remove backend from ID (#6263)

deno_webgpu/lib.rs

@@ -401,10 +401,7 @@ pub fn op_webgpu_request_adapter(
         force_fallback_adapter,
         compatible_surface: None, // windowless
     };
-    let res = instance.request_adapter(
+    let res = instance.request_adapter(&descriptor, backends, None);
-        &descriptor,
-        wgpu_core::instance::AdapterInputs::Mask(backends, |_| None),
-    );
 
     let adapter = match res {
         Ok(adapter) => adapter,

player/src/bin/play.rs

@@ -56,7 +56,7 @@ fn main() {
         global.instance_create_surface(
             window.display_handle().unwrap().into(),
             window.window_handle().unwrap().into(),
-            Some(wgc::id::Id::zip(0, 1, wgt::Backend::Empty)),
+            Some(wgc::id::Id::zip(0, 1)),
         )
     }
     .unwrap();
@@ -74,14 +74,15 @@ fn main() {
                         #[cfg(not(feature = "winit"))]
                         compatible_surface: None,
                     },
-                    wgc::instance::AdapterInputs::IdSet(&[wgc::id::AdapterId::zip(0, 0, backend)]),
+                    wgt::Backends::from(backend),
+                    Some(wgc::id::AdapterId::zip(0, 1)),
                 )
                 .expect("Unable to find an adapter for selected backend");
 
             let info = global.adapter_get_info(adapter);
             log::info!("Picked '{}'", info.name);
-            let device_id = wgc::id::Id::zip(1, 0, backend);
+            let device_id = wgc::id::Id::zip(0, 1);
-            let queue_id = wgc::id::Id::zip(1, 0, backend);
+            let queue_id = wgc::id::Id::zip(0, 1);
             let res = global.adapter_request_device(
                 adapter,
                 &desc,

player/src/lib.rs

@@ -352,11 +352,7 @@ impl GlobalPlay for wgc::global::Global {
                 let (encoder, error) = self.device_create_command_encoder(
                     device,
                     &wgt::CommandEncoderDescriptor { label: None },
-                    Some(
+                    Some(comb_manager.process().into_command_encoder_id()),
-                        comb_manager
-                            .process(device.backend())
-                            .into_command_encoder_id(),
-                    ),
                 );
                 if let Some(e) = error {
                     panic!("{e}");

player/tests/data/bind-group.ron

@@ -2,13 +2,13 @@
     features: [],
     expectations: [], //not crash!
     actions: [
-        CreateBuffer(Id(0, 1, Empty), (
+        CreateBuffer(Id(0, 1), (
             label: None,
             size: 16,
             usage: 64,
             mapped_at_creation: false,
         )),
-        CreateBindGroupLayout(Id(0, 1, Empty), (
+        CreateBindGroupLayout(Id(0, 1), (
             label: None,
             entries: [
                 (
@@ -20,29 +20,29 @@
                 ),
             ],
         )),
-        CreateBindGroup(Id(0, 1, Empty), (
+        CreateBindGroup(Id(0, 1), (
             label: None,
-            layout: Id(0, 1, Empty),
+            layout: Id(0, 1),
             entries: [
                 (
                     binding: 0,
                     resource: Buffer((
-                        buffer_id: Id(0, 1, Empty),
+                        buffer_id: Id(0, 1),
                         offset: 0,
                         size: None,
                     )),
                 )
             ],
         )),
-        CreatePipelineLayout(Id(0, 1, Empty), (
+        CreatePipelineLayout(Id(0, 1), (
             label: Some("empty"),
             bind_group_layouts: [
-                Id(0, 1, Empty),
+                Id(0, 1),
             ],
             push_constant_ranges: [],
         )),
         CreateShaderModule(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
                 flags: (bits: 3),
@@ -50,12 +50,12 @@
             data: "empty.wgsl",
         ),
         CreateComputePipeline(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
-                layout: Some(Id(0, 1, Empty)),
+                layout: Some(Id(0, 1)),
                 stage: (
-                    module: Id(0, 1, Empty),
+                    module: Id(0, 1),
                     entry_point: None,
                     constants: {},
                     zero_initialize_workgroup_memory: true,
@@ -70,9 +70,9 @@
                         SetBindGroup(
                             index: 0,
                             num_dynamic_offsets: 0,
-                            bind_group_id: Some(Id(0, 1, Empty)),
+                            bind_group_id: Some(Id(0, 1)),
                         ),
-                        SetPipeline(Id(0, 1, Empty)),
+                        SetPipeline(Id(0, 1)),
                     ],
                     dynamic_offsets: [],
                     string_data: [],

player/tests/data/buffer-copy.ron

@@ -10,7 +10,7 @@
     ],
     actions: [
         CreateBuffer(
-            Id(0, 1, Empty),
+            Id(0, 1),
             (
                 label: Some("dummy"),
                 size: 16,
@@ -19,7 +19,7 @@
             ),
         ),
         WriteBuffer(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             data: "data1.bin",
             range: (
                 start: 0,

player/tests/data/clear-buffer-texture.ron

@@ -20,7 +20,7 @@
         )
     ],
     actions: [
-        CreateTexture(Id(0, 1, Empty), (
+        CreateTexture(Id(0, 1), (
             label: Some("Output Texture"),
             size: (
                 width: 64,
@@ -36,7 +36,7 @@
         // First fill the texture to ensure it wasn't just zero initialized or "happened" to be zero.
         WriteTexture(
             to: (
-                texture: Id(0, 1, Empty),
+                texture: Id(0, 1),
                 mip_level: 0,
                 array_layer: 0,
             ),
@@ -52,7 +52,7 @@
             ),
         ),
         CreateBuffer(
-            Id(0, 1, Empty),
+            Id(0, 1),
             (
                 label: Some("Output Buffer"),
                 size: 16384,
@@ -62,7 +62,7 @@
         ),
 
