Class: PDF::Reader::WidthCalculator::BuiltIn

Inherits:
Object
  • Object
show all
Defined in:
lib/pdf/reader/width_calculator/built_in.rb

Overview

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

Instance Method Summary collapse

Constructor Details

#initialize(font) ⇒ BuiltIn

Returns a new instance of BuiltIn.



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# File 'lib/pdf/reader/width_calculator/built_in.rb', line 24

def initialize(font)
  @font = font
  @@all_metrics ||= PDF::Reader::SynchronizedCache.new

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

Instance Method Details

#glyph_height(code_point) ⇒ Object

TODO: no idea why my pdf is using a built-in font in vertical writing mode. Couldn’t find anything in the spec that described the desired behavior in this case.



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# File 'lib/pdf/reader/width_calculator/built_in.rb', line 52

def glyph_height(code_point)
  return 0
end

#glyph_width(code_point) ⇒ Object 



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# 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.metrics_for(code_point)
  if m.nil?
    name = @font.encoding.int_to_name(code_point)
    m = @metrics.metrics_for_name(name)
  end
  # assume that if the code point could not be found, then glyph width = 0
  m ? m[:wx] : 0
end