Re: wah-wah-effect

[Alexander Kobel]

Alexander Kobel wrote:
> Hi, Stefan,
>
> you could try to experiment with Hairpin #'stencil.  I imagine combining 
> the usual stencil with a "+" markup at the right side should work.
> Have a look for the ly:stencil-combine-at-edge and 
> ly:text-interface::interpret-markup (other possibilities exist, of 
> course; you can draw a "+" or a circle outside of a text block, but this 
> looks quite easy) functions.  You'll find examples for both functions 
> here on the list, or in the LSR.


Actually, the LSR nearly has the correct function, so it wasn't too much 
work to figure it out:


%% idea from: http://lsr.dsi.unimi.it/LSR/Item?id=233

hairpinPlus = \once \override Voice.Hairpin #'stencil =
#(lambda (grob)
  (ly:stencil-aligned-to
   (ly:stencil-combine-at-edge
    (ly:stencil-aligned-to (ly:hairpin::print grob) Y CENTER)
    X RIGHT
    (ly:stencil-aligned-to (grob-interpret-markup grob (markup "+")) Y 
CENTER))
   Y CENTER))

\layout { ragged-right = ##f }
\relative c' {
  \hairpinPlus
  c2\< c\!
}


I didn't know about grob-interpret-markup. Well, that's a great shortcut!


Cheers,
Alexander