Fix egui-wgpu performance regression (#3580)

Introduced in the recent multi-viewports work, we accidentally recreated
the wgpu surfaces every frame. This is now fixed.

I found this while improving the profiling of `eframe`

crates/eframe/Cargo.toml

@@ -70,7 +70,13 @@ persistence = [
 ## `eframe` will call `puffin::GlobalProfiler::lock().new_frame()` for you
 ##
 ## Only enabled on native, because of the low resolution (1ms) of clocks in browsers.
-puffin = ["dep:puffin", "egui/puffin", "egui_glow?/puffin", "egui-wgpu?/puffin"]
+puffin = [
+  "dep:puffin",
+  "egui/puffin",
+  "egui_glow?/puffin",
+  "egui-wgpu?/puffin",
+  "egui-winit/puffin",
+]
 
 ## Enables wayland support and fixes clipboard issue.
 wayland = ["egui-winit/wayland"]

crates/eframe/src/native/epi_integration.rs

@@ -47,6 +47,7 @@ pub fn viewport_builder<E>(
 
     #[cfg(not(target_os = "ios"))]
     if native_options.centered {
+        crate::profile_scope!("center");
         if let Some(monitor) = event_loop.available_monitors().next() {
             let monitor_size = monitor.size().to_logical::<f32>(monitor.scale_factor());
             let inner_size = inner_size_points.unwrap_or(egui::Vec2 { x: 800.0, y: 600.0 });
@@ -76,9 +77,16 @@ pub fn apply_window_settings(
 }
 
 fn largest_monitor_point_size<E>(event_loop: &EventLoopWindowTarget<E>) -> egui::Vec2 {
+    crate::profile_function!();
+
     let mut max_size = egui::Vec2::ZERO;
 
-    for monitor in event_loop.available_monitors() {
+    let available_monitors = {
+        crate::profile_scope!("available_monitors");
+        event_loop.available_monitors()
+    };
+
+    for monitor in available_monitors {
         let size = monitor.size().to_logical::<f32>(monitor.scale_factor());
         let size = egui::vec2(size.width, size.height);
         max_size = max_size.max(size);
@@ -210,14 +218,14 @@ impl EpiIntegration {
         self.close
     }
 
-    pub fn on_event(
+    pub fn on_window_event(
         &mut self,
         app: &mut dyn epi::App,
         event: &winit::event::WindowEvent<'_>,
         egui_winit: &mut egui_winit::State,
         viewport_id: ViewportId,
     ) -> EventResponse {
-        crate::profile_function!();
+        crate::profile_function!(egui_winit::short_window_event_description(event));
 
         use winit::event::{ElementState, MouseButton, WindowEvent};
 
@@ -247,7 +255,7 @@ impl EpiIntegration {
             _ => {}
         }
 
-        egui_winit.on_event(&self.egui_ctx, event, viewport_id)
+        egui_winit.on_window_event(&self.egui_ctx, event, viewport_id)
     }
 
     pub fn pre_update(&mut self) {

crates/eframe/src/native/glow_integration.rs

@@ -393,7 +393,7 @@ impl WinitApp for GlowWinitApp {
         event_loop: &EventLoopWindowTarget<UserEvent>,
         event: &winit::event::Event<'_, UserEvent>,
     ) -> Result<EventResult> {
-        crate::profile_function!();
+        crate::profile_function!(winit_integration::short_event_description(event));
 
         Ok(match event {
             winit::event::Event::Resumed => {
@@ -468,19 +468,20 @@ impl WinitApp for GlowWinitApp {
 
 impl GlowWinitRunning {
     fn run_ui_and_paint(&mut self, window_id: WindowId) -> EventResult {
+        crate::profile_function!();
+
         let Some(viewport_id) = self
-                .glutin
-                .borrow()
-                .viewport_from_window
-                .get(&window_id)
-                .copied()
-            else {
-                return EventResult::Wait;
-            };
+            .glutin
+            .borrow()
+            .viewport_from_window
+            .get(&window_id)
+            .copied()
+        else {
+            return EventResult::Wait;
+        };
 
         #[cfg(feature = "puffin")]
         puffin::GlobalProfiler::lock().new_frame();
-        crate::profile_scope!("frame");
 
         {
             let glutin = self.glutin.borrow();
@@ -565,15 +566,22 @@ impl GlowWinitRunning {
 
         let clipped_primitives = integration.egui_ctx.tessellate(shapes, pixels_per_point);
 
-        *current_gl_context = Some(
-            current_gl_context
-                .take()
-                .unwrap()
-                .make_not_current()
-                .unwrap()
-                .make_current(gl_surface)
-                .unwrap(),
-        );
+        {
+            // TODO: only do this if we actually have multiple viewports
+            crate::profile_scope!("change_gl_context");
+
+            let not_current = {
+                crate::profile_scope!("make_not_current");
+                current_gl_context
+                    .take()
+                    .unwrap()
+                    .make_not_current()
+                    .unwrap()
+            };
+
+            crate::profile_scope!("make_current");
+            *current_gl_context = Some(not_current.make_current(gl_surface).unwrap());
+        }
 
         let screen_size_in_pixels: [u32; 2] = window.inner_size().into();
 
