Re: How to get bounding NoteColumns of the first of consecutive TextSpanners

[Jean Abou Samra]

Le 06/03/2021 à 17:47, Thomas Morley a écrit :

> Hi Jean,
> [...]
>
> I took the liberty to modify your engraver,


You must not do this. All of the code I write is
forbidden form disclosure and restrictively licensed
such that modification is not allowed. The code itself
destroys itself when it has been used once, unless
you buy the appropriate, expensive authorization to
reuse it one more time. Oh, and it cannot be used on
non-Apple hardware.

;-)


> looking directly for Stems
> and eliminating the custom-grob-property, replacing it with
> details.subproperties.
> Making for:
>
> \version "2.23.1"
>
> Set_bounding_stems_engraver =
> #(lambda (context)
>      (let ((spanner-starting #f)
>            (spanner-ending #f)
>            (stem #f))
>        (make-engraver
>          (acknowledgers
>            ((line-spanner-interface engraver grob source-engraver)
>               (set! spanner-starting grob))
>            ((stem-interface engraver grob source-engraver)
>               (set! stem grob)))
>          (end-acknowledgers
>            ((line-spanner-interface engraver grob source-engraver)
>               (set! spanner-ending grob)))
>          ((stop-translation-timestep engraver)
>            ;; TODO In polyphonic situations there may be more than one Stem at
>            ;;      the same timestep
>            ;;      How to select?


In the same timestep, sure. And in the same
staff. In the same voice, though?


>            (if spanner-starting
>                (ly:grob-set-nested-property! spanner-starting
>                  '(details stem-left) stem))
>            (if spanner-ending
>                (ly:grob-set-nested-property! spanner-ending
>                  '(details stem-right) stem))
>            (set! spanner-starting #f)
>            (set! spanner-ending #f)
>            (set! stem #f)))))
>
> #(define (get-bounding-stem-dirs-jean spanner)
>    (let* ((details (ly:grob-property spanner 'details))
>           (stem-left (assoc-get 'stem-left details))
>           (stem-left-dir
>             (if (ly:grob? stem-left)
>                 (ly:grob-property stem-left 'direction)))
>           (stem-right (assoc-get 'stem-right details))
>           (stem-right-dir
>             (if (ly:grob? stem-right)
>                 (ly:grob-property stem-right 'direction))))
>      (cons stem-left-dir stem-right-dir)))
>
> #(define (text-stencil-jean txt)
>    (lambda (grob)
>      (let* ((bounding-stem-dirs
>               (get-bounding-stem-dirs-jean grob))
>             (stem-left-dir
>               (car bounding-stem-dirs))
>             (stem-right-dir
>               (cdr bounding-stem-dirs)))
>        ;; adjust left/right padding and left/right attach-dir
>        (if (and (number? stem-left-dir) (number? stem-right-dir))
>            (begin
>              ;; compensate Stem.thickness
>              ;; IR says it's 1.3

Probably because that is expressed in
line-thickness of the StaffSymbol?


>              (ly:grob-set-nested-property! grob
>                '(bound-details right padding) 0.13)
>              (ly:grob-set-nested-property! grob
>                '(bound-details left padding) 0)
>              ;; always start at right edge of left bound
>              (ly:grob-set-nested-property! grob
>                '(bound-details left attach-dir) 1)
>
>              (cond ((and (positive? stem-left-dir) (positive? stem-right-dir))
>                      (ly:grob-set-nested-property! grob
>                        '(bound-details right attach-dir) 1))
>                    ((and (positive? stem-left-dir) (negative? stem-right-dir))
>                      (ly:grob-set-nested-property! grob
>                        '(bound-details right attach-dir) 0))
>                    (else
>                      (ly:grob-set-nested-property! grob
>                        '(bound-details right attach-dir) -1)))))
>
>        (let* ((stil (ly:line-spanner::print grob))
>               (stil-center (interval-center (ly:stencil-extent stil X)))
>               (text-stil
>                 (grob-interpret-markup grob
>                   (if (not-first-broken-spanner? grob)
>                       (make-parenthesize-markup txt)
>                       txt)))
>               (text-center (interval-center (ly:stencil-extent text-stil X))))
>
>         (ly:stencil-add
>          ;; for reference or visual debugging add:
>          ;stil
>          (ly:stencil-translate-axis text-stil (- stil-center text-center) X)
>          )
>          ))))
>
> %%%%%%%%%%%%%%%%%%%%%%%%%%%
> %% EXAMPLEs
> %%%%%%%%%%%%%%%%%%%%%%%%%%%
>
> mus = <<
>    { \repeat unfold 8 b4 }
>
>    \new Voice \with {
>      \consists \Set_bounding_stems_engraver
>      \override TextSpanner.font-shape = #'upright
>      \override TextSpanner.style = #'solid
>    }
>    {
>      g'-\tweak stencil #(text-stencil-jean "1") \startTextSpan
>      a'\stopTextSpan
>        -\tweak stencil #(text-stencil-jean "1½") \startTextSpan
>      c''\stopTextSpan
>         -\tweak stencil #(text-stencil-jean "½") \startTextSpan
>      b'\stopTextSpan
>        -\tweak stencil #(text-stencil-jean "0") \startTextSpan
>      b'\stopTextSpan
>        -\tweak stencil #(text-stencil-jean "1") \startTextSpan
>      a'\stopTextSpan
>        -\tweak stencil #(text-stencil-jean "0") \startTextSpan
>      a'\stopTextSpan
>        -\tweak stencil #(text-stencil-jean "full") \startTextSpan
>      b'\stopTextSpan
>    }
>
>    { \repeat unfold 8 b }
> >>
> \score {
>    \mus
>    \layout {}
>    \layout {
>        line-width = 120
>        ragged-right = ##f
>    }
>    \layout {
>        ragged-right = ##f
>    }
> }
>
> Afaict, for my use-case both very nice codings work with line-breaks.

Impressive, I'll definitely reuse it! Thanks!

Best,
Jean