lib/ttfunk/table/cff/charset.rb in ttfunk-1.7.0 vs lib/ttfunk/table/cff/charset.rb in ttfunk-1.8.0
- old
+ new
@@ -1,29 +1,51 @@
# frozen_string_literal: true
module TTFunk
class Table
class Cff < TTFunk::Table
+ # CFF Charset
class Charset < TTFunk::SubTable
include Enumerable
+ # First glyph string. This is an implicit glyph present in all charsets.
FIRST_GLYPH_STRING = '.notdef'
+
+ # Format 0.
ARRAY_FORMAT = 0
+
+ # Format 1.
RANGE_FORMAT_8 = 1
+
+ # Format 2.
RANGE_FORMAT_16 = 2
+ # Predefined ISOAdobe charset ID.
ISO_ADOBE_CHARSET_ID = 0
+
+ # Predefined Expert charset ID.
EXPERT_CHARSET_ID = 1
+
+ # Predefined Expert Subset charset ID.
EXPERT_SUBSET_CHARSET_ID = 2
+ # Default charset ID.
DEFAULT_CHARSET_ID = ISO_ADOBE_CHARSET_ID
class << self
+ # Standard strings defined in the spec that do not need to be defined
+ # in the CFF.
+ #
+ # @return [TTFunk::OneBasedArray<String>]
def standard_strings
Charsets::STANDARD_STRINGS
end
+ # Strings for charset ID.
+ #
+ # @param charset_id [Integer]
+ # @return [TTFunk::OneBasedArray<String>]
def strings_for_charset_id(charset_id)
case charset_id
when ISO_ADOBE_CHARSET_ID
Charsets::ISO_ADOBE
when EXPERT_CHARSET_ID
@@ -32,37 +54,81 @@
Charsets::EXPERT_SUBSET
end
end
end
- attr_reader :entries, :length
- attr_reader :top_dict, :format, :count, :offset_or_id
+ # Encoded entries.
+ # @return [TTFunk::OneBasedArray<Integer>, Array<Range<Integer>>]
+ attr_reader :entries
+ # Length of encoded charset subtable.
+ # @return [Integer]
+ attr_reader :length
+
+ # Top dict.
+ # @return [TTFunk::Table::Cff::TopDict]
+ attr_reader :top_dict
+
+ # Encodign format.
+ # @return [Integer]
+ attr_reader :format
+
+ # Number of encoded items.
+ # @return [Integer]
+ attr_reader :items_count
+
+ # Offset or charset ID.
+ # @return [Integer]
+ attr_reader :offset_or_id
+
+ # @overload initialize(top_dict, file, offset = nil, length = nil)
+ # @param top_dict [TTFunk::Table:Cff::TopDict]
+ # @param file [TTFunk::File]
+ # @param offset [Integer]
+ # @param length [Integer]
+ # @overload initialize(top_dict, file, charset_id)
+ # @param top_dict [TTFunk::Table:Cff::TopDict]
+ # @param file [TTFunk::File]
+ # @param charset_id [Integer] 0, 1, or 2
def initialize(top_dict, file, offset_or_id = nil, length = nil)
@top_dict = top_dict
@offset_or_id = offset_or_id || DEFAULT_CHARSET_ID
if offset
super(file, offset, length)
else
- @count = self.class.strings_for_charset_id(offset_or_id).size
+ @items_count = self.class.strings_for_charset_id(offset_or_id).size
end
end
+ # Iterate over character names.
+ #
+ # @overload each()
+ # @yieldparam name [String]
+ # @return [void]
+ # @overload each()
+ # @return [Enumerator]
def each
return to_enum(__method__) unless block_given?
# +1 adjusts for the implicit .notdef glyph
- (count + 1).times { |i| yield self[i] }
+ (items_count + 1).times { |i| yield(self[i]) }
end
+ # Get character name for glyph index.
+ #
+ # @param glyph_id [Integer]
+ # @return [String, nil]
def [](glyph_id)
return FIRST_GLYPH_STRING if glyph_id.zero?
find_string(sid_for(glyph_id))
end
+ # Charset offset in the file.
+ #
+ # @return [Integer, nil]
def offset
# Numbers from 0..2 mean charset IDs instead of offsets. IDs are
# basically pre-defined sets of characters.
#
# In the case of an offset, add the CFF table's offset since the
@@ -71,17 +137,29 @@
if offset_or_id > 2
offset_or_id + top_dict.cff_offset
end
end
- # mapping is new -> old glyph ids
- def encode(mapping)
+ # Encode charset.
+ #
+ # @param charmap [Hash{Integer => Hash}] keys are the charac codes,
+ # values are hashes:
+ # * `:old` (<tt>Integer</tt>) - glyph ID in the original font.
+ # * `:new` (<tt>Integer</tt>) - glyph ID in the subset font.
+ # @return [String]
+ def encode(charmap)
# no offset means no charset was specified (i.e. we're supposed to
# use a predefined charset) so there's nothing to encode
return '' unless offset
- sids = mapping.keys.sort.map { |new_gid| sid_for(mapping[new_gid]) }
+ sids =
+ charmap
+ .values
+ .reject { |mapping| mapping[:new].zero? }
+ .sort_by { |mapping| mapping[:new] }
+ .map { |mapping| sid_for(mapping[:old]) }
+
ranges = TTFunk::BinUtils.rangify(sids)
range_max = ranges.map(&:last).max
range_bytes =
if range_max.positive?
@@ -136,11 +214,11 @@
if offset
return self.class.standard_strings[sid] if sid <= 390
idx = sid - 390
- if idx < file.cff.string_index.count
+ if idx < file.cff.string_index.items_count
file.cff.string_index[idx]
end
else
self.class.strings_for_charset_id(offset_or_id)[sid]
end
@@ -151,44 +229,44 @@
@format = read(1, 'C').first
case format_sym
when :array_format
- @count = top_dict.charstrings_index.count - 1
- @length = count * element_width
+ @items_count = top_dict.charstrings_index.items_count - 1
+ @length = @items_count * element_width
@entries = OneBasedArray.new(read(length, 'n*'))
when :range_format8, :range_format16
# The number of ranges is not explicitly specified in the font.
# Instead, software utilizing this data simply processes ranges
# until all glyphs in the font are covered.
- @count = 0
+ @items_count = 0
@entries = []
@length = 0
- until count >= top_dict.charstrings_index.count - 1
+ until @items_count >= top_dict.charstrings_index.items_count - 1
@length += 1 + element_width
sid, num_left = read(element_width, element_format)
- entries << (sid..(sid + num_left))
- @count += num_left + 1
+ @entries << (sid..(sid + num_left))
+ @items_count += num_left + 1
end
end
end
def element_width(fmt = format_sym)
{
array_format: 2, # SID
range_format8: 3, # SID + Card8
- range_format16: 4 # SID + Card16
+ range_format16: 4, # SID + Card16
}[fmt]
end
def element_format(fmt = format_sym)
{
array_format: 'n',
range_format8: 'nC',
- range_format16: 'nn'
+ range_format16: 'nn',
}[fmt]
end
def format_sym
case @format
@@ -202,10 +280,10 @@
def format_int(sym = format_sym)
{
array_format: ARRAY_FORMAT,
range_format8: RANGE_FORMAT_8,
- range_format16: RANGE_FORMAT_16
+ range_format16: RANGE_FORMAT_16,
}[sym]
end
end
end
end