1;;;; This file is part of LilyPond, the GNU music typesetter.
2;;;;
3;;;; Copyright (C) 2004--2020 Han-Wen Nienhuys <hanwen@xs4all.nl>
4;;;;
5;;;; LilyPond is free software: you can redistribute it and/or modify
6;;;; it under the terms of the GNU General Public License as published by
7;;;; the Free Software Foundation, either version 3 of the License, or
8;;;; (at your option) any later version.
9;;;;
10;;;; LilyPond is distributed in the hope that it will be useful,
11;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
12;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13;;;; GNU General Public License for more details.
14;;;;
15;;;; You should have received a copy of the GNU General Public License
16;;;; along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
17
18;; todo: figure out how to make module,
19;; without breaking nested ly scopes
20
21(define-class <Voice-state> ()
22  (event-list #:init-value '() #:accessor events #:init-keyword #:events)
23  (when-moment #:accessor moment #:init-keyword #:moment)
24  (tuning #:accessor tuning #:init-keyword #:tuning)
25  (split-index #:accessor split-index)
26  (vector-index)
27  (state-vector)
28  ;;;
29  ;; spanner-state is an alist
30  ;; of (SYMBOL . RESULT-INDEX), which indicates where
31  ;; said spanner was started.
32  (spanner-state #:init-value '() #:accessor span-state))
33
34(define-method (write (x <Voice-state> ) file)
35  (display (moment x) file)
36  (display " evs = " file)
37  (display (events x) file)
38  (display " active = " file)
39  (display (span-state x) file)
40  (display "\n" file))
41
42;; Return the duration of the longest event in the Voice-state.
43(define-method (duration (vs <Voice-state>))
44  (define (duration-max event d1)
45    (let ((d2 (ly:event-property event 'duration #f)))
46      (if d2
47          (if (ly:duration<? d1 d2) d2 d1)
48          d1)))
49
50  (fold duration-max (ly:make-duration 0 0 0) (events vs)))
51
52;; Return the moment that the longest event in the Voice-state ends.
53(define-method (end-moment (vs <Voice-state>))
54  (ly:moment-add (moment vs) (ly:duration-length (duration vs))))
55
56(define-method (note-events (vs <Voice-state>))
57  (define (f? x)
58    (ly:in-event-class? x 'note-event))
59  (filter f? (events vs)))
60
61;; Return a list of note events which is sorted and stripped of
62;; properties that we do not want to prevent combining parts.
63(define-method (comparable-note-events (vs <Voice-state>))
64  (define (note<? note1 note2)
65    (let ((p1 (ly:event-property note1 'pitch))
66          (p2 (ly:event-property note2 'pitch)))
67      (cond ((ly:pitch<? p1 p2) #t)
68            ((ly:pitch<? p2 p1) #f)
69            (else (ly:duration<? (ly:event-property note1 'duration)
70                                 (ly:event-property note2 'duration))))))
71  ;; TODO we probably should compare articulations too
72  (sort (map (lambda (x)
73               (ly:make-stream-event
74                (ly:make-event-class 'note-event)
75                (list (cons 'duration (ly:event-property x 'duration))
76                      (cons 'pitch (ly:event-property x 'pitch)))))
77             (note-events vs))
78        note<?))
79
80(define-method (silence-events (vs <Voice-state>))
81  (let ((result (filter (lambda(x)
82                          (or (ly:in-event-class? x 'rest-event)
83                              (ly:in-event-class? x 'multi-measure-rest-event)))
84                        (events vs))))
85    ;; There may be skips in the same part with rests for various
86    ;; reasons.  Regard the skips only if there are no rests.
87    (if (not (pair? result))
88        (set! result (filter (lambda(x) (ly:in-event-class? x 'skip-event))
89                             (events vs))))
90    result))
91
92(define-method (any-mmrest-events (vs <Voice-state>))
93  (define (f? x)
94    (ly:in-event-class? x 'multi-measure-rest-event))
95  (any f? (events vs)))
96
97(define-method (previous-voice-state (vs <Voice-state>))
98  (let ((i (slot-ref vs 'vector-index))
99        (v (slot-ref vs 'state-vector)))
100    (if (< 0 i)
101        (vector-ref v (1- i))
102        #f)))
103
104;; true if the part has ended
105(define-method (done? (vs <Voice-state>))
106  (let ((i (slot-ref vs 'vector-index))
107        (v (slot-ref vs 'state-vector)))
108    ;; the last entry represents the end of the part
109    (= (1+ i) (vector-length v))))
110
111;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
112
113(define-class <Split-state> ()
114  ;; The automatically determined split configuration
115  (configuration #:init-value '() #:accessor configuration)
116  ;; Allow overriding split configuration, takes precedence over configuration
117  (forced-configuration #:init-value #f #:accessor forced-configuration)
118  (when-moment #:accessor moment #:init-keyword #:moment)
119  ;; voice-states are states starting with the Split-state or later
120  ;;
121  (is #:init-keyword #:voice-states #:accessor voice-states)
122  (synced  #:init-keyword #:synced #:init-value  #f #:getter synced?))
