Class: Musicality::PortamentoConverter

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

Class Method Summary collapse

Class Method Details

.portamento_elements(start_pitch, target_pitch, cents_per_step, duration, attack) ⇒ Object 



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# File 'lib/musicality/performance/conversion/portamento_converter.rb', line 15

def self.portamento_elements(start_pitch, target_pitch, cents_per_step, duration, attack)
  pitches = portamento_pitches(start_pitch, target_pitch, cents_per_step)
  subdur = Rational(duration, pitches.size)
  first = true
  pitches.map do |pitch|
    el = NoteSequence::Element.new(subdur, pitch, first ? attack : Attack::NONE)
    first = false
    el
  end
end

.portamento_pitches(start_pitch, target_pitch, cents_per_step) ⇒ Object 



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# File 'lib/musicality/performance/conversion/portamento_converter.rb', line 4

def self.portamento_pitches(start_pitch, target_pitch, cents_per_step)
  start, finish = start_pitch.total_cents, target_pitch.total_cents
  step_size = finish >= start ? cents_per_step : -cents_per_step
  nsteps = ((finish - 1 - start) / step_size.to_f).ceil
  cents = Array.new(nsteps+1){|i| start + i * step_size }
  
  cents.map do |cent|
    Pitch.new(cent: cent)
  end
end