resize and put into res/drawable-* directories

create_drawables.sh

#!/bin/sh
show_help() {
cat << EOF
Usage: ${0##*/} -i INPUT_FILE -o OUTPUT_RES_DIR -s MDPI_SIZE -n NAME
EOF
}

while getopts "hi:s:o:n:" opt; do
    case $opt in
        i)
            input=$OPTARG
            ;;
        s)
            size=$OPTARG
            ;;
        o)
            output=${OPTARG%/}
            ;;
        n)
            name=$OPTARG
            ;;
        h)
            show_help
            exit 0
            ;;
        '?')
            show_help >&2
            exit 1
            ;;
    esac
done

if [ -z ${input} ] || [ -z ${size} ] || [ -z ${output} ] || [ -z ${name} ]
    then
        show_help >&2
        exit 1
fi

mkdir ${output}/drawable-mdpi > /dev/null 2>&1
mkdir ${output}/drawable-hdpi > /dev/null 2>&1
mkdir ${output}/drawable-xhdpi > /dev/null 2>&1
convert ${input} -resize ${size} ${output}/drawable-mdpi/${name}.png
convert ${input} -resize $(echo ${size}*1.5 | bc) ${output}/drawable-hdpi/${name}.png
convert ${input} -resize $((size*2)) ${output}/drawable-xhdpi/${name}.png