Nicola Papale 79021c78c6 Fix perf degradation on web builds (#11227) ... # Objective - Since #10702, the way bevy updates the window leads to major slowdowns as seen in - #11122 - #11220 - Slow is bad, furthermore, _very_ slow is _very_ bad. We should fix this issue. ## Solution - Move the app update code into the `Event::WindowEvent { event: WindowEvent::RedrawRequested }` branch of the event loop. - Run `window.request_redraw()` When `runner_state.redraw_requested` - Instead of swapping `ControlFlow` between `Poll` and `Wait`, we always keep it at `Wait`, and use `window.request_redraw()` to schedule an immediate call to the event loop. - `runner_state.redraw_requested` is set to `true` when `UpdateMode::Continuous` and when a `RequestRedraw` event is received. - Extract the redraw code into a separate function, because otherwise I'd go crazy with the indentation level. - Fix #11122. ## Testing I tested the WASM builds as follow: ```sh cargo run -p build-wasm-example -- --api webgl2 bevymark python -m http.server --directory examples/wasm/ 8080 # Open browser at http://localhost:8080 ``` On main, even spawning a couple sprites is super choppy. Even if it says "300 FPS". While on this branch, it is smooth as butter. I also found that it fixes all choppiness on window resize (tested on Linux/X11). This was another issue from #10702 IIRC. So here is what I tested: - On `wasm`: `many_foxes` and `bevymark`, with `argh::from_env()` commented out, otherwise we get a cryptic error. - Both with `PresentMode::AutoVsync` and `PresentMode::AutoNoVsync` - On main, it is consistently choppy. - With this PR, the visible frame rate is consistent with the diagnostic numbers - On native (linux/x11) I ran similar tests, making sure that `AutoVsync` limits to monitor framerate, and `AutoNoVsync` doesn't. ## Future work Code could be improved, I wanted a quick solution easy to review, but we really need to make the code more accessible. - #9768 - ~~**`WinitSettings::desktop_app()` is completely borked.**~~ actually broken on main as well ### Review guide Consider enable the non-whitespace diff to see the _real_ change set.		2024-01-06 19:40:13 +00:00
..
src	Fix perf degradation on web builds (#11227)	2024-01-06 19:40:13 +00:00
Cargo.toml	Update winit dependency to 0.29 (#10702)	2023-12-21 07:40:47 +00:00