based on https://nshipster.com/macos-dynamic-desktop/
The
apkey corresponds to a dictionary containing integers for thedandlkeys.
the plaintext reads like so...
// highlighter acting weird
// ignore first/last bracket
{
ap = {
d = 15;
l = 0;
};
}mattt was unable to figure out what these keys are, and the repository is now read-only, but i'm fairly confident i know what these are.
here are the images in the mojave desktop wallpaper:
it's important to note the order in which these occur. the first image is the Light mode still. for some reason i expected the next image to be the dark mode still, ie macos would check for the 0th and 1st images, but that appears not to be the case. however i think that expectation came from how other DDs are ordered. i can't be sure right now, but i believe the catalina dd follows this pattern.
this brings up an interesting pattern: the light and dark stills are not at a hardcoded index. looking at the individual images from the mojave dd, we can see that the light still is at 0, and the dark still is at... 15.
huh.
but what does ap stand for? im not quite as confident here, but i think i know.
let's take some context clues. what was added in mojave, specifically in relation to the light and dark stills?
light and dark appearance.
appearance...
appearance...
there it is. appearance-based wallpapers. ap is a dictionary that specifies the light and dark indexes when in appearance-based mode.
all of this is in a bplist mapped to a metadata key called solar. i suspect this key may differ in some of the more recent appearance-based-only wallpapers, ie big sur graphic. heck, it might be a completely different format. there's more to uncover here, so feel free to add anything you find.