Re: Call for help with bar lines

[Thomas Morley]

2012/9/26 Marc Hohl <address@hidden>:
> Hello list,
>
> I am quite frustrated – yesterday I managed to get the shift out of
> input/regression/beam-feather-breaking.ly which was one of the
> last problematic files for my patch.
>
> Today, I looked at the new results: it seems to me that
> *every* other regtest file is affected now, but the one mentioned above
> is missing – that's not what the patch is supposed to do.
>
> https://www.yousendit.com/download/TEhYa3ZMTEROQnpWUThUQw
>
> (side note: I did not take a full test cycle, since the last
> regtest results showed only major changes in a couple of files, most of them
> were deliberate, and beam-feather-breaking.ly was the one with the biggest
> optical difference, so I checked just this one and did a make all && make
> doc
> afterwards, which went trough without complaining).
>
> I double-checked the dimensions of the empty bar line: it is
> (0.0 . 0.0) for the current master *and* my patch, so this cannot be
> the culprit.
>
> \version "2.17.4"
>
> #(define (my-bar-line::print grob)
>   (let ((stencil (ly:bar-line::print grob)))
>
>        (for-each display (list "\n\nBar line extent:" (ly:stencil-extent
> stencil X) " for bar line "
>                                (ly:grob-property grob 'glyph-name)))
>        stencil))
>
> music = {
>   \override Staff.BarLine #'stencil = #my-bar-line::print
>   c4 c c c \bar ""
>   c c c c \bar "|."
> }
>
> \score {
>   \new Staff {
>     \new Voice { \music }
>   }
> }
>
>
> Can anyone with more knowledge than me give me a hint what's wrong?
> IIUC correctly, lilypond draws a bar line at the beginning of each line,
> but in most cases, this is an invisible one.
> If you look at the results of input/regression/lyrics-spanbar.ly,
> the whole stuff is shifted that much to the right that lilypond moves
> the rightmost rest to a new line! I can't believe that a bar line with
> zero width can be the cause for this...
>
> Any hints are highly appreciated!
>
> Regards,
>
> Marc
>
>
>
> _______________________________________________
> lilypond-devel mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/lilypond-devel

Hi Marc,

an idea, don't know if it's really helpful:

>From 2.16.0-bar-line.scm, bar-glyph-alist:
The old definition of  bar "empty" was: ("empty" . (() . ()))
The old definition of  bar "" was: ("" . ("" . ""))

The new patch converts bar "empty" into bar ""

If I understand correctly than "empty" eliminates the stencil, whereas
"" prints a stencil with dimensions (0.0 . 0.0).
And if there is _no_ stencil lily doesn't reserve any space _after_
it, but if there is a stencil, even a point-stencil, some space _is_
inserted.

Look at this example:

m =
\relative c' {
        \key ces\major
        ces
        \key cis \major
        cis
}

\new Staff \with { \override KeyCancellation #'stencil = #'() } \m
\new Staff \with { \override KeyCancellation #'stencil = #point-stencil } \m

You will notice a small, but visible difference.


HTH,
  Harm


BTW,

2012/9/21 Marc Hohl <address@hidden>:

> I had some bad feelings that I grabbed
> your ideas and modified it to my needs without some discussion
> with you.

Rubbish! :)
I'm very happy that I had some ideas, you could run with. You managed
to improve the ideas and their coding in an enormous degree.
Great! :D