scm/define-music-callbacks.scm

   1 ;;;; This file is part of LilyPond, the GNU music typesetter.
   2 ;;;;
   3 ;;;; Copyright (C) 1998--2011 Han-Wen Nienhuys <hanwen@xs4all.nl>
   4 ;;;;                 Jan Nieuwenhuizen <janneke@gnu.org>
   5 ;;;;                 Neil Puttock <n.puttock@gmail.com>
   6 ;;;;                 Carl Sorensen <c_sorensen@byu.edu>
   7 ;;;;
   8 ;;;; LilyPond is free software: you can redistribute it and/or modify
   9 ;;;; it under the terms of the GNU General Public License as published by
  10 ;;;; the Free Software Foundation, either version 3 of the License, or
  11 ;;;; (at your option) any later version.
  12 ;;;;
  13 ;;;; LilyPond is distributed in the hope that it will be useful,
  14 ;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 ;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 ;;;; GNU General Public License for more details.
  17 ;;;;
  18 ;;;; You should have received a copy of the GNU General Public License
  19 ;;;; along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
  20
  21 ;; TODO: should link back into user manual.
  22
  23 (define (mm-rest-child-list music)
  24   "Generate events for multimeasure rests,
  25 to be used by the sequential-iterator"
  26   (let ((location (ly:music-property music 'origin))
  27         (duration (ly:music-property music 'duration)))
  28     (list (make-music 'BarCheck
  29                       'origin location)
  30           (make-event-chord (cons (make-music 'MultiMeasureRestEvent
  31                                               'origin location
  32                                               'duration duration)
  33                                   (ly:music-property music 'articulations)))
  34           (make-music 'BarCheck
  35                       'origin location))))
  36
  37 (define (make-ottava-set music)
  38   "Set context properties for an ottava bracket."
  39   (let ((octavation (ly:music-property music 'ottava-number)))
  40
  41     (list (context-spec-music
  42            (make-apply-context
  43             (lambda (context)
  44               (let ((offset (* -7 octavation))
  45                     (string (assoc-get octavation '((2 . "15ma")
  46                                                     (1 . "8va")
  47                                                     (0 . #f)
  48                                                     (-1 . "8vb")
  49                                                     (-2 . "15mb")))))
  50                 (set! (ly:context-property context 'middleCOffset) offset)
  51                 (set! (ly:context-property context 'ottavation) string)
  52                 (ly:set-middle-C! context))))
  53            'Staff))))
  54
  55 (define (make-time-signature-set music)
  56   "Set context properties for a time signature."
  57   (let* ((num (ly:music-property music 'numerator))
  58          (den (ly:music-property music 'denominator))
  59          (structure (ly:music-property music 'beat-structure))
  60          (fraction (cons num den)))
  61     (list (descend-to-context
  62             (context-spec-music
  63               (make-apply-context
  64                 (lambda (context)
  65                   (let* ((time-signature-settings
  66                           (ly:context-property context 'timeSignatureSettings))
  67                          (my-base-fraction
  68                            (base-fraction fraction time-signature-settings))
  69                          (my-beat-structure
  70                            (if (null? structure)
  71                                (beat-structure my-base-fraction
  72                                                fraction
  73                                                time-signature-settings)
  74                                structure))
  75                          (beaming-exception
  76                            (beam-exceptions fraction time-signature-settings))
  77                          (new-measure-length (ly:make-moment num den)))
  78                      (ly:context-set-property!
  79                        context 'timeSignatureFraction fraction)
  80                      (ly:context-set-property!
  81                        context 'baseMoment (fraction->moment my-base-fraction))
  82                      (ly:context-set-property!
  83                        context 'beatStructure my-beat-structure)
  84                      (ly:context-set-property!
  85                        context 'beamExceptions beaming-exception)
  86                      (ly:context-set-property!
  87                        context 'measureLength new-measure-length))))
  88                 'Timing)
  89             'Score))))