--- /dev/null
+%
+% Copyright (C) 2008, 2009, 2010, 2011 NICTA
+% Author: Peter Chubb <peter.chubb AT nicta.com.au>
+% $Id: articulate.ly,v 1.7 2011-03-24 00:40:00 peterc Exp $
+%
+%
+% This program is free software; you can redistribute it and/or modify
+% it under the terms of the GNU General Public License, version 3,
+% as published by the Free Software Foundation.
+%
+% WARNING: this file under GPLv3 only, not GPLv3+
+%
+% This program is distributed in the hope that it will be useful,
+% but WITHOUT ANY WARRANTY; without even the implied warranty of
+% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+% See the GNU General Public License for more details. It is
+% available in the Lilypond source tree, or at
+% http://www.gnu.org/licenses/gpl-3.0.html
+%
+% This script tries to make MIDI output from LilyPond a little more realistic.
+% It tries to take articulations (slurs, staccato, etc) into account, by
+% replacing notes with sequential music of suitably time-scaled note plus
+% skip.
+%
+% It also tries to unfold trills turns etc., and take rallentendo
+% and accelerando into account.
+%
+% As my scheme knowledge is poor (I was teaching myself as I went), there
+% is much scope for improvement.
+
+%
+%%%USAGE
+% In the \score section do:
+% \unfoldRepeats \articulate <<
+% all the rest of the score
+% >>
+% or use the lilywrap script.
+%
+% TO DO (prioritised, the ones that'll make the most difference first)
+%
+% * Dynamics.
+% * Fix quantisation for dynamics on single note (replace note
+% with tied 128th notes?) -- started, needs work.
+% * Make \fp do the right thing (loud start, then quiet).
+%
+% * Inegalite. Notes on-beat steal time from notes off-beat.
+% Degree of stealing is a parameter: from 1.0 (straight)
+% to 1.5 (extreme swing). Also fix tenuto to use this.
+%
+% * add accel (to match rall), and molto rall. I've never seen
+% molto accel but some composer somewhere has probably used it.
+%
+% * Fermata, and Fermata Lunga
+% * Add more synonyms for accel and rall: rit ritard stringendo
+%
+% * Phrasing.
+% * Rall at end of piece
+% * Very slight accel into a phrase, rall out of it.
+% * Dynamics during a phrase???? unclear how these should be in
+% the general case
+%
+% * Trill algorithm needs work.
+%
+% * Cope with more ornaments/articulations.
+% inverted-turns, etc.
+% -- accent needs better control of dynamics.
+% -- Articulations: mezzo-staccato, portato.
+% -- Handling of generic ornaments (in lily, `\stopped'; in
+% most early music: ornament this note (trill, turn
+% or mordent as the player wishes))
+% * Automatic gruppetto at end of trill; better handling of
+% initial/final grace notes on trill
+% * Automatic ornaments.
+% * Spot cadences and ornament
+% * Look for quaver-dotted note for trills, for example.
+% * Fill in steps. (Needs lookahead/lookbehind.)
+% * `afterturn' -- a turn after the start of a note.
+% * accidentals for trills and turns
+
+% CHANGELOG
+% * From Iain Nicol: appoggiatura timings were out; add staccatissimo; fix
+% trillSpanner endpoints.
+% * Also handle Breathing events (by throwing them away). This isn't ideal;
+% one should really shorten the note before a little. But I don't know
+% how to do lookahead in scheme.
+% * Also ignore explicit line breaks.
+% * Add Mordents (reported by Patrick Karl)
+%
+
+#(use-modules (ice-9 debug))
+#(use-modules (scm display-lily))
+
+% PARAMETERS
+% How much to compress notes marked Staccato. CPE Bach says `as short as
+% may conveniently be played, as if the keys were too hot to touch'.
+% Most modern sources say 1/2 the notated length of a note.
+#(define ac:staccatoFactor '(1 . 2))
+
+% How much to compress notes marked staccatissimo.
+#(define ac:staccatissimoFactor '(1 . 4))
+
+% And tenuto (if we ever implement time stealing, this should be >1.0)
+#(define ac:tenutoFactor '(1 . 1))
+
+% How much to articulate normal notes. CPE Bach says 1/2 (and
+% staccato should be `as short as may conveniently be played') but this
+% sounds too short for modern music. 7/8 sounds about right.
+#(define ac:normalFactor '(7 . 8))
+
+% How much to slow down for a rall. or a poco rall.