@@ -646,6 +654,8 @@ impl GlowWinitRunning {
         window_id: WindowId,
         event: &winit::event::WindowEvent<'_>,
     ) -> EventResult {
+        crate::profile_function!(egui_winit::short_window_event_description(event));
+
         let viewport_id = self
             .glutin
             .borrow()
@@ -710,7 +720,7 @@ impl GlowWinitRunning {
             if let Some(viewport_id) = viewport_id {
                 let mut glutin = self.glutin.borrow_mut();
                 if let Some(viewport) = glutin.viewports.get_mut(&viewport_id) {
-                    break 'res self.integration.on_event(
+                    break 'res self.integration.on_window_event(
                         self.app.as_mut(),
                         event,
                         viewport.egui_winit.as_mut().unwrap(),
@@ -1127,11 +1137,11 @@ impl Viewport {
     /// Update the stored `ViewportInfo`.
     fn update_viewport_info(&mut self) {
         let Some(window) = &self.window else {
-                return;
-            };
+            return;
+        };
         let Some(egui_winit) = &self.egui_winit else {
-                return;
-            };
+            return;
+        };
         egui_winit.update_viewport_info(&mut self.info, window);
     }
 }
@@ -1245,15 +1255,15 @@ fn render_immediate_viewport(
         let mut glutin = glutin.borrow_mut();
 
         let Some(viewport) = glutin.viewports.get_mut(&ids.this) else {
-                return;
-            };
+            return;
+        };
         viewport.update_viewport_info();
         let Some(winit_state) = &mut viewport.egui_winit else {
-                return;
-            };
+            return;
+        };
         let Some(window) = &viewport.window else {
-                return;
-            };
+            return;
+        };
 
         let mut raw_input = winit_state.take_egui_input(window, ids);
         raw_input.viewports = glutin
@@ -1290,15 +1300,15 @@ fn render_immediate_viewport(
     } = &mut *glutin;
 
     let Some(viewport) = viewports.get_mut(&ids.this) else {
-            return;
-        };
+        return;
+    };
 
     let Some(winit_state) = &mut viewport.egui_winit else {
-            return;
-        };
+        return;
+    };
     let (Some(window), Some(gl_surface)) = (&viewport.window, &viewport.gl_surface) else {
-            return;
-        };
+        return;
+    };
 
     let screen_size_in_pixels: [u32; 2] = window.inner_size().into();
 

crates/eframe/src/native/run.rs

@@ -11,7 +11,11 @@ use winit::event_loop::{EventLoop, EventLoopBuilder};
 
 use egui::epaint::ahash::HashMap;
 
-use crate::{epi, native::winit_integration::EventResult, Result};
+use crate::{
+    epi,
+    native::winit_integration::{short_event_description, EventResult},
+    Result,
+};
 
 use super::winit_integration::{UserEvent, WinitApp};
 
@@ -397,69 +401,3 @@ pub fn run_wgpu(
     let wgpu_eframe = WgpuWinitApp::new(&event_loop, app_name, native_options, app_creator);
     run_and_exit(event_loop, wgpu_eframe);
 }
-
-// ----------------------------------------------------------------------------
-
-// For the puffin profiler!
-#[allow(dead_code)] // Only used for profiling
-fn short_event_description(event: &winit::event::Event<'_, UserEvent>) -> &'static str {
-    use winit::event::{DeviceEvent, Event, StartCause, WindowEvent};
-
-    match event {
-        Event::Suspended => "Event::Suspended",
-        Event::Resumed => "Event::Resumed",
-        Event::MainEventsCleared => "Event::MainEventsCleared",
-        Event::RedrawRequested(_) => "Event::RedrawRequested",
-        Event::RedrawEventsCleared => "Event::RedrawEventsCleared",
-        Event::LoopDestroyed => "Event::LoopDestroyed",
-        Event::UserEvent(user_event) => match user_event {
-            UserEvent::RequestRepaint { .. } => "UserEvent::RequestRepaint",
-            #[cfg(feature = "accesskit")]
-            UserEvent::AccessKitActionRequest(_) => "UserEvent::AccessKitActionRequest",
-        },
-        Event::DeviceEvent { event, .. } => match event {
-            DeviceEvent::Added { .. } => "DeviceEvent::Added",
-            DeviceEvent::Removed { .. } => "DeviceEvent::Removed",
-            DeviceEvent::MouseMotion { .. } => "DeviceEvent::MouseMotion",
-            DeviceEvent::MouseWheel { .. } => "DeviceEvent::MouseWheel",
-            DeviceEvent::Motion { .. } => "DeviceEvent::Motion",
-            DeviceEvent::Button { .. } => "DeviceEvent::Button",
-            DeviceEvent::Key { .. } => "DeviceEvent::Key",
-            DeviceEvent::Text { .. } => "DeviceEvent::Text",
-        },
-        Event::NewEvents(start_cause) => match start_cause {
-            StartCause::ResumeTimeReached { .. } => "NewEvents::ResumeTimeReached",
-            StartCause::WaitCancelled { .. } => "NewEvents::WaitCancelled",
-            StartCause::Poll => "NewEvents::Poll",
-            StartCause::Init => "NewEvents::Init",
-        },
-        Event::WindowEvent { event, .. } => match event {
-            WindowEvent::Resized { .. } => "WindowEvent::Resized",
-            WindowEvent::Moved { .. } => "WindowEvent::Moved",
-            WindowEvent::CloseRequested { .. } => "WindowEvent::CloseRequested",
-            WindowEvent::Destroyed { .. } => "WindowEvent::Destroyed",
-            WindowEvent::DroppedFile { .. } => "WindowEvent::DroppedFile",
-            WindowEvent::HoveredFile { .. } => "WindowEvent::HoveredFile",
-            WindowEvent::HoveredFileCancelled { .. } => "WindowEvent::HoveredFileCancelled",
-            WindowEvent::ReceivedCharacter { .. } => "WindowEvent::ReceivedCharacter",
-            WindowEvent::Focused { .. } => "WindowEvent::Focused",
-            WindowEvent::KeyboardInput { .. } => "WindowEvent::KeyboardInput",
-            WindowEvent::ModifiersChanged { .. } => "WindowEvent::ModifiersChanged",
-            WindowEvent::Ime { .. } => "WindowEvent::Ime",
-            WindowEvent::CursorMoved { .. } => "WindowEvent::CursorMoved",
-            WindowEvent::CursorEntered { .. } => "WindowEvent::CursorEntered",
-            WindowEvent::CursorLeft { .. } => "WindowEvent::CursorLeft",
-            WindowEvent::MouseWheel { .. } => "WindowEvent::MouseWheel",
-            WindowEvent::MouseInput { .. } => "WindowEvent::MouseInput",
-            WindowEvent::TouchpadMagnify { .. } => "WindowEvent::TouchpadMagnify",
-            WindowEvent::SmartMagnify { .. } => "WindowEvent::SmartMagnify",
-            WindowEvent::TouchpadRotate { .. } => "WindowEvent::TouchpadRotate",
-            WindowEvent::TouchpadPressure { .. } => "WindowEvent::TouchpadPressure",
-            WindowEvent::AxisMotion { .. } => "WindowEvent::AxisMotion",
-            WindowEvent::Touch { .. } => "WindowEvent::Touch",
-            WindowEvent::ScaleFactorChanged { .. } => "WindowEvent::ScaleFactorChanged",
-            WindowEvent::ThemeChanged { .. } => "WindowEvent::ThemeChanged",
-            WindowEvent::Occluded { .. } => "WindowEvent::Occluded",
-        },
-    }
-}

