Puzzle generator

puzzle.sh

#!/bin/sh
resolution=$(identify -format "%wx%h" "$1[0]")

IFS=x read -r -a resolution_array <<< $resolution

width=${resolution_array[0]}
height=${resolution_array[1]}

WIDTH_FACTOR=15
HEIGHT_FACTOR=15
LAST_TILE_X=$(( WIDTH_FACTOR-1 ))
LAST_TILE_Y=$(( HEIGHT_FACTOR-1 ))
IMAGE_PAPER_WIDTH=277
TILE_PAPER_WIDTH=$(( IMAGE_PAPER_WIDTH / WIDTH_FACTOR ))

(( tile_width=(width+WIDTH_FACTOR-1)/WIDTH_FACTOR ))
(( tile_height=(height+HEIGHT_FACTOR-1)/HEIGHT_FACTOR ))

tmpdir="$(mktemp -d --tmpdir puzzle.XXXXXXXXXX)"
cd "$tmpdir"

for i in $(seq 0 $(( LAST_TILE_Y )))
do
	offset_y=$(( tile_height*i ))
	if [[ i -eq LAST_TILE_Y ]]
	then
		current_tile_height=$(( height-offset_y ))
	else
		current_tile_height="$tile_height"
	fi
	for j in $(seq 0 $(( LAST_TILE_X )))
	do
		offset_x=$(( tile_width*j ))
		if [[ j -eq LAST_TILE_X ]]
		then
			current_tile_width=$(( width-offset_x ))
		else
			current_tile_width="$tile_width"
		fi
		convert "$1[0]" -crop "${current_tile_width}x${current_tile_height}+${offset_x}+${offset_y}" "tile-$(printf "%3.3d" $(( i*WIDTH_FACTOR+j )))-$current_tile_width-$current_tile_height.png"
	done
done

papername="paper.tex"
cat > "$papername" <<-LATEXDOC
	\documentclass[a4paper,12pt]{article}
	\usepackage{graphicx}
	\usepackage{tabularx}
	\usepackage{lscape}
	\usepackage[left=1cm, top=1cm, right=1cm, bottom=1cm]{geometry}
	\makeatletter
	\def\@oddfoot{}
	\makeatother
	\arrayrulewidth=0pt
	\begin{document}
		\begin{landscape}
			\noindent
LATEXDOC
			echo '\begin{tabularx}{'"$IMAGE_PAPER_WIDTH"'mm}{*{'"$WIDTH_FACTOR"'}{|X}|}\hline' >> "$papername"
			tile_files=($(find -name 'tile-*.png'|shuf))
			for i in $(seq 0 $(( LAST_TILE_Y )))
			do
				for j in $(seq 0 $(( LAST_TILE_X )))
				do
					current_tile_filename=${tile_files[$(( i*WIDTH_FACTOR+j ))]}
					IFS=- read -r -a current_tile_filename_parts <<< $current_tile_filename
					current_tile_width=${current_tile_filename_parts[2]}
					current_tile_paper_width=$(( TILE_PAPER_WIDTH*current_tile_width/tile_width ))
					echo -n '\includegraphics[width='"$current_tile_paper_width"'mm]{'"$current_tile_filename"'} ' >> "$papername"
					if [[ j -eq LAST_TILE_X ]]
					then
						echo '\\ \hline' >> "$papername"
					else
						echo '&' >> "$papername"
					fi
				done
			done
cat >> "$papername" <<-LATEXDOC
			\end{tabularx}
		\end{landscape}
	\end{document}
LATEXDOC

pdflatex "$papername"
cd -
mv "$tmpdir/paper.pdf" "$2"
rm -r "$tmpdir"