Fix Issues : Unexpected Monitor Behavior When Resizing with wgpu on Windows.

crates/eframe/src/native/glow_integration.rs

@@ -630,11 +630,16 @@ impl<'app> GlowWinitRunning<'app> {
         };
 
         viewport.info.events.clear(); // they should have been processed
-        let window = viewport.window.clone().unwrap();
-        let gl_surface = viewport.gl_surface.as_ref().unwrap();
-        let egui_winit = viewport.egui_winit.as_mut().unwrap();
 
-        egui_winit.handle_platform_output(&window, platform_output);
+        let (Some(egui_winit), Some(window), Some(gl_surface)) = (
+            viewport.egui_winit.as_mut(),
+            &viewport.window.clone(),
+            &viewport.gl_surface,
+        ) else {
+            return Ok(EventResult::Wait);
+        };
+
+        egui_winit.handle_platform_output(window, platform_output);
 
         let clipped_primitives = integration.egui_ctx.tessellate(shapes, pixels_per_point);
 
@@ -691,7 +696,7 @@ impl<'app> GlowWinitRunning<'app> {
                 }
             }
 
-            integration.post_rendering(&window);
+            integration.post_rendering(window);
         }
 
         {
@@ -720,7 +725,7 @@ impl<'app> GlowWinitRunning<'app> {
 
         integration.report_frame_time(frame_timer.total_time_sec()); // don't count auto-save time as part of regular frame time
 
-        integration.maybe_autosave(app.as_mut(), Some(&window));
+        integration.maybe_autosave(app.as_mut(), Some(window));
 
         if window.is_minimized() == Some(true) {
             // On Mac, a minimized Window uses up all CPU:
@@ -1478,7 +1483,7 @@ fn render_immediate_viewport(
     viewport.info.events.clear(); // they should have been processed
 
     let (Some(egui_winit), Some(window), Some(gl_surface)) = (
-        &mut viewport.egui_winit,
+        viewport.egui_winit.as_mut(),
         &viewport.window,
         &viewport.gl_surface,
     ) else {

crates/eframe/src/native/run.rs

@@ -77,48 +77,47 @@ impl<T: WinitApp> WinitAppWrapper<T> {
         event_loop: &ActiveEventLoop,
         event_result: Result<EventResult>,
     ) {
+        let mut now = Instant::now();
         let mut exit = false;
 
         log::trace!("event_result: {event_result:?}");
 
-        let combined_result = event_result.and_then(|event_result| {
-            match event_result {
-                EventResult::Wait => {
-                    event_loop.set_control_flow(ControlFlow::Wait);
-                    Ok(event_result)
-                }
-                EventResult::RepaintNow(window_id) => {
-                    log::trace!("RepaintNow of {window_id:?}",);
+        let mut event_result = event_result;
 
-                    if cfg!(target_os = "windows") {
-                        // Fix flickering on Windows, see https://github.com/emilk/egui/pull/2280
-                        self.winit_app.run_ui_and_paint(event_loop, window_id)
-                    } else {
-                        // Fix for https://github.com/emilk/egui/issues/2425
-                        self.windows_next_repaint_times
-                            .insert(window_id, Instant::now());
-                        Ok(event_result)
-                    }
-                }
-                EventResult::RepaintNext(window_id) => {
-                    log::trace!("RepaintNext of {window_id:?}",);
-                    self.windows_next_repaint_times
-                        .insert(window_id, Instant::now());
-                    Ok(event_result)
-                }
-                EventResult::RepaintAt(window_id, repaint_time) => {
-                    self.windows_next_repaint_times.insert(
-                        window_id,
-                        self.windows_next_repaint_times
-                            .get(&window_id)
-                            .map_or(repaint_time, |last| (*last).min(repaint_time)),
-                    );
-                    Ok(event_result)
-                }
-                EventResult::Exit => {
-                    exit = true;
-                    Ok(event_result)
-                }
+        if cfg!(target_os = "windows") {
+            if let Ok(EventResult::RepaintNow(window_id)) = event_result {
+                log::trace!("RepaintNow of {window_id:?}");
+                self.windows_next_repaint_times.insert(window_id, now);
+
+                // Fix flickering on Windows, see https://github.com/emilk/egui/pull/2280
+                event_result = self.winit_app.run_ui_and_paint(event_loop, window_id);
+
+                now = Instant::now();
+            }
+        }
+
+        let combined_result = event_result.map(|event_result| match event_result {
+            EventResult::Wait => {
+                event_loop.set_control_flow(ControlFlow::Wait);
+                event_result
+            }
+            EventResult::RepaintNow(window_id) => {
+                log::trace!("RepaintNow of {window_id:?}");
+                self.windows_next_repaint_times.insert(window_id, now);
+                event_result
+            }
+            EventResult::RepaintNext(window_id) => {
+                log::trace!("RepaintNext of {window_id:?}");
+                self.windows_next_repaint_times.insert(window_id, now);
+                event_result
+            }
+            EventResult::RepaintAt(window_id, when) => {
+                self.windows_next_repaint_times.insert(window_id, when);
+                event_result
+            }
+            EventResult::Exit => {
+                exit = true;
+                event_result
             }
         });
 

crates/eframe/src/native/wgpu_integration.rs

@@ -692,8 +692,6 @@ impl<'app> WgpuWinitRunning<'app> {
 
         integration.post_rendering(window);
 
-        let active_viewports_ids: ViewportIdSet = viewport_output.keys().copied().collect();
-
         handle_viewport_output(
             &integration.egui_ctx,
             &viewport_output,
@@ -702,11 +700,6 @@ impl<'app> WgpuWinitRunning<'app> {
             viewport_from_window,
         );
 
-        // Prune dead viewports:
-        viewports.retain(|id, _| active_viewports_ids.contains(id));
-        viewport_from_window.retain(|_, id| active_viewports_ids.contains(id));
-        painter.gc_viewports(&active_viewports_ids);
-
         let window = viewport_from_window
             .get(&window_id)
             .and_then(|id| viewports.get(id))