The current version being shown off here is extremely stuttery, is there a way to smooth the animation yet?
Realistically, you won’t need to chain window movement like this in most cases (other than our chatbox, I think none of our windows stay open when their parent window is moved). Fast auto-resizing, on the other hand, is more common, and works great.
We can get the position of our _own_ windows easily, but when it comes to getting Spotify’s position, we need to do some more complex polling, which is slower (and only works when the 3rd-party window is in focus).
What's Tandem are doing here is (interesting, but) atypical behaviour.
Is this a macOS specific issue, or is the JS API these guys are providing not able to catch up quickly enough?
In the actual Tandem app, windows moving like this is uncommon.
See this demo: http://stewd.io/pong/
It's still not 100% smooth, but it seems slightly better and demonstrates the ability to manually tween values. Similar performance in both Chrome and Safari.