#!/bin/bash

FILE=$1
TMPDIR=i/tmp
TEMPTEX=$TMPDIR/stapel.tex
STEPS=30
OUTPUTDIR=o/free/v/differentdithers

SIZE=400
IMGSIZE=250
BORDER=`expr \( $SIZE - $IMGSIZE \) \/ 2`
STEP=1

rm $TMPDIR/*

convert -resize $IMGSIZE $FILE $TMPDIR/resized.png

convert -scene 1 +adjoin \
       	-bordercolor '#FFFFFF' \
        -border $BORDERx$BORDER \
        -gravity center \
	 $TMPDIR/resized.png \
	 $TMPDIR/canvas.png

  while [ $STEP -le $STEPS ]
   do
	RING=`echo \`date +%N \`\`date +%N \` | tr -d '0'`
	RCHAR=`date +%N | tr -d '0' | rev | cut -c 1`
	RCHBR=`expr $RCHAR + 1`
	FACTOR=`echo $RING | cut -c $RCHAR-$RCHBR`

	RESIZE=`expr \( \`echo ${SIZE}00000\` \/ \`echo ${FACTOR}000\` \) | cut -c 1-3 | rev`

	#convert -resize $RESIZE +antialias canvas.png resized.gif

		convert $TMPDIR/canvas.png -colorspace Gray -negate \
			$TMPDIR/gray.png

		composite -compose CopyOpacity \
			$TMPDIR/gray.png \
			$TMPDIR/canvas.png $TMPDIR/matte.png

		convert $TMPDIR/matte.png -ordered-dither 2x2\
			+antialias $TMPDIR/ordered.gif

		convert $TMPDIR/ordered.gif -background white \
			-resize $RESIZE +antialias \
			-flatten +matte $TMPDIR/dither.gif
		
		convert -monochrome $TMPDIR/dither.gif $TMPDIR/mono.gif

	TOPSTEP=`expr \`expr $RESIZE \/ $STEPS\` \* $STEP` 
	DOWNSTEP=`expr \( \`expr $RESIZE \/ $STEPS\` \* $STEP \) + \
			\`expr $RESIZE \/ $STEPS\` + 5`

	convert	-fill white -draw "rectangle 0,0,$RESIZE,$TOPSTEP" \
		-fill white -draw "rectangle 0,$DOWNSTEP,$RESIZE,$RESIZE" \
		 $TMPDIR/mono.gif \
		 $TMPDIR/slit.png

	#autotrace -background-color=FFFFFF -corner-threshold `expr $RESIZE` -output-file=$TMPDIR/$STEP.pdf $TMPDIR/slit.png
	autotrace -background-color=FFFFFF -corner-threshold 300 -corner-always-threshold 300 -error-threshold 100 -output-file=$TMPDIR/$STEP.pdf $TMPDIR/slit.png

	STEP=`expr $STEP + 1`
  done

echo "\documentclass[10pt]{scrartcl}" 						  >  $TEMPTEX
echo "\usepackage{pdfpages}"							  >> $TEMPTEX
echo "\usepackage{geometry}"							  >> $TEMPTEX
echo "\geometry{paperwidth=141mm,paperheight=141mm}"				  >> $TEMPTEX
echo "\pagestyle{empty}"							  >> $TEMPTEX
echo "\setlength\oddsidemargin{-.2\paperwidth}"					  >> $TEMPTEX
echo "\setlength\\topmargin{.7\paperwidth}" 					  >> $TEMPTEX
echo "\\newcommand{\graphic}[2]{\includegraphics[width=\paperwidth,angle=#2]{#1}}">> $TEMPTEX
echo "\\begin{document}"							  >> $TEMPTEX
echo "\\begin{picture}(0,0)"							  >> $TEMPTEX

	for PDF in `find $TMPDIR -name "*.pdf"`
	do
	#echo  "\put(0,0){\graphic{"${PDF##*/}"}{0}}"				  >> $TEMPTEX
	echo  "\put(0,0){\graphic{"$PDF"}{0}}"					  >> $TEMPTEX
	done

echo "\end{picture}"								  >> $TEMPTEX
echo "\end{document}"								  >> $TEMPTEX

pdflatex -output-directory $OUTPUTDIR -jobname `date +%s` $TEMPTEX

exit 0;