latexbangla.sty

% ----------------------------------------------------------------
% LaTeXbangla package - Enhanced LaTeX integration for Bangla
% E-mail: adib.hasan8@gmail.com
% Released under the LaTeX Project Public License v1.3c or later
% See http://www.latex-project.org/lppl.txt
% ----------------------------------------------------------------
% This package simplifies the process of writing Bangla in LaTeX and
% addresses most of the common typesetting issues. Additional features
% include automatic transition between languages and many more. (See
% examples) The user can just type in usual LaTeX syntax and expect
% everything to work as it should.
% ------------------------------------------------------------------
% Copyright (C) 2016-9 by Adib Hasan adib.hasan8@gmail.com

% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License (LPPL), either
% version 1.3c of this license or (at your option) any later
% version. The latest version of this license is in the file:

% http://www.latex-project.org/lppl.txt

% This work is "maintained" (as per LPPL maintenance status) by
% Adib Hasan

% This work consists of the files:  latexbangla.sty,
%                                   latexbangla.tex, and
%                                   latexbangla.pdf
%
%
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{latexbangla_exp}[2016/10/31 v0.2 Enhanced LaTeX integration for Bangla]

\RequirePackage{polyglossia, fontspec, xkeyval, ifxetex}

% Because this package depends on ucharclasses which itself
% requires XeTeX's interchar classes
\RequireXeTeX

% I have personally tuned some parameters for the following Bangla Fonts so that
% they blend well with the English font. Other banglafonts *are* supported but 
% might look out of shape before you tune the following parameters.

\def\@@Kalpurush{Kalpurush}
\def\@Kalpurush#1{
    \ifcase#1{Kalpurush}    % name
    \or{MatchLowercase}     % Scale
    \or{1.1}                % main WordSpace
    \or{1.5}                % tt WordSpace
    \else\fi
}

\def\@@SiyamRupali{SiyamRupali}
\def\@SiyamRupali#1{
    \ifcase#1{SiyamRupali}  % name
    \or{0.8}                % Scale
    \or{1.2}                % main WordSpace
    \or{1.8}                % tt WordSpace
    \else\fi
}

\def\@@SolaimanLipi{SolaimanLipi}
\def\@SolaimanLipi#1{
    \ifcase#1{SolaimanLipi} % name
    \or{0.89}               % Scale
    \or{1.5}                % main WordSpace
    \or{2.1}                % tt WordSpace
    \else\fi
}

% package options
\DeclareOptionX{banglamainfont}{%
    \if\relax\detokenize{#1}\relax
        \errmessage{Bangla main font not defined}
    \else
        \def\bm@name{#1}
        \def\bm@@name{bmfont}
        \bm@init{\bm@name}
    \fi
}
\DeclareOptionX{banglattfont}{%
    \if\relax\detokenize{#1}\relax
        \errmessage{Bangla tt font not defined}
    \else
        \def\btt@name{#1}
        \def\btt@@name{bttfont}
        \btt@init{\btt@name}
    \fi
}

% should translate counter numbers (eg. page number, section number) to bangla?
\newif\ifchange@num
\change@numtrue
\DeclareOptionX{changecounternumbering}{
    \if\relax\detokenize{#1}\relax\fi
    \ifcase#1\change@numfalse\fi
}

% set bangla main font with given settings
\def\bm@init#1{%
    % if Kalpurush
    \ifx#1\@@Kalpurush%
        \def\bm@scale{\@Kalpurush{1}}%
        \def\bm@wordspace{\@Kalpurush{2}}%
    % else if SiyamRupali
    \else\ifx#1\@@SiyamRupali%
        \def\bm@scale{\@SiyamRupali{1}}%
        \def\bm@wordspace{\@SiyamRupali{2}}%
    % else if SolaimanLipi
    \else\ifx#1\@@SolaimanLipi%
        \def\bm@scale{\@SolaimanLipi{1}}%
        \def\bm@wordspace{\@SolaimanLipi{2}}%
    % else, my best bet is MatchLowercase with Latin,
    % but that does not quite work all the time
    \else
        \def\bm@scale{MatchLowercase}%
        \def\bm@wordspace{1}%
    \fi\fi\fi%
}

