+;;;; This file is part of LilyPond, the GNU music typesetter.
+;;;;
+;;;; Copyright (C) 2009--2011 Carl Sorensen <c_sorensen@byu.edu>
+;;;;
+;;;; LilyPond is free software: you can redistribute it and/or modify
+;;;; it under the terms of the GNU General Public License as published by
+;;;; the Free Software Foundation, either version 3 of the License, or
+;;;; (at your option) any later version.
+;;;;
+;;;; LilyPond 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.
+;;;;
+;;;; You should have received a copy of the GNU General Public License
+;;;; along with LilyPond. If not, see <http://www.gnu.org/licenses/>.
+
+;;; specify time signature default settings
+
+;;; format:
+;;;
+;;; alist of
+;;; (time-signature . default-properties) entries.
+;;;
+;;; where default-properties is an alist containing information about the
+;;; time signature. Each default-properties set can contain the
+;;; following entries:
+;;;
+;;; (baseMoment . (numerator . denominator))
+;;; (beatStructure . structure-list)
+;;; (beamExceptions . (alist of beam exceptions that don't follow beats))
+;;;
+;;; The alist of beam exceptions has the following entries:
+;;;
+;;; (end . grouping-rules)
+;;; (subdivide . grouping-rules) (not yet implemented, reserved for future use)
+;;;
+;;; grouping-rules is an alist containing (beam-type . grouping-list) entries
+;;;
+;;; beam-type is (numerator . denominator)
+;;; grouping-list is a list that specifies the
+;;; number of stems of the given duration that are grouped in a beamed unit.
+;;; For an exception, the duration used is beam-type. For measureBeats,
+;;; the duration used is baseMoment.
+;;;
+;;; If an exception is specified for a given beam-type, it will apply to all
+;;; beams of shorter durations that don't have an individual exception, so
+;;; ((1 . 8) . (3 3 2))
+;;; will cause all primary beams to be broken at 3/8, 6/8, and 8/8.
+;;;
+;;; ((1. 32) . (16 8 4 4))
+;;; will cause all 1/32, 1/64, and 1/128 beams to be broken at 1/2, 3/4,
+;;; 7/8, and 8/8.
+;;;
+;;; If no values are given for baseMoment and measureBeats, default values
+;;; will be assigned:
+;;; baseMoment gets the value (ly:make-moment 1 time-signature-denominator)
+;;; beatStructure gets a list of (3 3 3 ...), where the number of entries is the
+;;; number of beats, each containing 3 base-moments, if the time
+;;; signature numerator is greater than 3 and divisible by 3, and
+;;; a list of (1 1 1 ...), where the number of entries is the
+;;; number of base moments in a measure otherwise.
+;;;
+;;; NOTE: numerator is kept in beam-type because of
+;;; tuplets, e.g. (2 . 24) = (2 . 3) * (1 . 8)
+;;; for eighth-note triplets.
+
+(define-public default-time-signature-settings
+ '(
+ ;; in 2/2 time:
+ ;; use defaults, but end beams with 32nd notes each 1 4 beat
+ ((2 . 2) .
+ ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8))))))))
+
+ ;; in 2/4, 2/8 and 2/16 time:
+ ;; use defaults, so no entries are necessary
+
+ ;; in 3 2 time:
+ ;; use defaults, but end beams with 32nd notes and higher each 1 4 beat
+
+ ((3 . 2) .
+ ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8))))))))
+
+ ;; in 3 4 time:
+ ;; use defaults, but combine all beats into a unit if possible
+ ;;
+ ;; set all beams to end on beats, but 1 8 to beam entire measure
+ ;; in order to avoid beaming every beam type for the entire measure, we set
+ ;; triplets back to every beat.
+ ((3 . 4) .
+ ((beamExceptions . ((end . (((1 . 8) . (6)) ;1/8 note whole measure
+ ((1 . 12) . (3 3 3)))))))) ;Anything shorter by beat
+
+ ;; in 3 8 time:
+ ;; beam entire measure together
+ ((3 . 8) . ((beamExceptions . ((end . (((1 . 8) . (3))))))))
+
+ ;; in 3 16 time:
+ ;; use defaults -- no entries necessary
+
+ ;; in 4 2 time:
+ ;; use defaults, but end beams with 16th notes or finer each 1 4 beat
+ ((4 . 2) .
+ ((beamExceptions . ((end . (((1 . 16) . (4 4 4 4 4 4 4 4))))))))
+
+ ;; in 4 4 (common) time:
+ ;; use defaults, but combine beats 1,2 and 3,4 if only 8th notes
+ ;; NOTE: Any changes here need to be duplicated in
+ ;; ly/engraver-init.ly where the default time signature is set
+ ;; are set
+ ((4 . 4) .
