>> Is there an easy way to have a slur enclosed by parentheses or
>> brackets? Some urtext editions use parenthesized slurs to indicate
>> editorial additions.
>
> \parenthesize does not currently handle spanners, so you would need to
> do some manual work.
>
> Consider: [...]
Here is a slightly improved version with rotated parentheses. There's
certainly room for more improvements...
Werner
-------------------------------------------------------------------------------
\version "2.20.0"
parenthesizeSlur =
-\tweak stencil
#(lambda (grob)
(let* ((cp (ly:grob-property grob 'control-points))
(lp (grob-interpret-markup grob (markup #:fontsize -7 "(")))
(rp (grob-interpret-markup grob (markup #:fontsize -7 ")")))
(cp1 (first cp))
(cp2 (second cp))
(cpn-1 (list-ref cp (- (length cp) 2)))
(cpn (last cp))
(langle (/ (atan (- (cdr cp2) (cdr cp1))
(- (car cp2) (car cp1))) PI-OVER-180))
(rangle (/ (atan (- (cdr cpn) (cdr cpn-1))
(- (car cpn) (car cpn-1))) PI-OVER-180)))
(set! lp (ly:stencil-aligned-to lp Y CENTER))
(set! lp (ly:stencil-aligned-to lp X 0.5))
(set! lp (ly:stencil-translate lp (first cp)))
(set! rp (ly:stencil-aligned-to rp Y CENTER))
(set! rp (ly:stencil-aligned-to rp X -0.5))
(set! rp (ly:stencil-translate rp cpn))
(list-set! cp 0
(cons (cdr (ly:stencil-extent lp X))
(cdr cp1)))
(set! lp (ly:stencil-rotate lp langle 0 0))
(list-set! cp (1- (length cp))
(cons (car (ly:stencil-extent rp X))
(cdr cpn)))
(set! rp (ly:stencil-rotate rp rangle 0 0))
(ly:grob-set-property! grob 'control-points cp)
(apply ly:stencil-add (list lp rp
(ly:slur::print grob)))))
\etc
{ g'4\parenthesizeSlur (
\parenthesizeSlur \( b' c''2 ) |
g'2\parenthesizeSlur ( f'4 e' ) \) }
