class TTFunk::Table::Loca

Attributes

offsets[R]

Public Class Methods

encode(offsets) click to toggle source

Accepts an array of offsets, with each index corresponding to the glyph id with that index.

Returns a hash containing:

  • :table - the string representing the table's contents

  • :type - the type of offset (to be encoded in the 'head' table)

# File lib/ttfunk/table/loca.rb, line 15
def self.encode(offsets)
  long_offsets = offsets.any? do |offset|
    short_offset = offset / 2
    short_offset * 2 != offset || short_offset > 0xffff
  end

  if long_offsets
    { type: 1, table: offsets.pack('N*') }
  else
    { type: 0, table: offsets.map { |o| o / 2 }.pack('n*') }
  end
end

Public Instance Methods

index_of(glyph_id) click to toggle source
# File lib/ttfunk/table/loca.rb, line 28
def index_of(glyph_id)
  @offsets[glyph_id]
end
size_of(glyph_id) click to toggle source
# File lib/ttfunk/table/loca.rb, line 32
def size_of(glyph_id)
  @offsets[glyph_id + 1] - @offsets[glyph_id]
end

Private Instance Methods

parse!() click to toggle source
# File lib/ttfunk/table/loca.rb, line 38
def parse!
  type = file.header.index_to_loc_format == 0 ? 'n' : 'N'
  @offsets = read(length, "#{type}*")

  if file.header.index_to_loc_format == 0
    @offsets.map! { |v| v * 2 }
  end
end