1 ;;;; This file is part of LilyPond, the GNU music typesetter.
3 ;;;; Copyright (C) 2009--2011 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, 5/8, 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 ;;; If no value is given for beatCombinations, no beats will be combined without
65 ;;; beamExceptions rules.
67 ;;; NOTE: numerator is kept in beam-type because of
68 ;;; tuplets, e.g. (2 . 24) = (2 . 3) * (1 . 8)
69 ;;; for eighth-note triplets.
71 (define-public default-time-signature-settings
74 ;; use defaults, but end beams with 32nd notes each 1 4 beat
76 ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8))))))))
78 ;; in 2/4, 2/8 and 2/16 time:
79 ;; use defaults, so no entries are necessary
82 ;; use defaults, but end beams with 32nd notes and higher each 1 4 beat
85 ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8))))))))
88 ;; use defaults, but combine all beats into a unit if possible
90 ;; set all beams to end on beats, but 1 8 to beam entire measure
91 ;; in order to avoid beaming every beam type for the entire measure, we set
92 ;; triplets back to every beat.
94 ((beamExceptions . ((end . (((1 . 8) . (6)) ;1/8 note whole measure
95 ((1 . 12) . (3 3 3)))))))) ;Anything shorter by beat
98 ;; beam entire measure together
99 ((3 . 8) . ((beamExceptions . ((end . (((1 . 8) . (3))))))))
102 ;; use defaults -- no entries necessary
105 ;; use defaults, but end beams with 16th notes or finer each 1 4 beat
107 ((beamExceptions . ((end . (((1 . 16) . (4 4 4 4 4 4 4 4))))))))
109 ;; in 4 4 (common) time:
110 ;; use defaults, but combine beats 1,2 and 3,4 if only 8th notes
111 ;; NOTE: Any changes here need to be duplicated in
112 ;; ly/engraver-init.ly where the default time signature is set
115 ((beamExceptions . ((end . (((1 . 8) . (4 4)) ; 1/8 notes half measure
116 ((1 . 12) . (3 3 3 3)))))))) ;Anything shorter by beat
119 ;; combine beats 1 and 2, so beam in 2
120 ((4 . 8) . ((beatStructure . (2 2))))
122 ;; in 4/8 and 4/16 time:
123 ;; use defaults, so no entries necessary
126 ;; use defaults, but end beams with 32nd or finer each 1/4 beat
128 ((beamExceptions . ((end . (((1 . 16) . (4 4 4 4 4 4))))))))
131 ;; use defaults, but end beams with 32nd or finer each 1 8 beat
133 ((beamExceptions . ((end . (((1 . 32) . (4 4 4 4 4 4))))))))
136 ;; use defaults, so no entry necessary
139 ;; use defaults, but end beams with 32nd or finer each 1 4 beat
141 ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8 8 8))))))))
144 ;; use defaults, but end beams with 32nd notes each 1 8 beat
146 ((beamExceptions . ((end . (((1 . 32) . (4 4 4 4 4 4 4 4 4))))))))
149 ;; use defaults, so no entry necessary
152 ;; use defaults, but end beams with 32nd or finer notes each 1 4 beat
154 ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8 8 8 8 8 8 8))))))))
157 ;; use defaults, but end beams with 32nd notes each 1 8 beat
159 ((beamExceptions . ((end . (((1 . 32) . (4 4 4 4 4 4 4 4 4 4 4 4))))))))
162 ;; use defaults; no entry needed
165 ;; default: group (3 2)
167 ((baseMoment . (1 . 8))
168 (beatStructure . (3 2))))
171 ;; default: group (3 3 2)
173 ((baseMoment . (1 . 8))
174 (beatStructure . (3 3 2))))
176 )) ; end of alist definition
179 ;;; Accessor and constructor functions
182 (define (get-setting my-symbol time-signature time-signature-settings)
183 "Get setting @code{my-symbol} for @code{time-signature} from
184 @code{time-signature-settings}."
185 (let ((my-time-signature-settings
186 (assoc-get time-signature time-signature-settings '())))
187 (assoc-get my-symbol my-time-signature-settings '())))
189 (define-public (make-setting base-fraction
193 (cons 'baseMoment base-fraction)
194 (cons 'beatStructure beat-structure)
195 (cons 'beamExceptions beam-exceptions)))
197 (define-public (base-fraction time-signature time-signature-settings)
198 "Get @code{baseMoment} fraction value for @code{time-signature} from
199 @code{time-signature-settings}."
200 (let ((return-value (get-setting 'baseMoment
202 time-signature-settings)))
203 (if (null? return-value)
204 (cons 1 (cdr time-signature))
207 (define-public (beat-structure base-fraction time-signature time-signature-settings)
208 "Get beatStructure value in @code{base-fraction} units
209 for @code{time-signature} from
210 @code{time-signature-settings}."
211 (define (fraction-divide numerator denominator)
212 (/ (* (car numerator) (cdr denominator))
213 (* (cdr numerator) (car denominator))))
215 (let ((return-value (get-setting 'beatStructure
217 time-signature-settings)))
218 (if (null? return-value)
219 ;; calculate default beatStructure
220 (let* ((numerator (car time-signature))
221 (group-size (if (and (> numerator 3)
222 (zero? (remainder numerator 3)))
225 (beat-length (cons (* group-size (car base-fraction))
226 (cdr base-fraction)))
227 (beat-count (fraction-divide time-signature beat-length)))
228 (if (integer? beat-count)
229 (make-list beat-count group-size)
231 ;; use value obtained from time-signature-settings
234 (define-public (beam-exceptions time-signature time-signature-settings)
235 "Get beamExceptions value for @code{time-signature} from
236 @code{time-signature-settings}."
237 (get-setting 'beamExceptions time-signature time-signature-settings))
240 ;;; Functions for overriding time-signature settings
243 (define (override-property-setting context property setting value)
244 "Like the C++ code that executes \\override, but without type
247 (revert-property-setting context property setting)
248 (ly:context-set-property!
251 (cons (cons setting value) (ly:context-property context property)))))
253 (define (revert-property-setting context property setting)
254 "Like the C++ code that executes \revert, but without type
257 (define (entry-count alist entry-key)
258 "Count the number of entries in alist with a key of
262 ((equal? (caar alist) entry-key)
263 (+ 1 (entry-count (cdr alist) entry-key)))
264 (else (entry-count (cdr alist) entry-key))))
266 (define (revert-member alist entry-key)
267 "Return ALIST, with the first entry having a key of
268 ENTRY-KEY removed. ALIST is not modified, instead
269 a fresh copy of the list-head is made."
272 ((equal? (caar alist) entry-key) (cdr alist))
273 (else (cons (car alist)
274 (revert-member (cdr alist) entry-key)))))
276 ;; body of revert-property-setting
277 (let ((current-value (ly:context-property context property)))
278 (if (> (entry-count current-value setting) 1)
279 (ly:context-set-property!
282 (revert-member current-value setting)))))
284 (define-public (override-time-signature-setting time-signature setting)
285 "Override the time signature settings for the context in @var{rest},
286 with the new setting alist @var{setting}. "
289 (lambda (c) (override-property-setting
291 'timeSignatureSettings
296 (define-public (revert-time-signature-setting time-signature)
300 (revert-property-setting
302 'timeSignatureSettings