Class: SynthBlocks::Drum::SnareDrum

Inherits:
Core::Sound show all
Defined in:
lib/synth_blocks/drum/snare_drum.rb

Overview

Simple snare drum generator

Instance Attribute Summary

Attributes inherited from Core::Sound

#mode

Instance Method Summary collapse

Methods inherited from Core::Sound

#active_events, #get, #live_params, #release, #set

Constructor Details

#initialize(sfreq, preset = {}) ⇒ SnareDrum

Parameters

flt_frequency

Noise filter frequency

flt_envmod

Noise filter frequency modulation by envelope

flt_attack, flt_decay

Noise filter envelope params

flt_Q

Noise filter Q/resonance

noise_amp_attack, noise_amp_decay

Noise amp envelope params

noise_vol, drum_vol

Noise and Drum body volumes

base_frequency

Drum body base frequency (see KickDrum#initialize)

pitch_mod

Drum body pitch mod (see KickDrum#initialize)

pitch_attack, pitch_decay

Drum body pitch env params



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# File 'lib/synth_blocks/drum/snare_drum.rb', line 23

def initialize(sfreq, preset = {})
  super(sfreq, mode: :polyphonic)
  @preset = {
    flt_attack: 0.001,
    noise_amp_attack: 0.001,
    noise_vol: 0.5,
    drum_vol: 0.3,

    base_frequency: 110,
    pitch_mod: 440,
    pitch_decay: 0.03,
    amp_decay: 0.15,
    flt_Q: 1.1,
    flt_envmod: 2000,
    flt_frequency: 7000,
    flt_decay: 0.1,
    noise_amp_decay: 0.2
  }.merge(preset)
  @drum = SynthBlocks::Drum::KickDrum.new(sfreq, @preset)
  @filter = SynthBlocks::Core::StateVariableFilter.new(sfreq)
  @flt_env = SynthBlocks::Mod::Envelope.new(@preset[:flt_attack], @preset[:flt_decay])
  @amp_env = SynthBlocks::Mod::Envelope.new(@preset[:noise_amp_attack], @preset[:noise_amp_decay])
end

Instance Method Details

#duration(t) ⇒ Object

:nodoc:



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# File 'lib/synth_blocks/drum/snare_drum.rb', line 64

def duration(t) # :nodoc:
  [@preset[:noise_amp_attack] + @preset[:noise_amp_decay], @drum.duration(t)].max
end

#run(offset) ⇒ Object

run the generator



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# File 'lib/synth_blocks/drum/snare_drum.rb', line 69

def run(offset)
  drum_out = @drum.run(offset)
  # time in seconds
  t = time(offset)
  events = active_events(t)
  if events.empty?
    0.0
  else
    event = events[events.keys.last]
    # lfo_out = (@lfo.run(@preset[:lfo_frequency], waveform: @preset[:lfo_waveform]) + 1) / 8 + 0.5
    noise_out = rand * 2.0 - 1.0
    local_started = t - event[:started]
    noise_out = @filter.run(noise_out, @preset[:flt_frequency] + @flt_env.run(local_started) * @preset[:flt_envmod], @preset[:flt_Q])
    noise_out = 0.3 * noise_out * @amp_env.run(local_started)
    noise_out * @preset[:noise_vol] + drum_out * @preset[:drum_vol]
  end
end

#start(t, note = 36, velocity = 1.0) ⇒ Object

create a note on event

t

time in seconds since song start

note

MIDI note number

velocity

velocity (currently unused)



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# File 'lib/synth_blocks/drum/snare_drum.rb', line 51

def start(t, note = 36, velocity = 1.0)
  super(t, note, velocity)
  @drum.start(t, note, velocity)
end

#stop(t, note = 36) ⇒ Object

create a note off event

t

time in seconds since song start

note

MIDI note number



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# File 'lib/synth_blocks/drum/snare_drum.rb', line 59

def stop(t, note = 36)
  super(t, note)
  @drum.stop(t, note)
end