UpdateMode::Continuous or UpdateMode::reactive(Duration::from_secs_f64(1. / refresh_rate))

[kingwingfly]

Assume there's a 60 fps monitor, I want to update 60 times / s. So:

pub fn setup(
    mut cmds: Commands,
    winit: NonSend<WinitWindows>,
    window: Query<Entity, With<PrimaryWindow>>,
) {
    let window = window.single().expect("primary window should exist");
    let monitor = winit
        .get_window(window)
        .and_then(|w| w.current_monitor())
        .expect("primary window should have winit window and monitor");
    let refresh_rate = monitor
        .refresh_rate_millihertz()
        .expect("monitor should have refresh rate");

    cmds.insert_resource(WinitSettings {
        focused_mode: UpdateMode::reactive(Duration::from_secs_f64(1000. / refresh_rate as f64)),
        unfocused_mode: UpdateMode::reactive_low_power(Duration::from_secs(60)),
    });
}

But UpdateMode::Continuous looks like what I want, but its doc:

/// The [`App`](bevy_app::App) will update over and over, as fast as it possibly can, until an
/// [`AppExit`](bevy_app::AppExit) event appears.

Whether as fast as it possibly can means limited by performance and refresh-rate?

[kingwingfly]

I found that the refresh won't happen before mouse click releasing. So, I'd better choose UpdateMode::Continuous.