Re: treble and bass clef simultaneously

[Thomas Morley]

Am Do., 28. März 2019 um 23:52 Uhr schrieb Thomas Morley
<address@hidden>:
>
> Am Do., 28. März 2019 um 08:02 Uhr schrieb Werner LEMBERG <address@hidden>:
> >
> >
> > > here my factious approach: [...]
> >
> > Thanks a lot!  Attached is the same sample code as with Aaron's
> > solution.  Do you see a possibility to make leading skips work in the
> > second argument of \clefTst?
> >
> >
> >     Werner
>
> Probably like below.
> Again: not tested beyond the given example!
>
> \version "2.19.82"
>
> \layout {
>   \context {
>     \Voice
>     \name "ClefVoice"
>     \alias "Voice"
>     \consists "Clef_engraver"
>     clefGlyph = #"clefs.F"
>     middleCPosition = #6
>     clefPosition = #-8
>     explicitClefVisibility = ##(#f #t #t)
>     \override Clef.full-size-change = ##t
>     \override Clef.font-size = #-4
>     \override Clef.space-alist.next-note = #'(fixed-space . 2)
>     \override Clef.after-line-breaking =
>       #(lambda (grob)
>         (let ((col (ly:item-get-column grob)))
>           (if (eqv? (ly:item-break-dir grob) 1)
>               (ly:grob-translate-axis!
>                 grob
>                 (cdr (ly:grob-extent col col X))
>                 X))))
>   }
>   %% probably let ClefVoice be accepted by other contexts too
>   \context {
>       \Staff
>       \accepts "ClefVoice"
>   }
> }
>
>
> clefTst =
> #(define-music-function (m1 m2) (ly:music? ly:music?)
>
>
> (ly:music-set-property! m2 'elements
>  (call-with-values
>    (lambda ()
>      (partition
>        (lambda (m) (music-is-of-type? m 'skip-event))
>        (ly:music-property m2 'elements)))
>    (lambda (a b)
>      (append
>        a
>        (list
>          #{
>            \context ClefVoice = "ClefVoice" {
>              %% Mmmh, this is a Score-override, may cause problems ...
>              \temporary \override Score.BreakAlignment.before-line-breaking =
>                #(lambda (grob)
>                  (if (eqv? (ly:item-break-dir grob) 0)
>                      (ly:grob-set-property! grob 'break-align-orders
>                          (make-vector 3 '(span-bar
>                                            breathing-sign
>                                            staff-bar
>                                            key-cancellation
>                                            key-signature
>                                            time-signature
>                                            clef)))))
>                 \voiceTwo
>                 %\set forceClef = ##t
>                 #(make-sequential-music b)
>                 \revert Score.BreakAlignment.before-line-breaking
>            }
>          #})))))
>
> #{ << $m1 $m2 >> #})
>
>
> \new PianoStaff <<
>   \new Staff = "right" {
>     \repeat unfold 8 { c'8_[ b''' b''' c'] } |
>   }
>   \new Staff = "left" \relative c'' {
>     c8 g'' a g,, \clefTst { <fis ais cis> g } { c,,,4 } a'''8 g |
>     \clefTst { <fis ais cis>8 g } { s cis,,,8 } a'''8 g c g a g |
>
>     \break
>
>     \clefTst { <fis ais cis>8 g } { c,,,4 } a'''8 g c g a g |
>     c8 g'' a g,, \clefTst { <fis ais cis> g } { s ces,,,8 } a'''8 g |
>   }
> >>
>
> Cheers,
>   Harm

More robust:
clefTst =
#(define-music-function (m1 m2) (ly:music? ly:music?)
  (ly:music-set-property! m2 'elements
    (let* ((m2-elts (ly:music-property m2 'elements))
           (idx
             (list-index
               (lambda (m) (or (music-is-of-type? m 'note-event)
                               (music-is-of-type? m 'event-chord)))
               m2-elts)))
     (call-with-values
       (lambda () (split-at m2-elts idx))
       (lambda (a b)
         (append
           a
           (list
             #{
               \context ClefVoice = "ClefVoice" {
                 %% Mmmh, this is a Score-override, may cause problems ...
                 \temporary
                   \override Score.BreakAlignment.before-line-breaking =
                      #(lambda (grob)
                        (if (eqv? (ly:item-break-dir grob) 0)
                            (ly:grob-set-property! grob 'break-align-orders
                                (make-vector 3 '(span-bar
                                                  breathing-sign
                                                  staff-bar
                                                  key-cancellation
                                                  key-signature
                                                  time-signature
                                                  clef)))))
                    \voiceTwo
                    %\set forceClef = ##t
                    #(make-sequential-music b)
                    \revert Score.BreakAlignment.before-line-breaking
               }
             #}))))))

  #{ << $m1 $m2 >> #})

Cheers,
  Harm