Add get_default_configure to simplify user creation of SurfaceConfiguration (#3034)

CHANGELOG.md

@@ -57,6 +57,7 @@ Bottom level categories:
 - Implement `Hash` for `DepthStencilState` and `DepthBiasState`
 - Add the `"wgsl"` feature, to enable WGSL shaders in `wgpu-core` and `wgpu`. Enabled by default in `wgpu`. By @daxpedda in [#2890](https://github.com/gfx-rs/wgpu/pull/2890).
 - Implement `Clone` for `ShaderSource` and `ShaderModuleDescriptor` in `wgpu`. By @daxpedda in [#3086](https://github.com/gfx-rs/wgpu/pull/3086).
+- Add `get_default_config` for `Surface` to simplify user creation of `SurfaceConfiguration`. By @jinleili in [#3034](https://github.com/gfx-rs/wgpu/pull/3034)
 
 #### GLES
 

wgpu/examples/framework.rs

@@ -267,14 +267,7 @@ fn start<E: Example>(
     }: Setup,
 ) {
     let spawner = Spawner::new();
-    let mut config = wgpu::SurfaceConfiguration {
-        usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
-        format: surface.get_supported_formats(&adapter)[0],
-        width: size.width,
-        height: size.height,
-        present_mode: wgpu::PresentMode::Fifo,
-        alpha_mode: surface.get_supported_alpha_modes(&adapter)[0],
-    };
+    let mut config = surface.get_default_config(&adapter, size.width, size.height);
     surface.configure(&device, &config);
 
     log::info!("Initializing the example...");

wgpu/src/lib.rs

@@ -3713,6 +3713,23 @@ impl Surface {
         Context::surface_get_supported_alpha_modes(&*self.context, &self.id, &adapter.id)
     }
 
+    /// Return a default `SurfaceConfiguration` from width and height to use for the [`Surface`] with this adapter.
+    pub fn get_default_config(
+        &self,
+        adapter: &Adapter,
+        width: u32,
+        height: u32,
+    ) -> wgt::SurfaceConfiguration {
+        wgt::SurfaceConfiguration {
+            usage: wgt::TextureUsages::RENDER_ATTACHMENT,
+            format: self.get_supported_formats(adapter)[0],
+            width,
+            height,
+            present_mode: self.get_supported_present_modes(adapter)[0],
+            alpha_mode: wgt::CompositeAlphaMode::Auto,
+        }
+    }
+
     /// Initializes [`Surface`] for presentation.
     ///
     /// # Panics