[wgpu] Add depth stencil initialization to Painter (#2316)

crates/egui-wgpu/CHANGELOG.md

@@ -13,6 +13,7 @@ All notable changes to the `egui-wgpu` integration will be noted in this file.
 * Only a single vertex & index buffer is now created and resized when necessary (previously, vertex/index buffers were allocated for every mesh) ([#2148](https://github.com/emilk/egui/pull/2148)).
 * `Renderer::update_texture` no longer creates a new `wgpu::Sampler` with every new texture ([#2198](https://github.com/emilk/egui/pull/2198))
 * `Painter`'s instance/device/adapter/surface creation is now configurable via `WgpuConfiguration` ([#2207](https://github.com/emilk/egui/pull/2207))
+* Fix panic on using a depth buffer ([#2316](https://github.com/emilk/egui/pull/2316))
 
 ## 0.19.0 - 2022-08-20
 * Enables deferred render + surface state initialization for Android ([#1634](https://github.com/emilk/egui/pull/1634)).

crates/egui-wgpu/src/winit.rs

@@ -176,7 +176,7 @@ impl Painter {
                     width,
                     height,
                 });
-                self.configure_surface(width, height);
+                self.resize_and_generate_depth_texture_view(width, height);
             }
             None => {
                 self.surface_state = None;
@@ -195,8 +195,11 @@ impl Painter {
             .map(|rs| rs.device.limits().max_texture_dimension_2d as usize)
     }
 
-    pub fn on_window_resized(&mut self, width_in_pixels: u32, height_in_pixels: u32) {
+    pub fn resize_and_generate_depth_texture_view(
-        if self.surface_state.is_some() {
+        &mut self,
+        width_in_pixels: u32,
+        height_in_pixels: u32,
+    ) {
         self.configure_surface(width_in_pixels, height_in_pixels);
         let device = &self.render_state.as_ref().unwrap().device;
         self.depth_texture_view = self.depth_format.map(|depth_format| {
@@ -217,6 +220,11 @@ impl Painter {
                 })
                 .create_view(&wgpu::TextureViewDescriptor::default())
         });
+    }
+
+    pub fn on_window_resized(&mut self, width_in_pixels: u32, height_in_pixels: u32) {
+        if self.surface_state.is_some() {
+            self.resize_and_generate_depth_texture_view(width_in_pixels, height_in_pixels);
         } else {
             error!("Ignoring window resize notification with no surface created via Painter::set_window()");
         }