class PDF::Reader::WidthCalculator::BuiltIn

# File lib/pdf/reader/width_calculator/built_in.rb, line 23
def initialize(font)
  @font = font
  @@all_metrics ||= PDF::Reader::SynchronizedCache.new

  basefont = extract_basefont(font.basefont)
  metrics_path = File.join(File.dirname(__FILE__), "..","afm","#{basefont}.afm")

  if File.file?(metrics_path)
    @metrics = @@all_metrics[metrics_path] ||= AFM::Font.new(metrics_path)
  else
    raise ArgumentError, "No built-in metrics for #{font.basefont}"
  end
end

# File lib/pdf/reader/width_calculator/built_in.rb, line 37
def glyph_width(code_point)
  return 0 if code_point.nil? || code_point < 0

  m = @metrics.char_metrics_by_code[code_point]
  if m.nil?
    names = @font.encoding.int_to_name(code_point)

    m = names.map { |name|
      @metrics.char_metrics[name.to_s]
    }.compact.first
  end

  if m
    m[:wx]
  elsif @font.widths[code_point - 1]
    @font.widths[code_point - 1]
  elsif control_character?(code_point)
    0
  else
    0
  end
end

# File lib/pdf/reader/width_calculator/built_in.rb, line 62
def control_character?(code_point)
  @font.encoding.int_to_name(code_point).first.to_s[/\Acontrol..\Z/]
end

# File lib/pdf/reader/width_calculator/built_in.rb, line 66
def extract_basefont(font_name)
  if BUILTINS.include?(font_name)
    font_name
  else
    "Times-Roman"
  end
end