Re: change custom notehead for different stem direction

[Lukas-Fabian Moser]

Hi Orm,

Am 08.09.21 um 13:23 schrieb Orm Finnendahl:
>   below is a working example for the record. You can tweak the
> linewidth changing "setlinewidth 1" in flpizzleft and flpizzright or
> the angles/proportions of the lines in the line containing the moveto,
> lineto and stroke. Even if you don't know Postscript it should be
> fairly obvious. When changing the linewidth you might have to adjust
> the connection points for the stems accordingly.

Motivated in part by recent discussions on -devel on whether or not 
there's a long-term need for \postscript support, I rewrote your code 
without postscript, stream-lining a bit along the way:

\version "2.22.0"

flpizz =
\markup
\with-dimensions #'(0 . 0.9) #'(-0.4 . 0.4)
\path #0.2 #'((moveto 0.9 0.4)
              (lineto 0 0)
              (lineto 0.9 -0.4))

%{
% Uncomment if \flpizzleft and \flpizzright are both needed e.g. in markups

#(define-markup-command (Xflip layout props arg) (markup?)
   "Flips a markup horizontally keeping its extents (absolute positions)"
   (let* ((orig (interpret-markup layout props arg))
          (extent (ly:stencil-extent orig X)))
     (ly:stencil-translate-axis
      (ly:stencil-scale orig -1 1)
      (+ (car extent) (cdr extent))
      X)))

flpizzleft = \flpizz
flpizzright = \markup \Xflip \flpizzleft
%}

flutepizz = \temporary {
  \override NoteHead.stencil =
  #(lambda (grob)
     (let*
      ((notehead (grob-interpret-markup grob flpizz))
       (notecolumn (ly:grob-parent grob X))
       (stem (ly:grob-object notecolumn 'stem))
       (direction (ly:grob-property stem 'direction)))
      (if (positive? direction)
          (ly:stencil-scale notehead -1 1)
          notehead)))
  \override NoteHead.stem-attachment = #'(1.223 . -0.1)
}

flutepizzOff = \undo\flutepizz

{
  \flutepizz c''4 f'16 c' d' cis'' \flutepizzOff d''4
}

Lukas