class Musicality::DrumMachine

Public Class Methods

new(drum_patterns) click to toggle source
Calls superclass method
# File lib/musicality/composition/sequencing/drum_machine/drum_machine.rb, line 4
def initialize drum_patterns
  raise ArgumentError if drum_patterns.empty?

  prev_durations = []
  existing_part_notes = {}
  drum_patterns.each do |drum_pattern|
    durations = drum_pattern.part_notes.values.map do |notes|
      notes.inject(0) {|sum, note| sum + note.duration }
    end
    if durations.uniq.size != 1
      raise ArgumentError, "Drum pattern has part notes of differing total duration #{drum_pattern}"
    end
    duration = durations.first
    if duration <= 0
      raise ArgumentError, "Drum pattern has non-positive part notes"
    end

    drum_pattern.part_notes.each do |part_name, notes|
      # Create part with rest notes from all the previous patterns durations
      unless existing_part_notes.has_key?(part_name)
        existing_part_notes[part_name] = prev_durations.map { |d| Note.new(d) }
      end

      existing_part_notes[part_name] += notes
    end

    # For parts that exist previously but not in the current drum pattern, add a rest note
    existing_part_notes.each do |part_name, notes|
      unless drum_pattern.part_notes.has_key?(part_name)
        existing_part_notes[part_name].push Note.new(duration)
      end
    end

    prev_durations.push duration
  end

  part_sequenceables = Hash[ existing_part_notes.map do |part_name, note_array|
    [ part_name, NoteArray.new(note_array) ]
  end]

  super(part_sequenceables)
end

Public Instance Methods

make_empty_parts(drum_kit, part_dynamics = {}) click to toggle source
# File lib/musicality/composition/sequencing/drum_machine/drum_machine.rb, line 47
def make_empty_parts drum_kit, part_dynamics = {}
  Hash[ part_names.map do |part_name|
    unless drum_kit.part_settings.has_key?(part_name)
      raise ArgumentError, "Drum kit does not have settings for part: #{part_name}"
    end
    part_dynamic = part_dynamics.has_key?(part_name) ? part_dynamics[part_name] : Dynamics::MF
    part = Part.new(part_dynamic, settings: [drum_kit.part_settings[part_name]])
    [ part_name, part ]
  end]
end