#!/bin/bash

set -e

if [ "$#" -ne 2 ]; then
  echo "Usage: `basename $0` COLOR LATEXSRC"
  echo  
  echo "with COLOR being either a single color for text on transparent background or 'color1 on color2'"
  exit 1
fi


color=$1
input=$2

fg="${color% on *}"
bg="${color##* on }"

outpdf="/tmp/latexpic.pdf"
outpng="/tmp/latexpic.png"

cat <<EOF | pdflatex --output-directory /tmp --jobname latexpic --
\documentclass[12pt,varwidth]{standalone}

\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{xcolor}
\usepackage{pagecolor}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}

\color{$fg}

\begin{document}
$input
\end{document}
EOF

if [ "$fg" = "$bg" ]; then
  convert -density 600 "$outpdf" -quality 90 "$outpng"
else
  convert -background "$bg" -flatten -density 600 "$outpdf" -quality 90 "$outpng"
fi
xdg-open "$outpng"