123
124
125(define-method (write (x <Split-state> ) f)
126  (display (moment x) f)
127  (display " = " f)
128  (display (configuration x) f)
129  (if (synced? x)
130      (display " synced "))
131  (display "\n" f))
132
133(define-method (current-or-previous-voice-states (ss <Split-state>))
134  "Return voice states meeting the following conditions.  For a voice
135in sync, return the current voice state.  For a voice out of sync,
136return the previous voice state."
137  (let* ((vss (voice-states ss))
138         (vs1 (car vss))
139         (vs2 (cdr vss)))
140    (if (and vs1 (not (equal? (moment vs1) (moment ss))))
141        (set! vs1 (previous-voice-state vs1)))
142    (if (and vs2 (not (equal? (moment vs2) (moment ss))))
143        (set! vs2 (previous-voice-state vs2)))
144    (cons vs1 vs2)))
145
146;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
147
148
149(define (previous-span-state vs)
150  (let ((p (previous-voice-state vs)))
151    (if p (span-state p) '())))
152
153(define (make-voice-states evl)
154  (let* ((states (map (lambda (v)
155                        (make <Voice-state>
156                          #:moment (caar v)
157                          #:tuning (cdar v)
158                          #:events (map car (cdr v))))
159                      (reverse evl))))
160
161    ;; add an entry with no events at the moment the last event ends
162    (if (pair? states)
163        (let ((last-real-event (car states)))
164          (set! states
165                (cons (make <Voice-state>
166                        #:moment (end-moment last-real-event)
167                        #:tuning (tuning last-real-event)
168                        #:events '())
169                      states))))
170
171    ;; TODO: Add an entry at +inf.0 and see if it allows us to remove
172    ;; the many instances of conditional code handling the case that
173    ;; there is no voice state at a given moment.
174
175    (let ((vec (list->vector (reverse! states))))
176      (do ((i 0 (1+ i)))
177          ((= i (vector-length vec)) vec)
178        (slot-set! (vector-ref vec i) 'vector-index i)
179        (slot-set! (vector-ref vec i) 'state-vector vec)))))
180
181(define (make-split-state vs1 vs2)
182  "Merge lists VS1 and VS2, containing Voice-state objects into vector
183of Split-state objects, crosslinking the Split-state vector and
184Voice-state objects
185"
186  (define (helper ss-idx ss-list idx1 idx2)
187    (let* ((state1 (if (< idx1 (vector-length vs1)) (vector-ref vs1 idx1) #f))
188           (state2 (if (< idx2 (vector-length vs2)) (vector-ref vs2 idx2) #f))
189           (min (cond ((and state1 state2) (moment-min (moment state1) (moment state2)))
190                      (state1 (moment state1))
191                      (state2 (moment state2))
192                      (else #f)))
193           (inc1 (if (and state1 (equal? min (moment state1))) 1 0))
194           (inc2 (if (and state2 (equal? min (moment state2))) 1 0))
195           (ss-object (if min
196                          (make <Split-state>
197                            #:moment min
198                            #:voice-states (cons state1 state2)
199                            #:synced (= inc1 inc2))
200                          #f)))
201      (if state1
202          (set! (split-index state1) ss-idx))
203      (if state2
204          (set! (split-index state2) ss-idx))
205      (if min
206          (helper (1+ ss-idx)
207                  (cons ss-object ss-list)
208                  (+ idx1 inc1)
209                  (+ idx2 inc2))
210          ss-list)))
211  (list->vector (reverse! (helper 0 '() 0  0) '())))
212
213(define (analyse-spanner-states voice-state-vec)
214
215  (define (helper index active)
216    "Analyse EVS at INDEX, given state ACTIVE."
217
218    (define (analyse-tie-start active ev)
219      (if (ly:in-event-class? ev 'tie-event)
220          (acons 'tie (split-index (vector-ref voice-state-vec index))
221                 active)
222          active))
223
224    (define (analyse-tie-end active ev)
225      (if (ly:in-event-class? ev 'note-event)
226          (assoc-remove! active 'tie)
227          active))
228
229    (define (analyse-absdyn-end active ev)
230      (if (or (ly:in-event-class? ev 'absolute-dynamic-event)
231              (and (ly:in-event-class? ev 'span-dynamic-event)
232                   (equal? STOP (ly:event-property ev 'span-direction))))
233          (assoc-remove! (assoc-remove! active 'cresc) 'decr)
234          active))
235
236    (define (active<? a b)
237      (cond ((symbol<? (car a) (car b)) #t)
238            ((symbol<? (car b) (car a)) #f)
239            (else (< (cdr a) (cdr b)))))
240
241    (define (analyse-span-event active ev)
242      (let* ((name (car (ly:event-property ev 'class)))
243             (key (cond ((equal? name 'slur-event) 'slur)
244                        ((equal? name 'phrasing-slur-event) 'tie)
245                        ((equal? name 'beam-event) 'beam)
246                        ((equal? name 'crescendo-event) 'cresc)
247                        ((equal? name 'decrescendo-event) 'decr)
248                        (else #f)))
249             (sp (ly:event-property ev 'span-direction)))
250        (if (and (symbol? key) (ly:dir? sp))
251            (if (= sp STOP)
252                (assoc-remove! active key)
253                (acons key
254                       (split-index (vector-ref voice-state-vec index))
255                       active))
256            active)))
257
258    (define (analyse-events active evs)
259      "Run all analyzers on ACTIVE and EVS"
260      (define (run-analyzer analyzer active evs)
261        (if (pair? evs)
262            (run-analyzer analyzer (analyzer active (car evs)) (cdr evs))
263            active))
264      (define (run-analyzers analyzers active evs)
265        (if (pair? analyzers)
266            (run-analyzers (cdr analyzers)
267                           (run-analyzer (car analyzers) active evs)
268                           evs)
269            active))
270      (sort ;; todo: use fold or somesuch.
