Class: Deftones::Effects::Phaser

Inherits:
Core::Effect show all
Includes:
ModulationControl
Defined in:
lib/deftones/effect/phaser.rb

Instance Attribute Summary collapse

Attributes inherited from Core::Effect

#wet

Instance Method Summary collapse

Methods included from ModulationControl

#bipolar_modulation_value, #cancel_stop, #clear_modulation_event, #dispose, #initialize_modulation_control, #modulation_active_at?, #modulation_frequency, #modulation_phase_for, #modulation_sample_for, #modulation_type, #normalize_modulation_type, #resolve_modulation_time, #resolve_modulation_transport_time, #restart, #schedule_modulation_event, #start, #state, #stop, #sync, #synced?, #unipolar_modulation_value, #unsync

Methods inherited from Core::Effect

#multichannel_process?, #normalize_channel_output, #process, #process_effect

Constructor Details

#initialize(frequency: 0.5, octaves: 3.0, q: 0.8, base_frequency: 300.0, stages: 4, type: :sine, context: Deftones.context, **options) ⇒ Phaser

Returns a new instance of Phaser.



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# File 'lib/deftones/effect/phaser.rb', line 11

def initialize(
  frequency: 0.5,
  octaves: 3.0,
  q: 0.8,
  base_frequency: 300.0,
  stages: 4,
  type: :sine,
  context: Deftones.context,
  **options
)
  super(context: context, **options)
  @frequency = frequency.to_f
  @octaves = octaves.to_f
  @q = q.to_f
  @base_frequency = base_frequency.to_f
  @stages = stages.to_i
  @type = normalize_modulation_type(type)
  @phase = 0.0
  @filters = []
  initialize_modulation_control
end

Instance Attribute Details

#base_frequency ⇒ Object

Returns the value of attribute base_frequency.



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# File 'lib/deftones/effect/phaser.rb', line 8

def base_frequency
  @base_frequency
end

#frequency ⇒ Object

Returns the value of attribute frequency.



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# File 'lib/deftones/effect/phaser.rb', line 8

def frequency
  @frequency
end

#octaves ⇒ Object

Returns the value of attribute octaves.



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# File 'lib/deftones/effect/phaser.rb', line 8

def octaves
  @octaves
end

#q ⇒ Object

Returns the value of attribute q.



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# File 'lib/deftones/effect/phaser.rb', line 8

def q
  @q
end

#stages ⇒ Object

Returns the value of attribute stages.



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# File 'lib/deftones/effect/phaser.rb', line 9

def stages
  @stages
end

#type ⇒ Object

Returns the value of attribute type.



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# File 'lib/deftones/effect/phaser.rb', line 8

def type
  @type
end

Instance Method Details

#process_effect_block(input_block, num_frames, start_frame, _cache) ⇒ Object (private) 



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# File 'lib/deftones/effect/phaser.rb', line 39

def process_effect_block(input_block, num_frames, start_frame, _cache)
  filter_banks = stage_filters(input_block.channels)
  output = Array.new(input_block.channels) { Array.new(num_frames, 0.0) }

  num_frames.times do |index|
    current_time = (start_frame + index).to_f / context.sample_rate
    phase = modulation_phase_for(current_time)
    modulation = unipolar_modulation_value(phase, default: 0.5)
    input_block.channel_data.each_with_index do |channel, channel_index|
      output[channel_index][index] = filter_banks[channel_index].each_with_index.reduce(channel[index]) do |sample, (filter, stage_index)|
        stage_position = @stages == 1 ? 0.0 : (stage_index.to_f / (@stages - 1)) - 0.5
        cutoff = @base_frequency * (2.0**((modulation * @octaves) + (stage_position * 0.5)))
        filter.update(type: :notch, frequency: cutoff, q: @q, gain_db: 0.0, sample_rate: context.sample_rate)
        filter.process_sample(sample)
      end
    end
  end

  Core::AudioBlock.from_channel_data(output)
end

#stage_filters(channels) ⇒ Object (private) 



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# File 'lib/deftones/effect/phaser.rb', line 60

def stage_filters(channels)
  required_channels = [channels.to_i, 1].max
  while @filters.length < required_channels
    @filters << Array.new(@stages) { DSP::Biquad.new }
  end

  @filters.map! do |bank|
    bank.length == @stages ? bank : Array.new(@stages) { DSP::Biquad.new }
  end
  @filters
end