crates/eframe/src/native/wgpu_integration.rs

@@ -111,8 +111,8 @@ impl WgpuWinitApp {
 
     fn build_windows(&mut self, event_loop: &EventLoopWindowTarget<UserEvent>) {
         let Some(running) = &mut self.running else {
-                return;
-            };
+            return;
+        };
         let mut shared = running.shared.borrow_mut();
         let SharedState {
             viewports,
@@ -357,7 +357,7 @@ impl WinitApp for WgpuWinitApp {
         event_loop: &EventLoopWindowTarget<UserEvent>,
         event: &winit::event::Event<'_, UserEvent>,
     ) -> Result<EventResult> {
-        crate::profile_function!();
+        crate::profile_function!(winit_integration::short_event_description(event));
 
         self.build_windows(event_loop);
 
@@ -452,21 +452,21 @@ impl WgpuWinitRunning {
 
     /// This is called both for the root viewport, and all deferred viewports
     fn run_ui_and_paint(&mut self, window_id: WindowId) -> EventResult {
+        crate::profile_function!();
+
         let Some(viewport_id) = self
-                .shared
-                .borrow()
-                .viewport_from_window
-                .get(&window_id)
-                .copied()
-            else {
-                return EventResult::Wait;
-            };
+            .shared
+            .borrow()
+            .viewport_from_window
+            .get(&window_id)
+            .copied()
+        else {
+            return EventResult::Wait;
+        };
 
         #[cfg(feature = "puffin")]
         puffin::GlobalProfiler::lock().new_frame();
 
-        crate::profile_scope!("frame");
-
         let WgpuWinitRunning {
             app,
             integration,
@@ -474,30 +474,33 @@ impl WgpuWinitRunning {
         } = self;
 
         let (viewport_ui_cb, raw_input) = {
+            crate::profile_scope!("Prepare");
             let mut shared_lock = shared.borrow_mut();
 
             let SharedState {
                 viewports, painter, ..
             } = &mut *shared_lock;
 
-            let Some(viewport) = viewports.get(&viewport_id) else {
+            if viewport_id != ViewportId::ROOT {
+                let Some(viewport) = viewports.get(&viewport_id) else {
                     return EventResult::Wait;
                 };
 
-            if viewport_id != ViewportId::ROOT && viewport.viewport_ui_cb.is_none() {
-                // This will only happen if this is an immediate viewport.
-                // That means that the viewport cannot be rendered by itself and needs his parent to be rendered.
-                if let Some(viewport) = viewports.get(&viewport.ids.parent) {
-                    if let Some(window) = viewport.window.as_ref() {
-                        return EventResult::RepaintNext(window.id());
+                if viewport.viewport_ui_cb.is_none() {
+                    // This will only happen if this is an immediate viewport.
+                    // That means that the viewport cannot be rendered by itself and needs his parent to be rendered.
+                    if let Some(viewport) = viewports.get(&viewport.ids.parent) {
+                        if let Some(window) = viewport.window.as_ref() {
+                            return EventResult::RepaintNext(window.id());
+                        }
                     }
+                    return EventResult::Wait;
                 }
-                return EventResult::Wait;
             }
 
             let Some(viewport) = viewports.get_mut(&viewport_id) else {
-                    return EventResult::Wait;
-                };
+                return EventResult::Wait;
+            };
             viewport.update_viewport_info();
 
             let Viewport {
@@ -507,14 +510,19 @@ impl WgpuWinitRunning {
                 egui_winit,
                 ..
             } = viewport;
+
             let viewport_ui_cb = viewport_ui_cb.clone();
 
             let Some(window) = window else {
-                    return EventResult::Wait;
-                };
+                return EventResult::Wait;
+            };
 