271       (run-analyzers (list analyse-absdyn-end analyse-span-event
272                            ;; note: tie-start/span comes after tie-end/absdyn.
273                            analyse-tie-end analyse-tie-start)
274                      active evs)
275       active<?))
276
277    ;; must copy, since we use assoc-remove!
278    (if (< index (vector-length voice-state-vec))
279        (begin
280          (set! active (analyse-events active (events (vector-ref voice-state-vec index))))
281          (set! (span-state (vector-ref voice-state-vec index))
282                (list-copy active))
283          (helper (1+ index) active))))
284
285  (helper 0 '()))
286
287(define recording-group-functions
288  ;;Selected parts from @var{toplevel-music-functions} not requiring @code{parser}.
289  (list
290   (lambda (music) (expand-repeat-chords! '(rhythmic-event) music))
291   expand-repeat-notes!))
292
293
294;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
295(define-public (recording-group-emulate music odef)
296  "Interpret @var{music} according to @var{odef}, but store all events
297in a chronological list, similar to the @code{Recording_group_engraver} in
298LilyPond version 2.8 and earlier."
299  (let*
300      ((context-list '())
301       (now-mom (ly:make-moment 0 0))
302       (global (ly:make-global-context odef))
303       (mom-listener (lambda (tev) (set! now-mom (ly:event-property tev 'moment))))
304       (new-context-listener
305        (lambda (sev)
306          (let*
307              ((child (ly:event-property sev 'context))
308               (this-moment-list (cons (ly:context-id child) '()))
309               (dummy (set! context-list (cons this-moment-list context-list)))
310               (acc '())
311               (accumulate-event-listener
312                (lambda (ev)
313                  (set! acc (cons (cons ev #t) acc))))
314               (save-acc-listener
315                (lambda (tev)
316                  (if (pair? acc)
317                      (let ((this-moment
318                             (cons (cons now-mom
319                                         (ly:context-property child 'instrumentTransposition))
320                                   ;; The accumulate-event-listener above creates
321                                   ;; the list of events in reverse order, so we
322                                   ;; have to revert it to the original order again
323                                   (reverse acc))))
324                        (set-cdr! this-moment-list
325                                  (cons this-moment (cdr this-moment-list)))
326                        (set! acc '()))))))
327            (ly:add-listener accumulate-event-listener
328                             (ly:context-event-source child) 'StreamEvent)
329            (ly:add-listener save-acc-listener
330                             (ly:context-event-source global) 'OneTimeStep)))))
331    (ly:add-listener new-context-listener
332                     (ly:context-events-below global) 'AnnounceNewContext)
333    (ly:add-listener mom-listener (ly:context-event-source global) 'Prepare)
334    (ly:interpret-music-expression
335     (make-non-relative-music
336      (fold (lambda (x m) (x m)) music recording-group-functions))
337     global)
338    context-list))
339
340(define-public (determine-split-list evl1 evl2 chord-range)
341  "@var{evl1} and @var{evl2} should be ascending. @var{chord-range} is a pair of numbers (min . max) defining the distance in steps between notes that may be combined into a chord or unison."
342  (let* ((pc-debug #f)
343         (voice-state-vec1 (make-voice-states evl1))
344         (voice-state-vec2 (make-voice-states evl2))
345         (result (make-split-state voice-state-vec1 voice-state-vec2))
346         (chord-min-diff (car chord-range))
347         (chord-max-diff (cdr chord-range)))
348
349    ;; Go through all moments recursively and check if the events of that
350    ;; moment contain a part-combine-force-event override. If so, store its
351    ;; value in the forced-configuration field, which will override. The
352    ;; previous configuration is used to determine non-terminated settings.
