#!/bin/bash
# Part of latex2rtf by Scott Prahl (Nov 2009)
#
# This version uses latex and dvips
#              with convert (Part of ImageMagick)
#
# This script file will convert a latex file into a PNG image.
# Because latex2rtf also needs to convert EPS files, these are 
# also converted.  By default latex2png assumes that the input
# file is a latex file, however, if the extension is .eps, then
# the file is treated an EPS file. 
#
# When the latex file contains the tag 'INLINE_DOT_ON_BASELINE' then
# a dot is assumed to have been placed at the beginning of a latex
# This dot is used to locate the baseline of the equation for 
# alignment in the RTF file.  This shell script will create a PGN
# (portable gray map) file that can be used to determine the 
# height of the equation baseline
#
#set -x  # uncomment for debugging
#

DVIPS="dvips -q -l 1 -E -R"
LATEX="latex --interaction batchmode --output-format dvi"
PDFLATEX="latex --interaction batchmode --output-format pdf"
XELATEX="xelatex --interaction batchmode"
CONVERT="convert"
PDF2EPS="eps2eps"
GREP="grep"
AWK="awk"
SED="sed"
# !!!!!!!!!!!!!!!! Note !!!!!!!!!!!!!!
# Under MS Windows, although this script runs under bash shell,
# LaTeX is run in the Windows environment and thus needs the ";" as separator.
TEXINPSEP=":" #Unix
#TEXINPSEP=";"  #MS Windows
VERSION="1.50"

help()
{
cat <<HELP
latex2png -- convert latex file to PNG image

USAGE: latex2png [-d density] [-o offset] [-h] [-e] [-k] [-c] [-g] [-m] [-H home dir] file[.tex|.eps]

OPTIONS: 
         -c color image
         -g gray image  
         -m monochrome  (default)
         -e only create EPS files
         
         -d density     (default 300 dpi)
         -o offset      (default 5)
         -h             help
         -H /home/dir   directory to be included in search path (default '.')
         -k             keep intermediate files (for debugging)

EXAMPLES: 
         latex2png -d 144 /tmp/file   #create /tmp/file.png at 144 dpi
         latex2png file.eps           #create file.png
         latex2png file.tex           #create file.png via latex
         latex2png -H . /tmp/file     #search the cwd for image files

HELP
exit 0
}

version()
{
echo "latex2png $VERSION"
exit 0
}

opt_d=300       # default to 300 dpi
opt_o=5	        # default for 300 dpi
opt_k=0         # default to killing intermediate files
home_dir="."    # default to current directory
ext="tex"       # default to latex input
out="-depth 24" # default to color output
inline=0        # default to no special equation processing

while [ -n "$1" ]; do
case $1 in
    -e) opt_eps=1;         shift 1;; #create eps file
    -g) out="-depth 8";    shift 1;; #gray
    -c) out="-depth 24";   shift 1;; #color
    -m) out="-monochrome"; shift 1;; #monochrome
    -h) help;              shift 1;;
    -k) opt_k=1;           shift 1;; 
    -d) opt_d=$2;          shift 2;; #shift by 2 due to argument
    -o) opt_o=$2;          shift 2;;
    -H) home_dir=$2;       shift 2;;
    -v) version;           shift 1;;
    --) break;;
    -*) echo "latex2png: error: no such option $1"; exit 1;;
    *)  break;;
esac
done

# is there an input file?
if [ -z "$1" ] ; then
    echo "latex2png: error: no input file specified"
    exit 1
fi

# is it an eps file?
if [ `echo $1 | ${GREP} -c eps` -eq 1 ] ; then
   ext="eps"
   if [ $opt_eps ] ; then
        exit 1
   fi
fi

#process 'latex2png file.tex' and 'latex2png file' equivalently
name=`basename $1 ".$ext"`
dir=`dirname $1`

#add $home_dir to latex/dvips search path
cd $home_dir
TEXINPUTS=`pwd`${TEXINPSEP}
export TEXINPUTS
cd $dir
    
# does the input file exist?
if [ ! -f "$name.$ext" ] ; then
 echo "latex2png: error: input file $name.$ext does not exist in directory $dir"
 exit 1
fi

if [ $ext = "tex" ] ; then

    inline=`${GREP} -c INLINE_DOT_ON_BASELINE $name.$ext`

    rm -f $name.dvi
    rm -f $name.pdf
    rm -f $name.eps
    rm -f $name.png


    $PDFLATEX $name > /dev/null
    if [ -e "$name.pdf" ] ; then
       $PDF2EPS $name.pdf $name.eps
       if [ ! -e "$name.eps" ] ; then
          echo "latex2png: error: eps2eps failed to translate $name.pdf to $name.eps"
          exit 1
       fi
    else
       if [ $opt_k -eq 1 ] ; then
          echo "latex2png: pdflatex failed to translate $name.tex to $name.pdf, trying xelatex"
       fi
       $XELATEX $name > /dev/null
       if [ -e "$name.pdf" ] ; then
          $PDF2EPS $name.pdf $name.eps
          if [ ! -e "$name.eps" ] ; then
             echo "latex2png: error: eps2eps failed to translate $name.pdf to $name.eps"
             exit 1
          fi
       else
          if [ $opt_k -eq 1 ] ; then
             echo "latex2png: xelatex failed to translate $name.tex to $name.dvi, trying latex"
          fi
          $LATEX $name > /dev/null
          if [ -e "$name.dvi" ] ; then
             $DVIPS -o $name.eps $name.dvi
             if [ ! -e "$name.eps" ] ; then
               if [ $opt_k -eq 1 ] ; then
                  echo "latex2png: error: dvips failed to translate $name.dvi to $name.eps"
                  exit 1
               fi
               exit 1
             fi
          else
             echo "latex2png: error: pdflatex, xelatex and latex all failed to translate $name.tex"
             exit 1
          fi
       fi
    fi
 
