+% Copyright (C) 2009-2013 by Elie Roux <elie.roux@telecom-bretagne.eu>

+Copyright (C) 2009-2013 by by Elie Roux <elie.roux@telecom-bretagne.eu>

+ [2013/04/16 v2.2 OpenType layout system]%

+\usepackage{metalogo,multicol,mdwlist,fancyvrb,xspace}

+\usepackage[x11names]{xcolor}

+%

+\def\primarycolor{DodgerBlue4}

+\def\secondarycolor{Goldenrod4}

+%

+ bookmarks=true,

+ colorlinks=true,

+ linkcolor=\primarycolor,

+ urlcolor=\secondarycolor,

+ citecolor=\primarycolor,

+ pdftitle={The luaotfload package},

+ pdfsubject={OpenType layout system for Plain TeX and LaTeX},

+ pdfauthor={Elie Roux & Khaled Hosny},

+]{hyperref}

+%usepackage{unicode-math}%% broken

+\setmainfont[Numbers=OldStyle,Ligatures=TeX]{Linux Libertine O}

+\setmonofont[Ligatures=TeX,Scale=MatchLowercase]{Liberation Mono}

+%setsansfont[Ligatures=TeX]{Linux Biolinum O}

+\setsansfont[Ligatures=TeX,Scale=MatchLowercase]{Iwona Medium}

+%setmathfont{XITS Math}

+

+%%\definecolor{niceblue}{rgb}{0.4,0.6,1.000}

+

+\newcommand\TEX {\TeX\xspace}

+\newcommand\LUA {Lua\xspace}

+\newcommand\PDFTEX {pdf\TeX\xspace}

+\newcommand\LUATEX {\LUA\TeX\xspace}

+\newcommand\XETEX {\XeTeX\xspace}

+\newcommand\LATEX {\LaTeX\xspace}

+\newcommand\CONTEXT{Con\TeX t\xspace}

+

+\def\definehighlight[#1][#2]%

+ {\ifcsname #1\endcsname\else

+ \expandafter\def\csname #1\endcsname%

+ {\bgroup#2\csname #1_indeed\endcsname}

+ \expandafter\def\csname #1_indeed\endcsname##1%

+ {##1\egroup}%

+ \fi}

+

+\def\restoreunderscore{\catcode`\_=12\relax}

+

+\definehighlight [fileent][\ttfamily\restoreunderscore] %% files, dirs

+\definehighlight [texmacro][\sffamily\itshape\textbackslash] %% cs

+\definehighlight[luafunction][\sffamily\itshape\restoreunderscore] %% lua identifiers

+\definehighlight [identifier][\sffamily] %% names

+\definehighlight [abbrev][\rmfamily\scshape] %% acronyms

+\definehighlight [emphasis][\rmfamily\slshape] %% level 1 emph

+% \title{The \identifier{luaotfload} package}

+% \date{2013/04/16 v2.2}

+% This package is an adaptation of the \CONTEXT font loading system, providing

+% the ability to load \identifier{OpenType} fonts with extended font loading syntax

+% Font management and installation has always been painful with \TEX. A lot of

+% files are needed for one font (\abbrev{tfm}, \abbrev{pfb}, \abbrev{map},

+% \abbrev{fd}, \abbrev{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

+% \emphasis{smart font} technologies like \identifier{OpenType} fonts. These fonts can

+% systems like Arabic and Indic\footnote{%

+% Unfortunately, \identifier{luaotfload} doesn't support Indic scripts right

+% now.

+% } scripts.

+% They are widely deployed

+% 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

+% \identifier{luaotfload} supports an extended font loading syntax which looks

+% |\font\foo={|\meta{prefix}|:|\meta{font name}|:|\meta{font features}|}| \meta{\TEX font features}

+% For compatibility with \XETEX, surrounding the \meta{font name} with square

+% \fileent{texmf} ones, and requires a font names database; see

+% specified then \identifier{kpathsea} is used to locate the font (which will

+% typically be in the \fileent{texmf} tree or the current directory).

+% tags\footnote{%

+% Cf. \url{http://www.microsoft.com/typography/otspec/featurelist.htm}

+% }

+% \item [mode]

+% \identifier{luaotfload} has two OpenType processing modes; \identifier{base}

+% and \identifier{node}.

