Class: TTFunk::Table::Cff::TopDict

Inherits:
Dict show all
Defined in:
lib/ttfunk/table/cff/top_dict.rb

Overview

CFF top dict.

Constant Summary collapse

DEFAULT_CHARSTRING_TYPE =

Default charstring type.

2
POINTER_PLACEHOLDER_LENGTH =

Length of placeholders for pointer operators.

5
PLACEHOLDER_LENGTH =

Length of placeholders for other operators.

5
POINTER_OPERATORS =

Operators whose values are offsets that point to other parts of the file.

{
  charset: 15,
  encoding: 16,
  charstrings_index: 17,
  private: 18,
  font_index: 1236,
  font_dict_selector: 1237,
}.freeze
OPERATORS =

All the operators we currently care about.

{
  **POINTER_OPERATORS,
  ros: 1230,
  charstring_type: 1206,
}.freeze
OPERATOR_CODES =

Inverse operator mapping.

OPERATORS.invert

Constants inherited from Dict

Dict::MAX_OPERANDS, Dict::OPERAND_BZERO, Dict::OPERATOR_BZERO, Dict::VALID_SCI_EXPONENT_RE, Dict::VALID_SCI_SIGNIFICAND_RE, Dict::WIDE_OPERATOR_ADJUSTMENT, Dict::WIDE_OPERATOR_BZERO

Instance Attribute Summary

Attributes inherited from SubTable

#file, #length, #table_offset

Instance Method Summary collapse

Methods inherited from Dict

#[], #[]=, #each

Methods inherited from SubTable

#eot?, #initialize, #read

Constructor Details

This class inherits a constructor from TTFunk::SubTable

Instance Method Details

#cff ⇒ TTFunk::Table::Cff

CFF table in this file.

Returns:

Source Code
lib/ttfunk/table/cff/top_dict.rb, line 207
207
def cff

208
  file.cff

209
end

#cff_offset ⇒ Integer

Ofsset of CFF table in the file.

Returns:

  • (Integer)
Source Code
lib/ttfunk/table/cff/top_dict.rb, line 214
214
def cff_offset

215
  cff.offset

216
end

#charset ⇒ TTFunk::Table::Cff::Charset?

Charset specified in this dict.

Returns:

Source Code
lib/ttfunk/table/cff/top_dict.rb, line 123
123
def charset

124
  @charset ||=

125
    if (charset_offset_or_id = self[OPERATORS[:charset]])

126
      if charset_offset_or_id.empty?

127
        Charset.new(self, file)

128
      else

129
        Charset.new(self, file, charset_offset_or_id.first)

130
      end

131
    end

132
end

#charstring_type ⇒ Integer

Charstring type specified in this dict.

Returns:

  • (Integer)
Source Code
lib/ttfunk/table/cff/top_dict.rb, line 167
167
def charstring_type

168
  @charstring_type =

169
    self[OPERATORS[:charstring_type]] || DEFAULT_CHARSTRING_TYPE

170
end

#charstrings_index ⇒ TTFunk::Table::Cff::CharstringsIndex?

Charstrings index specified in this dict.

OpenType fonts with TrueType outlines use a glyph index to specify and access glyphs within a font; e.g., to index within the loca table and thereby access glyph data in the glyf table. This concept is retained in OpenType CFF fonts, except that glyph data is accessed through the CharStrings INDEX of the CFF table.

— CFF — Compact Font Format Table

Returns:

Source Code
lib/ttfunk/table/cff/top_dict.rb, line 157
157
def charstrings_index

158
  @charstrings_index ||=

159
    if (charstrings_offset = self[OPERATORS[:charstrings_index]])

160
      CharstringsIndex.new(self, file, cff_offset + charstrings_offset.first)

161
    end

162
end

#encode ⇒ TTFunk::EncodedString

Encode dict.

Returns:

Source Code
lib/ttfunk/table/cff/top_dict.rb, line 41
41
def encode(*)

42
  EncodedString.new do |result|

43
    each_with_index do |(operator, operands), _idx|

44
      if operator == OPERATORS[:private]

45
        result << encode_private

46
      elsif pointer_operator?(operator)

47
        result << Placeholder.new(

48
          OPERATOR_CODES[operator],

49
          length: POINTER_PLACEHOLDER_LENGTH,

50
        )

51
      else

52
        operands.each { |operand| result << encode_operand(operand) }

53
      end

54
55
      result << encode_operator(operator)

56
    end

57
  end

58
end







    
      

  

  
    #encoding  ⇒ TTFunk::Table::Cff::Encoding? 
  

  

  


  

    
Encoding specified in this dict.



