Include a script that can optimize svg files

Now we need to think about how we want this to be executed.

REVIEW: 126740

CCMAIL: plasma-devel@kde.org

optimize-svg.sh

+#!/usr/bin/env bash
+
+if ! command -v svgo >/dev/null
+then
+    echo "Please install svgo: npm install svgo"
+    exit 1
+fi
+# regarding convertStyleToAttrs, see: https://github.com/svg/svgo/issues/489
+# regarding convertPathData, see: https://github.com/svg/svgo/issues/490
+ARGS="--pretty --disable=convertStyleToAttrs --disable=convertPathData"
+
+function generatePng {
+    inkscape -z -D $1 --export-png=$2 --export-width=200 --export-background=transparent > /dev/null
+}
+
+# args: pngA pngB final.svg temp.svg
+function evaluateOptimization {
+#     that regex is to just take A from "A (B)"
+    res=`compare -metric MAE $1 $2 /dev/null 2>&1 | sed "s/^\\([0-9]*\\).*/\\1/"` #-fuzz 5
+    if [ "$res" -gt 100 ]; then
+        echo "huuuuge difference of $res in $3"
+    else
+        mv $4 $3
+    fi
+}
+
+find . -name "*.svg" -size 4k -print0 | while IFS= read -r -d '' file
+do
+    echo "doing... $file"
+    generatePng "$file" /tmp/A.png
+    svgo -i "$file" -o "$file".tmp.svg $ARGS
+    generatePng "$file".tmp.svg /tmp/B.png
+    evaluateOptimization /tmp/A.png /tmp/B.png "$file" "$file".tmp.svg
+done
+
+find . -name "*.svgz" -print0 | while IFS= read -r -d '' file
+do
+    echo "z-doing... $file"
+    generatePng "$file" /tmp/A.png
+    gunzip "$file" -S .svgz -c | svgo -i - $ARGS | gzip -c > "$file".tmp.svgz
+    generatePng "$file".tmp.svgz /tmp/B.png
+    evaluateOptimization /tmp/A.png /tmp/B.png "$file" "$file".tmp.svgz
+done