Allow selecting GPU from env

examples/with_winit/Cargo.toml

@@ -15,6 +15,7 @@ pollster = "0.2.5"
 # for picosvg
 roxmltree = "0.13"
 clap = { version = "4.1.0", features = ["derive"] }
+env_logger = "0.10.0"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 vello = { path = "../../", features = ["hot_reload"] }

examples/with_winit/src/main.rs

@@ -225,6 +225,7 @@ enum UserEvent {
 
 fn main() {
     let args = Args::parse();
+    env_logger::init();
     #[cfg(not(target_arch = "wasm32"))]
     {
         use winit::{dpi::LogicalSize, window::WindowBuilder};

src/util.rs

@@ -96,13 +96,12 @@ impl RenderContext {
 
     /// Creates a compatible device handle id.
     async fn new_device(&mut self, compatible_surface: Option<&Surface>) -> Option<usize> {
-        let adapter = self
-            .instance
-            .request_adapter(&RequestAdapterOptions {
-                compatible_surface,
-                ..Default::default()
-            })
-            .await?;
+        let adapter = wgpu::util::initialize_adapter_from_env_or_default(
+            &self.instance,
+            wgpu::Backends::PRIMARY,
+            compatible_surface,
+        )
+        .await?;
         let features = adapter.features();
         let limits = Limits::default();
         let (device, queue) = adapter