Class: Deftones::Music::Time

Inherits:
Object
  • Object
show all
Defined in:
lib/deftones/music/time.rb

Constant Summary collapse

SYMBOL_MAP = 
{
  whole: "1n",
  half: "2n",
  quarter: "4n",
  eighth: "8n",
  sixteenth: "16n",
  quarter_triplet: "4t",
  eighth_triplet: "8t",
  dotted_quarter: "4n.",
  dotted_eighth: "8n.",
  measure: "1m"
}.freeze

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(value, transport: Deftones.transport) ⇒ Time

Returns a new instance of Time.



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# File 'lib/deftones/music/time.rb', line 8

def initialize(value, transport: Deftones.transport)
  @value = value
  @transport = transport
  @disposed = false
end

Instance Attribute Details

#transport ⇒ Object (readonly)

Returns the value of attribute transport.



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# File 'lib/deftones/music/time.rb', line 6

def transport
  @transport
end

#value ⇒ Object (readonly)

Returns the value of attribute value.



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# File 'lib/deftones/music/time.rb', line 6

def value
  @value
end

Class Method Details

.arithmetic_expression?(value) ⇒ Boolean (private)

Returns:

  • (Boolean) 


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# File 'lib/deftones/music/time.rb', line 149

def arithmetic_expression?(value)
  value.match?(/[+\-*\/()]/) && !value.match?(/\A-?\d+(?:\.\d+)?\z/)
end

.beat_duration(bpm) ⇒ Object (private) 



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# File 'lib/deftones/music/time.rb', line 153

def beat_duration(bpm)
  60.0 / bpm.to_f
end

.compute_rpn(tokens, bpm:, time_signature:, ppq:) ⇒ Object (private)

Raises:



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# File 'lib/deftones/music/time.rb', line 204

def compute_rpn(tokens, bpm:, time_signature:, ppq:)
  stack = []

  tokens.each do |token|
    if operator?(token)
      raise Deftones::InvalidTimeError, "Invalid time expression" if stack.length < 2

      right = stack.pop
      left = stack.pop
      stack << left.public_send(token, right)
    else
      stack << parse_literal(token, bpm: bpm, time_signature: time_signature, ppq: ppq)
    end
  end

  raise Deftones::InvalidTimeError, "Invalid time expression" unless stack.length == 1

  stack.first
end

.evaluate_expression(value, bpm:, time_signature:, ppq:) ⇒ Object (private) 



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# File 'lib/deftones/music/time.rb', line 157

def evaluate_expression(value, bpm:, time_signature:, ppq:)
  compute_rpn(to_rpn(tokenize(value)), bpm: bpm, time_signature: time_signature, ppq: ppq)
end

.normalize_unary_minus(tokens) ⇒ Object (private) 



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# File 'lib/deftones/music/time.rb', line 224

def normalize_unary_minus(tokens)
  normalized = []

  tokens.each_with_index do |token, index|
    if token == "-" && (index.zero? || operator?(tokens[index - 1]) || tokens[index - 1] == "(")
      normalized << "0"
    end
    normalized << token
  end

  normalized
end

.operator?(token) ⇒ Boolean (private)

Returns:

  • (Boolean) 


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# File 'lib/deftones/music/time.rb', line 237

def operator?(token)
  %w[+ - * /].include?(token)
end

.parse(value, bpm: Deftones.transport.bpm, time_signature: Deftones.transport.time_signature, ppq: Deftones.transport.ppq) ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 93

def parse(value, bpm: Deftones.transport.bpm, time_signature: Deftones.transport.time_signature,
          ppq: Deftones.transport.ppq)
  case value
  when Numeric
    value.to_f
  when Symbol
    parse(SYMBOL_MAP.fetch(value), bpm: bpm, time_signature: time_signature, ppq: ppq)
  when String
    return evaluate_expression(value, bpm: bpm, time_signature: time_signature, ppq: ppq) if arithmetic_expression?(value)

    parse_literal(value, bpm: bpm, time_signature: time_signature, ppq: ppq)
  when /\A(\d+)n\z/
    parse_literal(value, bpm: bpm, time_signature: time_signature, ppq: ppq)
  else
    return value.to_seconds if value.respond_to?(:to_seconds)
  end
rescue KeyError, ArgumentError => error
  raise error if error.is_a?(Deftones::InvalidTimeError)

  raise Deftones::InvalidTimeError, "Unknown time format: #{value}"
end

.parse_literal(value, bpm:, time_signature:, ppq:) ⇒ Object (private) 



