1 ;;;; This file is part of LilyPond, the GNU music typesetter.
3 ;;;; Copyright (C) 2009--2012 Carl Sorensen <c_sorensen@byu.edu>
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.
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.
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/>.
18 ;;; specify time signature default settings
23 ;;; (time-signature . default-properties) entries.
25 ;;; where default-properties is an alist containing information about the
26 ;;; time signature. Each default-properties set can contain the
27 ;;; following entries:
29 ;;; (baseMoment . (numerator . denominator))
30 ;;; (beatStructure . structure-list)
31 ;;; (beamExceptions . (alist of beam exceptions that don't follow beats))
33 ;;; The alist of beam exceptions has the following entries:
35 ;;; (end . grouping-rules)
36 ;;; (subdivide . grouping-rules) (not yet implemented, reserved for future use)
38 ;;; grouping-rules is an alist containing (beam-type . grouping-list) entries
40 ;;; beam-type is (numerator . denominator)
41 ;;; grouping-list is a list that specifies the
42 ;;; number of stems of the given duration that are grouped in a beamed unit.
43 ;;; For an exception, the duration used is beam-type. For measureBeats,
44 ;;; the duration used is baseMoment.
46 ;;; If an exception is specified for a given beam-type, it will apply to all
47 ;;; beams of shorter durations that don't have an individual exception, so
48 ;;; ((1 . 8) . (3 3 2))
49 ;;; will cause all primary beams to be broken at 3/8, 6/8, and 8/8.
51 ;;; ((1 . 32) . (16 8 4 4))
52 ;;; will cause all 1/32, 1/64, and 1/128 beams to be broken at 1/2, 3/4,
55 ;;; If no values are given for baseMoment and measureBeats, default values
57 ;;; baseMoment gets the value (ly:make-moment 1 time-signature-denominator)
58 ;;; beatStructure gets a list of (3 3 3 ...), where the number of entries is the
59 ;;; number of beats, each containing 3 base-moments, if the time
60 ;;; signature numerator is greater than 3 and divisible by 3, and
61 ;;; a list of (1 1 1 ...), where the number of entries is the
62 ;;; number of base moments in a measure otherwise.
64 ;;; NOTE: numerator is kept in beam-type because of
65 ;;; tuplets, e.g. (2 . 24) = (2 . 3) * (1 . 8)
66 ;;; for eighth-note triplets.
69 (define-public default-time-signature-settings
72 ;; use defaults, but end beams with 32nd notes each 1 4 beat
74 ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8))))))))
76 ;; in 2/4, 2/8 and 2/16 time:
77 ;; use defaults, so no entries are necessary
80 ;; use defaults, but end beams with 32nd notes and higher each 1 4 beat
83 ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8))))))))
86 ;; use defaults, but combine all beats into a unit if possible
88 ;; set all beams to end on beats, but 1 8 to beam entire measure
89 ;; in order to avoid beaming every beam type for the entire measure, we set
90 ;; triplets back to every beat.
