Re: Cluster fill-style

[Jean Abou Samra]

Le 27/05/2022 à 11:41, Simon Bailey a écrit :
> Hi,
>
> I'm in the process of typesetting some music that includes an 
> electronic component – still working out the best way to show that in 
> the score. Clusters might work, but is there any way to change the 
> fill style, so it's not solid black? maybe dotted or hashed something?
>
> Thanks, kind regards,
> sb



That doesn't exist by default, but you can code it. See
the proof of concept below. Note that this requires a version
in the 2.23 series.

Best,
Jean



\version "2.23.9"

#(use-modules (ice-9 match))

#(define (cluster::dashed-fill grob)
   (let* ((columns (ly:grob-object grob 'columns))
          (column-list (ly:grob-array->list columns))
          (x-refp (ly:grob-common-refpoint-of-array grob columns X))
          (y-refp (ly:grob-common-refpoint-of-array grob columns Y))
          (exts (map (lambda (c)
                       (ly:grob-extent c y-refp Y))
                     column-list))
          (coords (map (lambda (c)
                         (ly:grob-relative-coordinate c x-refp X))
                       column-list))
          (details (ly:grob-property grob 'details))
          (increment (assq-ref details 'increment))
          (contour-thickness (assq-ref details 'contour-thickness))
          (polygon-points-1 (map cons coords (map car exts)))
          (polygon-points-2 (map cons coords (map cdr exts)))
          (polygon-stencil
           (ly:round-polygon (append-reverse polygon-points-1 
polygon-points-2)
                             contour-thickness
                             1
                             #f)))
     (let loop ((exts exts)
                (coords coords)
                (current (car coords))
                (stil empty-stencil))
       (if (null? (cdr coords))
           (ly:stencil-translate
            (ly:stencil-add stil polygon-stencil)
            (cons (- (ly:grob-relative-coordinate grob x-refp X))
                  (- (ly:grob-relative-coordinate grob y-refp Y))))
           (let* ((t (/ (- current (car coords))
                        (- (cadr coords)
                           (car coords))))
                  (1-t (- 1 t))
                  (ext1 (car exts))
                  (ext2 (cadr exts))
                  (lo (+ (* 1-t (car ext1))
                         (* t (car ext2))))
                  (hi (+ (* 1-t (cdr ext1))
                         (* t (cdr ext2))))
                  (part (ly:line-interface::line grob current lo 
current hi))
                  (new-stil (ly:stencil-add stil part))
                  (next (+ current increment))
                  (stay (<= next (cadr coords))))
             (loop (if stay exts (cdr exts))
                   (if stay coords (cdr coords))
                   next
                   new-stil))))))

\layout {
  \context {
    \Voice
    \override ClusterSpanner.stencil = #cluster::dashed-fill
    \override ClusterSpanner.style = #'dashed-line
    \override ClusterSpanner.thickness = 1.5
    \override ClusterSpanner.dash-period = 0.6
    \override ClusterSpanner.details.increment = 0.45
    \override ClusterSpanner.details.contour-thickness = 0.2
  }
}


\makeClusters { <c' c''>2 <d' a'> <g' f'''> <f g''> }