use let-else to reduce indentation levels

crates/eframe/src/native/run.rs

@@ -1093,7 +1093,7 @@ mod glow_integration {
                         if let (Some(glutin), Some(gl), Some(painter)) =
                             (glutin.upgrade(), gl.upgrade(), painter.upgrade())
                         {
-                            Self::render_sync_viewport(
+                            Self::render_immediate_viewport(
                                 egui_ctx,
                                 viewport_builder,
                                 id_pair,
@@ -1123,7 +1123,7 @@ mod glow_integration {
 
         #[inline(always)]
         #[allow(clippy::too_many_arguments)]
-        fn render_sync_viewport(
+        fn render_immediate_viewport(
             egui_ctx: &egui::Context,
             mut viewport_builder: ViewportBuilder,
             id_pair: ViewportIdPair,
@@ -1430,7 +1430,10 @@ mod glow_integration {
                 return EventResult::Wait;
             }
 
-            if let Some(viewport_id) = self.viewport_id_from_window_id(&window_id) {
+            let Some(viewport_id) = self.viewport_id_from_window_id(&window_id) else {
+                return EventResult::Wait;
+            };
+
             #[cfg(feature = "puffin")]
             puffin::GlobalProfiler::lock().new_frame();
             crate::profile_scope!("frame");
@@ -1451,8 +1454,7 @@ mod glow_integration {
             {
                 let glutin = glutin.borrow();
                 let viewport = &glutin.viewports[&viewport_id].clone();
-                    if viewport.borrow().viewport_ui_cb.is_none() && viewport_id != ViewportId::ROOT
+                if viewport.borrow().viewport_ui_cb.is_none() && viewport_id != ViewportId::ROOT {
-                    {
                     if let Some(parent_viewport) =
                         glutin.viewports.get(&viewport.borrow().id_pair.parent)
                     {
@@ -1557,13 +1559,11 @@ mod glow_integration {
 
                 let mut integration = integration.borrow_mut();
                 {
-                        let screenshot_requested =
+                    let screenshot_requested = &mut integration.frame.output.screenshot_requested;
-                            &mut integration.frame.output.screenshot_requested;
 
                     if *screenshot_requested {
                         *screenshot_requested = false;
-                            let screenshot =
+                        let screenshot = painter.borrow().read_screen_rgba(screen_size_in_pixels);
-                                painter.borrow().read_screen_rgba(screen_size_in_pixels);
                         integration.frame.screenshot.set(Some(screenshot));
                     }
 
@@ -1602,8 +1602,7 @@ mod glow_integration {
                             path.ends_with(".png"),
                             "Expected EFRAME_SCREENSHOT_TO to end with '.png', got {path:?}"
                         );
-                            let screenshot =
+                        let screenshot = painter.borrow().read_screen_rgba(screen_size_in_pixels);
-                                painter.borrow().read_screen_rgba(screen_size_in_pixels);
                         image::save_buffer(
                             &path,
                             screenshot.as_raw(),
@@ -1670,9 +1669,6 @@ mod glow_integration {
             }
 
             control_flow
-            } else {
-                EventResult::Wait
-            }
         }
 
         fn on_event(
@@ -2037,6 +2033,8 @@ mod wgpu_integration {
             egui_winit: &mut Option<egui_winit::State>,
             event_loop: &EventLoopWindowTarget<UserEvent>,
         ) {
+            crate::profile_function!();
+
             if let Ok(new_window) = create_winit_window_builder(builder).build(event_loop) {
                 windows_id.insert(new_window.id(), id);
 
@@ -2225,7 +2223,7 @@ mod wgpu_integration {
                             painter.upgrade(),
                             viewport_maps.upgrade(),
                         ) {
-                            Self::render_sync_viewport(
+                            Self::render_immediate_viewport(
                                 egui_ctx,
                                 viewport_builder,
                                 id_pair,
@@ -2257,7 +2255,7 @@ mod wgpu_integration {
 
         #[inline(always)]
         #[allow(clippy::too_many_arguments)]
-        fn render_sync_viewport(
+        fn render_immediate_viewport(
             egui_ctx: &egui::Context,
             mut viewport_builder: ViewportBuilder,
             id_pair: ViewportIdPair,
@@ -2427,7 +2425,10 @@ mod wgpu_integration {
         }
 
         fn run_ui_and_paint(&mut self, window_id: winit::window::WindowId) -> EventResult {
-            if let Some(running) = &mut self.running {
+            let Some(running) = &mut self.running else {
+                return EventResult::Wait;
+            };
+
             #[cfg(feature = "puffin")]
             puffin::GlobalProfiler::lock().new_frame();
             crate::profile_scope!("frame");
@@ -2583,12 +2584,7 @@ mod wgpu_integration {
                         ..
                     }) = viewports.get(&id_pair.this)
                     {
-                            process_viewport_commands(
+                        process_viewport_commands(commands, id_pair.this, None, &window.borrow());
-                                commands,
-                                id_pair.this,
-                                None,
-                                &window.borrow(),
-                            );
                     }
                 } else {
                     viewports.insert(
@@ -2632,12 +2628,10 @@ mod wgpu_integration {
                 .retain(|_, id| active_viewports_ids.contains(id));
             painter.borrow_mut().gc_viewports(&active_viewports_ids);
 
-                let Some(
+            let Some(Viewport {
-                    Viewport {
                 window: Some(window),
                 ..
-                    },
+            }) = viewport_maps
-                ) = viewport_maps
                 .borrow()
                 .get(&window_id)
                 .and_then(|id| viewports.borrow().get(id).cloned())
@@ -2660,9 +2654,6 @@ mod wgpu_integration {
             } else {
                 EventResult::Wait
             }
-            } else {
-                EventResult::Wait
-            }
         }
 
         fn on_event(