Re: Slur with left and/or right arrow head

[Thomas Morley]

Am Mo., 15. Apr. 2019 um 19:26 Uhr schrieb Lukas-Fabian Moser <address@hidden>:
>
> Folks,
>
> in https://archiv.lilypondforum.de/index.php?topic=1744.msg9669#msg9669,
> Harm invented a truly wonderful new feature allowing to add an arrow
> head to the right end of a Slur (or, for that matter, a Tie,
> PhrasingSlur etc.). I reproduce it here with only trivial changes
> (mainly omitting parser/location).
>
> Now I also need slurs with arrows pointing to the left (and ideally,
> also the option to have an arrow tip at both ends of the Slur). At first
> glance the asymmetry favoring the right hand side of a Slur seems to be
> hard-coded pretty deeply in Harm's code. Is there a cheap way to add a
> choice of "left or right end" (if not even the "or/and" possibility)?
>
> Best
> Lukas

Hi Lukas,

I started to implement the functionality, finally I more or less
rewrote anything.
As David K once said: rewriting all means at least knowing where the bugs are...

I dropped any functionality for the outside-staff-thingy, it was a
very special request in the thread you linked to.
Do you need it? - could probably be reimplemented.

You now can switch on/off arrows independently at left/right doing
    \override GrobName.details.arrow-left = #LEFT
    \override GrobName.details.arrow-right = #RIGHT

The function `pointing-curve´ (revertable by `revert-pointing-curve´)
sets the 'after-line-breaking property of GrobName to set the 'stencil
to
`add-arrow-head-to-curve´. This procedure reads the
'details,arrow-left/right and will act accordingly.
Using 'after-line-breaking keeps the possibility to use \shape for the curves.

For one thing I'm undecided:
should a broken (Phrasing)Slur/Tie have arrows at all parts or the
left arrow only at the left of the first part and the right arrow at
thr right of last part?

Furthermore I'm not sure what you mean with
> ideally, also the option to have an arrow tip at both ends of the Slur

Do you have an image?


ly-file/pdf attached.



Cheers,
  Harm

arrow-slur-03.ly
Description: Text Data

arrow-slur-03.pdf
Description: Adobe PDF document