class Prawn::SVG::TTF
Constants
- LANGUAGE_IDS
- SFNT_VERSION_STRINGS
- UTF_16BE_PLATFORM_IDS
Attributes
family[R]
subfamily[R]
Public Class Methods
new(filename)
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# File lib/prawn/svg/ttf.rb, line 8 def initialize(filename) load_data_from_file(filename) end
Private Instance Methods
load_data_from_file(filename)
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# File lib/prawn/svg/ttf.rb, line 14 def load_data_from_file(filename) File.open(filename, 'rb') do |f| offset_table = f.read(12) return unless offset_table && offset_table.length == 12 && SFNT_VERSION_STRINGS.include?(offset_table[0..3]) table_count = (offset_table[4].ord * 256) + offset_table[5].ord tables = f.read(table_count * 16) return unless tables && tables.length == table_count * 16 offset, length = table_count.times do |index| start = index * 16 break tables[start + 8..start + 15].unpack('NNN') if tables[start..start + 3] == 'name' end return unless length f.seek(offset) data = f.read(length) return unless data && data.length == length _, name_count, string_offset = data[0..5].unpack('nnn') names = {} name_count.times do |index| start = 6 + (index * 12) platform_id, _, language_id, name_id, length, offset = data[start..start + 11].unpack('nnnnnn') next unless offset next unless LANGUAGE_IDS.include?(language_id) next unless [1, 2, 16, 17].include?(name_id) offset += string_offset field = data[offset..offset + length - 1] next unless field && field.length == length names[name_id] = if UTF_16BE_PLATFORM_IDS.include?(platform_id) begin field.force_encoding(Encoding::UTF_16BE).encode(Encoding::UTF_8) rescue StandardError field end else field end end @family = names[16] || names[1] @subfamily = names[17] || names[2] end rescue Errno::ENOENT # in case the file disappears between the scan and the load, we don't want to crash end