Class: Fontisan::Type1Font

Inherits:
Object
  • Object
show all
Defined in:
lib/fontisan/type1_font.rb

Overview

Adobe Type 1 Font handler

Type1Font provides parsing and conversion capabilities for Adobe Type 1 fonts in PFB (Printer Font Binary) and PFA (Printer Font ASCII) formats.

Type 1 fonts were the standard for digital typography in the 1980s-1990s and consist of:

  • Font dictionary with metadata (FontInfo, FontName, Encoding, etc.)
  • Private dictionary with hinting and spacing information
  • CharStrings (glyph outline descriptions)
  • eexec encryption for protection

Examples:

Load a PFB file

font = Fontisan::Type1Font.from_file('font.pfb')
puts font.font_name
puts font.version

Load a PFA file

font = Fontisan::Type1Font.from_file('font.pfa')
puts font.full_name

Access decrypted font data

font = Fontisan::Type1Font.from_file('font.pfb')
puts font.decrypted_data

See Also:

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(data, container_format: nil, file_path: nil, mode: :full) ⇒ Type1Font

Initialize a new Type1Font instance

Parameters:

  • data (String) —

    Font file data (binary or text)

  • container_format (Symbol) (defaults to: nil) —

    Container variant (:pfb or :pfa, auto-detected if nil)

  • file_path (String, nil) (defaults to: nil) —

    Optional file path for reference

  • mode (Symbol) (defaults to: :full) —

    Loading mode (:metadata or :full, default: :full)



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# File 'lib/fontisan/type1_font.rb', line 99

def initialize(data, container_format: nil, file_path: nil, mode: :full)
  @file_path = file_path
  @container_format = container_format || detect_format(data)
  @data = data
  @loading_mode = mode

  parse_font_data
end

Instance Attribute Details

#container_format ⇒ Symbol (readonly)

Returns Container variant (:pfb or :pfa) — the on-disk encoding of a Type 1 font (binary vs ASCII). Distinct from #format, which is the high-level pipeline format.

Returns:

  • (Symbol) —

    Container variant (:pfb or :pfa) — the on-disk encoding of a Type 1 font (binary vs ASCII). Distinct from #format, which is the high-level pipeline format.



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# File 'lib/fontisan/type1_font.rb', line 38

def container_format
  @container_format
end

#decrypted_data ⇒ String? (readonly)

Returns Decrypted font data.

Returns:

  • (String, nil) —

    Decrypted font data



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# File 'lib/fontisan/type1_font.rb', line 72

def decrypted_data
  @decrypted_data
end

#file_path ⇒ String? (readonly)

Returns File path if loaded from file.

Returns:

  • (String, nil) —

    File path if loaded from file



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# File 'lib/fontisan/type1_font.rb', line 33

def file_path
  @file_path
end

#loading_mode ⇒ Symbol (readonly)

Returns Loading mode (:metadata or :full).

Returns:

  • (Symbol) —

    Loading mode (:metadata or :full)



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# File 'lib/fontisan/type1_font.rb', line 69

def loading_mode
  @loading_mode
end

Class Method Details

.from_file(file_path, mode: :full) ⇒ Type1Font

Load Type 1 font from file

Examples:

Load PFB file

font = Fontisan::Type1Font.from_file('font.pfb')

Load PFA file

font = Fontisan::Type1Font.from_file('font.pfa')

Parameters:

  • file_path (String) —

    Path to PFB or PFA file

  • mode (Symbol) (defaults to: :full) —

    Loading mode (:metadata or :full, default: :full)

Returns:

Raises:

  • (ArgumentError) —

    If file_path is nil

  • (Fontisan::Error) —

    If file cannot be read or parsed



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# File 'lib/fontisan/type1_font.rb', line 121

def self.from_file(file_path, mode: :full)
  raise ArgumentError, "File path cannot be nil" if file_path.nil?

  unless File.exist?(file_path)
    raise Fontisan::Error, "File not found: #{file_path}"
  end

  # Read file
  data = File.binread(file_path)

  new(data, file_path: file_path, mode: mode)
end

Instance Method Details

#charstrings ⇒ CharStrings?

Returns CharStrings dictionary.

Returns:

  • (CharStrings, nil) —

    CharStrings dictionary



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# File 'lib/fontisan/type1_font.rb', line 87

def charstrings
  parse_dictionaries! unless @charstrings
  @charstrings
end

#clear_text ⇒ String

Get clear text portion (before eexec)

Returns:

  • (String) —

    Clear text font dictionary



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# File 'lib/fontisan/type1_font.rb', line 137

def clear_text
  @clear_text ||= ""
end

#collection? ⇒ Boolean

Whether this object represents a font collection rather than a single font. Each font class is the authority on this question.

