path: root/luaotfload.dtx

% \iffalse meta-comment
%
% Copyright (C) 2009-2010 by Elie Roux    <elie.roux@telecom-bretagne.eu>
%                        and Khaled Hosny <khaledhosny@eglug.org>
%
% This work is distributed under the GNU General Public License v3.
% This work consists of this source file luaotfload.dtx and other
% files listed in the README.
%
% This file is used the source for the derived files
%    luaotfload.sty, luaotfload.lua
%
% Unpacking:
%    tex luaotfload.dtx
%
% Documentation:
%    pdflatex luaotfload.dtx
%
%    The class ltxdoc loads the configuration file ltxdoc.cfg
%    if available. Here you can specify further options, e.g.
%    use A4 as paper format:
%       \PassOptionsToClass{a4paper}{article}
%
%
%
%<*ignore>
\begingroup
  \def\x{LaTeX2e}%
\expandafter\endgroup
\ifcase 0\ifx\install y1\fi\expandafter
         \ifx\csname processbatchFile\endcsname\relax\else1\fi
         \ifx\fmtname\x\else 1\fi\relax
\else\csname fi\endcsname
%</ignore>
%<*install>
\input docstrip.tex
\Msg{************************************************************************}
\Msg{* Installation}
\Msg{* Package: luaotfload 2010/05/13 v1.08 ConTeXt font loading system}
\Msg{************************************************************************}

\keepsilent
\askforoverwritefalse

\let\MetaPrefix\relax

\preamble
This is a generated file.

Copyright (C) 2009-2010 by by Elie Roux    <elie.roux@telecom-bretagne.eu>
                          and Khaled Hosny <khaledhosny@eglug.org>

This work is distributed under the GNU General Public License v3.
This work consists of this source file luaotfload.dtx and other
files listed in the README.

This file luaotfload.dtx was to generate the derived files
    luaotfload.sty, luaotfload.lua

\endpreamble

\let\MetaPrefix\DoubleperCent


\generate{%
  \usedir{tex/luatex/luaodfload}%
  \file{luaotfload.sty}{\from{luaotfload.dtx}{package}}%
}

% The following hacks are to generate a lua file with lua comments starting by
% -- instead of %%

\def\MetaPrefix{-- }

\def\luapostamble{%
  \MetaPrefix^^J%
  \MetaPrefix\space End of File `\outFileName'.%
}

\def\currentpostamble{\luapostamble}%

\generate{%
  \usedir{tex/luatex/luaotfload}%
  \file{luaotfload.lua}{\from{luaotfload.dtx}{lua}}%%
}

\obeyspaces
\Msg{************************************************************************}
\Msg{*}
\Msg{* To finish the installation you have to move the following}
\Msg{* files into a directory searched by TeX:}
\Msg{*}
\Msg{*     luaotfload.sty, luaotfload.lua}
\Msg{*}
\Msg{* Happy TeXing!}
\Msg{*}
\Msg{************************************************************************}

\endbatchfile
%</install>
%<*ignore>
\fi
%</ignore>
%<*driver>
\NeedsTeXFormat{LaTeX2e}
\ProvidesFile{luaotfload.drv}%
  [2010/05/13 v1.08 ConTeXt font loading system]%
\documentclass{ltxdoc}
\usepackage{metalogo,multicol,mdwlist,fancyvrb}
\usepackage[colorlinks=true]{hyperref}