+% \identifier{base} mode works by mapping OpenType features to traditional \TEX

+% ligature and kerning mechanisms, thus supporting only non-contextual

+% substitutions and kerning pairs, but is slightly faster. \identifier{node}

+% works by direct processing of the node list at \LUA end and have more wide

+% support of OpenType features but can be slow especially with complex fonts

+% and can't be used in math mode.

+%

+% By default \identifier{node} mode is used, and you have to manually force

+% \identifier{base} mode when needed, e.~g. for math fonts.

+%

+% \item [script]

+% OpenType script string,\footnote{%

+% Cf. \url{http://www.microsoft.com/typography/otspec/scripttags.htm}.

+% }

+% default value is \identifier{dlft}.

+% Some fonts don't assign features to the |dflt|

+% OpenType language string,\footnote{%

+% Cf. \url{http://www.microsoft.com/typography/otspec/languagetags.htm}.

+% }

+% default value is \identifier{latn}.

+% Specification.\footnote{%

+% Cf. \url{http://www.adobe.com/devnet/opentype/afdko/topic_feature_file_syntax.html}

+% }

+% protrusion and expansion. The value of the key is the name of predefined \LUA

+% tables of protrusion and expansion values; see the end of

+% \fileent{otfl-fonts-ext.lua}

+% file for an example of such tables. The only predefined value is

+% \identifier{default}.

+%

+% For example, to enable default protrusion\footnote{%

+% You also need to set

+% \texmacro{pdfprotrudechars}|=2|

+% \texmacro{pdfadjustspacing}|=2|

+% to activate protrusion and expansion, respectively.

+% See

+% \href{http://mirrors.ctan.org/systems/pdftex/manual/pdftex-a.pdf}%

+% {\PDFTEX manual}

+% for details.

+% }:

+% \identifier{luaotfload} defines some additional font feature not defined in

+%

+% \item \identifier{anum}:

+% replaces European numbers with eastern Arabic numbers or Persian

+% numbers, depending on the value of \identifier{language}.

+% \item \identifier{tlig}:

+% applies legacy \TEX ligatures:

+% |``|, |''|, |`|, |'|, |"|, |--|, |---|, |!`| and |?`|.%

+% \footnote{%

+% For \XETEX users: this is the equivalent of the assignment

+% \verb|mapping=text-tex| using \XETEX's input remapping feature.

+% }

+%

+% As introduced in the previous section, \identifier{luaotfload} uses a database to

+% keep track of fonts available to \LUATEX. Using this database, fonts can be

+% When \identifier{luaotfload} is asked to load a font by font name, it will check

+% \identifier{luaotfload} provides a |mkluatexfontdb| utility to manually update

+% directly or as an argument to |texlua|, depending on your system.\footnote{%

+% On \abbrev{MS} \identifier{Windows} it can be run either by calling the

+% wrapper application |mkluatexfontdb.exe| or with

+% |texlua.exe mkluatexfontdb.lua|.

+% }

+% \identifier{luaotfload} will parse standard places for fonts in your system to

+% Some fonts are problematic in \LUATEX, if you found that your document takes

+% file it is stuck with. You can then instruct \identifier{luaotfload} to ignore

+% blacklisted files, one per line. Then put the file some where \identifier{kpse}

+% a |%| sign is ignored. \identifier{luaotfload} reads all files named named

+% \section{Used \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

+% from \CONTEXT as far as possible, but we changed their names to prevent name

+% The \CONTEXT files are renamed by adding the prefix |otfl-| to them (|otfl|

+% \item |font-age.lua|\footnote{%

+% Not renamed as it is loaded directly from % |fonts-enc.lua|.

+% }

+% \item |otfl-font-ltx.lua|\footnote{%

+% A heavily modified version of |luatex-fonts-def.lua|.

+% }

+% \part{\fileent{luaotfload.lua}}

+% At the moment, there are three candidates: The \identifier{generic}

+% callback as hard-coded in the font loader, the \identifier{old} wrapper,

+% and a simplified version of the latter (\identifier{patch}) that does

+% (NB: \CONTEXT handles this likewise in \fileent{font-vf.lua}.)

+%

+% \begin{enumerate}

+%

+% \item insert the functionality required for fontloader; and

+%

+% \item put it in place via the respective callbacks.