Returns:

  • (Boolean) 


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# File 'lib/fontisan/type1_font.rb', line 50

def collection? = false

#decrypt! ⇒ String

Decrypt the font if not already decrypted

Returns:

  • (String) —

    Decrypted font data



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# File 'lib/fontisan/type1_font.rb', line 165

def decrypt!
  return @decrypted_data if decrypted?

  if @encrypted_portion.nil? || @encrypted_portion.empty?
    @decrypted_data = @clear_text
  else
    encrypted_binary = if @container_format == :pfa
                         # Convert hex string to binary
                         [@encrypted_portion.gsub(/\s/, "")].pack("H*")
                       else
                         @encrypted_portion
                       end

    @decrypted_data = @clear_text +
      Type1::Decryptor.eexec_decrypt(encrypted_binary)
  end

  @decrypted_data
end

#decrypted? ⇒ Boolean

Check if font has been decrypted

Returns:

  • (Boolean) —

    True if font data has been decrypted



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# File 'lib/fontisan/type1_font.rb', line 151

def decrypted?
  !@decrypted_data.nil?
end

#encrypted? ⇒ Boolean

Check if font is encrypted

Returns:

  • (Boolean) —

    True if font has eexec encrypted portion



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# File 'lib/fontisan/type1_font.rb', line 158

def encrypted?
  !@encrypted_portion.nil? && !@encrypted_portion.empty?
end

#encrypted_portion ⇒ String

Get encrypted portion (as hex string for PFA)

Returns:

  • (String) —

    Encrypted portion



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# File 'lib/fontisan/type1_font.rb', line 144

def encrypted_portion
  @encrypted_portion ||= ""
end

#family_name ⇒ String?

Get family name from FontInfo

Returns:

  • (String, nil) —

    Family name or nil if not found



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# File 'lib/fontisan/type1_font.rb', line 225

def family_name
  return @font_dictionary&.font_info&.family_name if @font_dictionary

  extract_fontinfo_value("FamilyName")
end

#font_dictionary ⇒ FontDictionary?

Returns Font dictionary.

Returns:

  • (FontDictionary, nil) —

    Font dictionary



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# File 'lib/fontisan/type1_font.rb', line 75

def font_dictionary
  parse_dictionaries! unless @font_dictionary
  @font_dictionary
end

#font_name ⇒ String?

Get font name from font dictionary

Returns:

  • (String, nil) —

    Font name or nil if not found



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# File 'lib/fontisan/type1_font.rb', line 207

def font_name
  return @font_dictionary&.font_name if @font_dictionary

  extract_dictionary_value("/FontName")
end

#format ⇒ Symbol

High-level pipeline format identifier. Owned by the font class so the conversion pipeline can dispatch without case statements (OCP).

Returns:

  • (Symbol) —

    :type1



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# File 'lib/fontisan/type1_font.rb', line 44

def format = :type1

#full_name ⇒ String?

Get full name from FontInfo

Returns:

  • (String, nil) —

    Full name or nil if not found



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# File 'lib/fontisan/type1_font.rb', line 216

def full_name
  return @font_dictionary&.font_info&.full_name if @font_dictionary

  extract_fontinfo_value("FullName")
end

#glyph_names ⇒ Array<String>

Get list of glyph names

Returns:

  • (Array<String>) —

    Glyph names



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# File 'lib/fontisan/type1_font.rb', line 243

def glyph_names
  return [] unless @charstrings

  @charstrings.glyph_names
end

#outline_type ⇒ Symbol

Outline representation. Type 1 fonts use cubic PostScript CharStrings.

Returns:

  • (Symbol) —

    :postscript



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# File 'lib/fontisan/type1_font.rb', line 60

def outline_type = :postscript

#parse_dictionaries! ⇒ void

This method returns an undefined value.

Parse font dictionaries from decrypted data

Parses the font dictionary, private dictionary, and CharStrings from the decrypted font data.



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# File 'lib/fontisan/type1_font.rb', line 191

def parse_dictionaries!
  decrypt! unless decrypted?

  # Parse font dictionary
  @font_dictionary = Type1::FontDictionary.parse(@decrypted_data)

  # Parse private dictionary
  @private_dict = Type1::PrivateDict.parse(@decrypted_data)

  # Parse CharStrings
  @charstrings = Type1::CharStrings.parse(@decrypted_data, @private_dict)
end

#parsed_dictionaries? ⇒ Boolean

Check if dictionaries have been parsed

Returns:

  • (Boolean) —

    True if dictionaries have been parsed



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# File 'lib/fontisan/type1_font.rb', line 252

def parsed_dictionaries?
  !@font_dictionary.nil?
end

#private_dict ⇒ PrivateDict?

Returns Private dictionary.

Returns:

  • (PrivateDict, nil) —

    Private dictionary



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# File 'lib/fontisan/type1_font.rb', line 81

def private_dict
  parse_dictionaries! unless @private_dict
  @private_dict
end

#table_names ⇒ Array<String>

Type 1 fonts have no SFNT table directory; the table-oriented pipeline introspection does not apply.

Returns:

  • (Array<String>) —

    empty



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# File 'lib/fontisan/type1_font.rb', line 66

def table_names = []

#variation_type ⇒ Symbol

Type 1 fonts are not OpenType variable fonts.

Returns:

  • (Symbol) —

    :static



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# File 'lib/fontisan/type1_font.rb', line 55

def variation_type = :static

#version ⇒ String?

Get version from FontInfo

Returns:

  • (String, nil) —

    Version or nil if not found



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# File 'lib/fontisan/type1_font.rb', line 234

def version
  return @font_dictionary&.font_info&.version if @font_dictionary

  extract_fontinfo_value("version")
end