From: David Kastrup Date: Wed, 27 Nov 2013 12:49:48 +0000 (+0100) Subject: Issue 3679: Rewrite the autobeam logic to use GUILE fractions rather than moments X-Git-Tag: release/2.19.0-1~85 X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;h=80072e19b47514914cb095cbe974b9a180cd295e;p=lilypond.git Issue 3679: Rewrite the autobeam logic to use GUILE fractions rather than moments This makes the arithmetic considerably clearer. --- diff --git a/scm/auto-beam.scm b/scm/auto-beam.scm index b863e5c5a7..70f6b5f1a0 100644 --- a/scm/auto-beam.scm +++ b/scm/auto-beam.scm @@ -38,86 +38,78 @@ (let ((value (ly:context-property context name))) (if (not (null? value)) value default))) - (define (beamingmoment (car a)) - (fraction->moment (car b)))) - - (define (ending-moments group-list start-beat base-moment) + (define (ending-moments group-list start-beat base-length) (if (null? group-list) '() (let ((new-start (+ start-beat (car group-list)))) - (cons (ly:moment-mul (ly:make-moment new-start 1) base-moment) - (ending-moments (cdr group-list) new-start base-moment))))) + (cons (* new-start base-length) + (ending-moments (cdr group-list) new-start base-length))))) - (define (larger-setting test-beam sorted-alist) - (if (null? sorted-alist) - '() - (let* ((first-key (caar sorted-alist)) - (first-moment (fraction->moment first-key))) - (if (moment<=? test-beam first-moment) - (car sorted-alist) - (larger-setting test-beam (cdr sorted-alist)))))) + (define (larger-setting type sorted-alist) + (assoc type sorted-alist <=)) - (define (beat-end? moment beat-structure) - (pair? (member moment beat-structure))) ;; member returns a list if found, not #t + (define (beat-end? moment beat-endings) + (pair? (memv moment beat-endings))) ;; member returns a list if found, not #t ;; Start of actual auto-beam test routine ;; ;; ;; Don't start auto beams on grace notes - (if (and (!= (ly:moment-grace-numerator (ly:context-now context)) 0) - (= dir START)) - #f - (let* ((base-moment (get 'baseMoment (ly:make-moment 1 4))) - (measure-length (get 'measureLength (ly:make-moment 1 1))) + (and (or (zero? (ly:moment-grace (ly:context-now context))) + (!= dir START)) + (let* ((base-length (cond ((get 'baseMoment #f) => ly:moment-main) + (else 1/4))) + (measure-length (cond ((get 'measureLength #f) => ly:moment-main) + (else 1))) (time-signature-fraction (get 'timeSignatureFraction '(4 . 4))) (beat-structure (get 'beatStructure '(1 1 1 1))) - (beat-endings (ending-moments beat-structure 0 base-moment)) - (exceptions (sort (assoc-get 'end - (get 'beamExceptions '()) - '()) - beamingfraction test-beam)) - (non-grace (ly:make-moment - (ly:moment-main-numerator measure-pos) - (ly:moment-main-denominator measure-pos))) - (pos (if (ly:momentmoment default-beat-length) - test-beam)) - (exception-moments (ending-moments - exception-grouping 0 grouping-moment))) + default-beat-length + type)) + (exception-moments (and exception-grouping + (ending-moments + exception-grouping 0 grouping-moment)))) (if (= dir START) ;; Start rules -- #t if beam is allowed to start (or beam-half-measure ;; Start anywhere, but option for mid-measure - (not (equal? (ly:moment-add pos pos) measure-length)) + (not (= (+ pos pos) measure-length)) (not (= 3 (car time-signature-fraction))) ;; in triple meter - (not (= (cdr type) ;; when the beamed note is 1/6 of a measure + (not (= (denominator type) ;; when the beamed note is 1/6 of a measure (* 2 (cdr time-signature-fraction))))) ;; End rules -- #t if beam is required to end - (or (= (ly:moment-main-numerator pos) 0) ;; end at measure beginning - (if (null? exception-grouping) - (beat-end? pos beat-endings) ;; no exception, so check beat ending - (member pos exception-moments))))))) ;; check exception rule + (or (zero? pos) ;; end at measure beginning + (if exception-grouping + (beat-end? pos exception-moments) ;; check exception rule + (beat-end? pos beat-endings))))))) ;; no exception, so check beat ending + (define-public (extract-beam-exceptions music) "Creates a value useful for setting @code{beamExceptions} from @var{music}." diff --git a/scm/time-signature-settings.scm b/scm/time-signature-settings.scm index 82e22fe591..97efdce3d8 100644 --- a/scm/time-signature-settings.scm +++ b/scm/time-signature-settings.scm @@ -26,7 +26,7 @@ ;;; time signature. Each default-properties set can contain the ;;; following entries: ;;; -;;; (baseMoment . (numerator . denominator)) +;;; (baseMoment . (/ numerator denominator)) ;;; (beatStructure . structure-list) ;;; (beamExceptions . (alist of beam exceptions that don't follow beats)) ;;; @@ -37,7 +37,7 @@ ;;; ;;; grouping-rules is an alist containing (beam-type . grouping-list) entries ;;; -;;; beam-type is (numerator . denominator) +;;; beam-type is the length as a rational number ;;; 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, @@ -45,33 +45,32 @@ ;;; ;;; 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)) +;;; (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)) +;;; (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. ;;; +;;; Tuplets are referenced using their actual (scaled) length, so +;;; a 3/2 tuplet of the 1/8 kind would get exceptions looked up +;;; under 1/12. +;;; ;;; 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) +;;; baseMoment gets the value (/ 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)))))))) + ((beamExceptions . ((end . ((1/32 . (8 8 8 8)))))))) ;; in 2/4, 2/8 and 2/16 time: ;; use defaults, so no entries are necessary @@ -80,7 +79,7 @@ ;; 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)))))))) + ((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 @@ -89,12 +88,12 @@ ;; 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 + ((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)))))))) + ((3 . 8) . ((beamExceptions . ((end . ((1/8 . (3)))))))) ;; in 3 16 time: ;; use defaults -- no entries necessary @@ -102,7 +101,7 @@ ;; 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)))))))) + ((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 @@ -110,8 +109,8 @@ ;; 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 + ((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 @@ -123,7 +122,7 @@ ;; 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)))))))) + ((beamExceptions . ((end . ((1/16 . (4 4 4 4 4 4)))))))) ;; in 6 8 time: ;; use defaults, so no entries necessary @@ -134,7 +133,7 @@ ;; 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)))))))) + ((beamExceptions . ((end . ((1/32 . (8 8 8 8 8 8 8 8)))))))) ;; in 9 8 time ;; use defaults, so no entries necessary @@ -145,7 +144,7 @@ ;; 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)))))))) + ((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