\def\LuaTeX{Lua\TeX}
\def\ConTeXt{Con\TeX t}

\EnableCrossrefs
\CodelineIndex
\VerbatimFootnotes
\begin{document}
  \DocInput{luaotfload.dtx}%
\end{document}
%</driver>
% \fi
%
% \CheckSum{0}
%
% \CharacterTable
%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
%   Digits        \0\1\2\3\4\5\6\7\8\9
%   Exclamation   \!     Double quote  \"     Hash (number) \#
%   Dollar        \$     Percent       \%     Ampersand     \&
%   Acute accent  \'     Left paren    \(     Right paren   \)
%   Asterisk      \*     Plus          \+     Comma         \,
%   Minus         \-     Point         \.     Solidus       \/
%   Colon         \:     Semicolon     \;     Less than     \<
%   Equals        \=     Greater than  \>     Question mark \?
%   Commercial at \@     Left bracket  \[     Backslash     \\
%   Right bracket \]     Circumflex    \^     Underscore    \_
%   Grave accent  \`     Left brace    \{     Vertical bar  \|
%   Right brace   \}     Tilde         \~}
%
% \GetFileInfo{luaotfload.drv}
%
% \title{The \textsf{luaotfload} package}
% \date{2010/05/13 v1.08}
% \author{     Elie Roux\footnote{\texttt{elie.roux@telecom-bretagne.eu}}
%         \and Khaled Hosny\footnote{\texttt{khaledhosny@eglug.org}}}
%
% \maketitle
%
% \begin{abstract}
% This package is an adaptation of the \ConTeXt\ font loading system,
% providing the ability to load \textsf{OpenType} fonts with extended font
% loading syntax supporting a large selection of OpenType font features.
% \end{abstract}
%
% \tableofcontents
%
% \section{Documentation}
%
% \subsection{Introduction}
%
% Font management and installation has always been painful with \TeX.
% A lot of files are needed for one font (tfm, pfb, map, fd, vf), and as
% \TeX\ is 8-bit each font is limited to 256 characters.
% But the font world has evolved since \TeX, and new font technologies have
% appeared, most notably the so called \emph{smart font} technologies like
% \textsf{OpenType} fonts. These fonts can contain a lot of characters, and
% additional functionalities like ligatures, old-style numbers, small capitals,
% etc., and support more complex writing systems like Arabic and Indic scripts.
% They are widely deployed and available for all modern operating systems and
% are becoming the de facto standard fonts for advanced text layout.
% Until now the only way to use them directly in the \TeX\ world was by using
% them with \XeTeX.
%
% Unlike \XeTeX, \LuaTeX\ does not provide direct support for using these fonts
% by default, but it provides a way to hook Lua code in some points of the
% \TeX\ processing; for instance, we can improve the font loading system, and
% text procession, which what this package is about.
%
% \subsection{Loading fonts}
%
% \textsf{luaotfload} supports an extended font loading syntax which looks
% like:
%
% \begin{center}
% |\font\foo={|\meta{prefix}|:|\meta{font name}|:|\meta{font features}|}| \meta{\TeX\ font features}
% \end{center}
%
% \noindent
% The curly brackets are optional and are used for escaping spaces in font
% names (double quotes can also used for the same purpose).
%
% \paragraph{Prefix}
%
% The \meta{prefix} be either \texttt{file:} or \texttt{name:}, which specify
% whether to use a select the font from its filename or font name,
% respectively. If no prefix is specified, then \texttt{file:} is assumed.
%
% For compatibility with \XeTeX, surrounding the \meta{font name}
% with square brackets is synonymous to using the \texttt{file:} prefix.
%
% Accessing fonts by fontname allows loading system installed fonts as well as
% \textsc{texmf} ones, and requires a font names database that must be
% pre-generated using the bundled |mkluatexfontdb.lua| script.^^A
% \footnote{Run |mkluatexfontdb.lua --help| for help and usage information}
%
% \paragraph{Font name}
%
% The \meta{font name} can be either a font filename or actual font name
% based on the \meta{prefix} as mentioned above.
%
% Fonts loaded by filename may either include their absolute path in the
% filesystem or consist of just the filename with a path.
% If no path is specified then \textsf{kpathsea} is used to locate the font
% (which will typically be in the \textsc{texmf} tree or the current
% directory).
%
% For example,
% \begin{quote}
% \begin{verbatim}
% \font\1={file:ec-lmr10} at 10pt
% \font\2={/Users/Shared/Fonts/aldus.otf} at 11pt
% \font\3={name:TeX Gyre Pagella} at 9pt
% \end{verbatim}
% \end{quote}
%
%
% \paragraph{Font features}
%
% \meta{font features} are a list of items separated by semi-colons,
% which are either
% |key=value| font parameters, or switches to enable/disable certain font
% features in the form of |+feat|/|-feat|.
% The supported keys are:
% \begin{description}
% \item [mode] \hfill \\
% \textsf{luaotfload} has two OpenType processing modes;
% \texttt{base} or \texttt{node}.
% Using \texttt{mode=base}
% only supports a subset of OpenType features and works by mapping those
% features to traditional \TeX\ ligature and kerning mechanisms and is a bit
% faster
% Using \texttt{mode=node} hopefully supports OpenType fully and
% works by direct processing of the node list with Lua; it is slower and
% is not designed to work in math mode.
%
