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Font::TTF::Gdef - Opentype GDEF table support
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Font::TTF::Gdef - Opentype GDEF table support
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...
There are 4 tables in the GDEF table, each with their own structure:
- GLYPH
-
This is an the Font::TTF::Coverage manpage 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
-
Due to confusion in the GDEF specification, this field is currently withdrawn until
the confusion is resolved. That way, perhaps this stuff will work!
This class definition table stores the mark attachment point numbers for each
attachment mark, to indicate which attachment point the mark attaches to on its
base glyph.
Reads the table into the data structure
Writes out this table.
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Font::TTF::Gdef - Opentype GDEF table support
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