LustyMap complex map generator

make_lusty_map.sh

#!/bin/bash

usage() {
    echo "Usage: $0 [map_file=download.png] [threads=2xCPU] [prefix=map]"
    exit 1
}

if [ -z $1 ]; then
    MAP_FILE=download.png
fi

if [ -z $2 ]; then
    PREFIX="map" # prefix for output files
fi

if [ -z $3 ]; then
    THREAD_MAX=`echo "$(nproc)*2" | bc` # How many CPUs you have * 2
fi

if [ ! -f $MAP_FILE ]; then
    echo "Could not find $MAP_FILE"
    usage
fi

SIZE=$(identify -format "%w" $MAP_FILE)     # The map size (must be square and divisable by 20)

if [ $SIZE -ne $(identify -format "%w" $MAP_FILE) ]; then
  echo "Image must be square."
  usage
fi

if [ $(echo "$SIZE%20" | bc) -ne "0" ]; then
    echo "SIZE must be divisable by 20."
    usage
fi

GRID_SIZE=$(echo "$SIZE/20" | bc)

echo "Grid size is $GRID_SIZE"

thread_max() {
    local CHECK_INTERVAL="0.1"
    local CUR_THREADS=
    local MAX=
    [[ $1 ]] && MAX=$1 || return 127

    # reset MAX value, 0 is easy to remember
    [ $MAX -eq 0 ] && {
        MAX=1
        echo "waiting for all tasks finish"
    }

    while true; do
        CUR_THREADS=`jobs -p | wc -w`

        # workaround about jobs bug. If don't execute it explicitily,
        # CUR_THREADS will stick at 1, even no jobs running anymore.
        jobs &>/dev/null

        if [ $CUR_THREADS -ge $MAX ]; then
            sleep $CHECK_INTERVAL
        else
            return 0
        fi
    done
}

rm *.jpeg
rm *.gz

echo -n "Generating 400 map files ($PREFIX-X-Y.jpeg)"
NUM=0
for x in {0..19}; do
    (( xp = $x * $GRID_SIZE))
    for y in {0..19}; do
        (( yp = $y * $GRID_SIZE))
        (( NUM = $NUM + 1 ))
        thread_max $THREAD_MAX
        echo -n " $NUM/400"
        convert $MAP_FILE -crop ${GRID_SIZE}x${GRID_SIZE}+$xp+$yp $PREFIX-$y-$x.jpeg &
    done
done
echo
thread_max 0
echo "Archiving to ${PREFIX}_parts.tar.gz"
tar czf ${PREFIX}_parts.tar.gz *.jpeg