+% (or speed up for accel or poco accel)
+#(define ac:rallFactor (ly:make-moment 60 100)) % 40% slowdown
+#(define ac:pocoRallFactor (ly:make-moment 90 100)) % 10% slowdown
+
+% The absolute time for a twiddle in a trill, in minutes.
+% Start with 1/4 seconds == 1/240 minutes
+#(define ac:maxTwiddleTime (ly:make-moment 1 240))
+
+
+% Internal variables, don't touch.
+% (should probably be part of a context somehow)
+
+% Whether to slur, or not
+#(define ac:inSlur #f)
+#(define ac:inPhrasingSlur #f)
+
+% Whether the current noteevent is in a trill spanner
+#(define ac:inTrill #f)
+
+% assume start in C major. Key change events override this.
+% Could get from context, but don't know how.
+#(define ac:current-key (make-music
+ 'KeyChangeEvent
+ 'tonic
+ (ly:make-pitch -1 0 0)
+ 'pitch-alist
+ (list (cons 0 0)
+ (cons 1 0)
+ (cons 2 0)
+ (cons 3 0)
+ (cons 4 0)
+ (cons 5 0)
+ (cons 6 0))))
+
+
+#(define ac:currentTempo (ly:make-moment 15 1)) % 4 = 60, measured wholes per minute
+#(define ac:lastTempo ac:currentTempo) % for 'a tempo' or 'tempo I'
+
+% The duration of the current note. Start at a crotchet
+% for no good reason.
+#(define ac:currentDuration (ly:make-duration 2 0 1 1))
+
+% Debugging: display a moment plus some text.
+% Returns its moment argument so can be used in-line.
+#(define (display-moment text m)
+ (display text)
+ (display (list (ly:moment-main-numerator m) "/" (ly:moment-main-denominator m)))
+ m
+)
+
+% Track tempo (and maybe later, other context properties)
+% as they change. Needs to better cope with saving only Tempo I,
+% otherwise "a tempo" goes back to the tempo before the last change.
+#(define (ac:adjust-props sym music)
+ (case sym
+ ((tempoWholesPerMinute)
+ (set! ac:currentTempo (ly:music-property music 'value))
+ (set! ac:lastTempo ac:currentTempo)
+ )))
+
+% Raise note one step in the current diatonic scale.
+#(define (ac:up note)
+ (let* ((pitch (ly:music-property note 'pitch))
+ (notename (ly:pitch-notename pitch))
+ (new-notename (if (eq? notename 6) 0 (+ 1 notename)))
+ (alterations (ly:music-property ac:current-key 'pitch-alist))
+ (new-alteration (cdr (assq new-notename alterations)))
+ (new-octave (if (eq? new-notename 0) (+ 1 (ly:pitch-octave pitch))
+ (ly:pitch-octave pitch)))
+ )
+ (set! (ly:music-property note 'pitch)(ly:make-pitch new-octave new-notename new-alteration))))
+
+
+% Lower note one step in the current diatonic scale.
+#(define (ac:down note)
+ (begin (let* ((pitch (ly:music-property note 'pitch))
+ (notename (ly:pitch-notename pitch))
+ (new-notename (if (eq? notename 0) 6 (- notename 1)))
+ (alterations (ly:music-property ac:current-key 'pitch-alist))
+ (new-alteration (cdr (assq new-notename alterations)))
+ (new-octave (if (eq? new-notename 6) (- (ly:pitch-octave pitch) 1)
+ (ly:pitch-octave pitch)))
+ )
+ (set! (ly:music-property note 'pitch)(ly:make-pitch new-octave new-notename new-alteration))))
+)
+
+% Shorten a note, and save the note's original duration in ac:currentDuration
+#(define (ac:articulate-one-note m fraction)
+ "Replace m with m*fraction"
+ (if (eq? 'NoteEvent (ly:music-property m 'name))
+ (let*
+ ((dur (ly:music-property m 'duration))
+ (l (ly:duration-log dur))
+ (d (ly:duration-dot-count dur))
+ (factor (ly:duration-factor dur))
+ (num (car fraction))
+ (denom (cdr fraction)))
+ (begin
+ (set! ac:currentDuration dur)
+ (set! (ly:music-property m 'duration)
+ (ly:make-duration l d
+ (* num (car factor))
+ (* denom (cdr factor))))))
+ m))
+
+% helper routine to set duration.
