Class: Interval::Pitch

Inherits:
Object
  • Object
show all
Defined in:
lib/interval.rb

Constant Summary collapse

NOTE_NAMES = 
%w{c d e f g a b}
NOTE_NAMES_TO_I = 
{'c' => 0, 'd' => 1, 'e' => 2, 'f' => 3, 'g' => 4, 'a' => 5, 'b' => 6}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#accidental ⇒ Object

Returns the value of attribute accidental.



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# File 'lib/interval.rb', line 14

def accidental
  @accidental
end

#notename_i ⇒ Object

Returns the value of attribute notename_i.



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# File 'lib/interval.rb', line 13

def notename_i
  @notename_i
end

#octave ⇒ Object

Returns the value of attribute octave.



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# File 'lib/interval.rb', line 12

def octave
  @octave
end

Class Method Details

.accidental_name(i) ⇒ Object 



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# File 'lib/interval.rb', line 110

def accidental_name(i)
  names =
  { -2 => " double flat",
    -1 => " flat",
    0 => "",
    1 => " sharp",
    2 => " double sharp" }
  names[i]
end

.from_int(midiint) ⇒ Object 



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# File 'lib/interval.rb', line 37

def from_int(midiint)
  p = new
  p.octave = (midiint - 48) / 12
  p.notename_i = {0 => 0, 1 => 0, 
                2 => 1, 3 => 1, 
                4 => 2, 
                5 => 3, 6 => 3, 
                7 => 4, 8 => 4,
                9 => 5, 10 => 5, 
                11 => 6}[midiint % 12]
  p.accidental = midiint - (p.octave + 4) * 12 - ([0, 2, 4, 5, 7, 9, 11][p.notename_i])
  p
end

.from_string(str) ⇒ Object 



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# File 'lib/interval.rb', line 17

def from_string(str)
  p = new
  ary = str.split(//) 
  possible_notename = ary.shift.downcase
  raise "invalid notename: #{possible_notename}" unless Pitch::NOTE_NAMES_TO_I.has_key?(possible_notename)
  p.notename_i = note_s_to_i(possible_notename)

  octave = 0
  accidental = 0
  while(char = ary.shift)
    octave = octave + 1 if char == "'"
    octave = octave - 1 if char == ","
    accidental = accidental + 1 if char == "#"
    accidental = accidental - 1 if char == "b"
  end
  p.octave = octave
  p.accidental = accidental
  p
end

.note_s_to_i(s) ⇒ Object

end



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# File 'lib/interval.rb', line 106

def note_s_to_i(s)
  NOTE_NAMES_TO_I[s]
end

.notename_s(s) ⇒ Object 



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# File 'lib/interval.rb', line 51

def notename_s(s)
  NOTE_NAMES[s]
end

.random(normal = false) ⇒ Object

if normal=true then only return notes you would “normally” see. what is the word for that, natural?



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# File 'lib/interval.rb', line 57

def random(normal=false)
  p = new
  p.notename_i = NOTE_NAMES_TO_I.values.rand
  p.octave = 0

  accidentals = []
  if normal
    accidentals = case p.notename
                  when 'c', 'f' 
                    [0, 1]
                  when 'e', 'b'
                    [-1, 0]
                  else [-1, 0, 1]
                  end
  else
    accidentals = [-1, 0, 1]
  end
  p.accidental = accidentals.rand
  p
end

Instance Method Details

#+(other) ⇒ Object 



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# File 'lib/interval.rb', line 148

def +(other)
  if other.kind_of?(Interval)
    plus_interval(other)
  else
    raise "todo"
  end
end

#-(other) ⇒ Object 



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# File 'lib/interval.rb', line 156

def -(other)
  if other.kind_of?(Interval)
    minus_interval(other)
  else
    raise "todo"
  end
end

#notename ⇒ Object

def notename_i=(i) end



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# File 'lib/interval.rb', line 132

def notename
  self.class.notename_s(notename_i)
end

#semitone_pitch ⇒ Object 



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# File 'lib/interval.rb', line 121

def semitone_pitch
  [0, 2, 4, 5, 7, 9, 11][notename_i] + accidental + (octave * 12) + 48
end

#to_long_name ⇒ Object 



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# File 'lib/interval.rb', line 136

def to_long_name
  "%s%s" % [notename.upcase, self.class.accidental_name(accidental)]
end

#to_s ⇒ Object 



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# File 'lib/interval.rb', line 144

def to_s
  to_short_name
end

#to_short_name ⇒ Object 



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# File 'lib/interval.rb', line 140

def to_short_name
  "%s%s" % [notename, accidental > 0 ? ('#' * accidental.abs) : ('b' * accidental.abs)]
end