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# File 'lib/deftones/music/time.rb', line 117

def parse_literal(value, bpm:, time_signature:, ppq:)
  case value
  when /\A(\d+)n\z/
    beats = 4.0 / Regexp.last_match(1).to_f
    beats * beat_duration(bpm)
  when /\A(\d+)t\z/
    beats = (4.0 / Regexp.last_match(1).to_f) * (2.0 / 3.0)
    beats * beat_duration(bpm)
  when /\A(\d+)n\.\z/
    parse("#{Regexp.last_match(1)}n", bpm: bpm, time_signature: time_signature, ppq: ppq) * 1.5
  when /\A(\d+)m\z/i
    measures = Regexp.last_match(1).to_f
    beats_per_measure = Array(time_signature).first || 4
    measures * beats_per_measure * beat_duration(bpm)
  when /\A(\d+):(\d+):(\d+)\z/
    bars = Regexp.last_match(1).to_f
    beats = Regexp.last_match(2).to_f
    sixteenths = Regexp.last_match(3).to_f
    beats_per_measure = Array(time_signature).first || 4
    ((bars * beats_per_measure) + beats + (sixteenths * 0.25)) * beat_duration(bpm)
  when /\A(\d+(?:\.\d+)?)hz\z/i
    frequency = Regexp.last_match(1).to_f
    raise Deftones::InvalidTimeError, "Hz time values must be positive" unless frequency.positive?

    1.0 / frequency
  when /\A(-?\d+(?:\.\d+)?)i\z/i
    (Regexp.last_match(1).to_f / ppq.to_f) * beat_duration(bpm)
  else
    Float(value)
  end
end

.precedence(token) ⇒ Object (private) 



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# File 'lib/deftones/music/time.rb', line 241

def precedence(token)
  %w[* /].include?(token) ? 2 : 1
end

.to_rpn(tokens) ⇒ Object (private)

Raises:



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# File 'lib/deftones/music/time.rb', line 177

def to_rpn(tokens)
  output = []
  operators = []

  tokens.each do |token|
    if operator?(token)
      while operators.any? && operator?(operators.last) && precedence(operators.last) >= precedence(token)
        output << operators.pop
      end
      operators << token
    elsif token == "("
      operators << token
    elsif token == ")"
      raise Deftones::InvalidTimeError, "Mismatched parentheses" unless operators.include?("(")

      output << operators.pop until operators.last == "("
      operators.pop
    else
      output << token
    end
  end

  raise Deftones::InvalidTimeError, "Mismatched parentheses" if operators.any? { |operator| ["(", ")"].include?(operator) }

  output.concat(operators.reverse)
end

.tokenize(expression) ⇒ Object (private) 



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# File 'lib/deftones/music/time.rb', line 161

def tokenize(expression)
  tokens = []
  offset = 0
  pattern = /\G\s*(\d+:\d+:\d+|\d+(?:\.\d+)?hz|-?\d+(?:\.\d+)?i|\d+n\.?|\d+t|\d+m|[()+\-*\/]|-?\d+(?:\.\d+)?)/

  while offset < expression.length
    match = expression.match(pattern, offset)
    raise Deftones::InvalidTimeError, "Invalid time expression: #{expression}" unless match

    tokens << match[1]
    offset = match.end(0)
  end

  normalize_unary_minus(tokens)
end

Instance Method Details

#dispose ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 60

def dispose
  @disposed = true
  self
end

#disposed? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/deftones/music/time.rb', line 65

def disposed?
  @disposed
end

#from_type(type) ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 55

def from_type(type)
  @value = type.respond_to?(:value_of) ? type.value_of : type
  self
end

#quantize(subdiv, percent = 1.0) ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 51

def quantize(subdiv, percent = 1.0)
  UnitHelpers.quantize_seconds(to_seconds, subdiv, transport: transport, percent: percent)
end

#to_bars_beats_sixteenths ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 27

def to_bars_beats_sixteenths
  transport.seconds_to_position(to_seconds)
end

#to_frequency ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 31

def to_frequency
  1.0 / [to_seconds, 1.0e-6].max
end

#to_midi ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 35

def to_midi
  Note.to_midi(Note.from_frequency(to_frequency))
end

#to_milliseconds ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 39

def to_milliseconds
  to_seconds * 1000.0
end

#to_notation ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 47

def to_notation
  UnitHelpers.closest_notation(to_seconds, transport: transport)
end

#to_s ⇒ Object Also known as: toString 



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# File 'lib/deftones/music/time.rb', line 69

def to_s
  value.to_s
end

#to_samples(sample_rate = Deftones.context.sample_rate) ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 43

def to_samples(sample_rate = Deftones.context.sample_rate)
  UnitHelpers.samples_for_seconds(to_seconds, sample_rate)
end

#to_seconds ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 14

def to_seconds
  self.class.parse(
    value,
    bpm: transport.bpm,
    time_signature: transport.time_signature,
    ppq: transport.ppq
  )
end

#to_ticks ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 23

def to_ticks
  transport.seconds_to_ticks(to_seconds)
end

#value_of ⇒ Object 



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# File 'lib/deftones/music/time.rb', line 75

def value_of
  to_seconds
end