+#(define (ac:setduration music duration)
+ "Set a note's duration."
+ (let ((eventtype (ly:music-property music 'name)))
+ (if
+ (or
+ (eq? eventtype 'NoteEvent)
+ (eq? eventtype 'RestEvent)
+ (eq? eventtype 'SkipEvent))
+ (set! (ly:music-property music 'duration) duration))))
+
+% Add an articulation event to a note.
+% Used in afterGrace to mark all notes as tenuto, so they're not shortened
+#(define (ac:add-articulation type music)
+ (music-map (lambda (m)
+ (if (eq? 'EventChord (ly:music-property m 'name))
+ (set! (ly:music-property m 'elements)
+ (append (ly:music-property m 'elements)
+ (list (make-music 'ArticulationEvent 'articulation-type type)))))
+ m)
+ music))
+
+% Convert a long note to an equivalent set of short notes, tied together.
+% This is needed to get smooth dynamics changes.
+% Need to deal properly with stuff other than the notes (dynamics, markup etc)
+% Still experimental, so disabled for now.
+#(define (ac:to128 music) music)
+
+#(define (ac:to128_disabled music)
+ (if (or (eq? 'SkipEvent (ly:music-property music 'name))
+ (eq? 'NoteEvent (ly:music-property music 'name)))
+ (let* ((dur (ly:music-property music 'duration))
+ (log2 (ly:duration-log dur))
+ (shiftcount (- 6 log2))
+ (lastm (ly:music-deep-copy (shift-duration-log music shiftcount 0))))
+ (set! (ly:music-property music 'elements)
+ (cons (make-music 'TieEvent) (ly:music-property music 'elements)))
+ (make-sequential-music (list
+ (make-repeat "unfold" (1- (expt 2 shiftcount))
+ (make-sequential-music (list music)) '())
+ lastm)))
+ music))
+
+
+% absolute time in minutes of a length of music, as a rational number (moment)
+#(define (ac:abstime music)
+ (ly:moment-div (ly:music-length music) ac:currentTempo))
+
+% convert absolute time (in minutes) to a moment in the current tempo
+#(define (ac:abs->mom m)
+ (ly:moment-mul m ac:currentTempo))
+
+
+% a moment that is ac:maxTwiddletime seconds at the current tempo.
+#(define (ac:targetTwiddleTime)
+ (ac:abs->mom ac:maxTwiddleTime))
+
+
+% Nearest twiddletime (in minutes) achievable with power-of-2 divisions of
+% the original music. (twiddletime is the time for one pair of notes
+% in a trill)
+% If the music has a precomputed twiddletime (e.g., from \afterGrace) use that.
+#(define (ac:twiddletime music)
+ (let* ((tr (filter (lambda (x)
+ (and (eq? 'ArticulationEvent (ly:music-property x 'name))
+ (string= "trill" (ly:music-property x 'articulation-type))))
+ (ly:music-property music 'elements)))
+ (pre-t (if (pair? tr) (ly:music-property (car tr) 'twiddle)
+ '()))
+ (t (ac:targetTwiddleTime)))
+ (if (ly:moment? pre-t)
+ pre-t
+ (let loop ((len (ly:music-length music)))
+ (if (ly:moment<? t len)
+ (loop (ly:moment-mul len (ly:make-moment 1 2)))
+ len)))))
+
+
+
+% Note: I'm assuming early music practice of starting on the auxiliary note.
+% Needs to add gruppetto if it's a long trill (TODO)
+#(define (ac:trill music)
+ " Replace music with time-compressed repeats of the music,
+ maybe accelerating if the length is longer than a crotchet "
+ (let* ((hemisemidur (ly:make-duration 5 0 1 1))
+ (orig-len (ly:music-length music))
+ (t (ac:twiddletime music))
+ (uppernote '())
+ (note_moment (ly:moment-mul t (ly:make-moment 1 2)))
+ (c1 (ly:moment-div orig-len note_moment))
+ (c2 (inexact->exact
+ (round (/ (ly:moment-main-numerator c1)
+ (* 2 (ly:moment-main-denominator c1))))))
+ (count (if (< c2 2) 2 c2)))
+
+ (set! (ly:music-property music 'elements)
+ (filter (lambda (y) (eq? 'NoteEvent (ly:music-property y 'name)))
+ (ly:music-property music 'elements)))
+ (map (lambda (y) (ac:setduration y hemisemidur))
+ (ly:music-property music 'elements))
+ (set! uppernote (ly:music-deep-copy music))
+ (map (lambda (y) (ac:up y))
+ (filter
+ (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
+ (ly:music-property uppernote 'elements)))
+
+ (let* ((trillMusicElements
+ (let loop ((so_far (list uppernote music))
+ (c count))
+ (if (> c 1)
+ (loop (append (list (ly:music-deep-copy uppernote) (ly:music-deep-copy music)) so_far) (1- c))
+ so_far)))
+ (trillMusic (make-sequential-music trillMusicElements))
+ (newlen (ly:music-length trillMusic))
+ (factor (ly:moment-div orig-len newlen)))
+ (ly:music-compress trillMusic factor)
+; accelerating the music seems to put lily into an infinite loop in
+; its layout and midi engines.
