generate_pngs.sh

#!/usr/bin/env bash
#
# Generate a set of PNG images for multiple densities from SVG image.
#
# Usage: ./generate_pngs.sh input.svg
#
# Prerequisites:
#   macOS: brew install librsvg
#   Linux: sudo apt install librsvg2-bin
#
svg_file=$1
output_dir="$(pwd)/res"

generated_densities=( "mdpi:1"
                      "hdpi:1.5"
                      "xhdpi:2"
                      "xxhdpi:3"
                      "xxxhdpi:4" )

function generate_pngs {
    svg_file_name=$(basename "${svg_file}")
    svg_name="${svg_file_name%.*}"
    echo "Input: ${svg_file_name}"

    svg_full_path="$(cd "$(dirname "${svg_file}")"; pwd)/${svg_file_name}"

    for i in ${generated_densities[@]}
    do
        density=${i%%:*}
        scale=${i#*:}
        density_dir="${output_dir}/drawable-${density}"
        mkdir -p ${density_dir}
        png_file="${density_dir}/${svg_name}.png"

        echo "Generating PNG with density: ${density}"
        rsvg-convert -z ${scale} ${svg_full_path} > ${png_file}
    done
}

if ! type rsvg-convert >/dev/null 2>&1; then
    echo "rsvg-convert was not found. Please install librsvg2."
    exit 1
fi

if [[ -n "${svg_file}" ]]; then
    generate_pngs
else
    echo "Usage: generate_pngs.sh input.svg"
fi