Fix surfaces only compatible with first enabled backend (#5535)

Author: Wumpf

CHANGELOG.md

@@ -153,6 +153,7 @@ Bottom level categories:
 - Failing to set the device lost closure will call the closure before returning. By @bradwerth in [#5358](https://github.com/gfx-rs/wgpu/pull/5358).
 - Use memory pooling for UsageScopes to avoid frequent large allocations. by @robtfm in [#5414](https://github.com/gfx-rs/wgpu/pull/5414)
 - Fix deadlocks caused by recursive read-write lock acquisitions [#5426](https://github.com/gfx-rs/wgpu/pull/5426).
+- Fix surfaces being only compatible with first backend enabled on an instance, causing failures when manually specifying an adapter. By @Wumpf in [#5535](https://github.com/gfx-rs/wgpu/pull/5535).
 
 #### Naga
 - In spv-in, remove unnecessary "gl_PerVertex" name check so unused builtins will always be skipped. By @Imberflur in [#5227](https://github.com/gfx-rs/wgpu/pull/5227).

wgpu-core/src/any_surface.rs

@@ -1969,7 +1969,7 @@ impl Global {
                 };
 
                 let caps = unsafe {
-                    let suf = A::get_surface(surface);
+                    let suf = A::surface_as_hal(surface);
                     let adapter = &device.adapter;
                     match adapter.raw.adapter.surface_capabilities(suf.unwrap()) {
                         Some(caps) => caps,
@@ -2055,7 +2055,7 @@ impl Global {
                 // https://github.com/gfx-rs/wgpu/issues/4105
 
                 match unsafe {
-                    A::get_surface(surface)
+                    A::surface_as_hal(surface)
                         .unwrap()
                         .configure(device.raw(), &hal_config)
                 } {

wgpu-core/src/device/global.rs

@@ -11,7 +11,7 @@ pub trait HalApi: hal::Api + 'static + WasmNotSendSync {
     fn create_instance_from_hal(name: &str, hal_instance: Self::Instance) -> Instance;
     fn instance_as_hal(instance: &Instance) -> Option<&Self::Instance>;
     fn hub(global: &Global) -> &Hub<Self>;
-    fn get_surface(surface: &Surface) -> Option<&Self::Surface>;
+    fn surface_as_hal(surface: &Surface) -> Option<&Self::Surface>;
 }
 
 impl HalApi for hal::api::Empty {
@@ -25,7 +25,7 @@ impl HalApi for hal::api::Empty {
     fn hub(_: &Global) -> &Hub<Self> {
         unimplemented!("called empty api")
     }
-    fn get_surface(_: &Surface) -> Option<&Self::Surface> {
+    fn surface_as_hal(_: &Surface) -> Option<&Self::Surface> {
         unimplemented!("called empty api")
     }
 }
@@ -46,8 +46,8 @@ impl HalApi for hal::api::Vulkan {
     fn hub(global: &Global) -> &Hub<Self> {
         &global.hubs.vulkan
     }
-    fn get_surface(surface: &Surface) -> Option<&Self::Surface> {
-        surface.raw.downcast_ref::<Self>()
+    fn surface_as_hal(surface: &Surface) -> Option<&Self::Surface> {
+        surface.vulkan.as_ref()
     }
 }
 
@@ -67,8 +67,8 @@ impl HalApi for hal::api::Metal {
     fn hub(global: &Global) -> &Hub<Self> {
         &global.hubs.metal
     }
-    fn get_surface(surface: &Surface) -> Option<&Self::Surface> {
-        surface.raw.downcast_ref::<Self>()
+    fn surface_as_hal(surface: &Surface) -> Option<&Self::Surface> {
+        surface.metal.as_ref()
     }
 }
 
@@ -88,8 +88,8 @@ impl HalApi for hal::api::Dx12 {
     fn hub(global: &Global) -> &Hub<Self> {
         &global.hubs.dx12
     }
-    fn get_surface(surface: &Surface) -> Option<&Self::Surface> {
-        surface.raw.downcast_ref::<Self>()
+    fn surface_as_hal(surface: &Surface) -> Option<&Self::Surface> {
+        surface.dx12.as_ref()
     }
 }
 
@@ -110,7 +110,7 @@ impl HalApi for hal::api::Gles {
     fn hub(global: &Global) -> &Hub<Self> {
         &global.hubs.gl
     }
-    fn get_surface(surface: &Surface) -> Option<&Self::Surface> {
-        surface.raw.downcast_ref::<Self>()
+    fn surface_as_hal(surface: &Surface) -> Option<&Self::Surface> {
+        surface.gl.as_ref()
     }
 }

wgpu-core/src/hal_api.rs

@@ -241,7 +241,7 @@ impl<A: HalApi> Hub<A> {
             if let Element::Occupied(ref surface, _epoch) = *element {
                 if let Some(ref mut present) = surface.presentation.lock().take() {
                     if let Some(device) = present.device.downcast_ref::<A>() {
-                        let suf = A::get_surface(surface);
+                        let suf = A::surface_as_hal(surface);
                         unsafe {
                             suf.unwrap().unconfigure(device.raw());
                             //TODO: we could destroy the surface here