> Le 19 nov. 2022 à 02:37, Gregory Evans <[email protected]> a
> écrit :
>
> Hello Jean,
> thank you for the information about after-line-breaking and the timing of
> skyline computing. Is there an equivalent property to trigger callback after
> the skylines are calculated?
>
I’m afraid not. There are lower-level techniques you can use for that though,
but see below for why you won’t need them.
> I am trying to use (ly:stencil-add ...) to add to the stencil of a notehead
> by drawing a line from one notehead in one staff to a notehead in another
> staff.
>
Have you seen the VoiceFollower grob? Try using that instead.
By reading things in 'left-bound-info and 'right-bound-info, you can also spare
yourself quite some code.
> The notehead grob does not appear to have a cross-staff property to delay
> stencil callback.
>
NoteHead is a very fundamental grob at the heart of a lot of code (note
collision handling, beams, note spacing, etc.). That code makes reasonable
assumptions about the note heads and doesn’t expect cross-staff note heads.
> \language "english"
> \version "2.23.14"
>
> #(set-global-staff-size 12)
>
> \score {
> <<
> \new Staff {
> \override NoteHead.cross-staff = ##t
> \once \override NoteHead.after-line-breaking = #(lambda (grob)
> (let*
> (
> (sys (ly:grob-system grob))
> (x-extent (ly:grob-extent grob sys X))
> (y-extent (ly:grob-extent grob sys Y))
> )
> (display (list x-extent ))
> )
> )
> c'1
> c'1
> c'1
> c'1
> }
> \new Staff {
> c'1
> c'1
> c'1
> c'1
> }
> >>
> }
> A larger example of the function (without a great deal of context) looks like
> this:
>
> interrupt = #(define-music-function (value) (number?)
> #{
> \once \override Staff.NoteHead.after-line-breaking = #(lambda (grob)
> (let* (
> (stem (ly:grob-object grob 'stem))
> (stem-dir (ly:grob-property stem 'direction))
> (stem-thickness (ly:grob-property stem 'thickness))
> (thickness (/ stem-thickness 10))
> (notecol (ly:grob-parent grob X))
> (meta (assoc 'other-grob (ly:grob-property notecol 'meta)))
Have you seen ly:grob-object and ly:grob-set-object! ?
That would be way cleaner than abusing 'meta for this purpose. There is also
'details you can use instead of 'meta.
> (other (if meta
> (cdr meta)
> grob
> ))
> (notehead-width (cdr (ly:grob-property grob 'X-extent)))
> (sys (ly:grob-system grob))
> (now-pos (ly:grob-extent grob sys X))
> (next-pos (ly:grob-extent other sys X))
>
> ;;the offending lines
> (now-pos-y (ly:grob-extent grob common Y))
> (next-pos-y (ly:grob-extent other common Y))
>
> (x-distance
> (if (= stem-dir -1)
> (+ (- (get-distance now-pos next-pos) notehead-width )
> (/ thickness 2))
> (- (get-distance now-pos next-pos) (/ thickness 2))
> ))
> (y-distance
> (if (= stem-dir -1)
> (+ (- (get-distance now-pos-y next-pos-y)
> notehead-width ) (/ thickness 2))
> (- (get-distance now-pos-y next-pos-y) (/ thickness 2))
> ))
>
> ;; alternative which takes input number
> ;(ps-bracket
> ; (if (= stem-dir -1)
> ; (draw-ps-bracket x-distance notehead-width (- value
> 0.5) thickness)
> ; (draw-ps-bracket x-distance notehead-width value
> thickness)
> ; ))
> (ps-bracket
Does 'ps' stand for PostScript?
Best,
Jean