% By default \texttt{mode=base} is used, but it is advisable to always
% enable \texttt{node} made, except for math fonts, otherwise many OpenType
% features will not function properly or even not work at all, especially for
% advanced scripts like Arabic.
%
% \item [script] \hfill \\
% OpenType script string, default value is |dflt|. Some fonts don't assign
% features to the |dflt| script, in which case the script need to be set
% explicitly.
%
% \item [language] \hfill \\
% OpenType language string, default value is |latn|.
%
% \item [featurefile] \hfill \\
% feature files are textual representation of OpenType tables and can be used to
% extend OpenType features of the font on fly. The file name of the feature file
% is passed, then features defined in the file can be enabled/disabled like any
% other feature. The actual syntax is described at
% \url{http://fontforge.sourceforge.net/featurefile.html} and
% \url{http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html}.
%
% For example, to set a |tkrn| feature from |mykern.fea| file:
%
% |\font\lmr=Latin Modern Roman:featurefile=mykern.fea;+tkrn|
%
% \item [color] \hfill \\
% font color, defined as a triplet of two-digit hexadecimal RGB values, with
% optionally another value for the transparency
% (where |00| is completely transparent and |FF| is opaque.)
%
% For example, to set text in semitransparent red:
%
% |\font\lmr=Latin Modern Roman:color=FF0000BB|
%
% \item [protrusion \& expansion] \hfill \\
% Both keys control microtypographic features of the font, namely glyph
% protrusion and expansion. The value of the key is the name of predefined
% Lua tables of protrusion and expansion values; see the end of
% \texttt{otfl-font-dum.lua} file for an example of such tables. The only
% predefined value is |default|.
%
% For example, to enable default protrusion\footnote{You also need to set
% |\pdfprotrudechars2 \pdfadjustspacing2| to activate protrusion and expansion,
% respectively. See PDF\TeX\ manual for details}:
%
% |\font\lmr=Latin Modern Roman:protrusion=default|
%
% \end{description}
%
% \subparagraph{Non-standard font features}
% \textsf{luaotfload} defines some additional font feature not defined in
% OpenType, currently three features are defined:
%
% \begin{itemize*}
% \item \texttt{anum}: replaces European numbers with eastern Arabic numbers or
% Persian numbers, depending on the value of |language|.
% \item \texttt{tlig}: applies legacy \TeX\ ligatures (|``''-- -- !` ?` <<>>|).
% \item \texttt{trep}: applies legacy \TeX\ replacements (|`'"|).
% \end{itemize*}
%
% (For \XeTeX\ users: these last two are the equivalent of writing
%  \texttt{mapping=text-tex} using \XeTeX's input remapping feature.)
%
% \subsection{Required \ConTeXt\ files}
%
% This package is a wrapper for several files taken from the \ConTeXt\ macro
% package. The philosophy is to let \ConTeXt\ do all the implementation and
% update these files from time to time. To do so we did not modify the files
% taken from \ConTeXt, we only changed their names to prevent name clashes.
% You can thus update the font system of this package simply by updating the
% files taken from \ConTeXt, without (theoretically) changing the \texttt{.sty}
% file nor the main \texttt{.lua} file.
%
% The \ConTeXt\ files are renamed by adding the prefix \texttt{otfl-} to them
% (\texttt{otfl} as \texttt{OTF L}oad). The files are:
%
% \begin{multicols}{3}
% \begin{itemize*}
% \item \texttt{luat-dum.lua}
% \item \texttt{data-con.lua}
% \item \texttt{node-ini.lua}
% \item \texttt{node-inj.lua}
% \item \texttt{node-fnt.lua}
% \item \texttt{node-dum.lua}
% \item \texttt{font-ini.lua}
% \item \texttt{font-tfm.lua}
% \item \texttt{font-cid.lua}
% \item \texttt{font-ott.lua}
% \item \texttt{font-otf.lua}
% \item \texttt{font-otd.lua}
% \item \texttt{font-oti.lua}
% \item \texttt{font-otb.lua}
% \item \texttt{font-otn.lua}
% \item \texttt{font-ota.lua}
% \item \texttt{font-otc.lua}
% \item \texttt{font-def.lua}
% \item \texttt{font-xtx.lua}
% \item \texttt{font-map.lua}
% \item \texttt{font-dum.lua}
% \end{itemize*}
% \end{multicols}
%
% The following files have been written for this package:
% \begin{multicols}{3}
% \begin{itemize*}
% \item \texttt{font-clr.lua}
% \item \texttt{font-nms.lua}
% \item \texttt{luat-ovr.lua}
% \end{itemize*}
% \end{multicols}
%
% \subsection{Troubleshooting}
%
% If you encounter problems with some fonts, please first update to the latest
% version of this package before reporting a bug, as this package is under
% active development.
%
% A very common problem is the lack of features for some OpenType fonts
% even when specified. It can be related to the fact that some fonts do not
% provide features for the |dflt| script, which is the default one in this
% package, so you may have to specify the script in the command line, for
% example:
%
% |\font\myfont = MyFont.otf:script=latn;+liga;|
%
% Also remember to set |mode=node| as most OpenType features
% (such as contextual substitution, |calt|), will not work without it.
%
% \part{\texttt{luaotfload.lua}}
%
% \iffalse
%<*lua>
% \fi
%
%    First some usual initializations.
%
%    \begin{macrocode}
module('luaotfload', package.seeall)