+%

+% \end{enumerate}

+%

+% \emphasis{merged font loader code}.

+% In \identifier{luaotfload} this is contained in the file

+%

+% \begin{itemize}

+%

+% \item \luafunction{generic_context}:

+% encapsulation mechanism, callback functions

+%

+% \item \luafunction{non generic_context}:

+% customized code insertion

+%

+% \end{itemize}

+%

+% \identifier{luatexbase}-style callback handling here.

+% \identifier{luatexbase}.

+% in \CONTEXT\ in the concept of \emphasis{node processor}.

+% \part{\fileent{luaotfload.sty}}

+% Classical Plain+\LATEX package initialization.

+ [2013/04/16 v2.2 OpenType layout system]

+\RequireLuaModule{luaotfload}

+

+\csname ifluaotfloadloaded\endcsname

+\let\ifluaotfloadloaded\endinput

+\bgroup\expandafter\expandafter\expandafter\egroup

+\expandafter\ifx\csname ProvidesPackage\endcsname\relax

+ \input luatexbase.sty

+\else

+ \NeedsTeXFormat{LaTeX2e}

+ \ProvidesPackage{luaotfload}%

+ [2013/04/16 v2.2 OpenType layout system]

+ \RequirePackage{luatexbase}

+\fi

+% %% As soon as we feel the need this file will file will contain an extension

+% %% to the standard plain register allocation. For the moment we stick to a

+% %% rather dumb attribute allocator. We start at 256 because we don't want

+% %% any interference with the attributes used in the font handler.

+% %%\newcount \lastallocatedattribute \lastallocatedattribute=255

+% %%\def\newattribute#1%

+% %% {\global\advance\lastallocatedattribute 1

+% %% \attributedef#1\lastallocatedattribute}

+%

+% \begin{macrocode}

+\endinput

+local dummy_function = function () end

+No final decision has been made on how to handle font definition. At

+the moment, there are three candidates: The \identifier{generic}

+callback as hard-coded in the font loader, the \identifier{old}

+wrapper, and a simplified version of the latter (\identifier{patch})

+that does nothing besides applying font patches.

+local error, warning, info, log =

+ luatexbase.provides_module(luaotfload.module)

+

+--[[doc--

+This is a necessary initalization in order not to rebuild an existing

+font.

+Maybe 600 should be replaced by \texmacro{pdfpkresolution} %% (why?)

+or \luafunction{texconfig.pk_dpi} (and it should be replaced

+dynamically), but we don't have access (yet) to the

+\identifier{texconfig} table, so we let it be 600.

+Anyway, it does still work fine even if \texmacro{pdfpkresolution} is

+changed.

+--doc]]--

+

+kpse.init_prog("", 600, "/")

+--[[doc--

+We set the minimum version requirement for \LUATEX to v0.74, as it was

+the first version to include version 5.2 of the \LUA interpreter.

+--doc]]--

+local luatex_version = 74

+

+--[[doc--

+\subsection{Module loading}

+

+We load the files imported from \CONTEXT with this function.

+It automatically prepends the prefix \fileent{otfl-} to its argument,

+so we can refer to the files with their actual \CONTEXT name.

+--doc]]--

+

+local fl_prefix = "otfl" -- “luatex” for luatex-plain

+\luafunction{find_vf_file} derives the name of the virtual font file

+from the filename.

+(NB: \CONTEXT handles this likewise in \fileent{font-vf.lua}.)

+

+\subsection{Preparing the Font Loader}

+The wrapper file is \fileent{otfl-fonts.lua} which we imported from

+\href{http://standalone.contextgarden.net/current/context/experimental/tex/generic/context/luatex/}{\LUATEX-Plain}.

+

+\begin{enumerate}

+

+ \item insert the functionality required for fontloader; and

+

+ \item put it in place via the respective callbacks.

+

+\end{enumerate}

+

+In \identifier{luaotfload} this is contained in the file

+\fileent{otfl-fonts-merged.lua}.

+

+ \begin{itemize}

+ \item \luafunction{generic_context}:

+ encapsulation mechanism, callback functions

+ \item \luafunction{non generic_context}:

+ customized code insertion

+ \end{itemize}

+

+

+With \luafunction{non_generic_context} we can tailor the font loader

+insertion to our file naming habits (key \luafunction{load_before}).

