Support for events with an array of memberships from different devices was removed over a year ago in matrix-js-sdk ffd3c9575e9def576739baf6b1dc329b0db55c0c.
It turns out that for a blurry gradient background, low-res raster images look very convincing when scaled up and interpolated. That means that we can rasterize our gradient SVGs for improved paint performance when resizing the window, while still keeping them quite lightweight (just a couple of kilobytes each).
When someone starts or stops speaking, the layout will often be recomputed only to find out that there is ultimately no layout change. We can ignore these redundant updates to avoid re-rendering the InCallView and Grid components, which are relatively slow.
For that specific, common case, this reduces JS CPU usage by as much as 70% in my testing.
It's very uncommon to have this debug option enabled, and yet it currently causes the footer to re-render on every layout update, which is a small but avoidable cost.
I don't believe this affects the cost of running the useSprings hook, but it at least skips the animation frames that would otherwise follow, so it's worth a try.
It turns out that the timers which repeatedly poll the RTP stats of each video track all run independently of each other and can add up to a small but constant sink of CPU. Meanwhile we can replace these timers with HTMLVideoElement 'resize' event listeners, which is way more efficient and reacts instantly to orientation changes.
A change in a tile's speaking indicator could cause its entire tree of context menu components to re-render, which is expensive. Isolating the behavior subscriptions in their own component avoids this.
With the React Compiler, our component code is transformed at build time to automatically apply various forms of memoization. This changes the runtime semantics of our code a little bit and therefore could surface new bugs in the next release cycle in case any components fail to follow the rules of React. See https://react.dev/learn/react-compiler for more information.
This results in a small bundle size increase and modest performance gains, but I think it's worth it given the potential for larger performance gains once we tune the component structure a bit more.
