NAME

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

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

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

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

       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 Maximum class value in a class table.

METHODS

   new($isCover [, vals])
       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)
       Reads the coverage/class table from the given file handle

   out($fh, $state)
       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
       Returns a vector of all the glyph ids covered by this coverage table or class

   @map=$c->sort
       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)
       Outputs this coverage/class in XML

AUTHOR

       Martin Hosken Martin_Hosken@sil.org.

LICENSING

       Copyright (c) 1998-2013, 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.