Add support for externally loaded banners (for Carousel menu)

[b-]

Describe the feature

Right now, when setting the menu to Carousel mode it just shows pixelated banners for each game, from the disc images.

It would be super cool to be able to put higher resolution images in to make the carousel menu more friendly.

This could also provide a mechanism to put custom banners for .dol files, a la homebrew channel on Wii.

forgive me if this already is a thing, but I couldn’t find any documentation for it.

[Diegorella]

I believe the shortest path would be: :SD/swiss/banner

being an idea that the most plausible would be to synchronize the same name .ISO with the image of the .banner...

[Extrems]

I'm not so sure about that since walking through the FAT so much would decrease browsing speed.

[b-]

That makes sense, but what about loading external banners once, and store the resulting structure in a cache file (so reading it back in would not involve walking the FAT), with a menu option to dump the cache and reload?

Edit: this is without knowing enough about FAT to know if there's any reasonable way to automatically check for dirty cache upon loading, and reload files accordingly.