Placing a text at the end of a hairpin (decrescendo)
The book Music Notation on the Twentieth Century, by Kurt Stone, suggests to use "niente" or its abbreviation "n." instead of a hairpin ending on a "o" (page 18). Lilypond actually supports the latter but the former is not implemented. I defined "n." as a dynamic text and also created one of my own: "pd." as an abbreviation of "perdendosi", a term I feel more appropriated for winds than niente. However, there was a situation where I couldn't place the new dynamics: at the end of a measure, right before the bar line. A popular solution is to use a second voice with spacers to place the dynamics correctly but I found this is hardly a good solution. I first attempted to tweak the Scheme code to center text under a hairpin and managed to get a decent result but, as I know nothing of Scheme, the solution was far from perfect. I then created a post in the Nabble forum and the user named Thomas Morley kindly provided a solution in the form of the Scheme function copied below. All credit belongs to him. I'm adding this snippet to the repository at his request.
\version "2.24.0"
%% from output-lib.scm, extended to get the possibility to return other
%% hairpin-length than default
#(define ((elbowed-hairpin coords x-length-corr mirrored?) grob)
"Create hairpin based on a list of @var{coords} in @code{(cons x y)}
form. @code{x} is the portion of the width consumed for a given line
and @code{y} is the portion of the height. For example,
@code{'((0.3 . 0.7) (0.8 . 0.9) (1.0 . 1.0))} means that at the point
where the hairpin has consumed 30% of its width, it must
be at 70% of its height. Once it is to 80% width, it
must be at 90% height. It finishes at
100% width and 100% height. @var{mirrored?} indicates if the hairpin
is mirrored over the Y-axis or if just the upper part is drawn.
Returns a function that accepts a hairpin grob as an argument
and draws the stencil based on its coordinates.
The length of that hairpin may be adjusted with @var{x-length-corr}
@lilypond[verbatim,quote]
#(define simple-hairpin
(elbowed-hairpin '((1.0 . 1.0)) #t))
\\relative c' {
\\override Hairpin.stencil = #simple-hairpin
a\\p\\< a a a\\f
}
@end lilypond
"
(define (pair-to-list pair)
(list (car pair) (cdr pair)))
(define (normalize-coords goods x y)
(map
(lambda (coord)
(cons (* x (car coord)) (* y (cdr coord))))
goods))
(define (my-c-p-s points thick decresc?)
(make-connected-path-stencil
points
thick
(if decresc? -1.0 1.0)
1.0
#f
#f))
;; outer let to trigger suicide
(let ((sten (ly:hairpin::print grob)))
(if (grob::is-live? grob)
(let* ((decresc? (eq? (ly:grob-property grob 'grow-direction) LEFT))
(thick (ly:grob-property grob 'thickness 0.1))
(thick (* thick (layout-line-thickness grob)))
(x-ext (ly:stencil-extent sten X))
(xex (cons (car x-ext) (- (cdr x-ext) x-length-corr)))
(lenx (interval-length xex))
(yex (ly:stencil-extent sten Y))
(leny (interval-length yex))
(xtrans (+ (car xex) (if decresc? lenx 0)))
(ytrans (car yex))
(uplist (map pair-to-list
(normalize-coords coords lenx (/ leny 2))))
(downlist (map pair-to-list
(normalize-coords coords lenx (/ leny -2)))))
(ly:stencil-translate
(ly:stencil-add
(my-c-p-s uplist thick decresc?)
(if mirrored? (my-c-p-s downlist thick decresc?) empty-stencil))
(cons xtrans ytrans)))
'())))
#(define (shortened-hairpin corr)
(elbowed-hairpin '((1.0 . 1.0)) corr #t))
#(define-markup-command (vstrut layout props)
()
#:category other
"
@cindex creating vertical space in text
Create a box of the same height as the current font, using the \"fp\" as
a reference.
"
(let ((ref-mrkp (interpret-markup layout props "fp")))
(ly:make-stencil (ly:stencil-expr empty-stencil)
empty-interval
(ly:stencil-extent ref-mrkp Y))))
#(define (hairpin-with-right-text text grob)
"Rebuild a hairpin and add @var{text} to the right.
The hairpin is shortened by the length of @var{text},
@code{bound-padding} is taken into account"
(let* ((text-stil (grob-interpret-markup grob (markup #:vstrut text)))
(text-stil-x-extent (ly:stencil-extent text-stil X))
(text-stil-length (interval-length text-stil-x-extent))
(staff-space
(ly:output-def-lookup (ly:grob-layout grob) 'staff-space))
(x-corr (+ text-stil-length (/ staff-space 2))))
(ly:grob-set-property! grob 'stencil (shortened-hairpin x-corr))
(let* ((stencil (ly:grob-property grob 'stencil))
(stil-x-ext
(ordered-cons
(car (ly:stencil-extent stencil X))
(cdr (ly:stencil-extent stencil X))))
(new-stencil
(ly:stencil-add
(ly:stencil-aligned-to stencil Y CENTER)
(ly:stencil-translate-axis
(ly:stencil-aligned-to text-stil Y CENTER)
(+ (cdr stil-x-ext) staff-space)
X))))
(ly:grob-set-property! grob 'stencil new-stencil))))
#(define (hairpin-with-right-text-callback txt)
"
Returns a stencil build by @code{hairpin-with-right-text} for unbroken or the
last of broken hairpins.
"
(lambda (grob)
(let* ((orig (ly:grob-original grob))
(siblings (ly:spanner-broken-into orig)))
(if (or (null? siblings)
(equal? grob (car (last-pair siblings))))
(hairpin-with-right-text txt grob)))))
hairpinWithRightText =
#(define-music-function (text) (markup?)
"
Returns a hairpin with text at the right.
"
#{
\once \override Voice.Hairpin.after-line-breaking =
#(hairpin-with-right-text-callback text)
#})
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% EXAMPLES
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\new Staff \relative c' {
\hairpinWithRightText \markup \italic "pd."
cis''2(\> c~ c1) d\!
}
<<
\new Staff \relative c' {
\hairpinWithRightText \markup \italic "dal niente"
cis''2(\pppp\> c~
\break
c2 b)\!
}
\new Staff \relative c' {
\hairpinWithRightText \markup \italic "pd."
cis''2(\pppp\> c~
c2 b)\!
}
>>
<<
\new Staff \relative c' {
\hairpinWithRightText \markup \italic "molto"
f'2(\fff\< e~
e) r\!
}
\new Staff \relative c' {
\hairpinWithRightText \markup \dynamic "pp"
f'2(\fff\> e~
e) r\!
}
\new Staff \relative c' {
f'2(\fff\> e~
e) \override DynamicText.self-alignment-X = #RIGHT r\pp
}
>>
