Re: Slur position : "catching" Llilypond values...

[Nick Payne]

On 15/02/11 02:02, David Nalesnik wrote:
> On 2/14/11, Dmytro O. Redchuk<address@hidden>  wrote:
>
> > Would be great it if allows to specify which grob's positions to alter, like
> > this:
> >
> > \offsetPositions #"Arpeggio" #'(-2 . 2)
> Hi, Dmytro --
>
> I actually have been working on a snippet which generalizes another
> function -- namely, the oft-cited snippet for applying 'extra-offset
> to broken slurs.
>
> http://www.lilypond.org/doc/v2.12/Documentation/user/lilypond/Difficult-tweaks#Difficult-tweaks
>
> It should be easy to do a similar thing with the positions snippet.
>
> Here is my function:
>
> offsetBrokenSpanner =
> #(define-music-function (parser location name offsets) (string? pair?)
>      #{
>        \overrideProperty $name #'after-line-breaking #(broken-spanner $offsets)
>      #}
> )
>
> #(define ((broken-spanner offsets) grob)
>    (let* (
>           ; have we been split?
>           (orig (ly:grob-original grob))
>
>           ; if yes, get the split pieces (our siblings)
>           (siblings (if (ly:grob? orig)
>                       (ly:spanner-broken-into orig) '() )))
>
>     (if (and (>= (length siblings) 2)
>               (eq? (car (last-pair siblings)) grob))
>       (ly:grob-set-property! grob 'extra-offset offsets))))
>
>
> To modify a slur:
>
> \offsetBrokenSpanner #"Slur" #'(x . y)
>
> To modify a grob in a higher context:
>
> \offsetBrokenSpanner #"Staff.OttavaBracket" #'(x . y)
>
> My only hesitation is this statement in the NR (section referenced above):
>
> "When applying this trick, the new after-line-breaking callback should
> also call the old one after-line-breaking, if there is one. For
> example, if using this with Hairpin, ly:hairpin::after-line-breaking
> should also be called."
>
> I confess I don't fully understand this, and hence I'm unsure if my
> function is overly simplifed.  However, calling \offsetBrokenSpanner
> #"Hairpin" #'(x . y) seems to work as expected.
>
> [Note: the issue of contexts is why I used \overrideProperty instead
> of \override.  For some reason, \override will not accept
> "Staff.OttavaBracket" as a valid grob name.  I wonder if there is any
> drawback to using \overrideProperty, since I've seen it so
> infrequently.]

This is something similar:

\version "2.13.48"

#(define ((grob2-extra-offset offset) grob)
    (let* (
        (orig (ly:grob-original grob))
        (siblings (if (ly:grob? orig)
            (ly:spanner-broken-into orig)
            '())))
    (if (and (>= (length siblings) 2)
        (eq? (car (last-pair siblings)) grob))
    (ly:grob-set-property! grob 'extra-offset offset))))

albOffset = #(define-music-function (parser location type move) (string? 
pair?) #{
    \once \override $type #'after-line-breaking = #(grob2-extra-offset 
$move)
#})

#(set-global-staff-size 24)

\relative c'' {
    \time 6/4
<< {
        a'8 g fis e dis e \acciaccatura e d4. c'8 b4 |
        c4 r2 s2. |
        dis8 b c b a g b2\rest <e gis,>4 |
    } \\ {
        fis,,,8 e' dis e fis b, c4. g8 a4 |
        dis2 r4 s2. |
        b2 r4 r2. |
    } \\ {
        fis4 s2 s2. |
        s8 e'' fis e g fis ~ fis4. gis8 a4 ~ |
        a4 c,2\rest s2. |
    } \\ {
        s1. |
        c8\rest b a g a c dis4. e,8
        \albOffset "Tie" #'(0 . 1)
        fis4 ~ |
        fis4 s2 fis'8 e dis cis dis b |
    } >>
}

Nick