#!/bin/sh

# Width and height of thumbnail page
w=1024
h=768

# Width, height and margin of thumbnail
tw=160
th=160
tm=10

# Vertical upwards adjustment to leave space for text label
vadj=9

# Vertical spacing between thumbnail and text
tspc=6

# JPEG quality
quality=50

tm2=$(($tm * 2))
nt_h=$(($w / ($tw + $tm2)))
nt_v=$(($h / ($th + $tm2)))
tmadd_h=$((($w - (($tw + $tm2) * $nt_h)) / $nt_h))
tmadd_v=$((($h - (($th + $tm2) * $nt_v)) / $nt_v))

tm_h=$(($tm + ($tmadd_h / 2)))
tm_v=$(($tm + ($tmadd_v / 2)))
tw_tot=$(($tw + $tm2 + $tmadd_h))
th_tot=$(($th + $tm2 + $tmadd_v))

tmpfile1=$(mktemp ~/.mkthumb.XXXXXX) || exit 1
tmpfile2=$(mktemp ~/.mkthumb.XXXXXX) || exit 1
tmpfile3=$(mktemp ~/.mkthumb.XXXXXX) || exit 1

rm -f [0-9][0-9][0-9]thumb.???

exec 2>/dev/null
x=0; y=0
n=1; tfile=$(printf "%03dthumb.ppm" $n)

for f in *.*; do
    [ ! -f "$f" ] && continue
    case "$f" in
    *.[Tt][Ii][Ff])
	cmd=tifftopnm;;
    *.[Jj][Pp][Gg])
	cmd=djpeg;;
    *.[Pp][Nn][Gg])
	cmd=pngtopnm;;
    *.[Gg][Ii][Ff])
	cmd=giftoppm;;
    *.[Ee][Pp][Ss] | *.[Pp][Ss])
	cmd="ps2ppm -r300 -dEPSFitPage"
	crop="| pnmcrop -white";;
    *.[Jj][Bb][Gg])
	cmd=jbgtopbm;;
    *)
	continue;;
    esac
    eval $cmd \"$f\" $crop | pnmscale -xysize $tw $th >$tmpfile1 || continue
    res=$(pnmfile $tmpfile1 | nawk '{print $4 " " $6}')
    xres=${res% *}; yres=${res#* }
    pbmtext "$f" | pnmcrop -white | pnminvert >$tmpfile2
    tres=$(pnmfile $tmpfile2 | nawk '{print $4 " " $6}')
    txres=${tres% *}; tyres=${tres#* }
    if [ $txres -gt $tw ]; then
	pnmcut 0 0 $tw $tyres $tmpfile2 >$tmpfile3
	mv -f $tmpfile3 $tmpfile2
	txres=$tw
    fi
    colfile=$(mktemp ~/.mkthumb.XXXXXX) || exit 1
    ppmmake black $tw_tot $th_tot | \
	pnmpaste $tmpfile1 $(($tm_h + (($tw - $xres) / 2))) \
	    $(($tm_v + (($th - $yres) / 2) - $vadj)) | \
	pnmpaste $tmpfile2 $(($tm_h + (($tw - $txres) / 2))) \
	    $(($tm_v + (($th - $yres) / 2) + $yres - $vadj + $tspc)) >$colfile
    colfiles="$colfiles $colfile"
    x=$(($x + $tw_tot))
    if [ $(($x + $tw_tot)) -gt $w ]; then
	rowfile=$(mktemp ~/.mkthumb.XXXXXX) || exit 1
	pnmcat -lr $colfiles >$rowfile
	rowfiles="$rowfiles $rowfile"
	rm -f $colfiles
	colfiles=
	x=0; y=$(($y + $th_tot))
	if [ $(($y + $th_tot)) -gt $h ]; then
	    pnmcat -tb -jleft $rowfiles >$tfile
	    rm -f $rowfiles
	    rowfiles=
	    y=0
	    n=$(($n + 1)); tfile=$(printf "%03dthumb.ppm" $n)
	fi
    fi
done

if [ -n "$colfiles" -o -n "$rowfiles" ]; then
    if [ -n "$colfiles" ]; then
	rowfile=$(mktemp ~/.mkthumb.XXXXXX) || exit 1
	pnmcat -lr $colfiles >$rowfile
	rowfiles="$rowfiles $rowfile"
    fi
    pnmcat -tb -jleft $rowfiles >$tfile
fi
 
for f in [0-9][0-9][0-9]thumb.ppm; do
    if ! [ -f "$f" ]; then continue; fi
    cjpeg -quality $quality $f >${f%.ppm}.jpg
    rm -f $f
done
rm -f $tmpfile1 $tmpfile2 $tmpfile3 $colfiles $rowfiles
.