High cpu and gpu usage on Windows

[coffee-git]

Hi! Tried to run examples, why is CPU and GPU usage so high? Windows 11, rustc 1.72.0, compiled with release profile.

[ogoffart]

Do you know what slint backend and renderer are you using? (Is it the default? Do you have Qt?)

The main page of the gallery has a progress indicator that animates. Do you see the same usage when not showing the animated progress indicator?

[coffee-git]

Just cargo build --release, all other settings are default. Todo example when i just move mouse over the window. When i start adding new entries, about 30 percent of CPU usage.

[coffee-git]

Better with skia renderer, but the gpu load still high

[tronical]

The gallery runs an animation and I think that we don't throttle it (on Windows). So we try to render as fast as we can, possibly at a rate higher than the screen refresh rate. That would result in a CPU and GPU load that's higher than necessary to achieve the desired animation.

[coffee-git]

Just realized that most gui application uses about the same amount of resources. Didn't pay attention to it before.
Is it possible to limit the number of frames for FemtoVG?

[ogoffart]

Is it possible to limit the number of frames

IIRC this will be a feature coming with winit 0.29

[tronical]

I think there's a bug on our side here. We default to letting the OpenGL driver pick a swap interval, which happens to be correct for EGL. But it looks like on Windows it's zero, while we should really default to vsync.

Winit's upcoming frame throttling is a potential alternative, but unfortunately it's only implemented for Wayland at the moment.

[tronical]

I created #3516 to track the vsync setting.

Edit: This is fixed now :)