That's an ugly React-related patent application for sure.

I hope this application doesn't go anywhere, as there would seem to be a lot of prior art. For example, the Cocoa API in macOS implements the method of Claim 1 pretty much to the letter:

https://developer.apple.com/documentation/appkit/nsview/1483...

This API was introduced in OS X 10.3, so that would be 14 years ago.

React doesn't do layout so it can't do occlusion.

The patent description explicitly states it's about React:

"Although many embodiments are described herein in the context of React, embodiments are not limited to React or to rendering only updated views as determined by React libraries."

I know that patent claims are typically much more specific than what the abstract suggests, and I only gave the claims a cursory read, but... surely there is prior art for this? I mean, I'm sure many non-web GUI systems avoid overdraw and at the very least, game rendering engines do, right? At least, I was under the illusion that overdraw was a big deal that at least shader-heavy renderers or old-school 80's/90's tile based renderers?