had only seen 
finale, sibelius etc before) he commented

< Thanks for sending it to me. The quality is very impressive, and
aesthetically pleasing. >

One thing he pointed out (amongst other things I am working through) is that 
the figures in the bass are unconventionally far from the notes they refer to. 
The figures all begin at the same vertical offset, computed to miss the worst 
case note. In the hand engraved scores I've looked at the figures start a short 
distance below the note, or the bottom staff line if the note is entirely 
within the staff. (i.e. they are ragged top and bottom).

Also the example in the 1.8.0 documentation assumed that the default 
direction was going to be #-1, so as it stands it generates a 
back-to-front set of figures.
With all this in mind,  the following revised example works with 1.8.0

\score {
    <
     \context Voice \notes { \clef bass dis4  c d ais}
     \context FiguredBass
       \figures {
\property FiguredBass.BassFigure \override #'font-relative-size = #-3
\property FiguredBass.BassFigure \set #'direction = #-1
\property FiguredBass.BassFigure \set #'extra-offset = #'(0 . 3.5)
\once \property FiguredBass.BassFigure \set #'extra-offset = #'(0 . 2.5) 
< 6 >4
< 7 >8 < 6+ [_!] >
\once \property FiguredBass.BassFigure \set #'extra-offset = #'(0 . 2.5) 
< 6 >4
<6 5 [3+] >
       }
     >
}

This is rather verbose - is there some tweak available to make the 
figures automatically sit just below whatever is above? I have a 
sneaking suspicion that this bit is the right bit to tweak
(BassFigure
...
(Y-offset-callbacks . (,Self_alignment_interface::aligned_on_self))
...

but have no idea how (aligned_on_something_else? :-\ )

Richard