  





  


Returns:







  Source Code
  
lib/ttfunk/table/cff/top_dict.rb, line 137

  
137
def encoding

138
  # PostScript type 1 fonts, i.e. CID fonts, i.e. some fonts that use

139
  # the CFF table, don't specify an encoding, so this can be nil

140
  @encoding ||=

141
    if (encoding_offset_or_id = self[OPERATORS[:encoding]])

142
      Encoding.new(self, file, encoding_offset_or_id.first)

143
    end

144
end







    
      

  

  
    #finalize(new_cff_data, charmap)  ⇒ void 
  

  

  


  

    
This method returns an undefined value.
Finalize the table.



  





  

Parameters:


    
  
    
  • 
      
        new_cff_data
      
      
        (TTFunk::EncodedString)
      
      
      
    
    • 
  
    
  • 
      
        charmap
      
      
        (Hash{Integer => Hash})
      
      
      
        —
        
    keys are the charac codes,
values are hashes:
    

      
  
    • :old (Integer) - glyph ID in the original font.
      • 
  
    • :new (Integer) - glyph ID in the subset font.
      • 

    

    
      
    
    • 
  








  Source Code
  
lib/ttfunk/table/cff/top_dict.rb, line 68

  
68
def finalize(new_cff_data, charmap)

69
  if charset

70
    finalize_subtable(new_cff_data, :charset, charset.encode(charmap))

71
  end

72
73
  if encoding

74
    finalize_subtable(new_cff_data, :encoding, encoding.encode(charmap))

75
  end

76
77
  if charstrings_index

78
    finalize_subtable(new_cff_data, :charstrings_index, charstrings_index.encode(charmap))

79
  end

80
81
  if font_index

82
    finalize_subtable(new_cff_data, :font_index, font_index.encode)

83
84
    font_index.finalize(new_cff_data)

85
  end

86
87
  if font_dict_selector

88
    finalize_subtable(new_cff_data, :font_dict_selector, font_dict_selector.encode(charmap))

89
  end

90
91
  if private_dict

92
    encoded_private_dict = private_dict.encode

93
    encoded_offset = encode_integer32(new_cff_data.length)

94
    encoded_length = encode_integer32(encoded_private_dict.length)

95
96
    new_cff_data.resolve_placeholder(:"private_length_#{@table_offset}", encoded_length)

97
    new_cff_data.resolve_placeholder(:"private_offset_#{@table_offset}", encoded_offset)

98
99
    private_dict.finalize(encoded_private_dict)

100
    new_cff_data << encoded_private_dict

101
  end

102
end







    
      

  

  
    #font_dict_selector  ⇒ TTFunk::Table::Cff::FdSelector? 
  

  

  


  

    
Font dict selector specified in this dict.



  





  


Returns:







  Source Code
  
lib/ttfunk/table/cff/top_dict.rb, line 185

  
185
def font_dict_selector

186
  @font_dict_selector ||=

187
    if (fd_select_offset = self[OPERATORS[:font_dict_selector]])

188
      FdSelector.new(self, file, cff_offset + fd_select_offset.first)

189
    end

190
end







    
      

  

  
    #font_index  ⇒ TTFunk::Table::Cff::FontIndex? 
  

  

  


  

    
Font index specified in this dict.



  





  


Returns:







  Source Code
  
lib/ttfunk/table/cff/top_dict.rb, line 175

  
175
def font_index

176
  @font_index ||=

177
    if (font_index_offset = self[OPERATORS[:font_index]])

178
      FontIndex.new(self, file, cff_offset + font_index_offset.first)

179
    end

180
end







    
      

  

  
    #private_dict  ⇒ TTFunk::Table::Cff::PrivateDict? 
  

  

  


  

    
Private dict specified in this dict.



  





  


Returns:







  Source Code
  
lib/ttfunk/table/cff/top_dict.rb, line 195

  
195
def private_dict

196
  @private_dict ||=

197
    if (info = self[OPERATORS[:private]])

198
      private_dict_length, private_dict_offset = info

199
200
      PrivateDict.new(file, cff_offset + private_dict_offset, private_dict_length)

201
    end

202
end







    
      

  

  
    #ros  ⇒ Array(Integer, Integer, Integer)? 
  

  

  


  

    
Registry Ordering Supplement.



  





  


Returns:


    
  
    
  • 
      
      
        (Array(Integer, Integer, Integer), nil)
      
      
      
    
    • 
  







  Source Code
  
lib/ttfunk/table/cff/top_dict.rb, line 107

  
107
def ros

108
  self[OPERATORS[:ros]]

109
end







    
      

  

  
    #ros?  ⇒ Boolean 
  

  
    Also known as:
    is_cid_font?
    
  

  


  

    
Is Registry Ordering Supplement present in this dict?



  





  


Returns:


    
  
    
  • 
      
      
        (Boolean)
      
      
      
    
    • 
  







  Source Code
  
lib/ttfunk/table/cff/top_dict.rb, line 114

  
114
def ros?

115
  !ros.nil?

116
end