Class: SynthBlocks::Sequencer::SequencerDSL::Song

Inherits:
Object
  • Object
show all
Defined in:
lib/synth_blocks/sequencer/sequencer_dsl.rb

Overview

A

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(bpm, patterns) ⇒ Song

:nodoc:



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# File 'lib/synth_blocks/sequencer/sequencer_dsl.rb', line 123

def initialize(bpm, patterns) # :nodoc:
  @tempo = bpm
  @events = []
  @per_beat = 60.0 / @tempo.to_f
  @per_bar = @per_beat * 4.0
  @per_step = @per_beat / 4.0
  @patterns = patterns
  @latest_time = 0
end

Instance Attribute Details

#events ⇒ Object (readonly)

:nodoc:



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# File 'lib/synth_blocks/sequencer/sequencer_dsl.rb', line 122

def events
  @events
end

#per_bar ⇒ Object (readonly)

:nodoc:



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# File 'lib/synth_blocks/sequencer/sequencer_dsl.rb', line 122

def per_bar
  @per_bar
end

#per_beat ⇒ Object (readonly)

:nodoc:



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# File 'lib/synth_blocks/sequencer/sequencer_dsl.rb', line 122

def per_beat
  @per_beat
end

Instance Method Details

#length ⇒ Object

Returns the length of the song in seconds plus 2 seconds to allow for reverb tails etc.



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# File 'lib/synth_blocks/sequencer/sequencer_dsl.rb', line 169

def length
  (@latest_time + 2.0).ceil
end

#pattern(name, at: 0, repeat: 1, length: nil) ⇒ Object

inserts a pattern into the song

name

pattern needs to be defined by def_pattern

at

Position in bars to insert the pattern to

repeat

number of times the pattern should repeat

length

if you want to only use part of the pattern



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# File 'lib/synth_blocks/sequencer/sequencer_dsl.rb', line 145

def pattern(name, at: 0, repeat: 1, length: nil)
  p = @patterns[name]
  pattern_length = length || p.steps
  start = at.to_f * @per_bar

  p.sounds.each do |sound, events|
    repeat.times do |rep|

      events.each do |event|
        step, data = event
        next if step > pattern_length

        time = start + (rep.to_f * pattern_length.to_f * @per_step.to_f) + step.to_f * @per_step
        @latest_time =  time if time > @latest_time
        type, *rest = data
        @events << [sound, [type, time, *rest]]
      end
    end
  end
end

#play ⇒ Object

Sends all scheduled events to the instruments



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# File 'lib/synth_blocks/sequencer/sequencer_dsl.rb', line 175

def play
  @events.each do |event|
    instrument, data = event
    instrument.send(*data)
  end
end

#run(block) ⇒ Object

:nodoc:



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# File 'lib/synth_blocks/sequencer/sequencer_dsl.rb', line 133

def run(block) # :nodoc:
  instance_eval(&block)
end