353    (define (analyse-forced-combine result-idx prev-res)
354
355      (define (get-forced-event x)
356        (cond
357         ((and (ly:in-event-class? x 'SetProperty)
358               (eq? (ly:event-property x 'symbol) 'partCombineForced))
359          (cons (ly:event-property x 'value #f)
360                (ly:event-property x 'once #f)))
361         ((and (ly:in-event-class? x 'UnsetProperty)
362               (eq? (ly:event-property x 'symbol) 'partCombineForced))
363          (cons #f (ly:event-property x 'once #f)))
364         (else #f)))
365
366      (define (part-combine-events vs)
367        (if (not vs)
368            '()
369            (filter-map get-forced-event (events vs))))
370      ;; end part-combine-events
371
372      ;; forced-result: Take the previous config and analyse whether
373      ;; any change happened.... Return new once and permanent config
374      (define (forced-result evt state)
375        ;; sanity check, evt should always be (new-state . once)
376        (if (not (and (pair? evt) (pair? state)))
377            state
378            (if (cdr evt)
379                ;; Once-event, leave permanent state unchanged
380                (cons (car evt) (cdr state))
381                ;; permanent change, leave once state unchanged
382                (cons (car state) (car evt)))))
383      ;; end forced-combine-result
384
385      ;; body of analyse-forced-combine:
386      (if (< result-idx (vector-length result))
387          (let* ((now-state (vector-ref result result-idx)) ; current result
388                 ;; Extract all part-combine force events
389                 (evts (if (synced? now-state)
390                           (append
391                            (part-combine-events (car (voice-states now-state)))
392                            (part-combine-events (cdr (voice-states now-state))))
393                           '()))
394                 ;; result is (once-state permament-state):
395                 (state (fold forced-result (cons 'automatic prev-res) evts))
396                 ;; Now let once override permanent changes:
397                 (force-state (if (equal? (car state) 'automatic)
398                                  (cdr state)
399                                  (car state))))
400            (set! (forced-configuration (vector-ref result result-idx))
401                  force-state)
402            ;; For the next moment, ignore the once override (car stat)
403            ;; and pass on the permanent override, stored as (cdr state)
404            (analyse-forced-combine (1+ result-idx) (cdr state)))))
405    ;; end analyse-forced-combine
406
407
408    (define (analyse-time-step result-idx)
409      (define (put x . index)
410        "Put the result to X, starting from INDEX backwards.
411
412Only set if not set previously.
413"
414        (let ((i (if (pair? index) (car index) result-idx)))
415          (if (and (<= 0 i)
416                   (not (symbol? (configuration (vector-ref result i)))))
417              (begin
418                (set! (configuration (vector-ref result i)) x)
419                (put x (1- i))))))
420
421      (define (copy-state-from state-vec vs)
422        (define (copy-one-state key-idx)
423          (let* ((idx (cdr key-idx))
424                 (prev-ss (vector-ref result idx))
425                 (prev (configuration prev-ss)))
426            (if (symbol? prev)
427                (put prev))))
428        (for-each copy-one-state (span-state vs)))
429
430      (define (analyse-notes now-state)
431        (let* ((vs1 (car (voice-states now-state)))
432               (vs2 (cdr (voice-states now-state)))
433               (notes1 (comparable-note-events vs1))
434               (notes2 (comparable-note-events vs2)))
435          (cond
436           ;; if neither part has notes, do nothing
437           ((and (not (pair? notes1)) (not (pair? notes2))))
438
439           ;; if one part has notes and the other does not
440           ((or (not (pair? notes1)) (not (pair? notes2))) (put 'apart))
441
442           ;; if either part has a chord
443           ((or (> (length notes1) 1)
444                (> (length notes2) 1))
445            (if (and (<= chord-min-diff 0) ; user requests combined unisons
446                     (equal? notes1 notes2)) ; both parts have the same chord
447                (put 'chords)
448                (put 'apart)))
449
450           ;; if the durations are different
451           ;; TODO articulations too?
452           ((and (not (equal? (ly:event-property (car notes1) 'duration)
453                              (ly:event-property (car notes2) 'duration))))
454            (put 'apart))
455
456           (else
457            ;; Is the interval outside of chord-range?
458            (if (let ((diff (ly:pitch-steps
459                             (ly:pitch-diff
460                              (ly:event-property (car notes1) 'pitch)
461                              (ly:event-property (car notes2) 'pitch)))))
462                  (or (< diff chord-min-diff)
463                      (> diff chord-max-diff)
464                      ))
465                (put 'apart)
466                ;; copy previous split state from spanner state
467                (begin
468                  (if (previous-voice-state vs1)
469                      (copy-state-from voice-state-vec1
470                                       (previous-voice-state vs1)))
471                  (if (previous-voice-state vs2)
472                      (copy-state-from voice-state-vec2
473                                       (previous-voice-state vs2)))
474                  (if (and (null? (span-state vs1)) (null? (span-state vs2)))
475                      (put 'chords))))))))
476
477      (if (< result-idx (vector-length result))
478          (let* ((now-state (vector-ref result result-idx))
479                 (vs1 (car (voice-states now-state)))
480                 (vs2 (cdr (voice-states now-state))))
481
482            (cond ((not vs1) (put 'apart))
483                  ((not vs2) (put 'apart))
484                  (else
485                   (let ((active1 (previous-span-state vs1))
486                         (active2 (previous-span-state vs2))
487                         (new-active1 (span-state vs1))
488                         (new-active2 (span-state vs2)))
489                     (if #f ; debug
490                         (display (list (moment now-state) result-idx
491                                        active1 "->" new-active1
492                                        active2 "->" new-active2
493                                        "\n")))
494                     (if (and (synced? now-state)
495                              (equal? active1 active2)
496                              (equal? new-active1 new-active2))
497                         (analyse-notes now-state)
498
499                         ;; active states different:
500                         (put 'apart)))
501
502                   ;; go to the next one, if it exists.
