#!/bin/sh
SRC=$1
BASE=`echo $SRC | sed 's/\.[^.]*$//'`
pngtopnm -background '#ffffff' $SRC > $BASE.ppm
pngtopnm -alpha $SRC > $BASE-mask.pgm
LAYERS=""
while read SIZE COLORS
do
  pnmscale -xysize $SIZE $SIZE $BASE.ppm |
   ppmquant $COLORS > $BASE-$SIZE.ppm 2>/dev/null
  pnmscale -xysize $SIZE $SIZE $BASE-mask.pgm > $BASE-$SIZE-mask.pgm
  LAYERS="$LAYERS $BASE-$SIZE.ppm $BASE-$SIZE-mask.pgm"
done <<'EOF'
16 16
32 16
48 256
EOF
ppmtowinicon -andpgms $LAYERS > $BASE-favicon.ico