Class: Musicality::PartSequencer

Inherits:
Object
  • Object
show all
Defined in:
lib/musicality/performance/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.



4
5
6
7
8
9
10
11
12
13
14
15
16
 
# File 'lib/musicality/performance/midi/part_sequencer.rb', line 4

def initialize part, dynamics_sample_rate: 50, cents_per_step: 10
  notes = part.notes.map {|n| n.clone }
  replace_portamento_with_glissando(notes)
  
  extractor = NoteSequenceExtractor.new(notes)
  note_sequences = extractor.extract_sequences(cents_per_step)
  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 



18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
 
# File 'lib/musicality/performance/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.attack)
      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