Class: HeadMusic::Notation::MusicXML::ClefSelector

Inherits:
Object
  • Object
show all
Defined in:
lib/head_music/notation/music_xml/clef_selector.rb

Overview

Chooses a clef for a voice based on the midpoint of its pitch range.

Constant Summary collapse

MIDDLE_C_MIDI_NOTE_NUMBER = 
60

Class Method Summary collapse

Class Method Details

.for(voice) ⇒ Object

Returns the treble clef for a voice with no notes (rest-only or empty), and otherwise the clef whose side of middle C matches the midpoint of the voice’s lowest and highest pitches. A midpoint exactly on middle C is treated as treble.



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# File 'lib/head_music/notation/music_xml/clef_selector.rb', line 11

def self.for(voice)
  return HeadMusic::Rudiment::Clef.get(:treble_clef) unless voice.lowest_pitch

  if midpoint(voice) < MIDDLE_C_MIDI_NOTE_NUMBER
    HeadMusic::Rudiment::Clef.get(:bass_clef)
  else
    HeadMusic::Rudiment::Clef.get(:treble_clef)
  end
end

.midpoint(voice) ⇒ Object (private) 



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# File 'lib/head_music/notation/music_xml/clef_selector.rb', line 21

def self.midpoint(voice)
  (voice.lowest_pitch.midi_note_number + voice.highest_pitch.midi_note_number) / 2.0
end