This directory contains several extensions to the core engine.
An extension is a separately compilable unit which can be linked by
a client application to add new functionalities to the engine.
There are two kinds of extensions: an `API extension' provides
clients with new APIs to access internal engine structures or data,
while an `engine extension' implements new TrueType data or table
management.
This directory contains the following:
ftxcmap: An API extension to iterate over cmaps.
ftxgasp: A simple API extension which returns the TrueType `gasp'
table to client applications, when found in a font file.
Though this table is always loaded by the engine, there
is no function in the core API to access it. The reason
is simple: to demonstrate a simple API extension with
`ftxgasp'!
ftxkern: This engine extension is used to access kerning data,
when available in a font file. Note that it implements
on-the-fly loading and retrieving of kerning tables.
However, it doesn't interpret or process the data, and
client applications should use it according to the
TrueType specification.
ftxpost: An engine extension to load the PostScript glyph names
of the `post' table. See the `ftzoom' program for an
example how to use it.
ftxwidth: A simple extension used to load the widths and heights
of a given range of glyphs in a face. Results are
expressed in unscaled font units. This is required by
the latest version of the FreeType/2 DLL to speed up
font loading in the GRE (the OS/2 GRaphics Engine). It
can be used by other applications though...
ftxerr18: This extension simply converts a TrueType engine error
code into a corresponding string describing the error.
It is useful if you intend to write a package for end
users and want to give them not `Error code 135' but
`OS/2 table missing'. See docs/errstr.txt for a
description how to use it (really simple!). ftxerr18
supports localization of error strings (that is: error
strings are automatically translated into supported
languages) using gettext(). See docs/i18n.txt about
using gettext.
ftxsbit: Embedded bitmap support. This is an engine extension.
See e.g. the `ftstrtto' program for its usage.
ftxopen,
ftxgsub,
ftxgpos,
ftxgdef: This is experimental stuff for TrueType Open support!
Please ignore it or help debugging :-)
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