503                   (analyse-time-step (1+ result-idx)))))))
504
505    (define (analyse-a2 result-idx)
506      (if (< result-idx (vector-length result))
507          (let* ((now-state (vector-ref result result-idx))
508                 (vs1 (car (voice-states now-state)))
509                 (vs2 (cdr (voice-states now-state))))
510
511            (define (analyse-synced-silence)
512              (let ((rests1 (if vs1 (silence-events vs1) '()))
513                    (rests2 (if vs2 (silence-events vs2) '())))
514                (cond
515
516                 ;; equal rests or equal skips, but not one of each
517                 ((and (= 1 (length rests1))
518                       (= 1 (length rests2))
519                       (equal? (ly:event-property (car rests1) 'class)
520                               (ly:event-property (car rests2) 'class))
521                       (equal? (ly:event-property (car rests1) 'duration)
522                               (ly:event-property (car rests2) 'duration)))
523                  (set! (configuration now-state) 'unisilence))
524
525                 ;; rests of different durations or mixed with
526                 ;; skips or multi-measure rests
527                 (else
528                  ;; TODO For skips, route the rest to the shared
529                  ;; voice and the skip to the voice for its part?
530                  (set! (configuration now-state) 'apart-silence))
531
532                 )))
533
534            (define (analyse-unsynced-silence vs1 vs2)
535              (let ((any-mmrests1 (if vs1 (any-mmrest-events vs1) #f))
536                    (any-mmrests2 (if vs2 (any-mmrest-events vs2) #f)))
537                (cond
538                 ;; If a multi-measure rest begins now while the other
539                 ;; part has an ongoing multi-measure rest (or has
540                 ;; ended), start displaying the one that begins now.
541                 ((and any-mmrests1
542                       (equal? (moment vs1) (moment now-state))
543                       (or (not vs2) any-mmrests2))
544                  (set! (configuration now-state) 'silence1))
545
546                 ;; as above with parts swapped
547                 ((and any-mmrests2
548                       (equal? (moment vs2) (moment now-state))
549                       (or (not vs1) any-mmrests1))
550                  (set! (configuration now-state) 'silence2))
551                 )))
552
553            (if (or vs1 vs2)
554                (let ((notes1 (if vs1 (comparable-note-events vs1) '()))
555                      (notes2 (if vs2 (comparable-note-events vs2) '())))
556                  (cond ((and (equal? (configuration now-state) 'chords)
557                              (pair? notes1)
558                              (equal? notes1 notes2))
559                         (set! (configuration now-state) 'unisono))
560
561                        ((synced? now-state)
562                         (if (and (= 0 (length notes1))
563                                  (= 0 (length notes2)))
564                             (analyse-synced-silence)))
565
566                        (else ;; not synchronized
567                         (let* ((vss
568                                 (current-or-previous-voice-states now-state))
569                                (vs1 (car vss))
570                                (vs2 (cdr vss)))
571                           (if (and
572                                (or (not vs1) (= 0 (length (note-events vs1))))
573                                (or (not vs2) (= 0 (length (note-events vs2)))))
574                               (analyse-unsynced-silence vs1 vs2))))
575                        )))
576            (analyse-a2 (1+ result-idx)))))
577
578    (define (analyse-solo12 result-idx)
579
580      (define (previous-config vs)
581        (let* ((pvs (previous-voice-state vs))
582               (spi (if pvs (split-index pvs) #f))
583               (prev-split (if spi (vector-ref result spi) #f)))
584          (if prev-split
585              (configuration prev-split)
586              'apart)))
587
588      (define (put-range x a b)
589        ;; (display (list "put range "  x a b "\n"))
590        (do ((i a (1+ i)))
591            ((> i b) b)
592          (set! (configuration (vector-ref result i)) x)))
593
594      (define (put x)
595        ;; (display (list "putting "  x "\n"))
596        (set! (configuration (vector-ref result result-idx)) x))
597
598      (define (current-voice-state now-state voice-num)
599        (define vs ((if (= 1 voice-num) car cdr)
600                    (voice-states now-state)))
601        (if (or (not vs) (equal? (moment now-state) (moment vs)))
602            vs
603            (previous-voice-state vs)))
604
605      (define (try-solo type start-idx current-idx)
606        "Find a maximum stretch that can be marked as solo.  Only set
607the mark when there are no spanners active.
608
609      return next idx to analyse.