+; (let* ((realfactor (exp (* (/ 1.0 count) (log 0.75))))
+; (factor (ly:make-moment (inexact->exact (round (* 1024 realfactor)))
+; 1024)))
+; (ac:accel trillMusic factor))
+ )))
+
+
+
+
+% If there's an articulation, use it.
+% If in a slur, use (1 . 1) instead.
+% Treat phrasing slurs as slurs, but allow explicit articulation.
+% (Maybe should treat staccato under a phrasing slur as mezzo-staccato?)
+%
+% Expect an EventChord.
+%
+% trills, turns, ornaments etc. are also treated as Articulations.
+% Split into two functions:
+% ac:getactions traverses the elements in the EventChord
+% and calculates the parameters.
+% ac:articulate-chord applies the actions to each NoteEvent in
+% the EventChord.
+#(define (ac:getactions music)
+ (let loop ((factor ac:normalFactor)
+ (newelements '())
+ (es (ly:music-property music 'elements))
+ (actions '()))
+ (if (null? es)
+ (begin
+ (set! (ly:music-property music 'elements) (reverse newelements))
+ (cond
+ (ac:inTrill (cons 'trill actions))
+ ((and (eq? factor ac:normalFactor) (or ac:inSlur ac:inPhrasingSlur))
+ (append actions (list 'articulation '(1 . 1)) ))
+ (else (append actions (list 'articulation factor)))))
+ ; else part
+ (let ((e (car es))
+ (tail (cdr es)))
+ (case (ly:music-property e 'name)
+
+ ((BeamEvent) ; throw away beam events, or they'll be duplicated by turn or trill
+ (loop factor newelements tail actions))
+ ((LineBreakEvent) ; pass through linebreak events.
+ (loop (cons 1 1) (cons e newelements) tail actions))
+ ((FingeringEvent) ; and fingering events too.
+ (loop factor newelements tail actions))
+
+ ((BreathingEvent) ; throw away BreathingEvent ---
+ ; should really shorten previous note a little.
+ (loop (cons 1 1) (cons e newelements) tail actions))
+
+ ((TieEvent)
+ (loop (cons 1 1) (cons e newelements) tail actions))
+
+ ((SkipEvent)
+ (loop (cons 1 1) (cons e newelements) tail actions))
+
+ ((RestEvent)
+ (loop (cons 1 1) (cons e newelements) tail actions))
+
+ ((ArticulationEvent)
+ (let ((articname (ly:music-property e 'articulation-type)))
+ ; TODO: add more here
+ (cond
+ ((string= articname "staccato")
+ (loop ac:staccatoFactor newelements tail actions))
+ ((string= articname "staccatissimo")
+ (loop ac:staccatissimoFactor newelements tail actions))
+ ((string= articname "tenuto")
+ (loop ac:tenutoFactor newelements tail actions))
+ ((string= articname "mordent")
+ (loop (cons 1 1) newelements tail (cons 'mordent actions)))
+ ((string= articname "prall")
+ (loop (cons 1 1) newelements tail (cons 'trill actions)))
+ ((string= articname "trill")
+ (loop (cons 1 1) newelements tail (cons 'trill actions)))
+ ((string= articname "turn")
+ (loop (cons 1 1) newelements tail (cons 'turn actions)))
+ (else (loop factor (cons e newelements) tail actions)))))
+
+ ((TextScriptEvent)
+ (let ((t (ly:music-property e 'text)))
+ (if (not (string? t))
+ (loop factor (cons e newelements) tail actions)
+ (begin
+ (cond
+ ((or
+ (string= t "rall")
+ (string= t "Rall")
+ (string= t "rit.")
