Re: NoteHead X-offset, conflict with ly:grob-relative-coordinate

[Thomas Morley]

2012/12/10 Paul Morris <address@hidden>:
>> I'm not top posting.
>
> % All the notes should be moved to the right-hand
> % side of the stem by overriding their X-offset
> % property, but something about the "rel-coord"
> % variable that is set by "ly:grob-relative-coordinate"
> % prevents this from working as it should.  After
> % removing that variable it works fine. Setting
> % X-extent also does not work (this is commented
> % out below).
>
> \version "2.16.1"
>
> CustomNoteHeads =
> #(lambda (grob)
>   (let* (
>     (notecol (ly:grob-parent grob 0))
>     (rel-coord (ly:grob-relative-coordinate grob notecol 0)))
>     (set! (ly:grob-property grob 'X-offset) 1.251178 )
>
>     ;; (set! (ly:grob-property grob 'X-extent) '(0 . 4) ))
> )
>
> \score {
>   \new Staff
>     \with {
>       \override NoteHead #'before-line-breaking = \CustomNoteHeads
>     }
>     { c' d' e' f' }
>   \layout { }
> }

Hi Paul,

please be very careful with the code you post.
You commented a _needed_ closing bracket.

Nevertheless, I can't explain why your code doesn't work.
Speculating, I'd say 'X-offset and 'X-extent are the wrong properties
with 'before-line-breaking.
Using 'extra-spacing-width and ly:grob-translate-axis! for offset in
X-axis seems to work:

\version "2.16.1"

CustomNoteHeads =
#(lambda (grob)
  (let* (
    (notecol (ly:grob-parent grob X))
    (rel-coord (ly:grob-relative-coordinate grob notecol 0)))

  (ly:grob-set-property! grob 'extra-spacing-width  '(-1 . 1))
  (ly:grob-translate-axis! grob 1.251178  X)))

\score {
  \new Staff
    \with {
      \override NoteHead #'before-line-breaking = \CustomNoteHeads
    }
    { c' d' e' f' }
  \layout { }
}


But there _is_ something strange with 'X-offset in chords.
In the examples below _none_ of the tweaks work. But if you uncomment
the tweak for the _first_ written note of the chord they work _all_.

\version "2.16.1"

\relative c' {
        <
         %\tweak  #'X-offset #1
         f
         \tweak  #'X-offset #2
         a
         \tweak  #'X-offset #3
         c
        >
        <
         %\tweak  #'X-offset #2
         a
         \tweak  #'X-offset #1
         f
         \tweak  #'X-offset #3
         c'
        >
}


No idea why.


Cheers,
  Harm