-;;;; auto-beam.scm -- Auto-beam-engraver settings
+;;;; This file is part of LilyPond, the GNU music typesetter.
;;;;
-;;;; source file of the GNU LilyPond music typesetter
+;;;; Copyright (C) 2000--2011 Jan Nieuwenhuizen <janneke@gnu.org>
;;;;
-;;;; (c) 2000--2009 Jan Nieuwenhuizen <janneke@gnu.org>
+;;;; 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/>.
-;; Determine end moment for auto beaming (or begin moment, but mostly
-;; 0== anywhere). We only consider the current time signature.
-;; In order of decreasing priority:
+;; Determine whether an auto beam should be extended to the right
+;; of the current stem. We start anywhere except on the last note
+;; of a beat. We end according to the follwing rules, in order
+;; of decreasing priority:
;;
;; 1. end <type>
-;; 2. end *
-;; 3. if 1-2 not specified, begin anywhere, end at beatLength intervals
+;; 2. end <greater type>
+;; 3. if 1-2 not specified, end at beatStructure intervals
;;
;; Rationale:
;;
;; [user override]
;; 1. override for specific duration type
-;; 2. override for all duration types in a time signature.
+;; 2. overrides apply to shorter durations
;;
-;; defined in scm/beam-settings.scm:
+;; defined in scm/time-signature-settings.scm:
;; 1. Default grouping for common time signatures
-;; 2. exceptions for specific time signature, for specific duration type
-
-(define-public (default-auto-beam-check context dir test-beam)
+(define-public (default-auto-beam-check context dir measure-pos test-beam)
(define (get name default)
(let ((value (ly:context-property context name)))
(if (not (null? value)) value default)))
- (define (ending-moments group-list start-beat beat-length)
+ (define (beaming<? a b)
+ (ly:moment<? (fraction->moment (car a))
+ (fraction->moment (car b))))
+
+ (define (ending-moments group-list start-beat base-moment)
(if (null? group-list)
'()
(let ((new-start (+ start-beat (car group-list))))
- (cons (ly:moment-mul (ly:make-moment new-start 1) beat-length)
- (ending-moments (cdr group-list) new-start beat-length)))))
+ (cons (ly:moment-mul (ly:make-moment new-start 1) base-moment)
+ (ending-moments (cdr group-list) new-start base-moment)))))
+
+ (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 (beat-end? moment beat-structure)
+ (pair? (member moment beat-structure))) ;; member returns a list if found, not #t
;; Start of actual auto-beam test routine
;;
(if (and (!= (ly:moment-grace-numerator (ly:context-now context)) 0)
(= dir START))
#f
- (if (= dir START)
- ;; start anywhere is currently implemented
- #t
- (let* ((beat-length (get 'beatLength (ly:make-moment 1 4)))
- (measure-length (get 'measureLength (ly:make-moment 1 1)))
- (time-signature-fraction
- (get 'timeSignatureFraction '(4 . 4)))
- (measure-pos (get 'measurePosition ZERO-MOMENT))
- (settings (get 'beamSettings '()))
- (function (if (= dir START) 'begin 'end))
- (type (cons (ly:moment-main-numerator test-beam)
- (ly:moment-main-denominator test-beam)))
- (pos (if (>= (ly:moment-main-numerator measure-pos) 0)
- measure-pos
- (ly:moment-add measure-length measure-pos)))
- (type-grouping (ly:beam-grouping
- settings
- time-signature-fraction
- function
- type))
- (default-grouping (ly:beam-grouping
- settings
- time-signature-fraction
- function
- '*))
- (beat-grouping (if (null? type-grouping)
- default-grouping
- type-grouping))
- (grouping-moment (if (null? type-grouping)
- beat-length
- test-beam))
- (grouping-moments (ending-moments
- beat-grouping 0 grouping-moment)))
- (if (null? beat-grouping)
- ;; no rule applies, so end at beatLength
- (= (ly:moment-main-denominator
- (ly:moment-div pos beat-length)) 1)
- ;; otherwise, end at beginning of measure or
- ;; at specified moment
- (or
- ;; start/end at beginning of measure
- (= (ly:moment-main-numerator pos) 0)
- ;; end if measure-pos matches a specified ending moment
- (member pos grouping-moments)))))))
+ (let* ((base-moment (get 'baseMoment (ly:make-moment 1 4)))
+ (measure-length (get 'measureLength (ly:make-moment 1 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 '())
+ '())
+ beaming<?))
+ (function (if (= dir START) 'begin 'end))
+ (type (moment->fraction test-beam))
+ (non-grace (ly:make-moment
+ (ly:moment-main-numerator measure-pos)
+ (ly:moment-main-denominator measure-pos)))
+ (pos (if (ly:moment<? non-grace ZERO-MOMENT)
+ (ly:moment-add measure-length non-grace)
+ non-grace))
+ (type-grouping (assoc-get type exceptions '()))
+ (default-rule (if (null? type-grouping)
+ (larger-setting test-beam exceptions)
+ '()))
+ (default-grouping (if (pair? default-rule)
+ (cdr default-rule)
+ '()))
+ (default-beat-length (if (pair? default-rule)
+ (car default-rule)
+ '()))
+ (exception-grouping (if (null? type-grouping)
+ default-grouping
+ type-grouping))
+ (grouping-moment (if (null? type-grouping)
+ (fraction->moment default-beat-length)
+ test-beam))
+ (exception-moments (ending-moments
+ exception-grouping 0 grouping-moment)))
+
+ (if (= dir START)
+ ;; Start rules
+ (or (not (equal? time-signature-fraction '(3 . 4))) ;; start anywher if not 3/4
+ (beat-end? pos beat-endings) ;; are we at start of beat?
+ (and (not (equal? test-beam base-moment)) ;; is beat split?
+ (not (beat-end? (ly:moment-add pos test-beam)
+ beat-endings)))) ;; will this note end the beat
+ ;; End rules
+ (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
+
projects / lilypond.git / blobdiff