@Eskander I think a shell extension probably is the optimal solution, but looking at these screenshots I feel optimistic that the script approach could be a very passable approach the meantime? It’s so close to being really great
How it actually works is all a bit of a mystery to me - do the unwelcome edge artefacts appear when you add the opacity? If so, would it make the output cleaner if I provided a png of a semi-transparent squircle at the desired level of opacity? Then the script just has to superimpose the scaled non-Suru icon on top of it, rather than altering the opacity of the squircle.
One thing to note: in Suru, the hi-res version in the app grid and the smaller sizes used on the launcher, etc., have different squircles for pixel-perfect optimisation (specifically, the 48x48px version and below have “chunkier” highlights and no blur on the drop shadow). If we wanted to include the Suru edge details on the squircle then ideally the script would produce multiple pngs using multiple squircles. So for each non-Suru icon, it would make the different sizes individually with a different squircle for each size. There would be five squircles per icon (hi-res, then 48px, 36px, 24px, 16px).
Having said which, I think even having the ghost of a squircle around the non-Suru icons (i.e., the low opacity white shape with no detail) is a lot better than the current mixed approach in Ubuntu. In Eskander’s first screenshot, the overall “eye impact” is great. I guess Firefox is a little blurry and some of the squircles have scaled a bit “pixelly” on the launcher (or is that the upload?). But even if it isn’t optimal, it’s better than current presentation of non-Suru icons IMHO and just needs cleaning up a bit?
Lastly, this script only works on apps that don’t already have a Suru icon, if I understand correctly? If it gets to a point where most of the non-Suru icons look great but a few haven’t come out as nicely, we can manually do those ones and then the script won’t run on them?
EDIT: Actually, looking at the launcher, the semi-transparent white squircles aren’t exactly the same shape as the Suru launcher icons. I think that’s because we’re scaling down the hi-res squircle. It would be super-easy for me to provide the exact squircle shapes for each of the five icons sizes in white, already at the desired opacity (literally five minutes of a job). So, let me know if that would be helpful.