    if [ $opt_eps ] ; then
        if [ $inline -eq 1 ] ; then
           # extract the BoundingBox of the eps with adjustment stuff
           # parameters are: llx lly urx ury
           bbb=`${GREP} -C 0 %%BoundingBox: $name.eps`
           llydraft=$(echo $bbb | $AWK -F" " '{print $3}' )
           urydraft=$(echo $bbb | $AWK -F" " '{print $5}' )
           # now create an eps without the adjustment stuff
           $SED -e "s/\^I_g//" $name.tex >$name.tmp
           rm $name.tex
           rm -f $name.pdf
           rm $name.eps
           mv $name.tmp $name.tex

           $PDFLATEX $name > /dev/null
           if [ -e "$name.pdf" ] ; then
              $PDF2EPS $name.pdf $name.eps
           else
              if [ $opt_k -eq 1 ] ; then
                 echo "latex2png: pdflatex failed to translate $name.tex w/o adj to $name.pdf, trying xelatex"
              fi
              $XELATEX $name > /dev/null
              if [ -e "$name.pdf" ] ; then
                 $PDF2EPS $name.pdf $name.eps
              else
                 if [ $opt_k -eq 1 ] ; then
                    echo "latex2png: error: xelatex failed to translate $name.tex w/o adj to $name.pdf, trying latex"
                 fi
                 $LATEX $name > /dev/null
                 if [ -e "$name.dvi" ] ; then
                    $DVIPS -o $name.eps $name.dvi
                 else
                    echo "latex2png: pdflatex, xelatex and latex all failed to translate $name.tex w/o adj"
                    exit 1
                 fi
              fi
           fi
           if [ ! -e "$name.eps" ] ; then
              echo "latex2png: error: failed to translate $name.tex to $name.eps"
              exit 1
           fi

           # extract the BoundingBox of the eps without adjustment stuff
           bbb=`${GREP} -C 0 %%BoundingBox: $name.eps`
           llyfin=$(echo $bbb | $AWK -F" " '{print $3}' )
           uryfin=$(echo $bbb | $AWK -F" " '{print $5}' )
           # use the maximum y extension
           if [ "$llydraft" -lt "$llyfin" ] ; then
              $SED -b -e "/%%BoundingBox:/s/$llyfin/$llydraft/" $name.eps >$name.tmp
              rm $name.eps
              mv $name.tmp $name.eps
           fi
           if [ "$urydraft" -gt "$uryfin" ] ; then
              $SED -b -e "/%%BoundingBox:/s/$uryfin/$urydraft/" $name.eps >$name.tmp
              rm $name.eps
              mv $name.tmp $name.eps
           fi
        fi
        if [ $opt_k -eq 0 ] ; then
            rm -f $name.pdf $name.dvi $name.aux $name.log $name.out
        fi
        exit 0
    fi
fi

# WH: added "-type TrueColor" to ensure compatibility with older versions of Word and with IrfanView
$CONVERT -units PixelsPerInch -density ${opt_d}x${opt_d} -trim +repage $name.eps -type TrueColor $out $name.png

if [ ! -e "$name.png" ] ; then
    echo "latex2png: error: convert (ImageMagick) failed to translate $name.eps to $name.png"
    exit 1
fi

# -i is for images of equations that include an extra dot on the baseline
#    this dot must be cropped out, and its height must be determined.
#    The height is determined from $name.pbm --- the first column of the image
#    The dot is cropped out of $name-tmp.png and any extra white space
#    is removed to create the final image $name.png
# 
if [ $inline -eq 1 ] ; then

	mv $name.png $name-tmp.png
	
	# remove fewer pixels from the left side on small images
	width=`identify -format "%[fx:w-2]" $name-tmp.png`
	if [ ${width} -gt ${opt_o} ] ; then
		width=${opt_o}
	fi
	
	# strip the initial dot and white space on the left
	# we must keep the white space on the bottom so we add border on the east
	# so that the bottom does not get trimmed away
	$CONVERT $name-tmp.png -chop ${width}x0 -gravity East -background white -splice 1x0 -trim +repage $name.png

	# extract first column of png and stick it in a bitmap
	$CONVERT $name-tmp.png -crop 1x0 +repage $name.pbm

    if [ $opt_k -eq 0 ] ; then
        rm -f $name-tmp.ppm
    fi
fi

if [ $opt_k -eq 0 ] ; then
    rm -f $name-tmp.png
    if [ $ext = "tex" ] ; then
        rm -f $name.dvi $name.aux $name.log $name.out $name.pdf $name.eps
    fi
fi

exit 0
