PPSSPP's .zim files

[Henrik]

ZIM is just optionally-zlib-compressed raw images, with mipmap support and a few flags that are useful for textures. ui_atlas.zim is just one big image (an "atlas texture") that contains all the imagery and the UI font.

The code to read and write ZIM files can be found in native/image.

I created this stuff for my own simple game engine which also links to native.

You can build your own .zim files using native/tools/atlastool and native/tools/zimtool. I haven't made a build setup for those public but it's not exactly hard.