Class: Music::Performance::PartSequencer

Inherits:
Object
  • Object
show all
Defined in:
lib/music-performance/arrangement/midi/part_sequencer.rb

Instance Method Summary collapse

Constructor Details

#initialize(part, dynamics_sample_rate: 50, cents_per_step: 10) ⇒ PartSequencer

Returns a new instance of PartSequencer.



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# File 'lib/music-performance/arrangement/midi/part_sequencer.rb', line 5

def initialize part, dynamics_sample_rate: 50, cents_per_step: 10
  replace_portamento_with_glissando(part.notes)
  
  extractor = NoteSequenceExtractor.new(part.notes, cents_per_step)
  note_sequences = extractor.extract_sequences
  note_events = gather_note_events(note_sequences)
  
  dynamic_events = gather_dynamic_events(part.start_dynamic,
    part.dynamic_changes, dynamics_sample_rate)
  
  @events = (note_events + dynamic_events).sort
end

Instance Method Details

#make_midi_track(midi_sequence, part_name, channel, ppqn, program) ⇒ Object 



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# File 'lib/music-performance/arrangement/midi/part_sequencer.rb', line 18

def make_midi_track midi_sequence, part_name, channel, ppqn, program
  track = begin_track(midi_sequence, part_name, channel, program)
  
  prev_offset = 0
  @events.each do |offset, event|
    if offset == prev_offset
      delta = 0
    else
      delta = MidiUtil.delta(offset - prev_offset, ppqn)
    end
    
    track.events << case event
    when MidiEvent::NoteOn
      vel = MidiUtil.note_velocity(event.accented)
      MIDI::NoteOn.new(channel, event.notenum, vel, delta)
    when MidiEvent::NoteOff
      MIDI::NoteOff.new(channel, event.notenum, 127, delta)
    when MidiEvent::Expression
      MIDI::Controller.new(channel, MIDI::CC_EXPRESSION_CONTROLLER, event.volume, delta)
    end
    
    prev_offset = offset
  end
 return track
end