1 ;;;; This file is part of LilyPond, the GNU music typesetter.
3 ;;;; Copyright (C) 2009--2014 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 the length as a rational number
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
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 ;;; Tuplets are referenced using their actual (scaled) length, so
56 ;;; a 3/2 tuplet of the 1/8 kind would get exceptions looked up
59 ;;; If no values are given for baseMoment and measureBeats, default values
61 ;;; baseMoment gets the value (/ time-signature-denominator)
62 ;;; beatStructure gets a list of (3 3 3 ...), where the number of entries is the
63 ;;; number of beats, each containing 3 base-moments, if the time
64 ;;; signature numerator is greater than 3 and divisible by 3, and
65 ;;; a list of (1 1 1 ...), where the number of entries is the
66 ;;; number of base moments in a measure otherwise.
68 (define-public default-time-signature-settings
71 ;; use defaults, but end beams with 32nd notes each 1 4 beat
73 ((beamExceptions . ((end . ((1/32 . (8 8 8 8))))))))
75 ;; in 2/4, 2/8 and 2/16 time:
76 ;; use defaults, so no entries are necessary
79 ;; use defaults, but end beams with 32nd notes and higher each 1 4 beat
82 ((beamExceptions . ((end . ((1/32 . (8 8 8 8 8 8))))))))
85 ;; use defaults, but combine all beats into a unit if possible
87 ;; set all beams to end on beats, but 1 8 to beam entire measure
88 ;; in order to avoid beaming every beam type for the entire measure, we set
89 ;; triplets back to every beat.
91 ((beamExceptions . ((end . ((1/8 . (6)) ;1/8 note whole measure
92 (1/12 . (3 3 3)))))))) ;Anything shorter by beat
95 ;; beam entire measure together
96 ((3 . 8) . ((beamExceptions . ((end . ((1/8 . (3))))))))
99 ;; use defaults -- no entries necessary
102 ;; use defaults, but end beams with 16th notes or finer each 1 4 beat
104 ((beamExceptions . ((end . ((1/16 . (4 4 4 4 4 4 4 4))))))))
106 ;; in 4 4 (common) time:
107 ;; use defaults, but combine beats 1,2 and 3,4 if only 8th notes
108 ;; NOTE: Any changes here need to be duplicated in
109 ;; ly/engraver-init.ly where the default time signature is set
112 ((beamExceptions . ((end . ((1/8 . (4 4)) ; 1/8 notes half measure
113 (1/12 . (3 3 3 3)))))))) ;Anything shorter by beat
116 ;; combine beats 1 and 2, so beam in 2
117 ((4 . 8) . ((beatStructure . (2 2))))
120 ;; use defaults, so no entries necessary
123 ;; use defaults, but end beams with 32nd or finer each 1/4 beat
125 ((beamExceptions . ((end . ((1/16 . (4 4 4 4 4 4))))))))
128 ;; use defaults, so no entries necessary
131 ;; use defaults, so no entries necessary
134 ;; use defaults, but end beams with 32nd or finer each 1 4 beat
136 ((beamExceptions . ((end . ((1/32 . (8 8 8 8 8 8 8 8))))))))
139 ;; use defaults, so no entries necessary
142 ;; use defaults, so no entries necessary
145 ;; use defaults, but end beams with 32nd or finer notes each 1 4 beat
147 ((beamExceptions . ((end . ((1/32 . (8 8 8 8 8 8 8 8 8 8 8 8))))))))
150 ;; use defaults, so no entries necessary
153 ;; use defaults, so no entries necessary
156 ;; default: group (3 2)
158 ((beatStructure . (3 2))))
161 ;; default: group (3 3 2)
163 ((beatStructure . (3 3 2))))
165 )) ; end of alist definition
168 ;;; Accessor and constructor functions
171 (define (get-setting my-symbol time-signature time-signature-settings)
172 "Get setting @code{my-symbol} for @code{time-signature} from
173 @code{time-signature-settings}."
174 (let ((my-time-signature-settings
175 (assoc-get time-signature time-signature-settings '())))
176 (assoc-get my-symbol my-time-signature-settings '())))
178 (define-public (make-setting base-fraction
182 (cons 'baseMoment (if (pair? base-fraction)
183 (/ (car base-fraction) (cdr base-fraction))
185 (cons 'beatStructure beat-structure)
186 (cons 'beamExceptions beam-exceptions)))
188 (define-public (base-length time-signature time-signature-settings)
189 "Get @code{baseMoment} rational value for @var{time-signature} from
190 @var{time-signature-settings}."
191 (let ((return-value (get-setting 'baseMoment
193 time-signature-settings)))
194 (if (null? return-value)
195 (/ (cdr time-signature))
198 (define-public (beat-structure base-length time-signature time-signature-settings)
199 "Get @code{beatStructure} value in @var{base-length} units
200 for @var{time-signature} from @var{time-signature-settings}."
202 (let ((return-value (get-setting 'beatStructure
204 time-signature-settings)))
205 (if (null? return-value)
206 ;; calculate default beatStructure
207 (let* ((numerator (car time-signature))
208 (group-size (if (and (> numerator 3)
209 (zero? (remainder numerator 3)))
212 (beat-count (/ (car time-signature)
216 (if (integer? beat-count)
217 (make-list beat-count group-size)
219 ;; use value obtained from time-signature-settings
222 (define-public (beam-exceptions time-signature time-signature-settings)
223 "Get @code{beamExceptions} value for @var{time-signature} from
224 @var{time-signature-settings}."