610"
611        (if (< current-idx (vector-length result))
612            (let* ((now-state (vector-ref result current-idx))
613                   (solo-state (current-voice-state now-state (if (equal? type 'solo1) 1 2)))
614                   (silent-state (current-voice-state now-state (if (equal? type 'solo1) 2 1)))
615                   (silent-notes (if silent-state (note-events silent-state) '()))
616                   (solo-notes (if solo-state (note-events solo-state) '())))
617              ;; (display (list "trying " type " at "  (moment now-state) solo-state silent-state        "\n"))
618              (cond ((not (equal? (configuration now-state) 'apart))
619                     current-idx)
620                    ((> (length silent-notes) 0) start-idx)
621                    ((not solo-state)
622                     (put-range type start-idx current-idx)
623                     current-idx)
624                    ((and
625                      (null? (span-state solo-state)))
626
627                     ;;
628                     ;; This includes rests. This isn't a problem: long rests
629                     ;; will be shared with the silent voice, and be marked
630                     ;; as unisilence. Therefore, long rests won't
631                     ;;  accidentally be part of a solo.
632                     ;;
633                     (put-range type start-idx current-idx)
634                     (try-solo type (1+ current-idx) (1+  current-idx)))
635                    (else
636                     (try-solo type start-idx (1+ current-idx)))))
637            ;; try-solo
638            start-idx))
639
640      (define (analyse-apart-silence result-idx)
641        "Analyse 'apart-silence starting at RESULT-IDX.  Return next index."
642
643        (define (analyse-synced-apart-silence vs1 vs2)
644          (let* ((rests1 (silence-events vs1))
645                 (rests2 (silence-events vs2)))
646            (cond
647             ;; multiple rests in the same part
648             ((and (or (not (= 1 (length rests1)))
649                       (not (= 1 (length rests2)))))
650              (put 'apart-silence))
651
652             ;; rest with multi-measure rest: choose the rest
653             ((and (ly:in-event-class? (car rests1) 'rest-event)
654                   (ly:in-event-class? (car rests2) 'multi-measure-rest-event))
655              (put 'silence1))
656
657             ;; as above with parts swapped
658             ((and (ly:in-event-class? (car rests1) 'multi-measure-rest-event)
659                   (ly:in-event-class? (car rests2) 'rest-event))
660              (put 'silence2))
661
662             ;; mmrest in both parts: choose the shorter one
663             ;; (equal mmrests are classified as unisilence earlier,
664             ;; so they shouldn't be seen here)
665             ((and (ly:in-event-class? (car rests1) 'multi-measure-rest-event)
666                   (ly:in-event-class? (car rests2) 'multi-measure-rest-event))
667              (if (ly:duration<? (ly:event-property (car rests1) 'duration)
668                                 (ly:event-property (car rests2) 'duration))
669                  (put 'silence1)
670                  (put 'silence2)))
671
672             (else
673              (put 'apart-silence)))))
674
675        (define (analyse-unsynced-apart-silence vs1 vs2)
676          (let* ((prev-state (if (> result-idx 0)
677                                 (vector-ref result (- result-idx 1))
678                                 #f))
679                 (prev-config (if prev-state
680                                  (configuration prev-state)
681                                  'apart-silence)))
682            (cond
683             ;; remain in the silence1/2 states until resync
684             ((equal? prev-config 'silence1)
685              (put 'silence1))
686
687             ((equal? prev-config 'silence2)
688              (put 'silence2))
689
690             (else
691              (put 'apart-silence)))))
692
693        (let* ((now-state (vector-ref result result-idx))
694               (vs1 (current-voice-state now-state 1))
695               (vs2 (current-voice-state now-state 2)))
696          (cond
697           ;; part 1 has ended
698           ((or (not vs1) (done? vs1))
699            (put 'silence2))
700
701           ;; part 2 has ended
702           ((or (not vs2) (done? vs2))
703            (put 'silence1))
704
705           ((synced? now-state)
706            (analyse-synced-apart-silence vs1 vs2))
707
708           (else
709            (analyse-unsynced-apart-silence vs1 vs2)))
710
711          (1+ result-idx)))
712
713      (define (analyse-apart result-idx)
714        "Analyse 'apart starting at RESULT-IDX.  Return next index."
715        (let* ((now-state (vector-ref result result-idx))
716               (vs1 (current-voice-state now-state 1))
717               (vs2 (current-voice-state now-state 2))
718               ;; (vs1 (car (voice-states now-state)))
719               ;; (vs2 (cdr (voice-states now-state)))
720               (notes1 (if vs1 (note-events vs1) '()))
721               (notes2 (if vs2 (note-events vs2) '()))
722               (n1 (length notes1))
723               (n2 (length notes2)))
724          ;; (display (list "analyzing step " result-idx "  moment " (moment now-state) vs1 vs2  "\n"))
725          (max
726           ;; we should always increase.
727           (cond ((and (= n1 0) (= n2 0))
728                  ;; If we hit this, it means that the previous passes
729                  ;; have designated as 'apart what is really
730                  ;; 'apart-silence.
