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| ;;;; This file is part of LilyPond, the GNU music typesetter. | |
| ;;;; | |
| ;;;; Copyright (C) 2000--2020 Han-Wen Nienhuys <[email protected]> | |
| ;;;; Jan Nieuwenhuizen <[email protected]> | |
| ;;;; | |
| ;;;; 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/>. | |
| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
| ;; autochange.scm - fairly related to part combining. | |
| (define-public (make-autochange-music music . ref-pitch) | |
| (define ref-pitch-steps | |
| (if (and (pair? ref-pitch) (car ref-pitch)) | |
| (ly:pitch-steps (car ref-pitch)) | |
| 0)) | |
| (define (generate-split-list change-moment prev-dir event-list acc) | |
| (if (null? event-list) | |
| acc | |
| (let* ((now-tun (caar event-list)) | |
| (evs (map car (cdar event-list))) | |
| (now (car now-tun)) | |
| (notes (filter (lambda (x) | |
| (ly:in-event-class? x 'note-event)) | |
| evs)) | |
| (pitch (if (pair? notes) | |
| (ly:event-property (car notes) 'pitch) | |
| #f)) | |
| (dir (if pitch | |
| (sign | |
| (- (ly:pitch-steps pitch) ref-pitch-steps)) | |
| 0))) | |
| ;; tail recursive. | |
| (if (and (not (= dir 0)) | |
| (not (= dir prev-dir))) | |
| (generate-split-list #f | |
| dir | |
| (cdr event-list) | |
| (cons (cons | |
| (if change-moment | |
| change-moment | |
| now) | |
| (if (< dir 0) 'down 'up)) acc)) | |
| (generate-split-list | |
| (if pitch #f (if change-moment change-moment now)) | |
| dir | |
| (cdr event-list) acc))))) | |
| (let* ((m (make-music 'AutoChangeMusic)) | |
| (m1 (context-spec-music (make-non-relative-music music) 'Voice "")) | |
| (context-list | |
| (recording-group-emulate m1 | |
| (ly:parser-lookup 'partCombineListener))) | |
| (rev (reverse! (cdar context-list))) | |
| (split (reverse! (generate-split-list | |
| #f | |
| 0 | |
| rev | |
| '()) | |
| '()))) | |
| (set! (ly:music-property m 'element) m1) | |
| (set! (ly:music-property m 'context-change-list) split) | |
| m)) | |