Class: Synthesizer::Modulation::Adsr

Inherits:
Object
  • Object
show all
Defined in:
lib/synthesizer/modulation/adsr.rb

Instance Method Summary collapse

Constructor Details

#initialize(attack:, attack_curve: Curve::EaseOut, hold: 0.0, decay:, sustain_curve: Curve::EaseOut, sustain:, release:, release_curve: Curve::EaseOut) ⇒ Adsr

Returns a new instance of Adsr.

Parameters:

  • attack (AudioStream::Rate | Float) —

    attack sec (0.0~)

  • attack_curve (Synthesizer::Curve) (defaults to: Curve::EaseOut)
  • hold (AudioStream::Rate | Float) (defaults to: 0.0) —

    hold sec (0.0~)

  • decay (AudioStream::Rate | Float) —

    decay sec (0.0~)

  • sustain_curve (Synthesizer::Curve) (defaults to: Curve::EaseOut)
  • sustain (Float) —

    sustain level (0.0~1.0)

  • release (AudioStream::Rate | Float) —

    release sec (0.0~)

  • release_curve (Synthesizer::Curve) (defaults to: Curve::EaseOut) 


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# File 'lib/synthesizer/modulation/adsr.rb', line 13

def initialize(attack:, attack_curve: Curve::EaseOut, hold: 0.0, decay:, sustain_curve: Curve::EaseOut, sustain:, release:, release_curve: Curve::EaseOut)
  @attack = AudioStream::Rate.sec(attack)
  @attack_curve = attack_curve
  @hold = AudioStream::Rate.sec(hold)
  @decay = AudioStream::Rate.sec(decay)
  @sustain_curve = sustain_curve
  @sustain = sustain
  @release = AudioStream::Rate.sec(release)
  @release_curve = release_curve
end

Instance Method Details

#amp_generator(note_perform, samplecount, depth, &block) ⇒ Object 



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# File 'lib/synthesizer/modulation/adsr.rb', line 92

def amp_generator(note_perform, samplecount, depth, &block)
  bottom = 1.0 - depth
  gen = generator(note_perform, samplecount, release_sustain: 0.0<bottom)

  -> {
    gen[] * depth + bottom
  }
end

#balance_generator(note_perform, samplecount, depth, &block) ⇒ Object 



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# File 'lib/synthesizer/modulation/adsr.rb', line 101

def balance_generator(note_perform, samplecount, depth, &block)
  gen = generator(note_perform, samplecount, release_sustain: true)

  -> {
    gen[] * depth
  }
end

#generator(note_perform, samplecount, release_sustain:) ⇒ Object 



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# File 'lib/synthesizer/modulation/adsr.rb', line 75

def generator(note_perform, samplecount, release_sustain:)
  soundinfo = note_perform.synth.soundinfo

  note_on = note_on_envelope(soundinfo, samplecount, sustain: true)
  note_off = note_off_envelope(soundinfo, samplecount, sustain: release_sustain)
  last = 0.0

  -> {
    if note_perform.note_on?
      last = note_on.next
    else
      note_off.next * last
    end
  }
end

#note_off_envelope(soundinfo, samplecount, sustain: false, &block) ⇒ Object 



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# File 'lib/synthesizer/modulation/adsr.rb', line 56

def note_off_envelope(soundinfo, samplecount, sustain: false, &block)
  Enumerator.new do |yld|
    # release
    release_len = (@release.sample(soundinfo) / samplecount).to_i
    release_len.times {|i|
      x = i.to_f / release_len
      y = 1.0 - @release_curve[x]
      yld << y
    }

    # sustain
    if sustain
      loop {
        yld << 0.0
      }
    end
  end.each(&block)
end

#note_on_envelope(soundinfo, samplecount, sustain: false, &block) ⇒ Object 



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# File 'lib/synthesizer/modulation/adsr.rb', line 24

def note_on_envelope(soundinfo, samplecount, sustain: false, &block)
  Enumerator.new do |yld|
    # attack
    attack_len = (@attack.sample(soundinfo) / samplecount).to_i
    attack_len.times {|i|
      x = i.to_f / attack_len
      y = @attack_curve[x]
      yld << y
    }

    # hold
    (@hold.sample(soundinfo) / samplecount).to_i.times {|i|
      yld << 1.0
    }

    # decay
    decay_len = (@decay.sample(soundinfo) / samplecount).to_i
    decay_len.times {|i|
      x = i.to_f / decay_len
      y = 1.0 - @sustain_curve[x] * (1.0 - @sustain)
      yld << y
    }

    # sustain
    if sustain
      loop {
        yld << @sustain
      }
    end
  end.each(&block)
end

#plot(soundinfo) ⇒ Object 



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# File 'lib/synthesizer/modulation/adsr.rb', line 132

def plot(soundinfo)
  data = plot_data(soundinfo)
  Plotly::Plot.new(data: [data])
end

#plot_data(soundinfo) ⇒ Object 



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# File 'lib/synthesizer/modulation/adsr.rb', line 109

def plot_data(soundinfo)
  samplecount = soundinfo.window_size.to_f
  note_on = note_on_envelope(soundinfo, samplecount, sustain: false)
  note_off = note_off_envelope(soundinfo, samplecount, sustain: false)
  last = 0.0

  xs = []
  ys = []

  note_on.each {|y|
    xs << xs.length
    ys << y
  }

  last = ys.last || 0.0
  note_off.each {|y|
    xs << xs.length
    ys << y * last
  }

  {x: xs, y: ys}
end