Initialize the window uniform from the surface

Reviewed-on: iris/iris#6

core/src/render/mod.rs

@@ -137,7 +137,10 @@ impl UiRenderNode {
             source: ShaderSource::Wgsl(SHAPE_SHADER.into()),
         });
 
-        let window_uniform = WindowUniform::default();
+        let window_uniform = WindowUniform {
+            width: config.width as f32,
+            height: config.height as f32,
+        };
         let window_buffer = device.create_buffer_init(&BufferInitDescriptor {
             label: Some("window"),
             contents: bytemuck::cast_slice(&[window_uniform]),

src/default/render.rs

@@ -45,6 +45,7 @@ impl UiRenderer {
         }
 
         self.queue.submit(std::iter::once(encoder.finish()));
+        self.window.pre_present_notify();
         output.present();
     }