use scale_factor for egui

crates/game/src/main.rs

@@ -16,6 +16,7 @@ struct WindowState {
     window: Window,
     egui_platform: egui_winit_platform::Platform,
     demo_app: egui_demo_lib::DemoWindows,
+    scale_factor: f64,
 }
 
 struct WinitState {
@@ -121,16 +122,18 @@ impl WinitState {
             window.window_handle().expect("window handle"),
         );
 
+        let scale_factor = window.scale_factor();
         self.windows2.insert(
             window_id,
             WindowState {
                 window,
+                scale_factor,
                 demo_app: egui_demo_lib::DemoWindows::default(),
                 egui_platform: egui_winit_platform::Platform::new(
                     egui_winit_platform::PlatformDescriptor {
                         physical_width: size.width,
                         physical_height: size.height,
-                        scale_factor: 1.0,
+                        scale_factor,
                         ..Default::default()
                     },
                 ),
@@ -229,6 +232,11 @@ impl ApplicationHandler for WinitState {
             winit::event::WindowEvent::RedrawRequested => {
                 self.handle_draw_request(window_id);
             }
+            winit::event::WindowEvent::ScaleFactorChanged { scale_factor, .. } => {
+                if let Some(window) = self.windows2.get_mut(&window_id) {
+                    window.scale_factor = scale_factor;
+                }
+            }
             _ => {} // unhandled event
         }
     }

crates/renderer/src/egui.rs

@@ -609,6 +609,7 @@ pub fn egui_pass(
         let pipeline = egui_state.pipeline.clone();
         let pipeline_layout = egui_state.pipeline_layout.clone();
         let descriptor_set = egui_state.descriptor_set;
+        let screen_rect = egui.screen_rect();
 
         move |ctx: &RenderContext| -> crate::Result<()> {
             let cmd = &ctx.cmd;
@@ -717,7 +718,7 @@ pub fn egui_pass(
                 vk::ShaderStageFlags::VERTEX,
                 0,
                 bytemuck::cast_slice(
-                    &[target.width() as f32, target.height() as f32].map(|f| f.to_bits()),
+                    &[screen_rect.width(), screen_rect.height()].map(|f| f.to_bits()),
                 ),
             );
             cmd.bind_descriptor_sets(