+ ((beamExceptions . ((end . (((1 . 8) . (4 4)) ; 1/8 notes half measure
+ ((1 . 12) . (3 3 3 3)))))))) ;Anything shorter by beat
+
+ ;; in 4/8 time:
+ ;; combine beats 1 and 2, so beam in 2
+ ((4 . 8) . ((beatStructure . (2 2))))
+
+ ;; in 4/16 time:
+ ;; use defaults, so no entries necessary
+
+ ;; in 6 4 time:
+ ;; use defaults, but end beams with 32nd or finer each 1/4 beat
+ ((6 . 4) .
+ ((beamExceptions . ((end . (((1 . 16) . (4 4 4 4 4 4))))))))
+
+ ;; in 6 8 time:
+ ;; use defaults, so no entries necessary
+
+ ;; in 6 16 time:
+ ;; use defaults, so no entries necessary
+
+ ;; in 9 4 time:
+ ;; use defaults, but end beams with 32nd or finer each 1 4 beat
+ ((9 . 4) .
+ ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8 8 8))))))))
+
+ ;; in 9 8 time
+ ;; use defaults, so no entries necessary
+
+ ;; in 9 16 time
+ ;; use defaults, so no entries necessary
+
+ ;; in 12 4 time:
+ ;; use defaults, but end beams with 32nd or finer notes each 1 4 beat
+ ((12 . 4) .
+ ((beamExceptions . ((end . (((1 . 32) . (8 8 8 8 8 8 8 8 8 8 8 8))))))))
+
+ ;; in 12 8 time:
+ ;; use defaults, so no entries necessary
+
+ ;; in 12 16 time:
+ ;; use defaults, so no entries necessary
+
+ ;; in 5 8 time:
+ ;; default: group (3 2)
+ ((5 . 8) .
+ ((beatStructure . (3 2))))
+
+ ;; in 8 8 time:
+ ;; default: group (3 3 2)
+ ((8 . 8) .
+ ((beatStructure . (3 3 2))))
+
+ )) ; end of alist definition
+
+;;;
+;;; Accessor and constructor functions
+;;;
+
+(define (get-setting my-symbol time-signature time-signature-settings)
+ "Get setting @code{my-symbol} for @code{time-signature} from
+@code{time-signature-settings}."
+ (let ((my-time-signature-settings
+ (assoc-get time-signature time-signature-settings '())))
+ (assoc-get my-symbol my-time-signature-settings '())))
+
+(define-public (make-setting base-fraction
+ beat-structure
+ beam-exceptions)
+ (list
+ (cons 'baseMoment base-fraction)
+ (cons 'beatStructure beat-structure)
+ (cons 'beamExceptions beam-exceptions)))
+
+(define-public (base-fraction time-signature time-signature-settings)
+ "Get @code{baseMoment} fraction value for @var{time-signature} from
+@var{time-signature-settings}."
+ (let ((return-value (get-setting 'baseMoment
+ time-signature
+ time-signature-settings)))
+ (if (null? return-value)
+ (cons 1 (cdr time-signature))
+ return-value)))
+
+(define-public (beat-structure base-fraction time-signature time-signature-settings)
+ "Get @code{beatStructure} value in @var{base-fraction} units
+for @var{time-signature} from @var{time-signature-settings}."
+ (define (fraction-divide numerator denominator)
+ (/ (* (car numerator) (cdr denominator))
+ (* (cdr numerator) (car denominator))))
+
+ (let ((return-value (get-setting 'beatStructure
+ time-signature
+ time-signature-settings)))
+ (if (null? return-value)
+ ;; calculate default beatStructure
+ (let* ((numerator (car time-signature))
+ (group-size (if (and (> numerator 3)
+ (zero? (remainder numerator 3)))
+ 3
+ 1))
+ (beat-length (cons (* group-size (car base-fraction))
+ (cdr base-fraction)))
+ (beat-count (fraction-divide time-signature beat-length)))
+ (if (integer? beat-count)
+ (make-list beat-count group-size)
+ '()))
+ ;; use value obtained from time-signature-settings
+ return-value)))
+
+(define-public (beam-exceptions time-signature time-signature-settings)
+ "Get @code{beamExceptions} value for @var{time-signature} from
+@var{time-signature-settings}."
+ (get-setting 'beamExceptions time-signature time-signature-settings))
+
+
+;;; Functions for overriding time-signature settings
+;;;
+
+(define (override-property-setting context property setting value)
+ "Like the C++ code that executes \\override, but without type
+checking."
+ (begin
+ (revert-property-setting context property setting)
+ (ly:context-set-property!
+ context
+ property
+ (cons (cons setting value) (ly:context-property context property)))))
+
+(define (revert-property-setting context property setting)
+ "Like the C++ code that executes \revert, but without type
+checking."
+
+ (define (entry-count alist entry-key)
+ "Count the number of entries in alist with a key of
+ENTRY-KEY."
+ (cond
+ ((null? alist) 0)
+ ((equal? (caar alist) entry-key)
+ (+ 1 (entry-count (cdr alist) entry-key)))
+ (else (entry-count (cdr alist) entry-key))))
+
+ (define (revert-member alist entry-key)
+ "Return ALIST, with the first entry having a key of
+ENTRY-KEY removed. ALIST is not modified, instead
+a fresh copy of the list-head is made."
