# Objective
- Simplifies/clarifies the winit loop.
- Fixes#12612.
## Solution
The Winit loop runs following this flow:
* NewEvents
* Any number of other events, that can be 0, including RequestRedraw
* AboutToWait
Bevy also uses the UpdateMode, to define how the next loop has to run.
It can be essentially:
* Continuous, using ControlFlow::Wait for windowed apps, and
ControlFlow::Poll for windowless apps
* Reactive/ReactiveLowPower, using ControlFlow::WaitUntil with a
specific wait delay
The changes are made to follow this pattern, so that
* NewEvents define if the WaitUntil has been canceled because we
received a Winit event.
* AboutToWait:
* checks if the window has to be redrawn
* otherwise calls app.update() if the WaitUntil timeout has elapsed
* updates the ControlFlow accordingly
To make the code more logical:
* AboutToWait checks if any Bevy's RequestRedraw event has been emitted
* create_windows is run every cycle, at the beginning of the loop
* the ActiveState (that could be renamed ActivityState) is updated in
AboutToWait, symmetrically for WillSuspend/WillResume
* the AppExit events are checked every loop cycle, to exit the app early
## Platform-specific testing
- [x] Windows
- [x] MacOs
- [x] Linux (x11)
- [x] Linux (Wayland)
- [x] Android
- [x] iOS
- [x] WASM/WebGL2 (Chrome)
- [x] WASM/WebGL2 (Firefox)
- [x] WASM/WebGL2 (Safari)
- [x] WASM/WebGpu (Chrome)
---------
Co-authored-by: François <francois.mockers@vleue.com>
5ee1b40298