luaotfload.module = {
    name          = "luaotfload",
    version       = 1.08,
    date          = "2010/05/13",
    description   = "ConTeXt font loading system.",
    author        = "Elie Roux & Hans Hagen",
    copyright     = "Elie Roux",
    license       = "GNU GPL v3"
}

luatexbase.provides_module(luaotfload.module)

%    \end{macrocode}
%
%    Some helper functions.
%
%    \begin{macrocode}

local format = string.format

local function log(...)
    luatexbase.module_log    ('luaotfload', format(...))
end

local function error(...)
    luatexbase.module_error  ('luaotfload', format(...))
end

local function warning(...)
    luatexbase.module_warning('luaotfload', format(...))
end

%    \end{macrocode}
%
%    The minimal required \LuaTeX\ version.
%
%    \begin{macrocode}

local luatex_version = 60

if tex.luatexversion < luatex_version then
    warning('LuaTeX v%.2f is old, v%.2f is recommended.',
             tex.luatexversion/100,
             luatex_version   /100)
end

%    \end{macrocode}
%
%    We load the \ConTeXt\ files with this function. It automatically adds the
%    \texttt{otfl-} prefix to it, so that we call it with the actual \ConTeXt\
%    name.
%
%    \begin{macrocode}

function luaotfload.loadmodule(name)
    local tofind = 'otfl-'..name
    local found = kpse.find_file(tofind,"tex")
    if found then
        log('loading file %s.', found)
        dofile(found)
    else
        error('file %s not found.', tofind)
    end
end

%    \end{macrocode}
%
%    We start loading some lua files. These two are some code not used by
%    \ConTeXt\ at all that allow other modules to be used, it provides some
%    low-level \ConTeXt\ functions.
%
%    \begin{macrocode}

luaotfload.loadmodule('luat-dum.lua') -- not used in context at all
luaotfload.loadmodule('luat-ovr.lua') -- override some luat-dum functions
luaotfload.loadmodule('data-con.lua') -- maybe some day we don't need this one

%    \end{macrocode}
%
%    This one is for node support.
%
%    \begin{macrocode}

luaotfload.loadmodule('node-ini.lua')

%    \end{macrocode}
%
%    By default \ConTeXt\ takes some private attributes for internal use. With
%    Plain and \LaTeX\ we can't do so, we use |\newluaattribute|. This
%    functions overrides a function defined in the previous module that
%    returns the number of a private attribute. We allocate new attributes in
%    the \texttt{.sty} file, and this function returns their number. Like this
%    we don't need any private attribute, and this package is compatible with
%    the others. We use the |otfl@| prefix for attributes.
%
%    \begin{macrocode}

function attributes.private(name)
    local number = luatexbase.attributes['otfl@'..name]
    if not number then
        error('asking for attribute %s, but not declared. '
            ..'Please report to the maintainer of luaotfload.',
               name)
    end
    return number
end

