harfbuzz.sty

\ProvidesPackage{harfbuzz}
\RequirePackage{luacode,luatexbase,kvoptions}

% use fontspec encoding for LuaLaTeX
% This may be needed 
\newattribute\harfbuzzenabled

\harfbuzzenabled=1
\begin{luacode*}
  require "hb_paths"
  require "hb_lualoader"
  luaharfbuzz = require "hb_shaper"
  local fontloader = require "hb_fontload"
  luatexbase.reset_callback("define_font")
  luatexbase.add_to_callback("define_font",fontloader.loader, "font loader")
  luatexbase.add_to_callback("pre_linebreak_filter",luaharfbuzz.process_nodes, "harfbuzz")
  luatexbase.add_to_callback("hpack_filter",luaharfbuzz.process_nodes, "harfbuzz_hpack")
  luatexbase.add_to_callback("vpack_filter",luaharfbuzz.process_nodes, "harfbuzz_vpack")
\end{luacode*}

\newcommand\startharfbuzz{%
%\begin{luacode*}
% \luaexec{
%   luatexbase.add_to_callback("pre_linebreak_filter",luaharfbuzz.process_nodes, "harfbuzz")
%   -- this fails
%   luatexbase.add_to_callback("hpack_filter",luaharfbuzz.process_nodes, "harfbuzz_hpack")
% }
%\end{luacode*}%
\harfbuzzenabled=1
}

\newcommand\stopharfbuzz{%
%\begin{luacode*}
% \luaexec{%
%   luatexbase.remove_from_callback("pre_linebreak_filter","harfbuzz")
%   -- hbox processing sometimes fails
%   luatexbase.remove_from_callback("hpack_filter","harfbuzz_hpack")
% }
%\end{luacode*}%
\harfbuzzenabled=0
}

\newcommand\SetFontOption[2]{%
  \luaexec{%
    % luaharfbuzz.options["\luatexluaescapestring{#1}"]="\luatexluaescapestrya"ing{#2}"
    luaharfbuzz.set_font_option("\luatexluaescapestring{#1}", "\luatexluaescapestring{#2}")
    luaharfbuzz.save_options(font.current())
  }
}

% Simple font selection scheme
\RequirePackage[EU2]{fontenc}
\newcommand\HbDeclareShape[5]{%
\DeclareFontShape{EU2}{#1}{#2}{#3}%
     {<-> "#4\if\relax\detokenize{#5}\relax\else:#5\fi"}{}%
   }
 

\newcommand\HbDeclareFamily[3]{%
  \DeclareFontFamily{EU2}{#3}{}
  % \DeclareFontShape{EU2}{hbrm}{m}{n}{<-> "#2"}{}
  \HbDeclareShape{#3}{m}{n}{#2}{#1}
  \HbDeclareShape{#3}{m}{it}{#2/I}{#1}
  \HbDeclareShape{#3}{bx}{n}{#2/B}{#1}
  \HbDeclareShape{#3}{bx}{it}{#2/BI}{#1}
  \HbDeclareShape{#3}{m}{sc}{#2}{#1+smcp}
}

\newcommand\MainFamily[2][]{%
  \HbDeclareFamily{#1}{#2}{hbrm}
  \renewcommand{\rmdefault}{hbrm}%
}

\newcommand\SansFamily[2][]{%
  \HbDeclareFamily{#1}{#2}{hbsf}
  \renewcommand{\sfdefault}{hbsf}
}


\newcommand\MonoFamily[2][]{%
  \HbDeclareFamily{#1}{#2}{hbtt}
  \renewcommand{\ttdefault}{hbtt}
}

\DeclareStringOption[0]{debug}[1]

\ProcessKeyvalOptions*

\luaexec{%
  luaharfbuzz.loglevel = tonumber("\luaescapestring{\harfbuzz@debug}")
}
\endinput