module HexaPDF::Font::TrueType::Table::CmapSubtable::Format12

def self.mapper(groups) #:nodoc:

:nodoc:
arrays.
The parameter +groups+ is an array containing [start_code, end_code, start_glyph_id] 
def self.mapper(groups) #:nodoc:
  code_map = Hash.new do |h, code|
    group = groups.bsearch {|g| g[1] >= code }
    h[code] = group[2] + (code - group[0]) if group && group[0] <= code
  end
  groups_by_gid = groups.sort_by {|g| g[2] }
  gid_map = Hash.new do |h, gid|
    group = groups_by_gid.bsearch {|g| g[2] + g[1] - g[0] >= gid }
    h[gid] = group[0] + (gid - group[2]) if group && group[2] <= gid
  end
  [code_map, gid_map]
end

def self.parse(io, _length)

It is assumed that the first twelve bytes of the subtable have already been consumed.

returns the contained code map.
Parses the format 12 cmap subtable from the given IO at the current position and

Format12.parse(io, length) -> code_map
:call-seq: 
def self.parse(io, _length)
  mapper(Array.new(io.read(4).unpack1('N')) { io.read(12).unpack('N3') })
end