Re: dotted semicircle indicating harmonics

[Aaron Hill]

On 2018-07-07 02:51, sylvius wrote:
> I still would like to know how to achieve a dotted semicircle but it’s
> probably a matter of PostScript rather than LilyPond.  Unfortunately
> I’m not very proficient with PostScript and so far I haven’t found a
> solution in various internet researches.

Does any of this help?

%%%%
  \version "2.19.82"
  semicircleDown = \markup {
    \with-dimensions #'(0 . 2) #'(0 . 1)
    \postscript #"2 0 moveto 1 0 1 0 180 arc 0.2 setlinewidth
                  [0.0 0.4] 0.2 setdash 1 setlinecap stroke"
  }
  semicircleUp = \markup {
    \translate #'(-0.83 . 0)
    \with-dimensions #'(0 . 3) #'(-1.5 . -1.25)
    \postscript #"0 0 moveto 1.5 0 1.5 180 360 arc 0.2 setlinewidth
                  [0.0 0.4] 0.2 setdash 1 setlinecap stroke"
  }
  music = {
    \key g \major
    \time 6/8
    <fis'_3 d''^2>4 r8
    <d'_3>4
      ^\semicircleDown
      _\markup { \semicircleUp }
      ^"harm:"
    r8
  }
  \score { \music }
%%%%

A couple of things to keep in mind.  In LilyPond, \postscript does not 
have any bounds or outline.  That is why you were seeing overlap with 
other things.  You will need to use \with-dimensions (or \with-outline) 
to explicitly define the bounds (or outline) so that LilyPond can know 
how to move things around.

The dash pattern here is a little more complicated, since I wanted to 
demonstrate how you can get rounded dots instead of boxy dashes.  
Otherwise, something like `[0.2] 0 setdash` (without setting the line 
cap) would have been sufficient to create an even dash the size of the 
line width, resulting in boxy "dots".

Finally, based on the transcription you linked, the lower arc wraps 
around the fingering number.  Note that in my example, I am "lying" 
about the true dimensions of the arc so that LilyPond will permit 
overlap of the vertical bounds.

-- Aaron Hill