-            if let Err(err) = pollster::block_on(painter.set_window(viewport_id, Some(window))) {
-                log::warn!("Failed to set window: {err}");
+            {
+                crate::profile_scope!("set_window");
+                if let Err(err) = pollster::block_on(painter.set_window(viewport_id, Some(window)))
+                {
+                    log::warn!("Failed to set window: {err}");
+                }
             }
 
             let mut raw_input = egui_winit.as_mut().unwrap().take_egui_input(
@@ -551,17 +559,17 @@ impl WgpuWinitRunning {
         } = &mut *shared;
 
         let Some(viewport) = viewports.get_mut(&viewport_id) else {
-                return EventResult::Wait;
-            };
+            return EventResult::Wait;
+        };
 
         let Viewport {
-                window: Some(window),
-                egui_winit: Some(egui_winit),
-                ..
-            } = viewport
-            else {
-                return EventResult::Wait;
-            };
+            window: Some(window),
+            egui_winit: Some(egui_winit),
+            ..
+        } = viewport
+        else {
+            return EventResult::Wait;
+        };
 
         integration.post_update();
 
@@ -637,6 +645,8 @@ impl WgpuWinitRunning {
         window_id: WindowId,
         event: &winit::event::WindowEvent<'_>,
     ) -> EventResult {
+        crate::profile_function!(egui_winit::short_window_event_description(event));
+
         let Self {
             integration,
             app,
@@ -705,7 +715,7 @@ impl WgpuWinitRunning {
         let event_response = viewport_id.and_then(|viewport_id| {
             shared.viewports.get_mut(&viewport_id).and_then(|viewport| {
                 viewport.egui_winit.as_mut().map(|egui_winit| {
-                    integration.on_event(app.as_mut(), event, egui_winit, viewport_id)
+                    integration.on_window_event(app.as_mut(), event, egui_winit, viewport_id)
                 })
             })
         });
@@ -769,12 +779,13 @@ impl Viewport {
 
     /// Update the stored `ViewportInfo`.
     pub fn update_viewport_info(&mut self) {
+        crate::profile_function!();
         let Some(window) = &self.window else {
-                return;
-            };
+            return;
+        };
         let Some(egui_winit) = &self.egui_winit else {
-                return;
-            };
+            return;
+        };
         egui_winit.update_viewport_info(&mut self.info, window);
     }
 }
@@ -834,10 +845,9 @@ fn render_immediate_viewport(
         }
         viewport.update_viewport_info();
 
-        let (Some(window), Some(winit_state)) = (&viewport.window, &mut viewport.egui_winit)
-            else {
-                return;
-            };
+        let (Some(window), Some(winit_state)) = (&viewport.window, &mut viewport.egui_winit) else {
+            return;
+        };
 
         let mut input = winit_state.take_egui_input(window, ids);
         input.viewports = viewports
@@ -873,14 +883,14 @@ fn render_immediate_viewport(
     } = &mut *shared;
 
     let Some(viewport) = viewports.get_mut(&ids.this) else {
-            return;
-        };
+        return;
+    };
     let Some(winit_state) = &mut viewport.egui_winit else {
-            return;
-        };
+        return;
+    };
     let Some(window) = &viewport.window else {
-            return;
-        };
+        return;
+    };
 
     if let Err(err) = pollster::block_on(painter.set_window(ids.this, Some(window))) {
         log::error!(

crates/eframe/src/native/winit_integration.rs

@@ -100,3 +100,18 @@ pub fn system_theme(window: &Window, options: &crate::NativeOptions) -> Option<c
         None
     }
 }
+
+/// Short and fast description of an event.
+/// Useful for logging and profiling.
+pub fn short_event_description(event: &winit::event::Event<'_, UserEvent>) -> &'static str {
+    use winit::event::Event;
+
+    match event {
+        Event::UserEvent(user_event) => match user_event {
+            UserEvent::RequestRepaint { .. } => "UserEvent::RequestRepaint",
+            #[cfg(feature = "accesskit")]
+            UserEvent::AccessKitActionRequest(_) => "UserEvent::AccessKitActionRequest",
+        },
+        _ => egui_winit::short_generic_event_description(event),
+    }
+}