+ (string= t "rall."))
+ (loop factor (cons e newelements) tail (cons 'rall actions)))
+ ((or
+ (string= t "poco rall.")
+ (string= t "poco rit."))
+ (loop factor (cons e newelements) tail (cons 'pocoRall actions)))
+ ((or (string= t "a tempo")
+ (string= t "tempo I"))
+ (loop factor (cons e newelements) tail (cons 'aTempo actions)))
+ (else (loop factor (cons e newelements) tail actions)))))))
+
+ ((SlurEvent)
+ (let ((direction (ly:music-property e 'span-direction)))
+ (set! ac:inSlur (eq? direction -1))
+ (loop factor newelements tail actions)))
+
+ ((TrillSpanEvent)
+ (let ((direction (ly:music-property e 'span-direction)))
+ (set! ac:inTrill (eq? direction -1))
+ (if ac:inTrill
+ (loop factor newelements tail (cons 'trill actions))
+ (loop factor (cons e newelements) tail actions))))
+
+ ((PhrasingSlurEvent)
+ (let ((direction (ly:music-property e 'span-direction)))
+ (set! ac:inPhrasingSlur (eq? direction -1))
+ (loop factor newelements tail actions)))
+
+ (else (loop factor (cons e newelements) tail actions)))))))
+
+
+
+#(define (ac:articulate-chord music)
+ (begin
+ (cond
+
+ ((eq? 'EventChord (ly:music-property music 'name))
+ (let loop ((actions (ac:getactions music)))
+ (if (null? actions)
+ (if (ly:moment> (ly:music-length music) (make-moment 1 4))
+ (ac:to128 music)
+ music)
+
+ (case (car actions)
+
+ ((articulation)
+ (map
+ (lambda (x) (ac:articulate-one-note x (cadr actions)))
+ (ly:music-property music 'elements))
+ (let*
+ ((num (caadr actions))
+ (denom (cdadr actions))
+ (mult (ly:duration-factor ac:currentDuration))
+ (newnum (* (- denom num) (car mult)))
+ (newdenom (* (cdr mult) denom))
+ (len (ly:duration-log ac:currentDuration))
+ (dots (ly:duration-dot-count ac:currentDuration)))
+
+ (if (not (eq? num denom))
+ (make-sequential-music
+ (list (ac:to128 music)
+ (make-music 'EventChord 'elements
+ (list
+ (make-music 'RestEvent 'duration (ly:make-duration len dots newnum newdenom))))))
+ music)))
+
+ ((rall)
+ (set! ac:currentTempo (ly:moment-mul ac:currentTempo ac:rallFactor))
+ (let ((pset (make-music 'PropertySet
+ 'value
+ ac:currentTempo
+ 'symbol
+ 'tempoWholesPerMinute)))
+ (if (null? (cdr actions))
+ (make-sequential-music (list pset music))
+ (make-sequential-music
+ (list pset (loop (cdr actions)))))))
+
+ ((pocoRall)
+ (set! ac:currentTempo (ly:moment-mul ac:currentTempo ac:pocoRallFactor))
+ (let ((pset (make-music 'PropertySet
+ 'value
+ ac:currentTempo
+ 'symbol
+ 'tempoWholesPerMinute)))
+ (if (null? (cdr actions))
+ (make-sequential-music (list pset music))
+ (make-sequential-music
+ (list pset (loop (cdr actions)))))))
+
+ ((aTempo)
+ (set! ac:currentTempo ac:lastTempo)
+ (let ((pset (make-music 'PropertySet
+ 'value
+ ac:currentTempo
+ 'symbol
+ 'tempoWholesPerMinute)))
+ (if (null? (cdr actions))
+ (make-sequential-music (list pset music))
+ (make-sequential-music
+ (list pset (loop (cdr actions)))))))
+
+ ((trill)
+ (ac:trill music))
+
+ ((mordent)
+ (let*
+ ((dur (ly:music-property
+ (car (ly:music-property music 'elements)) 'duration))
+ (factor (ly:duration-factor dur))
+ (gracenote (ly:music-deep-copy music))
+ (mainnote (ly:music-deep-copy music))
+ (belownote (ly:music-deep-copy music))
+ (mordent (make-sequential-music (list gracenote belownote)))
+)
+ (begin
+ (music-map (lambda (n)
+ (if (eq? 'NoteEvent (ly:music-property n 'name))
+ (set! (ly:music-property n 'duration)(ly:make-duration 3 0 1 1)))
+ n)
+ mordent)
+ (map (lambda (y) (ac:down y))
+ (filter
+ (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
