Class: Fontisan::Type1::CharStrings::CharStringParser

Inherits:
Object
  • Object
show all
Defined in:
lib/fontisan/type1/charstrings.rb

Overview

CharString parser

Parses Type 1 CharString bytecode into commands.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(private_dict = nil) ⇒ CharStringParser

Initialize parser

Parameters:

  • private_dict (PrivateDict) (defaults to: nil) —

    Private dictionary



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# File 'lib/fontisan/type1/charstrings.rb', line 305

def initialize(private_dict = nil)
  @private_dict = private_dict || PrivateDict.new
  @commands = []
  @seac_components = nil
end

Instance Attribute Details

#commands ⇒ Array (readonly)

Returns Parsed commands.

Returns:

  • (Array) —

    Parsed commands



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# File 'lib/fontisan/type1/charstrings.rb', line 294

def commands
  @commands
end

#private_dict ⇒ PrivateDict (readonly)

Returns Private dictionary.

Returns:



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# File 'lib/fontisan/type1/charstrings.rb', line 300

def private_dict
  @private_dict
end

#seac_components ⇒ Hash? (readonly)

Returns seac components if seac found.

Returns:

  • (Hash, nil) —

    seac components if seac found



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# File 'lib/fontisan/type1/charstrings.rb', line 297

def seac_components
  @seac_components
end

Instance Method Details

#parse(charstring) ⇒ Array

Parse CharString bytecode

Parameters:

  • charstring (String) —

    Binary CharString data

Returns:

  • (Array) —

    Parsed commands



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# File 'lib/fontisan/type1/charstrings.rb', line 315

def parse(charstring)
  return [] if charstring.nil? || charstring.empty?

  @commands = []
  @seac_components = nil

  i = 0
  while i < charstring.length
    byte = charstring.getbyte(i)

    if byte <= 31
      # Operator
      parse_operator(charstring, byte, i)
      break if @seac_components # Stop at seac for now

      i += 1
    elsif byte == 255
      # Escaped number (2 bytes follow)
      num = charstring.getbyte(i + 1) |
        (charstring.getbyte(i + 2) << 8)
      num = num - 32768 if num >= 32768
      @commands << [:number, num]
      i += 3
    elsif byte >= 32 && byte <= 246
      # Small number (-107 to 107)
      num = byte - 139
      @commands << [:number, num]
      i += 1
    else
      # Unknown
      i += 1
    end
  end

  @commands
end