%    \end{macrocode}
%
%    Some more modules. We don't load neither \texttt{font-enc.lua} nor
%    \texttt{font-afm.lua} as it will never be used here.
%
%    We also remove a warning from \texttt{node-fnt.lua} as it is \ConTeXt\
%    specific.
%
%    \begin{macrocode}

tex.attribute[0] = 0

luaotfload.loadmodule('node-res.lua')
luaotfload.loadmodule('node-inj.lua')
luaotfload.loadmodule('node-fnt.lua')
luaotfload.loadmodule('node-dum.lua')

luaotfload.loadmodule('font-ini.lua')
luaotfload.loadmodule('font-tfm.lua')
luaotfload.loadmodule('font-cid.lua')
luaotfload.loadmodule('font-map.lua')
luaotfload.loadmodule('font-ott.lua')
luaotfload.loadmodule('font-otf.lua')
luaotfload.loadmodule('font-otd.lua')
luaotfload.loadmodule('font-oti.lua')
luaotfload.loadmodule('font-otb.lua')
luaotfload.loadmodule('font-otn.lua')
luaotfload.loadmodule('font-ota.lua')
luaotfload.loadmodule('font-otc.lua')
luaotfload.loadmodule('font-def.lua')
luaotfload.loadmodule('font-xtx.lua')
luaotfload.loadmodule('font-dum.lua')
luaotfload.loadmodule('font-nms.lua')
luaotfload.loadmodule('font-clr.lua')

%    \end{macrocode}
%
%    Finally two functions
%
%    \begin{macrocode}

function luaotfload.register_callbacks()
    luatexbase.add_to_callback('pre_linebreak_filter',
                                nodes.simple_font_handler,
                               'luaotfload.pre_linebreak_filter')
    luatexbase.add_to_callback('hpack_filter',
                                nodes.simple_font_handler,
                               'luaotfload.hpack_filter')
    luatexbase.reset_callback('define_font')
    luatexbase.add_to_callback('define_font',
                                fonts.define.read,
                               'luaotfload.define_font', 1)
    luatexbase.add_to_callback('find_vf_file',
                                fonts.vf.find,
                               'luaotfload.find_vf_file')
end

function luaotfload.unregister_callbacks()
    luatexbase.remove_from_callback('pre_linebreak_filter',
                                    'luaotfload.pre_linebreak_filter')
    luatexbase.remove_from_callback('hpack_filter',
                                    'luaotfload.hpack_filter')
    luatexbase.remove_from_callback('define_font',
                                    'luaotfload.define_font')
    luatexbase.remove_from_callback('find_vf_file',
                                     'luaotfload.find_vf_file')
end
%    \end{macrocode}
% \iffalse
%</lua>
% \fi
%
% \part{\texttt{luaotfload.sty}}
%
% \iffalse
%<*package>
% \fi
%
%    Classical Plain+\LaTeX\ package initialization.
%
%    \begin{macrocode}
\csname ifluaotfloadloaded\endcsname
\let\ifluaotfloadloaded\endinput

\expandafter\ifx\csname ProvidesPackage\endcsname\relax
  \input luatextra.sty
\else
  \NeedsTeXFormat{LaTeX2e}
  \ProvidesPackage{luaotfload}%
    [2010/05/13 v1.08 ConTeXt font loading system]
  \RequirePackage{luatextra}
\fi

\expandafter\edef\csname otfl@AtEnd\endcsname{%
  \catcode64 \the\catcode64\relax
}

\catcode64 11

%    \end{macrocode}
%
%    The attributes are allocated here. The |otfl@| prefix is added to prevent
%    name collision.
%
%    \begin{macrocode}

\newluatexattribute\otfl@state
\newluatexattribute\otfl@markbase
\newluatexattribute\otfl@markdone
\newluatexattribute\otfl@markmark
\newluatexattribute\otfl@cursbase
\newluatexattribute\otfl@curscurs
\newluatexattribute\otfl@cursdone
\newluatexattribute\otfl@kernpair
\newluatexattribute\otfl@color

%    \end{macrocode}
%
%    Two small macros to register or unregister the callbacks. Without the
%    callbacks this package is totally turned off.
%
%    \begin{macrocode}

\def\otfl@off{
\directlua{luaotfload.unregister_callbacks()}
}

\def\otfl@on{
\directlua{luaotfload.register_callbacks()}
}

%    \end{macrocode}
%
%    We load the |lua| file, and we turn the package on.
%
%    \begin{macrocode}

\luatexUseModule{luaotfload}

\otfl@on

\otfl@AtEnd
%    \end{macrocode}
% \iffalse
%</package>
% \fi
% \Finale
\endinput