Pass `ScreenDescriptor` to `egui_wgpu::CallbackTrait::prepare` (#3960)

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`glyphon` requires the screen resolution during the `prepare` stage, and
passing that to the callback's `prepare` function seems pretty trivial.

---------

Co-authored-by: Emil Ernerfeldt <emil.ernerfeldt@gmail.com>

crates/egui-wgpu/src/renderer.rs

@@ -79,6 +79,7 @@ pub trait CallbackTrait: Send + Sync {
         &self,
         _device: &wgpu::Device,
         _queue: &wgpu::Queue,
+        _screen_descriptor: &ScreenDescriptor,
         _egui_encoder: &mut wgpu::CommandEncoder,
         _callback_resources: &mut CallbackResources,
     ) -> Vec<wgpu::CommandBuffer> {
@@ -890,6 +891,7 @@ impl Renderer {
                 user_cmd_bufs.extend(callback.prepare(
                     device,
                     queue,
+                    screen_descriptor,
                     encoder,
                     &mut self.callback_resources,
                 ));

crates/egui_demo_app/src/apps/custom3d_wgpu.rs

@@ -2,7 +2,7 @@ use std::num::NonZeroU64;
 
 use eframe::{
     egui_wgpu::wgpu::util::DeviceExt,
-    egui_wgpu::{self, wgpu},
+    egui_wgpu::{self, renderer::ScreenDescriptor, wgpu},
 };
 
 pub struct Custom3d {
@@ -148,6 +148,7 @@ impl egui_wgpu::CallbackTrait for CustomTriangleCallback {
         &self,
         device: &wgpu::Device,
         queue: &wgpu::Queue,
+        _screen_descriptor: &ScreenDescriptor,
         _egui_encoder: &mut wgpu::CommandEncoder,
         resources: &mut egui_wgpu::CallbackResources,
     ) -> Vec<wgpu::CommandBuffer> {