+ (ly:music-property belownote 'elements)))
+ (make-sequential-music (list (make-grace-music mordent) mainnote)))))
+ ((turn)
+ (let*
+ ((dur (ly:music-property
+ (car (ly:music-property music 'elements)) 'duration))
+ (factor (ly:duration-factor dur))
+ (newdur (ly:make-duration (+ (ly:duration-log dur) 2)
+ (ly:duration-dot-count dur) (car factor)(cdr factor))))
+ (begin
+ (map (lambda (y) (ac:setduration y newdur))
+ (ly:music-property music 'elements))
+ (let* ((above (ly:music-deep-copy music))
+ (below (ly:music-deep-copy music))
+ (newmusic (make-sequential-music (list above music below music))))
+ (begin
+ (map (lambda (y) (ac:down y))
+ (filter
+ (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
+ (ly:music-property below 'elements)))
+ (map (lambda (y) (ac:up y))
+ (filter
+ (lambda (z) (eq? 'NoteEvent (ly:music-property z 'name)))
+ (ly:music-property above 'elements)))
+ newmusic)))))
+ ))))
+
+ ((eq? 'KeyChangeEvent (ly:music-property music 'name))
+ (set! ac:current-key music)
+ music
+ )
+
+ ((eq? 'PropertySet (ly:music-property music 'name))
+ (ac:adjust-props (ly:music-property music 'symbol) music)
+ music)
+
+ (else music))
+ ))
+
+
+
+% At last ... here's the music function that aplies all the above to a
+% score.
+articulate = #(define-music-function (parser location music)
+ (ly:music?)
+ "Adjust times of note to add tenuto, staccato and
+ normal articulations.
+ "
+ (music-map ac:articulate-chord music)
+ )
+
+
+% Override \afterGrace to be in terms of audio, not spacing.
+% Special handling for a gruppetto after a trill.
+afterGrace =
+#(define-music-function
+ (parser location main grace)
+ (ly:music? ly:music?)p
+
+ (let*
+ ((main-length (ly:music-length main))
+ (grace-orig-length (ly:music-length grace))
+ (gracelen (ac:twiddletime main))
+ (grace-factor (ly:moment-div gracelen grace-orig-length))
+ (new-main-length (ly:moment-sub main-length gracelen))
+ (factor (ly:moment-div new-main-length main-length))
+ )
+ (map (lambda (y) (set! (ly:music-property y 'twiddle) gracelen))
+ (filter (lambda (z)
+ (and
+ (eq? 'ArticulationEvent (ly:music-property z 'name))
+ (string= "trill" (ly:music-property z 'articulation-type))))
+ (ly:music-property main 'elements)))
+ (ac:add-articulation "tenuto" grace)
+ (make-sequential-music (list (ly:music-compress main factor) (ly:music-compress grace grace-factor)))))
+
+% An appoggiatura takes half the duration of the main note,
+% or 1/3 if the note is dotted (i.e., half the undotted equivalent time)
+% Somewhere around the end of the 19th, start of 20th century the rules
+% changed, but my main interest is early music.
+appoggiatura =
+#(define-music-function (parser location grace main)
+ (ly:music? ly:music?)
+ (let* ((maindur (ly:music-length main))
+ (grace-orig-len (ly:music-length grace))
+ (main-orig-len (ly:music-length main))
+ (numerator (ly:moment-main-numerator maindur))
+ (factor (if (eq? (remainder numerator 3) 0)
+ (ly:make-moment 1 3) (ly:make-moment 1 2))))
+ (ly:music-compress grace
+ (ly:moment-mul factor (ly:moment-div main-orig-len grace-orig-len)))
+ (ly:music-compress main (ly:moment-sub (ly:make-moment 1 1) factor))
+
+ (set! (ly:music-property grace 'elements)
+ (append (ly:music-property grace 'elements)
+ (list (make-music 'SlurEvent 'span-direction -1))))
+ (set! (ly:music-property main 'elements)
+ (append (ly:music-property main 'elements)
+ (list (make-music 'SlurEvent 'span-direction 1))))
+ (make-sequential-music (list grace main))))
+
projects / lilypond.git / commitdiff