225 (get-setting 'beamExceptions time-signature time-signature-settings))
228 ;;; Functions for overriding time-signature settings
231 (define (override-property-setting context property setting value)
232 "Like the C++ code that executes \\override, but without type
235 (ly:context-set-property!
238 (cons (cons setting value) (ly:context-property context property)))))
240 (define (revert-property-setting context property setting)
241 "Like the C++ code that executes \revert, but without type
244 (define (entry-count alist entry-key)
245 "Count the number of entries in alist with a key of
249 ((equal? (caar alist) entry-key)
250 (+ 1 (entry-count (cdr alist) entry-key)))
251 (else (entry-count (cdr alist) entry-key))))
253 (define (revert-member alist entry-key)
254 "Return ALIST, with the first entry having a key of
255 ENTRY-KEY removed. ALIST is not modified, instead
256 a fresh copy of the list-head is made."
259 ((equal? (caar alist) entry-key) (cdr alist))
260 (else (cons (car alist)
261 (revert-member (cdr alist) entry-key)))))
263 ;; body of revert-property-setting
264 (let ((current-value (ly:context-property context property)))
265 (if (> (entry-count current-value setting) 0)
266 (ly:context-set-property!
269 (revert-member current-value setting)))))
271 (define-public (override-time-signature-setting time-signature setting)
272 "Override the time signature settings for the context in
273 @var{time-signature}, with the new setting alist @var{setting}."
276 (lambda (c) (override-property-setting
278 'timeSignatureSettings
283 (define-public (revert-time-signature-setting time-signature)
287 (revert-property-setting
289 'timeSignatureSettings
296 ;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
297 ;;; Formatting of complex/compound time signatures
299 (define (insert-markups l m)
300 (let ((ll (reverse l)))
301 (let join-markups ((markups (list (car ll)))
302 (remaining (cdr ll)))
303 (if (pair? remaining)
304 (join-markups (cons (car remaining) (cons m markups)) (cdr remaining))
307 ;;; Use a centered-column inside a left-column, because the centered column
308 ;;; moves its reference point to the center, which the left-column undoes.
309 (define (format-time-fraction time-sig-fraction)
310 (let* ((revargs (reverse (map number->string time-sig-fraction)))
312 (nums (reverse (cdr revargs))))
313 (make-override-markup '(baseline-skip . 0)
315 (make-left-column-markup
316 (list (make-center-column-markup
317 (list (make-line-markup (insert-markups nums "+"))
320 (define (format-complex-compound-time time-sig)
321 (make-override-markup '(baseline-skip . 0)
324 (insert-markups (map format-time-fraction time-sig)
325 (make-vcenter-markup "+"))))))
327 (define-public (format-compound-time time-sig)
329 ((not (pair? time-sig)) (null-markup))
330 ((pair? (car time-sig)) (format-complex-compound-time time-sig))
331 (else (format-time-fraction time-sig))))
334 ;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
335 ;;; Measure length calculation of (possibly complex) compound time signatures
337 (define (calculate-time-fraction time-sig-fraction)
338 (let* ((revargs (reverse time-sig-fraction))
340 (num (apply + (cdr revargs))))
341 (ly:make-moment num den)))
343 (define (calculate-complex-compound-time time-sig)
344 (let add-moment ((moment ZERO-MOMENT)
345 (remaining (map calculate-time-fraction time-sig)))
346 (if (pair? remaining)
347 (add-moment (ly:moment-add moment (car remaining)) (cdr remaining))
350 (define-public (calculate-compound-measure-length time-sig)
352 ((not (pair? time-sig)) (ly:make-moment 4 4))
353 ((pair? (car time-sig)) (calculate-complex-compound-time time-sig))
354 (else (calculate-time-fraction time-sig))))
357 ;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
358 ;;; Base beat length: Use the smallest denominator from all fraction
360 (define (calculate-compound-base-beat-full time-sig)
361 (apply max (map last time-sig)))
363 (define-public (calculate-compound-base-beat time-sig)
366 ((not (pair? time-sig)) 4)
367 ((pair? (car time-sig)) (calculate-compound-base-beat-full time-sig))
368 (else (calculate-compound-base-beat-full (list time-sig))))))
371 ;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
374 (define (normalize-fraction frac beat)
375 (let* ((thisbeat (car (reverse frac)))
376 (factor (/ beat thisbeat)))
377 (map (lambda (f) (* factor f)) frac)))
379 (define (beat-grouping-internal time-sig)
380 ;; Normalize to given beat, extract the beats and join them to one list
381 (let* ((beat (calculate-compound-base-beat-full time-sig))
382 (normalized (map (lambda (f) (normalize-fraction f beat)) time-sig))
383 (beats (map (lambda (f) (drop-right f 1)) normalized)))
384 (concatenate beats)))
386 (define-public (calculate-compound-beat-grouping time-sig)
388 ((not (pair? time-sig)) '(2 . 2))
389 ((pair? (car time-sig)) (beat-grouping-internal time-sig))
390 (else (beat-grouping-internal (list time-sig)))))