crates/egui-wgpu/src/lib.rs

@@ -67,21 +67,32 @@ impl RenderState {
         depth_format: Option<wgpu::TextureFormat>,
         msaa_samples: u32,
     ) -> Result<Self, WgpuError> {
-        let adapter = instance
-            .request_adapter(&wgpu::RequestAdapterOptions {
-                power_preference: config.power_preference,
-                compatible_surface: Some(surface),
-                force_fallback_adapter: false,
-            })
-            .await
-            .ok_or(WgpuError::NoSuitableAdapterFound)?;
-
-        let target_format =
-            crate::preferred_framebuffer_format(&surface.get_capabilities(&adapter).formats)?;
-
-        let (device, queue) = adapter
-            .request_device(&(*config.device_descriptor)(&adapter), None)
-            .await?;
+        crate::profile_scope!("RenderState::create"); // async yield give bad names using `profile_function`
+
+        let adapter = {
+            crate::profile_scope!("request_adapter");
+            instance
+                .request_adapter(&wgpu::RequestAdapterOptions {
+                    power_preference: config.power_preference,
+                    compatible_surface: Some(surface),
+                    force_fallback_adapter: false,
+                })
+                .await
+                .ok_or(WgpuError::NoSuitableAdapterFound)?
+        };
+
+        let capabilities = {
+            crate::profile_scope!("get_capabilities");
+            surface.get_capabilities(&adapter).formats
+        };
+        let target_format = crate::preferred_framebuffer_format(&capabilities)?;
+
+        let (device, queue) = {
+            crate::profile_scope!("request_device");
+            adapter
+                .request_device(&(*config.device_descriptor)(&adapter), None)
+                .await?
+        };
 
         let renderer = Renderer::new(&device, target_format, depth_format, msaa_samples);
 

crates/egui-wgpu/src/renderer.rs

@@ -189,7 +189,10 @@ impl Renderer {
             label: Some("egui"),
             source: wgpu::ShaderSource::Wgsl(Cow::Borrowed(include_str!("egui.wgsl"))),
         };
-        let module = device.create_shader_module(shader);
+        let module = {
+            crate::profile_scope!("create_shader_module");
+            device.create_shader_module(shader)
+        };
 
         let uniform_buffer = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
             label: Some("egui_uniform_buffer"),
@@ -200,7 +203,8 @@ impl Renderer {
             usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
         });
 
-        let uniform_bind_group_layout =
+        let uniform_bind_group_layout = {
+            crate::profile_scope!("create_bind_group_layout");
             device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
                 label: Some("egui_uniform_bind_group_layout"),
                 entries: &[wgpu::BindGroupLayoutEntry {
@@ -213,22 +217,27 @@ impl Renderer {
                     },
                     count: None,
                 }],
-            });
+            })
+        };
 
-        let uniform_bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
-            label: Some("egui_uniform_bind_group"),
-            layout: &uniform_bind_group_layout,
-            entries: &[wgpu::BindGroupEntry {
-                binding: 0,
-                resource: wgpu::BindingResource::Buffer(wgpu::BufferBinding {
-                    buffer: &uniform_buffer,
-                    offset: 0,
-                    size: None,
-                }),
-            }],
-        });
+        let uniform_bind_group = {
+            crate::profile_scope!("create_bind_group");
+            device.create_bind_group(&wgpu::BindGroupDescriptor {
+                label: Some("egui_uniform_bind_group"),
+                layout: &uniform_bind_group_layout,
+                entries: &[wgpu::BindGroupEntry {
+                    binding: 0,
+                    resource: wgpu::BindingResource::Buffer(wgpu::BufferBinding {
+                        buffer: &uniform_buffer,
+                        offset: 0,
+                        size: None,
+                    }),
+                }],
+            })
+        };
 
-        let texture_bind_group_layout =
+        let texture_bind_group_layout = {
+            crate::profile_scope!("create_bind_group_layout");
             device.create_bind_group_layout(&wgpu::BindGroupLayoutDescriptor {
                 label: Some("egui_texture_bind_group_layout"),
                 entries: &[
@@ -249,7 +258,8 @@ impl Renderer {
                         count: None,
                     },
                 ],
-            });
+            })
+        };
 
         let pipeline_layout = device.create_pipeline_layout(&wgpu::PipelineLayoutDescriptor {
             label: Some("egui_pipeline_layout"),
@@ -265,64 +275,68 @@ impl Renderer {
             bias: wgpu::DepthBiasState::default(),
         });
 
