Re: circle around stem

[Orm Finnendahl]

Hi,

 FYI: I mostly solved it by setting Stem.details.lengths (see below).

Setting this property within the stencil function doesn't seem to work
(it's the line: "(ly:grob-set-nested-property! grob '(details lengths)
'(3.5 3.5 4.25 5 6 7 8))" in #'damp-stem).

I assume this happens because the stencil function is called after the
length already has been determined, or because I misunderstand the
syntax and I'd be interested if someone can shed a light on that (and
maybe even provide a solution), but this already is very usable the
way it is.

--
Orm

8<-----------------------------------------------------------------------
#(define (damp-stem grob)
   (if (ly:stencil? (ly:stem::print grob))
    (let* ((stencil (ly:stem::print grob))
           (X-ext (ly:stencil-extent stencil X))
           (Y-ext (ly:stencil-extent stencil Y))
           (dir (ly:grob-property grob 'direction))
           (width (interval-length X-ext))
           (len (interval-length Y-ext))
           (y-offs (if (= dir 1) 1.29 (- len 1.29))))
     (ly:grob-set-nested-property! grob '(details lengths) '(3.5 3.5 4.25 5 6 7 
8))
     (ly:stencil-translate
      (grob-interpret-markup grob
       (markup
        (#:path width
         (list (list 'moveto -0 0)
          (list 'lineto -0 len)))
        (#:hspace -1.19)
        (#:raise y-offs 
         (#:draw-circle 0.45 width #f))))
      (cons 0 (interval-start Y-ext))))
    #f))

damp = { \once \override Stem.details.lengths = #'(3.5 3.5 4.25 5 6 7 8)
         \once \override Stem.stencil = #damp-stem }

{\autoBeamOff
 \override Stem.details.lengths = #'(3.5 3.5 4.25 5 6 7 8)
 \override Stem.stencil = #damp-stem c'4 c'8 c'16 c'32 c'64 c'128 s32 c''4 c''8 
c''16 c''32 c''64 c''128
 \revert Stem.details.lengths
 \revert Stem.stencil

 \damp c'32
 \damp c''32
 c''32
}
8<-----------------------------------------------------------------------




Am Freitag, den 08. Juli 2022 um 16:22:22 Uhr (+0200) schrieb Orm Finnendahl:
> Hi,
> 
>  trying to define an overwrite to draw a circle around a stem I came
> up with the code below. Unfortunately it doesn't automagically work
> for all use cases as can be seen in the attached image: The code
> doesn't take the number of flags into account. I know that the stem
> length can be altered with a tweak, but I'd prefer this to be
> corrected without manual intervention. Is there a way within the
> damp-stem function to force a minimum stem-length depending on the
> number of flags if notes aren't beamed?
> 
> --
> Orm
> 
> 8<-----------------------------------------------------------------------
> #(define (damp-stem grob)
>    (if (ly:stencil? (ly:stem::print grob))
>     (let* ((stencil (ly:stem::print grob))
>            (X-ext (ly:stencil-extent stencil X))
>            (Y-ext (ly:stencil-extent stencil Y))
>            (dir (ly:grob-property grob 'direction))
>            (width (interval-length X-ext))
>            (len (interval-length Y-ext))
>            (y-offs (if (= dir 1) 1.29 (- len 1.29))))
>      (ly:stencil-translate
>       (grob-interpret-markup grob
>        (markup
>         (#:path width
>          (list (list 'moveto -0 0)
>           (list 'lineto -0 len)))
>         (#:hspace -1.13)
>         (#:circle
>          (#:path 0.15
>           (list 
>            (list 'moveto 0 y-offs))))))
>       (cons 0 (interval-start Y-ext))))
>     #f))
> 
> damp = { \once  \override Stem.stencil = #damp-stem }
> 
> {\autoBeamOff
>  \override Stem.stencil = #damp-stem c'4 c'8 c'16 c'32 c'64 s32 c''4 c''8 
> c''16 c''32 c''64 }
> 8<-----------------------------------------------------------------------