+ (cond
+ ((null? alist) '())
+ ((equal? (caar alist) entry-key) (cdr alist))
+ (else (cons (car alist)
+ (revert-member (cdr alist) entry-key)))))
+
+ ;; body of revert-property-setting
+ (let ((current-value (ly:context-property context property)))
+ (if (> (entry-count current-value setting) 1)
+ (ly:context-set-property!
+ context
+ property
+ (revert-member current-value setting)))))
+
+(define-public (override-time-signature-setting time-signature setting)
+ "Override the time signature settings for the context in
+@var{time-signature}, with the new setting alist @var{setting}."
+ (context-spec-music
+ (make-apply-context
+ (lambda (c) (override-property-setting
+ c
+ 'timeSignatureSettings
+ time-signature
+ setting)))
+ 'Timing))
+
+(define-public (revert-time-signature-setting time-signature)
+ (context-spec-music
+ (make-apply-context
+ (lambda (c)
+ (revert-property-setting
+ c
+ 'timeSignatureSettings
+ time-signature)))
+ 'Timing))
+
+
+
+
+;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+;;; Formatting of complex/compound time signatures
+
+(define (insert-markups l m)
+ (let ((ll (reverse l)))
+ (let join-markups ((markups (list (car ll)))
+ (remaining (cdr ll)))
+ (if (pair? remaining)
+ (join-markups (cons (car remaining) (cons m markups)) (cdr remaining))
+ markups))))
+
+;;; Use a centered-column inside a left-column, because the centered column
+;;; moves its reference point to the center, which the left-column undoes.
+(define (format-time-fraction time-sig-fraction)
+ (let* ((revargs (reverse (map number->string time-sig-fraction)))
+ (den (car revargs))
+ (nums (reverse (cdr revargs))))
+ (make-override-markup '(baseline-skip . 0)
+ (make-number-markup
+ (make-left-column-markup (list
+ (make-center-column-markup (list
+ (make-line-markup (insert-markups nums "+"))
+ den))))))))
+
+(define (format-complex-compound-time time-sig)
+ (make-override-markup '(baseline-skip . 0)
+ (make-number-markup
+ (make-line-markup
+ (insert-markups (map format-time-fraction time-sig)
+ (make-vcenter-markup "+"))))))
+
+(define-public (format-compound-time time-sig)
+ (cond
+ ((not (pair? time-sig)) (null-markup))
+ ((pair? (car time-sig)) (format-complex-compound-time time-sig))
+ (else (format-time-fraction time-sig))))
+
+
+;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+;;; Measure length calculation of (possibly complex) compound time signatures
+
+(define (calculate-time-fraction time-sig-fraction)
+ (let* ((revargs (reverse time-sig-fraction))
+ (den (car revargs))
+ (num (apply + (cdr revargs))))
+ (ly:make-moment num den)))
+
+(define (calculate-complex-compound-time time-sig)
+ (let add-moment ((moment ZERO-MOMENT)
+ (remaining (map calculate-time-fraction time-sig)))
+ (if (pair? remaining)
+ (add-moment (ly:moment-add moment (car remaining)) (cdr remaining))
+ moment)))
+
+(define-public (calculate-compound-measure-length time-sig)
+ (cond
+ ((not (pair? time-sig)) (ly:make-moment 4 4))
+ ((pair? (car time-sig)) (calculate-complex-compound-time time-sig))
+ (else (calculate-time-fraction time-sig))))
+
+
+;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+;;; Base beat length: Use the smallest denominator from all fraction
+
+(define (calculate-compound-base-beat-full time-sig)
+ (apply max (map last time-sig)))
+
+(define-public (calculate-compound-base-beat time-sig)
+ (ly:make-moment 1
+ (cond
+ ((not (pair? time-sig)) 4)
+ ((pair? (car time-sig)) (calculate-compound-base-beat-full time-sig))
+ (else (calculate-compound-base-beat-full (list time-sig))))))
+
+
+;;;%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+;;; Beat Grouping
+
+(define (normalize-fraction frac beat)
+ (let* ((thisbeat (car (reverse frac)))
+ (factor (/ beat thisbeat)))
+ (map (lambda (f) (* factor f)) frac)))
+
+(define (beat-grouping-internal time-sig)
+ ;; Normalize to given beat, extract the beats and join them to one list
+ (let* ((beat (calculate-compound-base-beat-full time-sig))
+ (normalized (map (lambda (f) (normalize-fraction f beat)) time-sig))
+ (beats (map (lambda (f) (reverse (cdr (reverse f)))) normalized)))
+ (apply append beats)))
+
+(define-public (calculate-compound-beat-grouping time-sig)
+ (cond
+ ((not (pair? time-sig)) '(2 . 2))
+ ((pair? (car time-sig)) (beat-grouping-internal time-sig))
+ (else (beat-grouping-internal (list time-sig)))))