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Contents
# frozen_string_literal: true
# A pitch class is a set of pitches separated by octaves.
class HeadMusic::PitchClass
include Comparable
attr_reader :number
attr_reader :spelling
SHARP_SPELLINGS = %w[C C♯ D D♯ E F F♯ G G♯ A A♯ B].freeze
FLAT_SPELLINGS = %w[C D♭ D E♭ E F G♭ G A♭ A B♭ B].freeze
INTEGER_NOTATION = %w[0 1 2 3 4 5 6 7 8 9 t e].freeze
def self.get(identifier)
@pitch_classes ||= {}
if HeadMusic::Spelling.matching_string(identifier)
spelling = HeadMusic::Spelling.get(identifier)
number = spelling.pitch_class.to_i
end
number ||= identifier.to_i % 12
@pitch_classes[number] ||= new(number)
end
class << self
alias [] get
end
def initialize(pitch_class_or_midi_number)
@number = pitch_class_or_midi_number.to_i % 12
end
def to_i
number
end
def to_integer_notation
INTEGER_NOTATION[number]
end
def sharp_spelling
SHARP_SPELLINGS[number]
end
def flat_spelling
FLAT_SPELLINGS[number]
end
# Pass in the number of semitones
def +(other)
HeadMusic::PitchClass.get(to_i + other.to_i)
end
# Pass in the number of semitones
def -(other)
HeadMusic::PitchClass.get(to_i - other.to_i)
end
def ==(other)
to_i == other.to_i
end
alias enharmonic? ==
def <=>(other)
to_i <=> other.to_i
end
def intervals_to(other)
delta = other.to_i - to_i
inverse = delta.positive? ? delta - 12 : delta + 12
[delta, inverse].sort_by(&:abs).map { |interval| HeadMusic::ChromaticInterval.get(interval) }
end
def smallest_interval_to(other)
intervals_to(other).first
end
def white_key?
[0, 2, 4, 5, 7, 9, 11].include?(number)
end
def black_key?
!white_key?
end
private_class_method :new
end
Version data entries
12 entries across 12 versions & 1 rubygems