Thanks David and Paul - that's helpful. However, while the situation
improved the output is still not what i want:
\version "2.19.13"
voiceDivisi =
#(define-music-function (parser location m1 m2) (ly:music? ly:music?)
#{
\tag divI { $m1 }
\tag divII { $m2 }
\tag together << { \dynamicUp $m1 } \\ { \dynamicDown $m2 } >>
#})
music = \relative c' {
\voiceDivisi {
c4 d e f
}{
a,1
}
}
musicII = \relative c' {
\voiceDivisi {
f4 e d c
} {
a1
}
}
\new Staff \with { instrumentName = "part I" }
\removeWithTag divII.together { \music \musicII }
\new Staff \with { instrumentName = "part II" }
\removeWithTag divI.together { \music \musicII }
\new Staff \with { instrumentName = "combined" }
\removeWithTag divI.divII { \music \musicII }
if i understand correctly, "relativization" happens too late, i.e. after
the music is processed by the voiceDivisi function.
How should i work around this? Maybe instead of using tags i should write
a function with a switch statement inside? I know that i can put \relative
command inside \voiceDivisi, but i'd like to avoid this as it would add a
lot of typing.
best,
Janek
2014-10-11 21:01 GMT+02:00 David Kastrup <[email protected]>:
> Janek Warchoł <[email protected]> writes:
>
> > Hi,
> >
> > i have a function that takes music as an argument and uses it twice -
> each
> > time with a different tag appended, so that later on i can decide what to
> > output:
> >
> > voiceDivisi =
> > #(define-music-function (parser location m1 m2) (ly:music? ly:music?)
> > #{
> > \tag divI \context Voice = "divI" { #m1 }
> > \tag divII \context Voice = "divII" { #m2 }
> > \tag together \context Voice = "both" << #m1 #m2 >>
> > #})
> >
> > The problem is that when used with relative mode, the output gets crazy:
> >
> > music = \relative c' {
> > \voiceDivisi {
> > c4 d e f
> > }
> > {
> > e4 f g a
> > }
> > }
> >
> > \new Staff \keepWithTag divI \music
> > \new Staff \keepWithTag divII \music
> > \new Staff \keepWithTag together \music
> >
> > (see attachment)
> >
> > I have checked that the problem disappears when the function uses the
> > arguments (m1 and m2) only once. Is this a bug?
>
> No.
>
> <URL:
> http://www.lilypond.org/doc/v2.19/Documentation/extending/adding-articulation-to-notes-_0028example_0029
> >
>
> In an earlier example, we constructed music by repeating a given
> music argument. In that case, at least one repetition had to be a
> copy of its own. If it weren’t, strange things may happen. For
> example, if you use \relative or \transpose on the resulting music
> containing the same elements multiple times, those will be subjected
> to relativation or transposition multiple times. If you assign them
> to a music variable, the curse is broken since referencing ‘\name’
> will again create a copy which does not retain the identity of the
> repeated elements.
>
> > Can i work around it, or maybe i should be doing this in an altogether
> > different way?
>
> Use ly:music-deep-copy on one of the copies. Better both. Or write $x
> instead of #x in order to get such a copy.
>
> --
> David Kastrup
>
>
> _______________________________________________
> lilypond-user mailing list
> [email protected]
> https://lists.gnu.org/mailman/listinfo/lilypond-user
>
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