+Additionally, \luafunction{skip_loading} can be unset to force loading

+of the original libraries as though the merged code was absent.

+Another key, \luafunction{load_after} is called at the time when the

+font loader is actually inserted.

+In combination with the option \luafunction{no_callbacks_yet} in

+\luafunction{generic_context}, we can insert our own,

+\identifier{luatexbase}-style callback handling here.

+The imported font loader will call \luafunction{callback.register} once

+while reading \fileent{font-def.lua}.

+This is unavoidable unless we modify the imported files, but harmless

+if we make it call a dummy instead.

+

+Now that things are sorted out we can finally load the fontloader.

+

+By default, the fontloader requires a number of \emph{private

+attributes} for internal use.

+These must be kept consistent with the attribute handling methods as

+provided by \identifier{luatexbase}.

+Previously, when \identifier{luaotfload} imported individual files from

+\CONTEXT, the strategy was to override the function that allocates new

+attributes at the appropriate time during initialization, making it a

+wrapper around \luafunction{luatexbase.new_attribute}.

+

+\begin{verbatim}

+attributes.private = function (name)

+ local attr = "otfl@" .. name

+ local number = luatexbase.attributes[attr]

+ if not number then

+ number = luatexbase.new_attribute(attr)

+ end

+ return number

+end

+\end{verbatim}

+

+Now that the fontloader comes as a package, this hack is no longer

+applicable.

+The attribute handler installed by \identifier{luatex-fonts} (see the

+file \fileent{otfl-basics-nod.lua}) cannot be intercepted before the

+first call to it takes place.

+While it is not feasible to prevent insertion of attributes at the

+wrong places, we can still retrieve them from the closure surrounding

+the allocation function \luafunction{attributes.private}

+using \LUA’s introspection features.

+

+The recovered attribute identifiers are prefixed “\fileent{otfl@}” to

+avoid name clashes.

+--doc]]--

+

+do

+ local debug_getupvalue = debug.getupvalue

+

+ local nups = debug.getinfo(attributes.private, "u").nups

+ local nup, numbers = 0

+ while nup <= nups do

+ nup = nup + 1

+ local upname, upvalue = debug_getupvalue(attributes.private, nup)

+ if upname == "numbers" then

+ numbers = upvalue

+ break

+ end

+ end

+ if numbers then

+ local luatexbase_attributes = luatexbase.attributes

+ local prefix = "otfl@"

+ --- re-register attributes from “numbers”

+ --- ... pull request for luatexbase pending

+ for name, num in next, numbers do

+ name = prefix .. name

+ luatexbase_attributes[name] = num

+ end

+ end

+ --- The definitions used by the fontloader are never

+ --- called again so it is safe to nil them, I suppose.

+ debug.setupvalue(attributes.private, nup, { })

+ _G.attributes = nil --- needed for initialization only

+end

+

+--[[doc--

+

+\subsection{Callbacks}

+

+\identifier{luatexbase}.

+Note: \luafunction{pre_linebreak_filter} and \luafunction{hpack_filter}

+are coupled in \CONTEXT in the concept of \emph{node processor}.

+ --- fonts.readers.sequence[#fonts.readers.sequence+1] = "ofm"

+--[[doc--

+

+Now we load the modules written for \identifier{luaotfload}.

+

+--doc]]--

+loadmodule"font-pfb.lua" --- new in 2.0, added 2011

+loadmodule"font-ltx.lua" --- new in 2.0, added 2011

+

+--[[doc--

+

+We create a callback for patching fonts on the fly, to be used by other

+packages.

+It initially contains the empty function that we are going to override

+below.

+

+--doc]]--

+

+As of 2013, everything it does appear to be redundand, so we won’t use

+it unless somebody points out a cogent reason.

+font data objects and will stay here for reference / until breakage is

+reported.

+\emphasis{TODO}

+

+

+\subsection{\CONTEXT override}

+

+

+

+local read_font_file = fonts.definers.read

+ local tfmdata = read_font_file(...)-- spec -> size -> id -> tmfdata

+--[[doc--

+Finally we register the callbacks

+--doc]]--

+

+ define_font_wrapper,