Contents

class HeadMusic::RhythmicUnit
  include HeadMusic::NamedRudiment

  MULTIPLES = ['whole', 'double whole', 'longa', 'maxima']
  FRACTIONS = ['whole', 'half', 'quarter', 'eighth', 'sixteenth', 'thirty-second', 'sixty-fourth', 'hundred twenty-eighth', 'two hundred fifty-sixth']

  BRITISH_MULTIPLE_NAMES = %w[semibreve breve longa maxima]
  BRITISH_DIVISION_NAMES = %w[semibreve minim crotchet quaver semiquaver demisemiquaver hemidemisemiquaver semihemidemisemiquaver demisemihemidemisemiquaver]

  def self.for_denominator_value(denominator)
    get(FRACTIONS[Math.log2(denominator).to_i])
  end

  attr_reader :numerator, :denominator

  def self.get(name)
    get_by_name(name)
  end

  def initialize(canonical_name)
    @name ||= canonical_name
    @numerator = 2**numerator_exponent
    @denominator = 2**denominator_exponent
  end

  def relative_value
    @numerator.to_f / @denominator
  end

  def ticks
    HeadMusic::Rhythm::PPQN * 4 * relative_value
  end

  def notehead
    case relative_value
    when 8
      :maxima
    when 4
      :longa
    when 2
      :breve
    when 0.5, 1
      :open
    else
      :closed
    end
  end

  def flags
    FRACTIONS.include?(name) ? [FRACTIONS.index(name) - 2, 0].max : 0
  end

  def has_stem?
    relative_value < 1
  end

  def british_name
    if MULTIPLES.include?(name)
      BRITISH_MULTIPLE_NAMES[MULTIPLES.index(name)]
    elsif FRACTIONS.include?(name)
      BRITISH_DIVISION_NAMES[FRACTIONS.index(name)]
    elsif BRITISH_MULTIPLE_NAMES.include?(name) || BRITISH_DIVISION_NAMES.include?(name)
      name
    end
  end

  private_class_method :new

  private

  def numerator_exponent
    MULTIPLES.index(name) || BRITISH_MULTIPLE_NAMES.index(name) || 0
  end

  def denominator_exponent
    FRACTIONS.index(name) || BRITISH_DIVISION_NAMES.index(name) || 0
  end
end

Version data entries

10 entries across 10 versions & 1 rubygems

Version	Path
head_music-0.17.0	lib/head_music/rhythmic_unit.rb
head_music-0.16.2	lib/head_music/rhythmic_unit.rb
head_music-0.16.0	lib/head_music/rhythmic_unit.rb
head_music-0.14.8	lib/head_music/rhythmic_unit.rb
head_music-0.14.7	lib/head_music/rhythmic_unit.rb
head_music-0.14.5	lib/head_music/rhythmic_unit.rb
head_music-0.14.4	lib/head_music/rhythmic_unit.rb
head_music-0.14.2	lib/head_music/rhythmic_unit.rb
head_music-0.14.1	lib/head_music/rhythmic_unit.rb
head_music-0.13.2	lib/head_music/rhythmic_unit.rb