format10.rb in ttfunk-1.8.0

- old
+ new

@@ -1,14 +1,34 @@
 # frozen_string_literal: true
 
 module TTFunk
   class Table
     class Cmap
+      # Format 10: Trimmed array.
+      #
+      # This module conditionally extends {TTFunk::Table::Cmap::Subtable}.
       module Format10
+        # Language.
+        # @return [Integer]
         attr_reader :language
+
+        # Code map.
+        # @return [Hash{Integer => Integer}]
         attr_reader :code_map
 
+        # Encode the encoding record to format 10.
+        #
+        # @param charmap [Hash{Integer => Integer}] a hash mapping character
+        #   codes to glyph IDs from the original font.
+        # @return [Hash]
+        #   * `:charmap` (<tt>Hash{Integer => Hash}</tt>) keys are the characrers in
+        #     `charset`, values are hashes:
+        #     * `:old` (<tt>Integer</tt>) - glyph ID in the original font.
+        #     * `:new` (<tt>Integer</tt>) - glyph ID in the subset font.
+        #     that maps the characters in charmap to a
+        #   * `:subtable` (<tt>String</tt>) - serialized encoding record.
+        #   * `:max_glyph_id` (<tt>Integer</tt>) - maximum glyph ID in the new font.
         def self.encode(charmap)
           next_id = 0
           glyph_map = { 0 => 0 }
 
           sorted_chars = charmap.keys.sort
@@ -23,20 +43,27 @@
               map[code] = { old: charmap[code], new: glyph_map[charmap[code]] }
               glyph_indexes[code - low_char] = glyph_map[charmap[code]]
             end
 
           subtable = [
-            10, 0, 20 + entry_count * 4, 0, low_char, entry_count,
-            *glyph_indexes
+            10, 0, 20 + (entry_count * 4), 0, low_char, entry_count,
+            *glyph_indexes,
           ].pack('nnN*')
 
           { charmap: new_map, subtable: subtable, max_glyph_id: next_id + 1 }
         end
 
+        # Get glyph ID for character code.
+        #
+        # @param code [Integer] character code.
+        # @return [Integer] glyph ID.
         def [](code)
           @code_map[code] || 0
         end
 
+        # Is this encoding record format supported?
+        #
+        # @return [true]
         def supported?
           true
         end
 
         private