Marble color unifier.

mcu.sh

#!/bin/bash

# mcu.sh: Marble color unifier.
# (From "four bags with one red, one green, and one blue marble per bag"
# to "four bags with three marbles per bag")

# Downloads: Multiply_4_bags_3_marbles.svg
# Makes: 4x3_1.svg 4x3_1.png 4x3_2.svg 4x3_2.png
# Depends on: wget sed inkscape gm (GraphicsMagick)

set -xe

if [ -f Multiply_4_bags_3_marbles.svg ]
then
    echo "Multiply_4_bags_3_marbles.svg exists."
else
    wget 'https://upload.wikimedia.org/wikipedia/commons/3/36/Multiply_4_bags_3_marbles.svg'
fi

# Fill the background with white to eliminate the transparent color.
sed -e '569i <rect fill="white" stroke="none" x="0" y="0" width="616" height="723"/>' Multiply_4_bags_3_marbles.svg > 4x3_1.svg

inkscape --export-filename=4x3_1_o.png 4x3_1.svg
gm convert 4x3_1_o.png -resize '50%' -quality 92 4x3_1.png
rm 4x3_1_o.png

# Choose one to decide the color of the marbles.
sed -E 's/00cc00|0000cc/cc0000/' 4x3_1.svg > 4x3_2.svg
# sed -E 's/0000cc|cc0000/00cc00/' 4x3_1.svg > 4x3_2.svg
# sed -E 's/cc0000|00cc00/0000cc/' 4x3_1.svg > 4x3_2.svg

inkscape --export-filename=4x3_2_o.png 4x3_2.svg
gm convert 4x3_2_o.png -resize '50%' -quality 92 4x3_2.png
rm 4x3_2_o.png