-        let pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
-            label: Some("egui_pipeline"),
-            layout: Some(&pipeline_layout),
-            vertex: wgpu::VertexState {
-                entry_point: "vs_main",
-                module: &module,
-                buffers: &[wgpu::VertexBufferLayout {
-                    array_stride: 5 * 4,
-                    step_mode: wgpu::VertexStepMode::Vertex,
-                    // 0: vec2 position
-                    // 1: vec2 texture coordinates
-                    // 2: uint color
-                    attributes: &wgpu::vertex_attr_array![0 => Float32x2, 1 => Float32x2, 2 => Uint32],
-                }],
-            },
-            primitive: wgpu::PrimitiveState {
-                topology: wgpu::PrimitiveTopology::TriangleList,
-                unclipped_depth: false,
-                conservative: false,
-                cull_mode: None,
-                front_face: wgpu::FrontFace::default(),
-                polygon_mode: wgpu::PolygonMode::default(),
-                strip_index_format: None,
-            },
-            depth_stencil,
-            multisample: wgpu::MultisampleState {
-                alpha_to_coverage_enabled: false,
-                count: msaa_samples,
-                mask: !0,
-            },
-
-            fragment: Some(wgpu::FragmentState {
-                module: &module,
-                entry_point: if output_color_format.is_srgb() {
-                    log::warn!("Detected a linear (sRGBA aware) framebuffer {:?}. egui prefers Rgba8Unorm or Bgra8Unorm", output_color_format);
-                    "fs_main_linear_framebuffer"
-                } else {
-                    "fs_main_gamma_framebuffer" // this is what we prefer
+        let pipeline = {
+            crate::profile_scope!("create_render_pipeline");
+            device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
+                label: Some("egui_pipeline"),
+                layout: Some(&pipeline_layout),
+                vertex: wgpu::VertexState {
+                    entry_point: "vs_main",
+                    module: &module,
+                    buffers: &[wgpu::VertexBufferLayout {
+                        array_stride: 5 * 4,
+                        step_mode: wgpu::VertexStepMode::Vertex,
+                        // 0: vec2 position
+                        // 1: vec2 texture coordinates
+                        // 2: uint color
+                        attributes: &wgpu::vertex_attr_array![0 => Float32x2, 1 => Float32x2, 2 => Uint32],
+                    }],
                 },
-                targets: &[Some(wgpu::ColorTargetState {
-                    format: output_color_format,
-                    blend: Some(wgpu::BlendState {
-                        color: wgpu::BlendComponent {
-                            src_factor: wgpu::BlendFactor::One,
-                            dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
-                            operation: wgpu::BlendOperation::Add,
-                        },
-                        alpha: wgpu::BlendComponent {
-                            src_factor: wgpu::BlendFactor::OneMinusDstAlpha,
-                            dst_factor: wgpu::BlendFactor::One,
-                            operation: wgpu::BlendOperation::Add,
-                        },
-                    }),
-                    write_mask: wgpu::ColorWrites::ALL,
-                })],
-            }),
-            multiview: None,
-        });
+                primitive: wgpu::PrimitiveState {
+                    topology: wgpu::PrimitiveTopology::TriangleList,
+                    unclipped_depth: false,
+                    conservative: false,
+                    cull_mode: None,
+                    front_face: wgpu::FrontFace::default(),
+                    polygon_mode: wgpu::PolygonMode::default(),
+                    strip_index_format: None,
+                },
+                depth_stencil,
+                multisample: wgpu::MultisampleState {
+                    alpha_to_coverage_enabled: false,
+                    count: msaa_samples,
+                    mask: !0,
+                },
+
+                fragment: Some(wgpu::FragmentState {
+                    module: &module,
+                    entry_point: if output_color_format.is_srgb() {
+                        log::warn!("Detected a linear (sRGBA aware) framebuffer {:?}. egui prefers Rgba8Unorm or Bgra8Unorm", output_color_format);
+                        "fs_main_linear_framebuffer"
+                    } else {
+                        "fs_main_gamma_framebuffer" // this is what we prefer
+                    },
+                    targets: &[Some(wgpu::ColorTargetState {
+                        format: output_color_format,
+                        blend: Some(wgpu::BlendState {
+                            color: wgpu::BlendComponent {
+                                src_factor: wgpu::BlendFactor::One,
+                                dst_factor: wgpu::BlendFactor::OneMinusSrcAlpha,
+                                operation: wgpu::BlendOperation::Add,
+                            },
+                            alpha: wgpu::BlendComponent {
+                                src_factor: wgpu::BlendFactor::OneMinusDstAlpha,
+                                dst_factor: wgpu::BlendFactor::One,
+                                operation: wgpu::BlendOperation::Add,
+                            },
+                        }),
+                        write_mask: wgpu::ColorWrites::ALL,
+                    })],
+                }),
+                multiview: None,
+            }
+        )
+        };
 
         const VERTEX_BUFFER_START_CAPACITY: wgpu::BufferAddress =
             (std::mem::size_of::<Vertex>() * 1024) as _;

crates/egui-wgpu/src/winit.rs

@@ -143,6 +143,7 @@ impl Painter {
         present_mode: wgpu::PresentMode,
     ) {
         crate::profile_function!();
+
         let usage = if surface_state.supports_screenshot {
             wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::COPY_DST
         } else {
@@ -188,12 +189,15 @@ impl Painter {
         viewport_id: ViewportId,
         window: Option<&winit::window::Window>,
     ) -> Result<(), crate::WgpuError> {
-        crate::profile_function!();
+        crate::profile_scope!("Painter::set_window"); // profle_function gives bad names for async functions
 
         if let Some(window) = window {
             let size = window.inner_size();
             if self.surfaces.get(&viewport_id).is_none() {
-                let surface = unsafe { self.instance.create_surface(&window)? };
+                let surface = unsafe {
+                    crate::profile_scope!("create_surface");
+                    self.instance.create_surface(&window)?
+                };
 
                 let render_state = if let Some(render_state) = &self.render_state {
                     render_state
@@ -241,19 +245,24 @@ impl Painter {
                         supports_screenshot,
                     },
                 );
-            }
 
