Re: New snippet: remove staff if another is alive (for wind divisi)

[Thomas Morley]

2018-08-03 23:14 GMT+02:00 Saul Tobin <address@hidden>:
> Hi all,
>
> I just put together a snippet to make managing shared wind staves more
> automatic, particularly with triple winds that may be combined in different
> ways.
>
> \version "2.19.82"
>
> #(define remove-if-sibling
>    (lambda (offsets)
>      (lambda (grob)
>        (let* (
>                ;; The parent of a VerticalAxisGroup is a VerticalAlignment
>                (parent (ly:grob-parent grob 1))
>                ;; Get the children VerticalAxisGroups of the parent
>                (siblings (ly:grob-object parent 'elements))
>                (siblings-list
>                 (if (ly:grob-array? siblings)
>                     (ly:grob-array->list siblings)
>                     '()))
>                ;; Find the siblings above or below me by offsets
>                (my-vindex (ly:grob-get-vertical-axis-group-index grob))
>                (enemy-indices (map (lambda (offset) (+ offset my-vindex))
> offsets))
>                (enemy-vaxis? (lambda (v) (member
> (ly:grob-get-vertical-axis-group-index v)
>                                            enemy-indices)))
>                (enemy-vaxes
>                 (filter enemy-vaxis? siblings-list))
>                )
>          ;; Suicide if an enemy sibling is alive
>          (map
>           (lambda (enemy-vaxis)
>             (ly:pointer-group-interface::add-grob grob 'make-dead-when
> enemy-vaxis))
>           enemy-vaxes)
>          )
>        )
>      )
>    )
>
> %% Two Staff Example
>
> global = {
>   s1
>   \break
>   s1
>   \break
>   s1*2
> }
>
> I = {
>   c'''1
>   \context Staff = "1" { \set Staff.keepAliveInterfaces = #'() }
>   c'''1
>   c'''1
>   \context Staff = "1" { \unset Staff.keepAliveInterfaces }
>   c'''1
> }
>
> II = {
>   e''1
>   e''1
>   e''1
>   e''1
> }
>
> <<
>   \new Staff = "1+2" \with {
>     \override VerticalAxisGroup.before-line-breaking = #(remove-if-sibling
> '(1))
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \partcombine \I \II >>
>   \new Staff = "1" \with {
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \I >>
>   \new Staff = "2" \with {
>     \override VerticalAxisGroup.before-line-breaking = #(remove-if-sibling
> '(-2))
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \II >>
>>>
>
> %% Three Staff Example
>
> global = {
>   s1
>   \break
>   s1
>   \break
>   s1
>   \break
>   s1*2
> }
>
> I = {
>   c'''1
>   \context Staff = "1" { \set Staff.keepAliveInterfaces = #'() }
>   c'''1
>   c'''1
>   c'''1
>   \context Staff = "1" { \unset Staff.keepAliveInterfaces }
>   c'''1
> }
>
> II = {
>   e''1
>   e''1
>   e''1
>   e''1
>   e''1
> }
>
> III = {
>   a'1
>   a'1
>   \context Staff = "3" { \set Staff.keepAliveInterfaces = #'() }
>   a'1
>   a'1
>   a'1
> }
>
> <<
>   \new Staff = "1+2+3" \with {
>     \override VerticalAxisGroup.before-line-breaking = #(remove-if-sibling
> '(2 5))
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \I \II \III >>
>   \new Staff = "1+2" \with {
>     \override VerticalAxisGroup.before-line-breaking = #(remove-if-sibling
> '(1 -1))
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \partcombine \I \II >>
>   \new Staff = "1" \with {
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \I >>
>   \new Staff = "2+3" \with {
>     \override VerticalAxisGroup.before-line-breaking = #(remove-if-sibling
> '(2 -3))
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \partcombine \II \III >>
>   \new Staff = "2" \with {
>     \override VerticalAxisGroup.before-line-breaking = #(remove-if-sibling
> '(-1 -3 -4))
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \II >>
>   \new Staff = "3" \with {
>     \override VerticalAxisGroup.remove-empty = ##t
>     \override VerticalAxisGroup.remove-first = ##t
>   } << \global \III >>
>>>
>
> _______________________________________________
> lilypond-user mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/lilypond-user
>

Hi,

I had a closer look at your code.

You select via vertical-axis-group-index. This makes for a not
intuitive argument of your `remove-if-sibling`-procedure. Even worse,
the needed arguments may need to be changed if other staves are added
to the score.
Also I think divisis should be controlled, well, from the divisi-staves.

Inspired by your work I come up with the attached.

Cheers,
  Harm

divisi-saul-02-test.pdf
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divisi-saul-02-test.ly
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