731                  (analyse-apart-silence result-idx))
732                 ((and (= n2 0)
733                       (equal? (moment vs1) (moment now-state))
734                       (null? (previous-span-state vs1)))
735                  (try-solo 'solo1 result-idx result-idx))
736                 ((and (= n1 0)
737                       (equal? (moment vs2) (moment now-state))
738                       (null? (previous-span-state vs2)))
739                  (try-solo 'solo2 result-idx result-idx))
740
741                 (else (1+ result-idx)))
742           ;; analyse-moment
743           (1+ result-idx))))
744
745      (if (< result-idx (vector-length result))
746          (let ((conf (configuration (vector-ref result result-idx))))
747            (cond
748             ((equal? conf 'apart)
749              (analyse-solo12 (analyse-apart result-idx)))
750             ((equal? conf 'apart-silence)
751              (analyse-solo12 (analyse-apart-silence result-idx)))
752             (else
753              (analyse-solo12 (1+ result-idx))))))) ; analyse-solo12
754
755    (analyse-spanner-states voice-state-vec1)
756    (analyse-spanner-states voice-state-vec2)
757    (if #f
758        (begin
759          (display voice-state-vec1)
760          (display "***\n")
761          (display voice-state-vec2)
762          (display "***\n")
763          (display result)
764          (display "***\n")))
765
766    ;; Extract all forced combine strategies, i.e. events inserted by
767    ;; \partCombine(Apart|Automatic|SoloI|SoloII|Chords)[Once]
768    ;; They will in the end override the automaically determined ones.
769    ;; Initial state for both voices is no override
770    (analyse-forced-combine 0 #f)
771    ;; Now go through all time steps in a loop and find a combination strategy
772    ;; based only on the events of that one moment (i.e. neglecting longer
773    ;; periods of solo/apart, etc.)
774    (analyse-time-step 0)
775    ;; (display result)
776    ;; Check for unisono or unisilence moments
777    (analyse-a2 0)
778    ;;(display result)
779    (analyse-solo12 0)
780    ;; (display result)
781    (set! result (map
782                  ;; forced-configuration overrides, if it is set
783                  (lambda (x) (cons (moment x) (or (forced-configuration x) (configuration x))))
784                  (vector->list result)))
785    (if #f ;; pc-debug
786        (display result))
787    result))
788
789(define-public default-part-combine-mark-state-machine
790  ;; (current-state . ((split-state-event .
791  ;;                      (output-voice output-event next-state)) ...))
792  '((Initial . ((solo1   . (solo   SoloOneEvent Solo1))
793                (solo2   . (solo   SoloTwoEvent Solo2))
794                (unisono . (shared UnisonoEvent Unisono))))
795    (Solo1   . ((apart   . (#f     #f           Initial))
796                (chords  . (#f     #f           Initial))
797                (solo2   . (solo   SoloTwoEvent Solo2))
798                (unisono . (shared UnisonoEvent Unisono))))
799    (Solo2   . ((apart   . (#f     #f           Initial))
800                (chords  . (#f     #f           Initial))
801                (solo1   . (solo   SoloOneEvent Solo1))
802                (unisono . (shared UnisonoEvent Unisono))))
803    (Unisono . ((apart   . (#f     #f           Initial))
804                (chords  . (#f     #f           Initial))
805                (solo1   . (solo   SoloOneEvent Solo1))
806                (solo2   . (solo   SoloTwoEvent Solo2))))))
807
808(define-public (make-part-combine-marks state-machine split-list)
809  "Generate a sequence of part combiner events from a split list"
810
811  (define (get-state state-name)
812    (assq-ref state-machine state-name))
813
814  (let ((full-seq '()) ; sequence of { \context Voice = "x" {} ... }
815        (segment '()) ; sequence within \context Voice = "x" {...}
816        (prev-moment ZERO-MOMENT)
817        (prev-voice #f)
818        (state (get-state 'Initial)))
819
820    (define (commit-segment)
821      "Add the current segment to the full sequence and begin another."
822      (if (pair? segment)
823          (set! full-seq
824                (cons (make-music 'ContextSpeccedMusic
825                                  'context-id (symbol->string prev-voice)
826                                  'context-type 'Voice
827                                  'element (make-sequential-music (reverse! segment)))
828                      full-seq)))
829      (set! segment '()))
830
831    (define (handle-split split)
832      (let* ((moment (car split))
833             (action (assq-ref state (cdr split))))
834        (if action
835            (let ((voice (car action))
836                  (part-combine-event (cadr action))
837                  (next-state-name (caddr action)))
838              (if part-combine-event
839                  (let ((dur (ly:moment-sub moment prev-moment)))
840                    ;; start a new segment when the voice changes
841                    (if (not (eq? voice prev-voice))
842                        (begin
843                          (commit-segment)
844                          (set! prev-voice voice)))
845                    (if (not (equal? dur ZERO-MOMENT))
846                        (set! segment (cons (make-music 'SkipEvent
847                                                        'duration (make-duration-of-length dur)) segment)))
848                    (set! segment (cons (make-music part-combine-event) segment))
849
850                    (set! prev-moment moment)))
851              (set! state (get-state next-state-name))))))
852
853    (for-each handle-split split-list)
854    (commit-segment)
855    (make-sequential-music (reverse! full-seq))))
856
857(define-public default-part-combine-context-change-state-machine-one
858  ;; (current-state . ((split-state-event . (output-voice next-state)) ...))
