Module: Lydown::Rendering::Figures

Included in:
Notes
Defined in:
lib/lydown/rendering/figures.rb

Constant Summary collapse

BLANK_EXTENDER_START = 
'<->'
BLANK_EXTENDER_STOP = 
'<.>'
BLANK_EXTENDER = 
'<_>'
EXTENDERS_ON = 
"\\bassFigureExtendersOn "
EXTENDERS_OFF = 
"\\bassFigureExtendersOff "
ALTERATION_RE = 
/[#bh`']/
ALTERATION = 
{
  '#' => '_+',
  'b' => '_-',
  'h' => '_!',
  '`' => '\\\\',
  "'" => "/"
}
HIDDEN_FORMAT = 
"\\once \\override BassFigure #'implicit = ##t"

Instance Method Summary collapse

Instance Method Details

#add_figures(figures, value) ⇒ Object 



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# File 'lib/lydown/rendering/figures.rb', line 10

def add_figures(figures, value)
  # Add fill-in silences to catch up with music stream
  if @context['process/running_values']
    silence_figures = @event[:tenue] ?
      @context['process/last_figures'] :
      (@context['process/blank_extender_mode'] ? '<_>' : 's')
     
    @context['process/running_values'].each do |v|
      silence = silence_figures
      if v != @context['process/last_figures_value']
        silence = silence + v
        @context['process/last_figures_value'] = v
      end
      @context.emit(:figures, "#{silence} ")
    end
    @context['process/running_values'] = nil
  end

  figures = lilypond_figures(figures)
  if figures == BLANK_EXTENDER_START
    @context['process/blank_extender_mode'] = true
    figures = BLANK_EXTENDER
    @context.emit(:figures, EXTENDERS_ON)
  elsif figures == BLANK_EXTENDER_STOP
    @context['process/blank_extender_mode'] = false
    figures = BLANK_EXTENDER
    @event[:figure_extenders_off] = true
  else
    @context['process/last_figures'] = figures
  end
  
  if value != @context['process/last_figures_value']
    figures = figures + value
    @context['process/last_figures_value'] = value
  end

  @context.emit(:figures, "#{figures} ")
  @context.emit(:figures, EXTENDERS_ON) if @event[:figure_extenders_on]
  @context.emit(:figures, EXTENDERS_OFF) if @event[:figure_extenders_off]
end

#add_stand_alone_figures(figures) ⇒ Object 



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# File 'lib/lydown/rendering/figures.rb', line 51

def add_stand_alone_figures(figures)
  if @context['process/running_values']
    # for stand alone figures, we regard the stand alone figure as being
    # aligned to the last note. Therefore we pop its value from
    # running_values array.
    @context['process/running_values'].pop
  end
  value =  @context['process/figures_duration_value'] || @context['process/last_value']
  add_figures(figures, value)
end

#check_tenues(figures) ⇒ Object 



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# File 'lib/lydown/rendering/figures.rb', line 71

def check_tenues(figures)
  next_event = next_figures_event
  unless next_event
    # if next figures event is not found, check if there is a tenue, and
    # add extenders off flag
    @event[:figure_extenders_off] = @event[:tenue]
    return
  end

  if next_event[:figures]
    next_event[:tenue] = next_event[:figures].include?('_')
    if next_event[:tenue] && !@event[:tenue]
      @event[:figure_extenders_on] = true
    elsif !next_event[:tenue] && @event[:tenue]
      @event[:figure_extenders_off] = true
    end

    # transform underscores into figure components
    next_event[:figures].each_with_index do |component, idx|
      next_event[:figures][idx] = @event[:figures][idx] if component == '_'
    end
  end
end

#lilypond_figures(figures) ⇒ Object 



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# File 'lib/lydown/rendering/figures.rb', line 62

def lilypond_figures(figures)
  if figures
    check_tenues(figures)
    "<#{translate_figures(figures)}>"
  else
    "s"
  end
end

#next_figures_event ⇒ Object 



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# File 'lib/lydown/rendering/figures.rb', line 109

def next_figures_event
  idx = @idx + 1
  while idx < @stream.size
    event = @stream[idx]
    case event[:type]
    when :setting
      if ['part', 'movement'].include? event[:key]
        return nil
      end
    when :note
      return event if event[:figures]
    when :stand_alone_figures
      return event
    end
    idx += 1
  end
end

#translate_figures(figures) ⇒ Object 



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# File 'lib/lydown/rendering/figures.rb', line 95

def translate_figures(figures)
  figures.map {|n| n.gsub(ALTERATION_RE) {|a| ALTERATION[a]}}.join(' ')
end