Sha256: 89928c0305ae68d729d3062fda871e5c085287d8a8702cf0214e16c2f25b7038
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Size: 1.56 KB
Versions: 16
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Stored size: 1.56 KB
Contents
class HeadMusic::KeySignature
attr_reader :tonic_spelling
attr_reader :scale_type
attr_reader :scale
SHARPS = %w{F# C# G# D# A# E# B#}
FLATS = %w{Bb Eb Ab Db Gb Cb Fb}
def self.default
@default ||= new('C', :major)
end
def self.get(identifier)
return identifier if identifier.is_a?(HeadMusic::KeySignature)
@key_signatures ||= {}
tonic_spelling, scale_type_name = identifier.strip.split(/\s/)
hash_key = HeadMusic::Utilities::HashKey.for(identifier)
@key_signatures[hash_key] ||= new(tonic_spelling, scale_type_name)
end
delegate :pitch_class, to: :tonic_spelling, prefix: :tonic
delegate :to_s, to: :name
delegate :pitches, to: :scale
def initialize(tonic_spelling, scale_type = nil)
@tonic_spelling = HeadMusic::Spelling.get(tonic_spelling)
@scale_type = HeadMusic::ScaleType.get(scale_type) if scale_type
@scale_type ||= HeadMusic::ScaleType.default
@scale_type = @scale_type.parent || @scale_type
@scale = HeadMusic::Scale.get(@tonic_spelling, @scale_type)
end
def spellings
pitches.map(&:spelling).uniq
end
def sharps
spellings.select(&:sharp?).sort_by { |sharp| SHARPS.index(sharp.to_s) }
end
def flats
spellings.select(&:flat?).sort_by { |flat| FLATS.index(flat.to_s) }
end
def num_sharps
sharps.length
end
def num_flats
flats.length
end
def sharps_or_flats
flats.length > 0 ? flats : sharps
end
def name
[tonic_spelling.to_s, scale_type.to_s].join(' ')
end
def ==(other)
self.sharps_or_flats == self.class.get(other).sharps_or_flats
end
end
Version data entries
16 entries across 16 versions & 1 rubygems