Re: \RemoveEmptyStaffContext and cross-staff beams

[Mats Bengtsson]

I can see the problem you report with version 2.12, but with the latest 
2.13 version (compiled from todays GIT), it's even worse, since the beam 
stays flat also if you don't have \RemoveEmptyStaffContext.
I haven't tracked down exactly what has changed, but I had to reduce the 
setting of the auto-knee-gap property of Beam from the default value 5.5 to
\override Score.Beam #'auto-knee-gap = #4.75
to get the kneed beam that was obtained in earlier versions.
Regression bug!(?)

On the other hand, the problem you report has been in LilyPond for a 
very long time and seems to date back to
http://git.savannah.gnu.org/gitweb/?p=lilypond.git;a=commitdiff;h=17332ae36b238193723983455a91366be4e88e0b
I'm not sure why Han-Wen added this setting in the definition of 
\RemoveEmptyStaffContext, but he probably had a good reason. The 
question is if the same reason still applies or if it would work to 
allow kneed beams also in \RemoveEmptyStaffContext. If somebody is 
interested to try it out, just use
\layout {
   \context {
      \RemoveEmptyStaffContext
       \override Beam #'auto-knee-gap = #4.75
   }
}

and check if anything breaks. There doesn't seem to be any regression 
test on the combination of \RemoveEmptyStaffContext and kneed beams, so 
you would have to invent some yourself.

   /Mats

Jonathan Wilkes wrote:
> Hello,
>      In the following code, the beam goes between the staves when
> \RemoveEmptyStaffContext is commented out but goes above the top 
> staff when it's used.
>      This means you have to explicitly state all the stem directions to 
> get the beam to go in the middle of the staves when using \RemoveEmptyStaffContext.
>
> Is this a bug?
>
> -Jonathan
>
> Snippet below:
>
> \version "2.13.3"
>
> staffPiano = \new PianoStaff {
>         <<
>         \new Staff = "rh" { \relative c' {
>                 c8[ c c c \change Staff = "lh" g, g g g]
>                 }
>         }
>         \new Staff = "lh" { \relative c {
>                 \clef bass
>                 c1
>                 }
>         }
>         >>
> }
>
> \score {
>         \staffPiano
> }
>
> \layout {
>         \context {
>         \RemoveEmptyStaffContext
>         }
> }
>
>
>       
>
>
> _______________________________________________
> lilypond-user mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/lilypond-user
>   

--
=============================================
        Mats Bengtsson
        Signal Processing
        School of Electrical Engineering
        Royal Institute of Technology (KTH)
        SE-100 44  STOCKHOLM
        Sweden
        Phone: (+46) 8 790 8463                         
       Fax:   (+46) 8 790 7260
        Email: address@hidden
        WWW: http://www.s3.kth.se/~mabe
=============================================