Icon size

[andershol]

Currently some addons have an icon with a large file size. This means that the addon_catalog_cache.zip used by the addon manager and by the website is currently ~2MB. This PR adds aliases for some of the largest icons that are 1/7th-1/686th of the original size and shrinks the zip file to ~400kB. Warning is also added for icons larger than 10kB (all of the aliases are < 5kB).

Most icons should be close to identical to the original, but I did add on lighting to EasyProfileFrame, MakerWorkbench and Cubinets.

The icons could of course be pushed upstream. I only tried with one PR that got no response. But the individual addons do not see much benefit in fiddling with size of their icon.

It feels like this script is in the wrong repository. Perhaps it should be move to e.g. Addons.

It is a bit silly that the text of the SVG files are utf-8 encoded, base64 encoded and then added to the json, instead of just being added to the json, as the base64 encoding reduces the effectiveness of the compression. An "icon_data_raw" property could be added to the json instead of the "icon_data" for svg files. But that would not be backwards compatible (icons would disappear from old versions of the addon manager).

[andershol]

		freecad.gears workbench 36652 -> 4836 ~13.2%			WebTools 60355 -> 4187 ~6.9%
		Optics Design Workbench 39918 -> 3930 ~9.8%			DesignSPHysics 1436708 -> 3535 ~0.2%
		DFM 26266 -> 3263 ~12.4%			Assembly3 30188 -> 3246 ~10.8%
		Machines 23462 -> 3191 ~13.6%			AIGenFurniture Cabinet Generator 28470 -> 3154 ~11.1%
		Bill of Materials Workbench 28649 -> 2991 ~10.4%			FreeGrid Workbench 20682 -> 2500 ~12.1%
		Built-In Preference Packs beta 16980 -> 2120 ~12.5%			ElectroMagnetic Workbench 20586 -> 2077 ~10.1%
		Titleblock Workbench 25051 -> 1843 ~7.4%			boltsfc 20263 -> 1541 ~7.6%
		Detessellate 27678 -> 1503 ~5.4%			EasyProfileFrame 31417 -> 1332 ~4.2%
		Maker Workbench 19817 -> 1332 ~6.7%			Cubinets 17536 -> 1137 ~6.5%
		Reinforcement 27955 -> 1000 ~3.6%			PieMenu 26892 -> 967 ~3.6%
		NikraDAP 32433 -> 963 ~3%			Virtual Reality 7579 -> 936 ~12.3%
		Woodworking 30929 -> 915 ~3%			MOOC 36063 -> 811 ~2.2%
		Road 360865 -> 526 ~0.1%			Frame and beams workbench 12761 -> 282 ~2.2%
		Ondsel Lens Addon 30331 -> 166 ~0.5%

[andershol]

As luck would have it, after no activity for 3 months, the DesignSPHysics icon was merged into upstream an hour and a half after this issue was opened. 🤷

[chennes]

I'm sure you can get the Ondsel Lens merged :). Probably also Road, Machines, and AIGenFurniture. My preference would be to at least submit PRs for all of these and give their authors a chance to incorporate. And maybe @mnesarco could add this as an evaluation metric for the scanner.

[mnesarco]

This PR adds automatic svg icons optimization to cache: #408

Raw: 4.1MB to 1.9MB
Compressed: 1.5 MB to 775 kB

[andershol]

Yep, pretty bad. It is not clear what you are measuring, but by presumably optimizing all icons, you got a result twice as large as this PR got by optimizing only a couple of handfuls. I considered doing it automatically, and svgo looked most promising, but rejected it. Since it is relatively seldom a new addon is added, it probably make more sense just to reject icons over 10kB and warn if they are over 5kB.

[mnesarco]

Addons-Report now checks for icons over 16kB (can be changed if it is too conservative) and report them.

FreeCAD/Addon-Reports@252a28e