Make wacom tablet preserve aspect ratio

wacom_preserve_ratio.sh

SIZE=`xdpyinfo | grep dimensions | sed -r 's/^[^0-9]*([0-9]+x[0-9]+).*$/\1/'`

WIDTH=${SIZE%x*}
HEIGHT=${SIZE#*x}
echo "SIZE: $SIZE"
echo "WIDTH: $WIDTH"
echo "HEIGHT: $HEIGHT"
echo

WACOM_SIZE=`xsetwacom get 11 Area`
IFS=' ' read -r -a WACOM_SIZE_ARRAY <<< "$WACOM_SIZE"

echo $WACOM_SIZE

WACOM_WIDTH=${WACOM_SIZE_ARRAY[2]}
WACOM_HEIGHT=${WACOM_SIZE_ARRAY[3]}

echo "WACOM_WIDTH: $WACOM_WIDTH"
echo "WACOM_HEIGHT: $WACOM_HEIGHT"
echo

S=8
RATIO=$(bc <<< "scale=$S;$HEIGHT/$WIDTH")
echo "RATIO: $RATIO"
echo
NEW_HEIGHT=$(bc <<< "scale=$S;$WACOM_WIDTH*$RATIO")
echo "NEW_HEIGHT: $NEW_HEIGHT"
NEW_Y=$(bc <<< "scale=$S;$WACOM_HEIGHT-$NEW_HEIGHT")
echo "NEW_Y: $NEW_Y"

round_function () {
  ret=$( echo "$1" |
      awk '{
          x=$1
          ival = int(x)
          # see if fractional part
          if (ival == x)
            print ival
          else {
            if (x < 0) {
              aval = -x
              ival = int(aval)
              fraction = aval - ival
              if (fraction >= .5)
                print int(x) - 1
              else
                print int(x)
            } else {
              fraction = x - ival
              if (fraction >= .5)
                print ival + 1
              else
                print ival
            }
          }
        }'
    )
    echo "$ret"
}

ROUND_NEW_Y="$(round_function $NEW_Y)"
echo "ROUND_NEW_Y: $ROUND_NEW_Y"

# xsetwacom set 11 Area 0 24607 65024 40640
xsetwacom set 11 Area 0 $ROUND_NEW_Y $WACOM_WIDTH $WACOM_HEIGHT  # 11 is stylus, use "xsetwacom list devices" to get stylus id