% set bangla tt font with given settings
\def\btt@init#1{%
    % if Kalpurush
    \ifx#1\@@Kalpurush%
        \def\btt@scale{\@Kalpurush{1}}%
        \def\btt@wordspace{\@Kalpurush{3}}%
    % else if SiyamRupali
    \else\ifx#1\@@SiyamRupali%
        \def\btt@scale{\@SiyamRupali{1}}%
        \def\btt@wordspace{\@SiyamRupali{3}}%
    % else if SolaimanLipi
    \else\ifx#1\@@SolaimanLipi%
        \def\btt@scale{\@SolaimanLipi{1}}%
        \def\btt@wordspace{\@SolaimanLipi{3}}%
    % else, my best bet is MatchLowercase with Latin,
    % but that does not quite work all the time
    \else%
        \def\btt@scale{MatchLowercase}%
        \def\btt@wordspace{1.2}%
    \fi\fi\fi%
}

\ProcessOptionsX\relax

% Polyglossia settings
\ifchange@num
    \setmainlanguage[changecounternumbering=false]{bengali}
\else
    \setmainlanguage{bengali}
\fi

% define fontfamilies to be used by polyglossia
% Note: you can change the level of boldness and slant
\newfontfamily\bengalifont[%
    Script=Bengali,%
    Scale=\bm@scale,%
    NFSSFamily=\bm@@name,%
    WordSpace=\bm@wordspace,%
    AutoFakeSlant=0.15,
    AutoFakeBold=2.5
    ]{[\bm@name]}

\newfontfamily\bengalifonttt[%
    Script=Bengali,%
    Scale=\btt@scale,%
    NFSSFamily=\btt@@name,
    WordSpace=\btt@wordspace,%
    AutoFakeSlant=0.15,
    AutoFakeBold=2.5
    ]{[\btt@name]}


% ----   -----    -----    ----
% Use Latin Modern for English text. Note this will override settings from other font packages 
% like `courier', `palatino' etc. If you don't like this feature, comment out \setTransitionsForLatin

% define a new environment latin with Latin Modern
% you may load another English font with \newfontfamily (see above) and use it here
\newenvironment{latin}{\fontencoding{OT1}\ifx\f@family\btt@@name\fontfamily{lmtt}\else\fontfamily{lmr}\fi\selectfont}\relax

% Devanagari is required since Bangla fullstop dari ("0964) is in Devanagari block of Unicode
\RequirePackage[Latin, Bengali, Devanagari]{ucharclasses}

% When latin text is encountered, surround it with \begin{latin} and \end{latin}
\setTransitionsForLatin{\begin{latin}}{\end{latin}}
% ---- ----   ----   -----    -----



% two commands to convert counters and numerals to bangla
% uses Polyglossia's internal counter converters

% counter converter
\def\tobangla#1{\expandafter\bengalinumber\csname c@#1\endcsname}
% numeral converter
\def\numtobangla#1{\bengalinumber#1\@nil}




% converting all the useful counters not handled by polyglossia to bangla
\renewcommand{\thechapter}{\tobangla{chapter}}
\renewcommand{\theequation}{\thechapter.\tobangla{equation}}
\renewcommand{\thefigure}{\thechapter.\tobangla{figure}}
\renewcommand{\theenumi}{\tobangla{enumi}}
\renewcommand{\theenumii}{\tobangla{enumii}}
\renewcommand{\theenumiii}{\tobangla{enumiii}}
\renewcommand{\thefootnote}{\tobangla{footnote}}

% there is no glyph for bullet in bangla fonts
% so change list labels to $\bullet$
\renewcommand\labelitemi{$\bullet$}

% correct captions in polyglossia
\addto\captionsbengali{\renewcommand\abstractname{সারসংক্ষেপ}}
\addto\captionsbengali{\renewcommand\bibname{গ্রন্থসূত্র}}
\addto\captionsbengali{\renewcommand{\figurename}{চিত্র}}


% better support for accented letters
% \RequirePackage{xunicode}
% to allow escape codes. Ex: use \escape{\"{o}} for ő. 
% See the full list here: https://en.wikibooks.org/wiki/LaTeX/Special_Characters#Escaped_codes
\newcommand{\escape}[1]{\uccoff\begin{latin}{#1}\end{latin}\uccon}


\endinput