-            let Some(width) = NonZeroU32::new(size.width) else {
-                log::debug!("The window width was zero; skipping generate textures");
-                return Ok(());
-            };
-            let Some(height) = NonZeroU32::new(size.height) else {
-                log::debug!("The window height was zero; skipping generate textures");
-                return Ok(());
-            };
-            self.resize_and_generate_depth_texture_view_and_msaa_view(viewport_id, width, height);
+                let Some(width) = NonZeroU32::new(size.width) else {
+                    log::debug!("The window width was zero; skipping generate textures");
+                    return Ok(());
+                };
+                let Some(height) = NonZeroU32::new(size.height) else {
+                    log::debug!("The window height was zero; skipping generate textures");
+                    return Ok(());
+                };
+
+                self.resize_and_generate_depth_texture_view_and_msaa_view(
+                    viewport_id,
+                    width,
+                    height,
+                );
+            }
         } else {
-            log::warn!("All surfaces was deleted!");
+            log::warn!("No window - clearing all surfaces");
             self.surfaces.clear();
         }
         Ok(())

crates/egui-winit/src/lib.rs

@@ -174,14 +174,14 @@ impl State {
     }
 
     /// The current input state.
-    /// This is changed by [`Self::on_event`] and cleared by [`Self::take_egui_input`].
+    /// This is changed by [`Self::on_window_event`] and cleared by [`Self::take_egui_input`].
     #[inline]
     pub fn egui_input(&self) -> &egui::RawInput {
         &self.egui_input
     }
 
     /// The current input state.
-    /// This is changed by [`Self::on_event`] and cleared by [`Self::take_egui_input`].
+    /// This is changed by [`Self::on_window_event`] and cleared by [`Self::take_egui_input`].
     #[inline]
     pub fn egui_input_mut(&mut self) -> &mut egui::RawInput {
         &mut self.egui_input
@@ -233,13 +233,13 @@ impl State {
     /// Call this when there is a new event.
     ///
     /// The result can be found in [`Self::egui_input`] and be extracted with [`Self::take_egui_input`].
-    pub fn on_event(
+    pub fn on_window_event(
         &mut self,
         egui_ctx: &egui::Context,
         event: &winit::event::WindowEvent<'_>,
         viewport_id: ViewportId,
     ) -> EventResponse {
-        crate::profile_function!();
+        crate::profile_function!(short_window_event_description(event));
 
         use winit::event::WindowEvent;
         match event {
@@ -822,16 +822,14 @@ fn update_viewport_info(viewport_info: &mut ViewportInfo, window: &Window, pixel
     let inner_rect = inner_rect_px.map(|r| r / pixels_per_point);
     let outer_rect = outer_rect_px.map(|r| r / pixels_per_point);
 
-    let monitor = window.current_monitor().is_some();
-    let monitor_size = if monitor {
-        let size = window
-            .current_monitor()
-            .unwrap()
-            .size()
-            .to_logical::<f32>(pixels_per_point.into());
-        Some(egui::vec2(size.width, size.height))
-    } else {
-        None
+    let monitor_size = {
+        crate::profile_scope!("monitor_size");
+        if let Some(monitor) = window.current_monitor() {
+            let size = monitor.size().to_logical::<f32>(pixels_per_point.into());
+            Some(egui::vec2(size.width, size.height))
+        } else {
+            None
+        }
     };
 
     viewport_info.title = Some(window.title());
@@ -1339,6 +1337,76 @@ pub fn apply_viewport_builder_to_new_window(window: &Window, builder: &ViewportB
 
 // ---------------------------------------------------------------------------
 
+/// Short and fast description of an event.
+/// Useful for logging and profiling.
+pub fn short_generic_event_description<T>(event: &winit::event::Event<'_, T>) -> &'static str {
+    use winit::event::{DeviceEvent, Event, StartCause};
+
+    match event {
+        Event::Suspended => "Event::Suspended",
+        Event::Resumed => "Event::Resumed",
+        Event::MainEventsCleared => "Event::MainEventsCleared",
+        Event::RedrawRequested(_) => "Event::RedrawRequested",
+        Event::RedrawEventsCleared => "Event::RedrawEventsCleared",
+        Event::LoopDestroyed => "Event::LoopDestroyed",
+        Event::UserEvent(_) => "UserEvent",
+        Event::DeviceEvent { event, .. } => match event {
+            DeviceEvent::Added { .. } => "DeviceEvent::Added",
+            DeviceEvent::Removed { .. } => "DeviceEvent::Removed",
+            DeviceEvent::MouseMotion { .. } => "DeviceEvent::MouseMotion",
+            DeviceEvent::MouseWheel { .. } => "DeviceEvent::MouseWheel",
+            DeviceEvent::Motion { .. } => "DeviceEvent::Motion",
+            DeviceEvent::Button { .. } => "DeviceEvent::Button",
+            DeviceEvent::Key { .. } => "DeviceEvent::Key",
+            DeviceEvent::Text { .. } => "DeviceEvent::Text",
+        },
+        Event::NewEvents(start_cause) => match start_cause {
+            StartCause::ResumeTimeReached { .. } => "NewEvents::ResumeTimeReached",
+            StartCause::WaitCancelled { .. } => "NewEvents::WaitCancelled",
+            StartCause::Poll => "NewEvents::Poll",
+            StartCause::Init => "NewEvents::Init",
+        },
+        Event::WindowEvent { event, .. } => short_window_event_description(event),
+    }
+}
+
+/// Short and fast description of an event.
+/// Useful for logging and profiling.
+pub fn short_window_event_description(event: &winit::event::WindowEvent<'_>) -> &'static str {
+    use winit::event::WindowEvent;
+
+    match event {
+        WindowEvent::Resized { .. } => "WindowEvent::Resized",
+        WindowEvent::Moved { .. } => "WindowEvent::Moved",
+        WindowEvent::CloseRequested { .. } => "WindowEvent::CloseRequested",
+        WindowEvent::Destroyed { .. } => "WindowEvent::Destroyed",
+        WindowEvent::DroppedFile { .. } => "WindowEvent::DroppedFile",
+        WindowEvent::HoveredFile { .. } => "WindowEvent::HoveredFile",
+        WindowEvent::HoveredFileCancelled { .. } => "WindowEvent::HoveredFileCancelled",
+        WindowEvent::ReceivedCharacter { .. } => "WindowEvent::ReceivedCharacter",
+        WindowEvent::Focused { .. } => "WindowEvent::Focused",
+        WindowEvent::KeyboardInput { .. } => "WindowEvent::KeyboardInput",
+        WindowEvent::ModifiersChanged { .. } => "WindowEvent::ModifiersChanged",
+        WindowEvent::Ime { .. } => "WindowEvent::Ime",
+        WindowEvent::CursorMoved { .. } => "WindowEvent::CursorMoved",
+        WindowEvent::CursorEntered { .. } => "WindowEvent::CursorEntered",
+        WindowEvent::CursorLeft { .. } => "WindowEvent::CursorLeft",
+        WindowEvent::MouseWheel { .. } => "WindowEvent::MouseWheel",
+        WindowEvent::MouseInput { .. } => "WindowEvent::MouseInput",
+        WindowEvent::TouchpadMagnify { .. } => "WindowEvent::TouchpadMagnify",
+        WindowEvent::SmartMagnify { .. } => "WindowEvent::SmartMagnify",
+        WindowEvent::TouchpadRotate { .. } => "WindowEvent::TouchpadRotate",
+        WindowEvent::TouchpadPressure { .. } => "WindowEvent::TouchpadPressure",
+        WindowEvent::AxisMotion { .. } => "WindowEvent::AxisMotion",
+        WindowEvent::Touch { .. } => "WindowEvent::Touch",
+        WindowEvent::ScaleFactorChanged { .. } => "WindowEvent::ScaleFactorChanged",
+        WindowEvent::ThemeChanged { .. } => "WindowEvent::ThemeChanged",
+        WindowEvent::Occluded { .. } => "WindowEvent::Occluded",
+    }
+}
+
+// ---------------------------------------------------------------------------
+
 mod profiling_scopes {
     #![allow(unused_macros)]
     #![allow(unused_imports)]

