#!/bin/bash
E_ERR=1

# For trasparent image
#$bg = "Transparent"; 

# For trasparent image
bgf='White'

if [ "$#" -ne 2 ] 
then
	echo " Usage: `basename $0` formula_file density(75-1200)"
	echo " output formula_file.png "
	exit $E_ERR
fi
density=$2
formula=$(cat $1)
tex='\documentclass[fleqn]{article} 
     \usepackage{amssymb,amsmath} 
     \usepackage[latin1]{inputenc} 
     \newcommand{\grad}{\vec{\nabla}}
     \begin{document}  
     \thispagestyle{empty} 
     \mathindent0cm 
     \parindent0cm
     \begin{eqnarray*}
     '$formula'  
     \end{eqnarray*}
     \end{document}';

echo $tex > temp_formula.tex;

latex -interaction=nonstopmode temp_formula.tex

dvipng -q -T tight -bg $bgf -D $density temp_formula.dvi -o $1.png 

rm -f temp_formula.dvi

exit 0