92 ((beamExceptions . ((end . (((1 . 8) . (6)) ;1/8 note whole measure
93 ((1 . 12) . (3 3 3)))))))) ;Anything shorter by beat
96 ;; beam entire measure together
97 ((3 . 8) . ((beamExceptions . ((end . (((1 . 8) . (3))))))))
100 ;; use defaults -- no entries necessary
103 ;; use defaults, but end beams with 16th notes or finer each 1 4 beat
105 ((beamExceptions . ((end . (((1 . 16) . (4 4 4 4 4 4 4 4))))))))
107 ;; in 4 4 (common) time:
108 ;; use defaults, but combine beats 1,2 and 3,4 if only 8th notes
109 ;; NOTE: Any changes here need to be duplicated in
110 ;; ly/engraver-init.ly where the default time signature is set
113 ((beamExceptions . ((end . (((1 . 8) . (4 4)) ; 1/8 notes half measure
114 ((1 . 12) . (3 3 3 3)))))))) ;Anything shorter by beat
117 ;; combine beats 1 and 2, so beam in 2
118 ((4 . 8) . ((beatStructure . (2 2))))
121 ;; use defaults, so no entries necessary
124 ;; use defaults, but end beams with 32nd or finer each 1/4 beat
126 ((beamExceptions . ((end . (((1 . 16) . (4 4 4 4 4 4))))))))
129 ;; use defaults, so no entries necessary
132 ;; use defaults, so no entries necessary
135 ;; use defaults, but end beams with 32nd or finer each 1 4 beat
137 ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8 8 8))))))))
140 ;; use defaults, so no entries necessary
143 ;; use defaults, so no entries necessary
146 ;; use defaults, but end beams with 32nd or finer notes each 1 4 beat
148 ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8 8 8 8 8 8 8))))))))
151 ;; use defaults, so no entries necessary
154 ;; use defaults, so no entries necessary
157 ;; default: group (3 2)
159 ((beatStructure . (3 2))))
162 ;; default: group (3 3 2)
164 ((beatStructure . (3 3 2))))
166 )) ; end of alist definition
169 ;;; Accessor and constructor functions
172 (define (get-setting my-symbol time-signature time-signature-settings)
173 "Get setting @code{my-symbol} for @code{time-signature} from
174 @code{time-signature-settings}."
175 (let ((my-time-signature-settings
176 (assoc-get time-signature time-signature-settings '())))
177 (assoc-get my-symbol my-time-signature-settings '())))
179 (define-public (make-setting base-fraction
183 (cons 'baseMoment (if (pair? base-fraction)
184 (/ (car base-fraction) (cdr base-fraction))
186 (cons 'beatStructure beat-structure)
187 (cons 'beamExceptions beam-exceptions)))
189 (define-public (base-length time-signature time-signature-settings)
190 "Get @code{baseMoment} rational value for @var{time-signature} from
191 @var{time-signature-settings}."
192 (let ((return-value (get-setting 'baseMoment
194 time-signature-settings)))
195 (if (null? return-value)
196 (/ (cdr time-signature))
199 (define-public (beat-structure base-length time-signature time-signature-settings)
200 "Get @code{beatStructure} value in @var{base-length} units
201 for @var{time-signature} from @var{time-signature-settings}."
203 (let ((return-value (get-setting 'beatStructure
205 time-signature-settings)))
206 (if (null? return-value)
207 ;; calculate default beatStructure
208 (let* ((numerator (car time-signature))
209 (group-size (if (and (> numerator 3)
210 (zero? (remainder numerator 3)))
213 (beat-count (/ (car time-signature)
217 (if (integer? beat-count)
218 (make-list beat-count group-size)
220 ;; use value obtained from time-signature-settings
223 (define-public (beam-exceptions time-signature time-signature-settings)
224 "Get @code{beamExceptions} value for @var{time-signature} from
225 @var{time-signature-settings}."
226 (get-setting 'beamExceptions time-signature time-signature-settings))
229 ;;; Functions for overriding time-signature settings
232 (define (override-property-setting context property setting value)
233 "Like the C++ code that executes \\override, but without type
236 (ly:context-set-property!
239 (cons (cons setting value) (ly:context-property context property)))))
241 (define (revert-property-setting context property setting)
242 "Like the C++ code that executes \revert, but without type
245 (define (entry-count alist entry-key)
246 "Count the number of entries in alist with a key of
250 ((equal? (caar alist) entry-key)
251 (+ 1 (entry-count (cdr alist) entry-key)))
252 (else (entry-count (cdr alist) entry-key))))
254 (define (revert-member alist entry-key)
255 "Return ALIST, with the first entry having a key of
256 ENTRY-KEY removed. ALIST is not modified, instead
257 a fresh copy of the list-head is made."
260 ((equal? (caar alist) entry-key) (cdr alist))
261 (else (cons (car alist)
262 (revert-member (cdr alist) entry-key)))))
264 ;; body of revert-property-setting
265 (let ((current-value (ly:context-property context property)))
266 (if (> (entry-count current-value setting) 0)
267 (ly:context-set-property!