crates/egui-winit/src/window_settings.rs

@@ -52,6 +52,8 @@ impl WindowSettings {
         &self,
         mut viewport_builder: ViewportBuilder,
     ) -> ViewportBuilder {
+        crate::profile_function!();
+
         // `WindowBuilder::with_position` expects inner position in Macos, and outer position elsewhere
         // See [`winit::window::WindowBuilder::with_position`] for details.
         let pos_px = if cfg!(target_os = "macos") {
@@ -127,6 +129,8 @@ fn clamp_pos_to_monitors<E>(
     window_size_pts: egui::Vec2,
     position_px: &mut egui::Pos2,
 ) {
+    crate::profile_function!();
+
     let monitors = event_loop.available_monitors();
 
     // default to primary monitor, in case the correct monitor was disconnected.

crates/egui/src/context.rs

@@ -2391,7 +2391,7 @@ impl Context {
     /// [not_supported]: crate::load::LoadError::NotSupported
     /// [custom]: crate::load::LoadError::Loading
     pub fn try_load_bytes(&self, uri: &str) -> load::BytesLoadResult {
-        crate::profile_function!();
+        crate::profile_function!(uri);
 
         let loaders = self.loaders();
         let bytes_loaders = loaders.bytes.lock();
@@ -2428,7 +2428,7 @@ impl Context {
     /// [not_supported]: crate::load::LoadError::NotSupported
     /// [custom]: crate::load::LoadError::Loading
     pub fn try_load_image(&self, uri: &str, size_hint: load::SizeHint) -> load::ImageLoadResult {
-        crate::profile_function!();
+        crate::profile_function!(uri);
 
         let loaders = self.loaders();
         let image_loaders = loaders.image.lock();
@@ -2471,7 +2471,7 @@ impl Context {
         texture_options: TextureOptions,
         size_hint: load::SizeHint,
     ) -> load::TextureLoadResult {
-        crate::profile_function!();
+        crate::profile_function!(uri);
 
         let loaders = self.loaders();
         let texture_loaders = loaders.texture.lock();

crates/egui_glow/examples/pure_glow.rs

@@ -235,7 +235,7 @@ fn main() {
                     gl_window.resize(**new_inner_size);
                 }
 
-                let event_response = egui_glow.on_event(&event);
+                let event_response = egui_glow.on_window_event(&event);
 
                 if event_response.repaint {
                     gl_window.window().request_redraw();

crates/egui_glow/src/winit.rs

@@ -52,9 +52,9 @@ impl EguiGlow {
         }
     }
 
-    pub fn on_event(&mut self, event: &winit::event::WindowEvent<'_>) -> EventResponse {
+    pub fn on_window_event(&mut self, event: &winit::event::WindowEvent<'_>) -> EventResponse {
         self.egui_winit
-            .on_event(&self.egui_ctx, event, ViewportId::ROOT)
+            .on_window_event(&self.egui_ctx, event, ViewportId::ROOT)
     }
 
     /// Call [`Self::paint`] later to paint.