Call redraw while resizing windows

[alice-i-cecile]

Would it be possible to call redraw while we're resizing, so window gets updated immediately, rather than just stretching until we're done?

Originally posted by @MiniaczQ in #15814 (review)

[BenjaminBrienen]

I think this should be configurable behavior, and I'd be fine with either being the default.

[mrec]

I remember @raphlinus posting about this being a bit hairy on Windows some years back, though things may have improved since then.

Ref: rust-windowing/winit#786

FWIW his issues were with doing it perfectly smoothly though, not with doing it at all.

[alice-i-cecile]

Yeah, especially as a configurable behavior I'm fine with a bit of jank vs not doing it at all. This is much less important for Bevy than for Raph's focus on traditional desktop apps.

[doup]

I think I'm in the right issue, I noticed that window resizes don't lag anymore… but now it stretches in a funny way. I just wanted to share a video:

bevy-resize-wobble.mp4

This case is worse though (wait until the end of the video), when the resize is triggered by doble-clicking on the title bar (macOS) there is a huge delay until it refreshes. In this case I'm not moving the cursor after the resize which, I think, makes it worse:

bevy-resize-render-lag.mp4

[MiniaczQ]

It appears to be the discrepancy between layout engine and window stretching to fit