270 (revert-member current-value setting)))))
272 (define-public (override-time-signature-setting time-signature setting)
273 "Override the time signature settings for the context in
274 @var{time-signature}, with the new setting alist @var{setting}."
277 (lambda (c) (override-property-setting
279 'timeSignatureSettings
284 (define-public (revert-time-signature-setting time-signature)
288 (revert-property-setting
290 'timeSignatureSettings
297 ;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
298 ;;; Formatting of complex/compound time signatures
300 (define (insert-markups l m)
301 (let ((ll (reverse l)))
302 (let join-markups ((markups (list (car ll)))
303 (remaining (cdr ll)))
304 (if (pair? remaining)
305 (join-markups (cons (car remaining) (cons m markups)) (cdr remaining))
308 ;;; Use a centered-column inside a left-column, because the centered column
309 ;;; moves its reference point to the center, which the left-column undoes.
310 (define (format-time-fraction time-sig-fraction)
311 (let* ((revargs (reverse (map number->string time-sig-fraction)))
313 (nums (reverse (cdr revargs))))
314 (make-override-markup '(baseline-skip . 0)
316 (make-left-column-markup
317 (list (make-center-column-markup
318 (list (make-line-markup (insert-markups nums "+"))
321 (define (format-complex-compound-time time-sig)
322 (make-override-markup '(baseline-skip . 0)
325 (insert-markups (map format-time-fraction time-sig)
326 (make-vcenter-markup "+"))))))
328 (define-public (format-compound-time time-sig)
330 ((not (pair? time-sig)) (null-markup))
331 ((pair? (car time-sig)) (format-complex-compound-time time-sig))
332 (else (format-time-fraction time-sig))))
335 ;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
336 ;;; Measure length calculation of (possibly complex) compound time signatures
338 (define (calculate-time-fraction time-sig-fraction)
339 (let* ((revargs (reverse time-sig-fraction))
341 (num (apply + (cdr revargs))))
342 (ly:make-moment num den)))
344 (define (calculate-complex-compound-time time-sig)
345 (let add-moment ((moment ZERO-MOMENT)
346 (remaining (map calculate-time-fraction time-sig)))
347 (if (pair? remaining)
348 (add-moment (ly:moment-add moment (car remaining)) (cdr remaining))
351 (define-public (calculate-compound-measure-length time-sig)
353 ((not (pair? time-sig)) (ly:make-moment 4 4))
354 ((pair? (car time-sig)) (calculate-complex-compound-time time-sig))
355 (else (calculate-time-fraction time-sig))))
358 ;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
359 ;;; Base beat length: Use the smallest denominator from all fraction
361 (define (calculate-compound-base-beat-full time-sig)
362 (apply max (map last time-sig)))
364 (define-public (calculate-compound-base-beat time-sig)
367 ((not (pair? time-sig)) 4)
368 ((pair? (car time-sig)) (calculate-compound-base-beat-full time-sig))
369 (else (calculate-compound-base-beat-full (list time-sig))))))
372 ;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
375 (define (normalize-fraction frac beat)
376 (let* ((thisbeat (car (reverse frac)))
377 (factor (/ beat thisbeat)))
378 (map (lambda (f) (* factor f)) frac)))
380 (define (beat-grouping-internal time-sig)
381 ;; Normalize to given beat, extract the beats and join them to one list
382 (let* ((beat (calculate-compound-base-beat-full time-sig))
383 (normalized (map (lambda (f) (normalize-fraction f beat)) time-sig))
384 (beats (map (lambda (f) (drop-right f 1)) normalized)))
385 (concatenate beats)))
387 (define-public (calculate-compound-beat-grouping time-sig)
389 ((not (pair? time-sig)) '(2 . 2))
390 ((pair? (car time-sig)) (beat-grouping-internal time-sig))
391 (else (beat-grouping-internal (list time-sig)))))