class PDF::Reader::WidthCalculator::BuiltIn

Type1 fonts can be one of 14 “built in” standard fonts. In these cases, the reader is expected to have it’s own copy of the font metrics. see Section 9.6.2.2, PDF 32000-1:2008, pp 256

Constants

BUILTINS

Public Class Methods

new(font) click to toggle source
# File lib/pdf/reader/width_calculator/built_in.rb, line 24
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

Public Instance Methods

glyph_width(code_point) click to toggle source
# File lib/pdf/reader/width_calculator/built_in.rb, line 38
def glyph_width(code_point)
  return 0 if code_point.nil? || code_point < 0

  names = @font.encoding.int_to_name(code_point)
  metrics = names.map { |name|
    @metrics.char_metrics[name.to_s]
  }.compact.first

  if metrics
    metrics[:wx]
  else
    @font.widths[code_point - 1] || 0
  end
end

Private Instance Methods

control_character?(code_point) click to toggle source
# File lib/pdf/reader/width_calculator/built_in.rb, line 55
def control_character?(code_point)
  match = @font.encoding.int_to_name(code_point).first.to_s[/\Acontrol..\Z/]
  match ? true : false
end
extract_basefont(font_name) click to toggle source
# File lib/pdf/reader/width_calculator/built_in.rb, line 60
def extract_basefont(font_name)
  if BUILTINS.include?(font_name)
    font_name.to_s
  else
    "Times-Roman"
  end
end