#!/bin/bash
# This script is called by gaucho to acquire scaled and cropped
# bitmap images from input files
# It is called with the source image in the first argument and
# optionally -s <floating point scale> and -b <bbox in format
# left,top,w,h -- no blanks, please> specifications.  It should 
# output an image understood by the java toolkit on stdout (gif, 
# png, jpeg should all work on fairly recent awts)
# The bbox is understood as in the unscaled image.

#outputFilter=ppmtogif
#outputFilter=pnmtogif
outputFilter=pnmtopng

# Don't change -- you'll mess up the bounding boxes
psRes=600

# procBitmap is called as
# procBitmap inputFile inputFilter scale bbox
# where bbox is some specification pnmcut understands (or empty)
# inputFile is a bitmap image that is converted to pnm by inputFilter
function procBitmap() {

	local inputFile=$1
	local inputFilter=$2
	local scale=$3
	local bbox="$4"

	procFilter1=cat
	procFilter2=cat

	if [ ! -z "$bbox" ]
	then
		procFilter1="pnmcut ${bbox//,/ }"
	fi
	if [ $scale -ne 1 ]
	then
		procFilter2="pnmscale -reduce $scale"
	fi

	($inputFilter $inputFile | $procFilter1 | $procFilter2 | \
		ppmquant 64 | $outputFilter) 2> convert.log
}


# converts one page of a ps/pdf file to psRes dpi pbm
# the argument is pageno@filename
function vectorToPbm() {
	local inputFile=${1#*@}
	if [ t$inputFile == t$1 ]
	then
		local pgSelect=cat
	else
		local pgSelect="psselect -q ${1%%@*}"
	fi
	case $inputFile in
		*.pdf)
			local preFilter="pdf2ps $inputFile -"
			;;
		* )
			local preFilter="cat $inputFile"
			;;
	esac
	($preFilter | $pgSelect |\
		gs -sDEVICE=pbm -r${psRes}x$psRes -dBATCH -dNOPAUSE \
		-d SAFER -sOutputFile=- -q - ) 2> convert.log
}


# procVector is an integrated and usually faster alternative to
# combining vectorToPbm and procBitmap
function procVector() {
	local inputFile="${1#*@}"
	local scale=$3
	local bbox="$4"
	local renderRes=`echo "3 k $psRes $scale / p" | dc`
	
	if [ ! -z "$bbox" ]
	then
		local renderbbox=`echo $bbox | awk -F, \
		"{printf(\"%f %f %f %f\", \\\$1/$scale,\\\$2/$scale,\\\$3/$scale,\\\$4/$scale)}"`
		local cropFilter="pnmcut $renderbbox"
	else
		local cropFilter=cat
	fi

	if [ "t$inputFile" == "t$1" ]
	then
		local pgSelect=cat
	else
		local pgSelect="psselect -q ${1%%@*}"
	fi

	case $inputFile in
		*.pdf)
			local preFilter=pdf2ps
			;;
		* )
			local preFilter=cat
			;;
	esac

	($preFilter $inputFile | $pgSelect |\
		gs -sDEVICE=pgm -r$renderRes -dSAFER -dBATCH -dNOPAUSE \
		-dTextAlphaBits=4 -dGraphicsAlphaBits=4 -sOutputFile=- -q - \
		| $cropFilter | $outputFilter ) 2> convert.log
}


scale=1
while getopts "s:b:" option
do
	case $option in
		s) scale=$OPTARG;;
		b) bbox=$OPTARG;;
		*) echo "This can't happen";;
	esac
done

shift $(($OPTIND-1))

inputFilter=pngtopnm

case "$1" in
	*.gif) inputFilter=giftopnm; procFun=procBitmap;;
	*.png) inputFilter=pngtopnm; procFun=procBitmap;;
	*.jpg) inputFilter=djpeg procFun=procBitmap;;
	*.jpeg) inputFilter=djpeg; procFun=procBitmap;;
	*.ps | *.eps | *.epsi | *.PS | *.pdf) 
		procFun=procVector
		inputFilter=ignore
		;;
#	*.ps | *.eps | *.epsi | *.PS | *.pdf) 
#		inputFilter=vectorToPbm
#		procFun=procBitmap
#		scale=`echo "3 k $psRes 600 / $scale * p" | dc`
#		;;
	*) echo "Don't know image format of $1" > convert.log
		exit 1
		;;
esac

$procFun "$1" $inputFilter $scale "$bbox"