% \subsubsection{Images}
% \DescribeEnv{image}{Place images inside an |image| environment.  On paper, this centers the image.  On the web, this provides additional benefits.}
%    \begin{macrocode}
%<*classXimera>
%\newenvironment{image}[1][]{\begin{center}}{\end{center}}
\NewEnviron{image}[1][3in]{% 
  \begin{center}\resizebox{#1}{!}{\BODY}\end{center}% resize and center
}
%</classXimera>
%    \end{macrocode}
% \DescribeMacro{\alt}{Inside an |image| environment, |\alt| provides alt-text for assistive technology like screenreaders.}
%    \begin{macrocode}
%<*classXimera>
\newcommand{\alt}[1]{}
%</classXimera>
%    \end{macrocode}
% The |image| environment doesn't actually work in tex4ht as defined
% with NewEnviron; so this renewenvironment is needed.
% image-environment also gets formatted in a well, and when the user
% clicks on the image, it zooms in.
%    \begin{macrocode}
%<*htXimera>
\newcounter{imagealt}
\setcounter{imagealt}{0}
\renewenvironment{image}[1][]{\stepcounter{imagealt}%
  \ifvmode \IgnorePar\fi \EndP%
  \HCode{<div class="image-environment" role="img" aria-labelledby="image-alt-\arabic{imagealt}">}%
}{\HCode{</div>}}
\renewcommand{\alt}[1]{\HCode{<div style="display: none;" id="image-alt-\arabic{imagealt}">}#1\HCode{</div>}}
%</htXimera>
%    \end{macrocode}
% Although we accept many formats, SVG is preferred on the web.
% Since we have a different mechanism for producing |alt| text, we
% want to ignore tex4ht's own method fo producing alt text.
%    \begin{macrocode}
%<*cfgXimera>
\DeclareGraphicsExtensions{.jpg,.png,.gif,.svg}
\Configure{graphics*}
{svg}{
  {\Configure{Needs}{File: \Gin@base.svg}\Needs{}}
  \Picture[]{\csname Gin@base\endcsname.svg \csname a:Gin-dim\endcsname}%
}
%</cfgXimera>
%    \end{macrocode}
% This is a hack to kill |includegraphics| commands in
% |\documentclass{standalone}| files
%    \begin{macrocode}
%<*cfgXimera>
\ifcsname ifstandalone\endcsname
  \ifstandalone
    \renewcommand\includegraphics[2][]{}
  \fi
%</cfgXimera>
%    \end{macrocode}
% PGF sometimes causes trouble, but we simply don't care in tex4ht mode.
%    \begin{macrocode}
%<*htXimera>
\newcommand{\pgfsyspdfmark}[3]{}
%</htXimera>
%    \end{macrocode}
