Font::TTF::Coverage(3) User Contributed Perl Documentation Font::TTF::Coverage(3)

# [NAME](#NAME)

Font::TTF::Coverage - Opentype coverage and class definition objects

# [DESCRIPTION](#DESCRIPTION)

Coverage tables and class definition objects are virtually identical concepts in OpenType. Their difference comes purely in their storage. Therefore we can say that a coverage table is a class definition in which the class definition for each glyph is the corresponding index in the coverage table. The resulting data structure is that a Coverage table has the following fields:

[cover](#cover)

A boolean to indicate whether this table is a coverage table (TRUE) or a class definition (FALSE)

[val](#val)

A hash of glyph ids against values (either coverage index or class value)

[fmt](#fmt)

The storage format used is given here, but is recalculated when the table is written out.

[count](#count)

A count of the elements in a coverage table for use with add. Each subsequent addition is added with the current count and increments the count.

[max](#max)

Maximum class value in a class table.

# [METHODS](#METHODS)

## [new($isCover \[, vals\])](#new%28$isCover__,_vals_%29)

Creates a new coverage table or class definition table, depending upon the value of $isCover. if $isCover then vals may be a list of glyphs to include in order. If no $isCover, then vals is a hash of glyphs against class values.

## [read($fh)](#read%28$fh%29)

Reads the coverage/class table from the given file handle

## [out($fh, $state)](#out%28$fh,_$state%29)

Writes the coverage/class table to the given file handle. If $state is 1 then the output string is returned rather than being output to a filehandle.

## $c->add($glyphid\[, $class])

Adds a glyph id to the coverage or class table. Returns the index or class number of the glyphid added.

## [$c->signature](#$c)

Returns a vector of all the glyph ids covered by this coverage table or class

## [@map=$c->sort](#@map=$c)

Sorts the coverage table so that indexes are in ascending order of glyphid. Returns a map such that $map\[$new\_index]=$old\_index.

## [$c->out\_xml($context)](#$c~2)

Outputs this coverage/class in XML

# [AUTHOR](#AUTHOR)

Martin Hosken <http://scripts.sil.org/FontUtils>.

# [LICENSING](#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.

2026-09-25 perl v5.44.0

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Document: Font::TTF::Coverage(3pm) from perl-font-ttf 1.06-r0 (Chainguard OS)