NAME

Font::TTF::GDEF - Opentype GDEF table support

DESCRIPTION

The GDEF table contains various global lists of information which are apparantly used in other places in an OpenType renderer. But precisely where is open to speculation...

INSTANCE VARIABLES

There are up to 5 tables in the GDEF table, each with their own structure:

GLYPH

This is an Font::TTF::Coverage Class Definition table containing information as to what type each glyph is.

ATTACH

The attach table consists of a coverage table and then attachment points for each glyph in the coverage table:

COVERAGE

This is a coverage table

POINTS

This is an array of point elements. Each element is an array of curve points corresponding to the attachment points on that glyph. The order of the curve points in the array corresponds to the attachment point number specified in the MARKS coverage table (see below).

LIG

This contains the ligature caret positioning information for ligature glyphs

COVERAGE

A coverage table to say which glyphs are ligatures

LIGS

An array of elements for each ligature. Each element is an array of information for each caret position in the ligature (there being number of components - 1 of these, generally)

FMT

This is the format of the information and is important to provide the semantics for the value. This value must be set correctly before output

VAL

The value which has meaning according to FMT

DEVICE

For FMT = 3, a device table is also referenced which is stored here

MARKS

This class definition table defines the classes of mark glyphs that can be selected for processing using the MarkAttachmentType field of lookup FLAG words.

MARKSETS

Contains an array of coverage tables indexed by the FILTER value of a lookup.

METHODS

$t->read

Reads the table into the data structure

$t->out($fh)

Writes out this table.

$t->update

Sort COVERAGE tables.