Font::TTF::Kern(3pm) User Contributed Perl Documentation Font::TTF::Kern(3pm)
NAME
Font::TTF::Kern - Kerning tables
DESCRIPTION
Kerning tables are held as an ordered collection of subtables each
giving incremental information regarding the kerning of various pairs
of glyphs.
The basic structure of the kerning data structure is:
$kern = $f->{'kern'}{'tables'}[$tnum]{'kerns'}{$leftnum}{$rightnum};
Due to the possible complexity of some kerning tables the above
information is insufficient. Reference also needs to be made to the
type of the table and the coverage field.
INSTANCE VARIABLES
The instance variables for a kerning table are relatively
straightforward.
Version
Version number of the kerning table
Num Number of subtables in the kerning table
tables
Array of subtables in the kerning table
Each subtable has a number of instance variables.
kern
A two level hash array containing kerning values. The indexing
is left is via left class and right class. It may seem using
hashes is strange, but most tables are not type 2 and this
method saves empty array values.
type
Stores the table type. Only type 0 and type 2 tables are
specified for TrueType so far.
coverage
A bit field of coverage information regarding the kerning
value. See the TrueType specification for details.
Version
Contains the version number of the table.
Num Number of kerning pairs in this type 0 table.
left
An array indexed by glyph - left_first which returns a class
number for the glyph in type 2 tables.
right
An array indexed by glyph - right_first which returns a class
number for the glyph in type 2 tables.
left_first
the glyph number of the first element in the left array for
type 2 tables.
right_first
the glyph number of the first element in the right array for
type 2 tables.
num_left
Number of left classes
num_right
Number of right classes
METHODS
$t->read
Reads the whole kerning table into structures
$t->out($fh)
Outputs the kerning tables to the given file
$t->XML_element($context, $depth, $key, $value)
Handles outputting the kern hash into XML a little more tidily
$t->minsize()
Returns the minimum size this table can be. If it is smaller than this,
then the table must be bad and should be deleted or whatever.
BUGS
• Only supports kerning table types 0 & 2.
• No real support functions to do anything with the kerning tables
yet.
AUTHOR
Martin Hosken <http://scripts.sil.org/FontUtils>.
LICENSING
Copyright (c) 1998-2016, SIL International (http://www.sil.org)
This module is released under the terms of the Artistic License 2.0.
For details, see the full text of the license in the file LICENSE.
perl v5.34.0 2022-06-14 Font::TTF::Kern(3pm)
Generated by dwww version 1.15 on Wed Jun 26 18:13:38 CEST 2024.