Re: Cluster fill-style

[Jean Abou Samra]

Le 27/05/2022 à 22:20, Simon Bailey a écrit :
> Hi Jean,
>
> actually, there seems to be a bit of a problem:
>
> \new Voice {
>   R1*3 | r2 r4.
>   \makeClusters { <d f>8 | q1 | q8 <d d'> <d' f>2. | q1 | q1 | q2 r2 }
>   \barNumberCheck #10
>   \makeClusters {
>     <d, f>1 | q4. <d d'>8 <d' f>2 | q1 | q2 <d, f>2 |
>     \barNumberCheck #14 %1
>     q2 <d d'>2 | q2 <d a'> | <d a' d>2 q8. <f d'>8. <d d'>8 | q1 | q1 
> | q2. <d f>4 |
>   }
>   R1*47
>   \makeClusters { <c g>1 | q1 | <d e>1 | <d d'>1 | <d' e>1 | q1 | q1 | 
> q1 | }
>   R1*11
>   \barNumberCheck #86
> }
>
> gives the error message:
>
> Starting lilypond.exe 2.23.9 [Untitled]...
> Processing 
> `C:/Users/sia/AppData/Local/Temp/frescobaldi-kad5rc1x/tmpi_go0x11/document.ly 
> <http://document.ly>'
> Parsing...
> Interpreting music...[8][16][24][32][40][48][56][64][72][80]
> Preprocessing graphical objects...
> Finding the ideal number of pages...
> Fitting music on 1 page...
> Drawing systems...ice-9/eval.scm:155:9: In procedure car: Wrong type 
> argument in position 1 (expecting pair): ()
> Exited with return code 1.
>
> If i comment out the 3rd \makeClusters, it works though.
>
> Any ideas?


Without my code, the same example outputs a programming error,
so it's an existing bug. I've just filed an issue in the bug
tracker:

https://gitlab.com/lilypond/lilypond/-/issues/6354

Meanwhile, here is some code that works around the bug:



\version "2.23.10"

#(use-modules (ice-9 match)
              (srfi srfi-71))

#(define (cluster::dashed-fill grob)
   (let* ((columns (ly:grob-object grob 'columns))
          (column-list (ly:grob-array->list columns)))
     (if (not (pair? column-list)) ;; see issue #3654
         #f
         (let* ((x-refp (ly:grob-common-refpoint-of-array grob columns X))
                (y-refp (ly:grob-common-refpoint-of-array grob columns Y))
                (my-exts (map (lambda (c)
                               (ly:grob-extent c y-refp Y))
                             column-list))
                (my-coords (map (lambda (c)
                                 (ly:grob-relative-coordinate c x-refp X))
                               column-list))
                (after-me (find-tail (lambda (s)
                                       (eq? s grob))
                                     (ly:spanner-broken-into 
(ly:grob-original grob))))
                (neighbor (and after-me
                               (pair? (cdr after-me))
                               (cadr after-me)))
                (exts coords (if neighbor
                                 (let* ((neighbor-cols (ly:grob-object 
neighbor 'columns))
                                        (neighbor-col-list 
(ly:grob-array->list neighbor-cols)))
                                   (if (not (null? neighbor-col-list)) 
;; issue #3654 as well
                                       (let* ((first-neighbor-col (car 
neighbor-col-list))
                                              (neighbor-refp
(ly:grob-common-refpoint-of-array
                                                neighbor
                                                neighbor-cols
                                                Y))
                                              (bound (ly:spanner-bound 
grob RIGHT)))
                                         (values
                                          (append my-exts
                                                  (list (ly:grob-extent 
first-neighbor-col neighbor-refp Y)))
                                          (append my-coords
                                                  (list 
(ly:grob-relative-coordinate bound x-refp X)))))
                                       (values my-exts my-coords)))
                                 (values my-exts my-coords)))
                (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
  }
}

%%%

\paper {
  ragged-right = ##t
}

\new Voice {
  R1*3 | r2 r4.
  \makeClusters { <d f>8 | q1 | q8 <d d'> <d' f>2. | q1 | q1 | q2 r2 }
  \barNumberCheck #10
  \makeClusters {
    <d, f>1 | q4. <d d'>8 <d' f>2 | q1 | q2 <d, f>2 |
    \barNumberCheck #14 %1
    q2 <d d'>2 | q2 <d a'> | <d a' d>2 q8. <f d'>8. <d d'>8 | q1 | q1 | 
q2. <d f>4 |
  }
  R1*47
  \makeClusters { <c g>1 | q1 | <d e>1 | <d d'>1 | <d' e>1 | q1 | q1 | 
q1 | }
  R1*11
  \barNumberCheck #86
}




Regards,
Jean