(interfaces . ())))))
#(define box-types
'(
(BoxEvent
. ((description . "A box encompassing music at a single timestep.")
(types . (general-music box-event music-event event))
))
))
#(define music-boxer-types
'(
(MusicBoxerEvent
. ((description . "Used to signal where boxes encompassing music start and stop.")
(types . (general-music music-boxer-event span-event event))
))
))
#(set!
music-boxer-types
(map (lambda (x)
(set-object-property! (car x)
'music-description
(cdr (assq 'description (cdr x))))
(let ((lst (cdr x)))
(set! lst (assoc-set! lst 'name (car x)))
(set! lst (assq-remove! lst 'description))
(hashq-set! music-name-to-property-table (car x) lst)
(cons (car x) lst)))
music-boxer-types))
#(set!
box-types
(map (lambda (x)
(set-object-property! (car x)
'music-description
(cdr (assq 'description (cdr x))))
(let ((lst (cdr x)))
(set! lst (assoc-set! lst 'name (car x)))
(set! lst (assq-remove! lst 'description))
(hashq-set! music-name-to-property-table (car x) lst)
(cons (car x) lst)))
box-types))
#(set! music-descriptions
(append music-boxer-types music-descriptions))
#(set! music-descriptions
(append box-types music-descriptions))
#(set! music-descriptions
(sort music-descriptions alist<?))
#(define (add-bound-item spanner item)
(if (null? (ly:spanner-bound spanner LEFT))
(ly:spanner-set-bound! spanner LEFT item)
(ly:spanner-set-bound! spanner RIGHT item)))
musicBoxerEngraver =
#(lambda (context)
(let ((span '())
(finished '())
(current-event '())
(event-start '())
(event-stop '()))
`((listeners
(music-boxer-event .
,(lambda (engraver event)
(if (= START (ly:event-property event 'span-direction))
(set! event-start event)
(set! event-stop event)))))
(acknowledgers
(note-column-interface .
,(lambda (engraver grob source-engraver)
(if (ly:spanner? span)
(begin
(ly:pointer-group-interface::add-grob span 'elements grob)
(add-bound-item span grob)))
(if (ly:spanner? finished)
(begin
(ly:pointer-group-interface::add-grob finished 'elements grob)
(add-bound-item finished grob)))))
(inline-accidental-interface .
,(lambda (engraver grob source-engraver)
(if (ly:spanner? span)
(begin
(ly:pointer-group-interface::add-grob span 'elements grob)))
(if (ly:spanner? finished)
(ly:pointer-group-interface::add-grob finished 'elements grob))))
(script-interface .
,(lambda (engraver grob source-engraver)
(if (ly:spanner? span)
(begin
(ly:pointer-group-interface::add-grob span 'elements grob)))
(if (ly:spanner? finished)
(ly:pointer-group-interface::add-grob finished 'elements grob))))
(finger-interface .
,(lambda (engraver grob source-engraver)
(if (ly:spanner? span)
(begin
(ly:pointer-group-interface::add-grob span 'elements grob)))
(if (ly:spanner? finished)
(ly:pointer-group-interface::add-grob finished 'elements grob))))
;; add additional interfaces to acknowledge here
)
(process-music .
,(lambda (trans)
(if (ly:stream-event? event-stop)
(if (null? span)
(ly:warning "No start to this box.")
(begin
(set! finished span)
(ly:engraver-announce-end-grob trans finished event-start)
(set! span '())
(set! event-stop '()))))
(if (ly:stream-event? event-start)
(begin
(set! span (ly:engraver-make-grob trans 'MusicBoxer event-start))
(set! event-start '())))))
(stop-translation-timestep .
,(lambda (trans)
(if (and (ly:spanner? span)
(null? (ly:spanner-bound span LEFT)))
(ly:spanner-set-bound! span LEFT
(ly:context-property context 'currentMusicalColumn)))
(if (ly:spanner? finished)
(begin
(if (null? (ly:spanner-bound finished RIGHT))
(ly:spanner-set-bound! finished RIGHT
(ly:context-property context 'currentMusicalColumn)))
(set! finished '())
(set! event-start '())
(set! event-stop '())))))
(finalize
(lambda (trans)
(if (ly:spanner? finished)
(begin
(if (null? (ly:spanner-bound finished RIGHT))
(set! (ly:spanner-bound finished RIGHT)
(ly:context-property context 'currentMusicalColumn)))
(set! finished '())))
(if (ly:spanner? span)
(begin
(ly:warning "unterminated box :-(")
(ly:grob-suicide! span)
(set! span '()))))))))
boxEngraver =
#(lambda (context)
(let ((box '())
(ev '()))
`((listeners
(box-event .
,(lambda (engraver event)
(set! ev event))))
(acknowledgers
(note-column-interface .
,(lambda (engraver grob source-engraver)
(if (ly:grob? box)
(begin
; (set! (ly:grob-parent box X) grob) ;; ??
(set! (ly:grob-parent box Y) grob)
(ly:pointer-group-interface::add-grob box 'elements grob)))))
(inline-accidental-interface .
,(lambda (engraver grob source-engraver)
(if (ly:item? box)
(ly:pointer-group-interface::add-grob box 'elements grob))))
(script-interface .
,(lambda (engraver grob source-engraver)
(if (ly:item? box)
(ly:pointer-group-interface::add-grob box 'elements grob))))
(finger-interface .
,(lambda (engraver grob source-engraver)
(if (ly:item? box)
(ly:pointer-group-interface::add-grob box 'elements grob))))
;; add additional interfaces to acknowledge here
)
(process-music .
,(lambda (trans)
(if (ly:stream-event? ev)
(begin
(set! box (ly:engraver-make-grob trans 'Box ev))
(set! ev '())))))
(stop-translation-timestep .
,(lambda (trans)
(set! box '()))))))
musicBoxerStart =
#(make-span-event 'MusicBoxerEvent START)
musicBoxerEnd =
#(make-span-event 'MusicBoxerEvent STOP)
box = #(make-music 'BoxEvent)
\layout {
\context {
\Global
\grobdescriptions #all-grob-descriptions
}
\context {
\Score
\consists \musicBoxerEngraver % for spans
\consists \boxEngraver
}
}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% EXAMPLE %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
melody = \relative c'' {
\set fingeringOrientations = #'(left)
%1
\repeat volta 2 {
%\once\override Score.Box.padding = 1
\box <g-3 c-2 f-1>1
\musicBoxerStart d8-4 g,-0 d' g, d'-4 g,-0 d' \musicBoxerEnd g,
}
%2
\repeat volta 2 {
\box <d'-4 c'-2 f-1>1\f\fermata
\musicBoxerStart g8-3 d-0 g d g8-4 d-0 g \musicBoxerEnd d\accent
}
}
\score {
\new Staff \melody
}