bevy_winit(emit raw winit events)

[HugoPeters1024]

Objective

• Exposes raw winit events making Bevy even more modular and powerful for custom plugin developers (e.g. a custom render plugin).

XRef: #5977
It doesn't quite close the issue as sending events is not supported (or not very useful to be precise). I would think that supporting that requires some extra considerations by someone a bit more familiar with the bevy_winit crate. That said, this PR could be a nice step forward.

Solution

Emit RawWinitWindowEvent objects for each received event.

Testing

I verified that the events are emitted using a basic test app. I don't think it makes sense to solidify this behavior in one of the examples.

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Showcase

My example usage for a custom egui_winit integration:

for ev in winit_events.read() {
    if ev.window_id == window.id {
        let _ = egui_winit.on_window_event(&window, &ev.event);
    }
}

[BenjaminBrienen]

Only a tiny nit! Just change one of them (whichever doesn't follow the typical usage).

[HugoPeters1024]

I rebased to hopefully get the CI fix for mac os screenshots

[tychedelia]

Not so sure that just doing a plain copy is the best way, esp since 99% of users won't use this, but I did just run into a situation with egui as well that requires the underlying winit events.

[HugoPeters1024]

Not so sure that just doing a plain copy is the best way, esp since 99% of users won't use this, but I did just run into a situation with egui as well that requires the underlying winit events.

Thanks for the review. I acknowledge that indeed most users would not and probably should not use this. But it can be a powerful escape hatch as many 3rd party packages take raw egui events as input.

[tychedelia]

Another alternative would be to provide a way to convert bevy events back into winit events. I'm doing this in my project and it seems to work okay, although is a lossy process w.r.t. some of the original event information.