859  '((Initial . ((apart         . (one    . Initial))
860                (apart-silence . (one    . Initial))
861                (apart-spanner . (one    . Initial))
862                (chords        . (shared . Initial))
863                (silence1      . (shared . Initial))
864                (silence2      . (null   . Demoted))
865                (solo1         . (solo   . Initial))
866                (solo2         . (null   . Demoted))
867                (unisono       . (shared . Initial))
868                (unisilence    . (shared . Initial))))
869
870    ;; After a part has been used as the exclusive input for a
871    ;; passage, we want to use it by default for unisono/unisilence
872    ;; passages because Part_combine_iterator might have killed
873    ;; multi-measure rests in the other part.  Here we call such a
874    ;; part "promoted".  Part one begins promoted.
875    (Demoted . ((apart         . (one    . Demoted))
876                (apart-silence . (one    . Demoted))
877                (apart-spanner . (one    . Demoted))
878                (chords        . (shared . Demoted))
879                (silence1      . (shared . Initial))
880                (silence2      . (null   . Demoted))
881                (solo1         . (solo   . Initial))
882                (solo2         . (null   . Demoted))
883                (unisono       . (null   . Demoted))
884                (unisilence    . (null   . Demoted))))))
885
886(define-public default-part-combine-context-change-state-machine-two
887  ;; (current-state . ((split-state-event . (output-voice next-state)) ...))
888  '((Initial . ((apart         . (two    . Initial))
889                (apart-silence . (two    . Initial))
890                (apart-spanner . (two    . Initial))
891                (chords        . (shared . Initial))
892                (silence1      . (null   . Initial))
893                (silence2      . (shared . Promoted))
894                (solo1         . (null   . Initial))
895                (solo2         . (solo   . Promoted))
896                (unisono       . (null   . Initial))
897                (unisilence    . (null   . Initial))))
898
899    ;; See the part-one state machine for the meaning of "promoted".
900    (Promoted . ((apart         . (two    . Promoted))
901                 (apart-silence . (two    . Promoted))
902                 (apart-spanner . (two    . Promoted))
903                 (chords        . (shared . Promoted))
904                 (silence1      . (null   . Initial))
905                 (silence2      . (shared . Promoted))
906                 (solo1         . (null   . Initial))
907                 (solo2         . (solo   . Promoted))
908                 (unisono       . (shared . Promoted))
909                 (unisilence    . (shared . Promoted))))))
910
911(define-public (make-part-combine-context-changes state-machine split-list)
912  "Generate a sequence of part combiner context changes from a split list"
913
914  (define (get-state state-name)
915    (assq-ref state-machine state-name))
916
917  (let ((change-list '())
918        (prev-voice #f)
919        (state (get-state 'Initial)))
920
921    (define (handle-split split)
922      (let* ((moment (car split))
923             (action (assq-ref state (cdr split))))
924        (if action
925            (let ((voice (car action))
926                  (next-state-name (cdr action)))
927              (if (not (eq? voice prev-voice))
928                  (begin
929                    (set! change-list (cons (cons moment voice) change-list))
930                    (set! prev-voice voice)))
931              (set! state (get-state next-state-name))))))
932
933    (for-each handle-split split-list)
934    (reverse! change-list)))
935
936;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
937
938(define-public (add-quotable name mus)
939  (let* ((tab (eval 'musicQuotes (current-module)))
940         (voicename (get-next-unique-voice-name))
941         ;; recording-group-emulate returns an assoc list (reversed!), so
942         ;; hand it a proper unique context name and extract that key:
943         (ctx-spec (context-spec-music mus 'Voice voicename))
944         (listener (ly:parser-lookup 'partCombineListener))
945         (context-list (reverse (recording-group-emulate ctx-spec listener)))
946         (raw-voice (assoc voicename context-list))
947         (quote-contents (and raw-voice (cdr raw-voice))))
948
949    ;; If the context-specced quoted music does not contain anything, try to
950    ;; use the first child, i.e. the next in context-list after voicename
951    ;; That's the case e.g. for \addQuote "x" \relative c \new Voice {...}
952    ;;
953    ;; Note that if raw-voice is #f, so is quote-contents, in which
954    ;; case the following loop is skipped.
955    (if (null? quote-contents)
956        (let find-non-empty ((current-tail (member raw-voice context-list)))
957          ;; if voice has contents, use them, otherwise check next ctx
958          (cond ((null? current-tail) #f)
959                ((and (pair? (car current-tail))
960                      (pair? (cdar current-tail)))
961                 (set! quote-contents (cdar current-tail)))
962                (else (find-non-empty (cdr current-tail))))))
963
964    (if (pair? quote-contents)
965        (hash-set! tab name (list->vector (reverse! quote-contents)))
966        (ly:music-warning mus (_ "quoted music `~a' is empty") name))))
967