Class: Ucode::Glyphs::EmbeddedFonts::CodepointMapper::ToUnicodeStrategy

Inherits:
Strategy
  • Object
show all
Defined in:
lib/ucode/glyphs/embedded_fonts/codepoint_mapper/tounicode_strategy.rb

Overview

Strategy 1 — read the Type0 font's /ToUnicode CMap stream and parse it into a {codepoint => gid} map. Highest fidelity when present; usually missing for subsetted CID fonts (the case the trace fallback exists for).

Instance Method Summary collapse

Methods inherited from Strategy

#positional?

Constructor Details

#initialize(source:, mutool_show:) ⇒ ToUnicodeStrategy

Returns a new instance of ToUnicodeStrategy.

Parameters:



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# File 'lib/ucode/glyphs/embedded_fonts/codepoint_mapper/tounicode_strategy.rb', line 18

def initialize(source:, mutool_show:)
  super()
  @source = source
  @mutool_show = mutool_show
end

Instance Method Details

#map(descriptor) ⇒ Object 



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# File 'lib/ucode/glyphs/embedded_fonts/codepoint_mapper/tounicode_strategy.rb', line 29

def map(descriptor)
  cmap_text = @mutool_show.stream(@source.pdf_to_s,
                                  descriptor.tounicode_ref)
  cid_to_cp = ToUnicode.parse(cmap_text)
  cid_to_cp.each_with_object({}) do |(cid, cp), h|
    h[cp] = cid
  end
end

#supports?(descriptor) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/ucode/glyphs/embedded_fonts/codepoint_mapper/tounicode_strategy.rb', line 24

def supports?(descriptor)
  descriptor.cid_map_kind == :identity &&
    !descriptor.tounicode_ref.nil?
end