Class: Musa::Transcriptors::FromGDV::ToMIDI::Mordent

Inherits:
Musa::Transcription::FeatureTranscriptor show all
Defined in:
lib/musa-dsl/transcription/from-gdv-to-midi.rb

Overview

Process: .mor

Instance Method Summary collapse

Methods inherited from Musa::Transcription::FeatureTranscriptor

#check

Constructor Details

#initialize(duration_factor: nil) ⇒ Mordent

Returns a new instance of Mordent.



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# File 'lib/musa-dsl/transcription/from-gdv-to-midi.rb', line 36

def initialize(duration_factor: nil)
  @duration_factor = duration_factor || 1/4r
end

Instance Method Details

#transcript(gdv, base_duration:, tick_duration:) ⇒ Object 



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# File 'lib/musa-dsl/transcription/from-gdv-to-midi.rb', line 40

def transcript(gdv, base_duration:, tick_duration:)
  mor = gdv.delete :mor

  if mor
    direction = :up

    check(mor) do |mor|
      case mor
      when true, :up
        direction = :up
      when :down, :low
        direction = :down
      end
    end

    short_duration = [base_duration * @duration_factor, tick_duration].max

    gdvs = []

    gdvs << gdv.clone.tap { |gdv| gdv[:duration] = short_duration }

    case direction
    when :up
      gdvs << gdv.clone.tap { |gdv| gdv[:grade] += 1; gdv[:duration] = short_duration }
    when :down
      gdvs << gdv.clone.tap { |gdv| gdv[:grade] -= 1; gdv[:duration] = short_duration }
    end

    gdvs << gdv.clone.tap { |gdv| gdv[:duration] -= 2 * short_duration }

    super gdvs, base_duration: base_duration, tick_duration: tick_duration
  else
    super
  end
end