class Musicality::DrumPattern

Constants

DRUM_PART_PITCHES
DUMMY_PITCH

Attributes

duration[R]
part_notes[R]

Public Class Methods

apply_accents(notes, accent_offsets) click to toggle source
# File lib/musicality/composition/sequencing/drum_machine/drum_pattern.rb, line 54
def self.apply_accents notes, accent_offsets
  cum_dur = 0

  notes.each do |note|
    if note.pitches.any? && accent_offsets.include?(cum_dur)
      note.mark_accented!
    end
    cum_dur += note.duration
  end
end
determine_accent_offsets(accent_rhythm) click to toggle source
# File lib/musicality/composition/sequencing/drum_machine/drum_pattern.rb, line 40
def self.determine_accent_offsets accent_rhythm
  accent_offsets = []
  cum_dur = 0

  accent_rhythm.durations.each do |dur|
    if dur > 0
      accent_offsets.push cum_dur
    end
    cum_dur += dur
  end

  return accent_offsets
end
new(duration, part_portions) click to toggle source
# File lib/musicality/composition/sequencing/drum_machine/drum_pattern.rb, line 15
def initialize duration, part_portions
  @duration = duration

  non_drumpart_names = part_portions.select do |part_name|
    !DRUM_PARTS.include?(part_name)
  end
  if non_drumpart_names.any?
    raise ArgumentError, "Part names used that are not drum parts: #{non_drumpart_names.inspect}"
  end

  accent_offsets = if part_portions.has_key?(DrumParts::ACCENT)
    DrumPattern.determine_accent_offsets(
      part_portions.delete(DrumParts::ACCENT).to_rhythm_class.to_rhythm(duration))
  else
    []
  end

  @part_notes = Hash[ part_portions.map do |part_name, portions|
    pitch = DRUM_PART_PITCHES[part_name] || DUMMY_PITCH
    notes = portions.to_rhythm_class.to_rhythm(duration).to_notes(pitch)
    DrumPattern.apply_accents(notes, accent_offsets)
    [ part_name, notes ]
  end ]
end