         CreateBuffer(
-            Id(1, 1, Empty),
+            Id(1, 1),
             (
                 label: Some("Buffer to be cleared"),
                 size: 16,
@@ -72,7 +72,7 @@
         ),
         // Make sure there is something in the buffer, otherwise it might be just zero init!
         WriteBuffer(
-            id: Id(1, 1, Empty),
+            id: Id(1, 1),
             data: "data1.bin",
             range: (
                 start: 0,
@@ -82,7 +82,7 @@
         ),
         Submit(1, [
             ClearTexture(
-                dst: Id(0, 1, Empty),
+                dst: Id(0, 1),
                 subresource_range: ImageSubresourceRange(
                     aspect: all,
                     baseMipLevel: 0,
@@ -93,12 +93,12 @@
             ),
             CopyTextureToBuffer(
                 src: (
-                    texture: Id(0, 1, Empty),
+                    texture: Id(0, 1),
                     mip_level: 0,
                     array_layer: 0,
                 ),
                 dst:  (
-                    buffer: Id(0, 1, Empty),
+                    buffer: Id(0, 1),
                     layout: (
                         offset: 0,
                         bytes_per_row: Some(256),
@@ -112,7 +112,7 @@
             ),
             // Partial clear to prove
             ClearBuffer(
-                dst: Id(1, 1, Empty),
+                dst: Id(1, 1),
                 offset: 4,
                 size: Some(8),
             )

player/tests/data/pipeline-statistics-query.ron

@@ -9,13 +9,13 @@
         ),
     ],
     actions: [
-        CreatePipelineLayout(Id(0, 1, Empty), (
+        CreatePipelineLayout(Id(0, 1), (
             label: Some("empty"),
             bind_group_layouts: [],
             push_constant_ranges: [],
         )),
         CreateShaderModule(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
                 flags: (bits: 3),
@@ -23,12 +23,12 @@
             data: "empty.wgsl",
         ),
         CreateComputePipeline(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
-                layout: Some(Id(0, 1, Empty)),
+                layout: Some(Id(0, 1)),
                 stage: (
-                    module: Id(0, 1, Empty),
+                    module: Id(0, 1),
                     entry_point: None,
                     constants: {},
                     zero_initialize_workgroup_memory: true,
@@ -37,7 +37,7 @@
             ),
         ),
         CreateQuerySet(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: Some("Compute Invocation QuerySet"),
                 count: 2,
@@ -45,7 +45,7 @@
             ),
         ),
         CreateBuffer(
-            Id(0, 1, Empty),
+            Id(0, 1),
             (
                 label: Some("Compute Invocation Result Buffer"),
                 size: 16,
@@ -57,9 +57,9 @@
             RunComputePass(
                 base: (
                     commands: [
-                        SetPipeline(Id(0, 1, Empty)),
+                        SetPipeline(Id(0, 1)),
                         BeginPipelineStatisticsQuery(
-                            query_set_id: Id(0, 1, Empty),
+                            query_set_id: Id(0, 1),
                             query_index: 0,
                         ),
                         Dispatch((2, 3, 7,)),
@@ -71,10 +71,10 @@
                 ),
             ),
             ResolveQuerySet(
-                query_set_id: Id(0, 1, Empty),
+                query_set_id: Id(0, 1),
                 start_query: 0,
                 query_count: 1,
-                destination: Id(0, 1, Empty),
+                destination: Id(0, 1),
                 destination_offset: 0,
             )
         ]),

player/tests/data/quad.ron

@@ -10,14 +10,14 @@
     ],
     actions: [
         CreateShaderModule(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
                 flags: (bits: 3),
             ),
             data: "quad.wgsl",
         ),
-        CreateTexture(Id(0, 1, Empty), (
+        CreateTexture(Id(0, 1), (
             label: Some("Output Texture"),
             size: (
                 width: 64,
@@ -31,12 +31,12 @@
             view_formats: [],
         )),
         CreateTextureView(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
-            parent_id: Id(0, 1, Empty),
+            parent_id: Id(0, 1),
             desc: (),
         ),
         CreateBuffer(
-            Id(0, 1, Empty),
+            Id(0, 1),
             (
                 label: Some("Output Buffer"),
                 size: 16384,
@@ -44,19 +44,19 @@
                 mapped_at_creation: false,
             ),
         ),
-        CreatePipelineLayout(Id(0, 1, Empty), (
+        CreatePipelineLayout(Id(0, 1), (
             label: None,
             bind_group_layouts: [],
             push_constant_ranges: [],
         )),
         CreateRenderPipeline(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
-                layout: Some(Id(0, 1, Empty)),
+                layout: Some(Id(0, 1)),
                 vertex: (
                     stage: (
-                        module: Id(0, 1, Empty),
+                        module: Id(0, 1),
                         entry_point: None,
                         constants: {},
                         zero_initialize_workgroup_memory: true,
@@ -66,7 +66,7 @@
                 ),
                 fragment: Some((
                     stage: (
-                        module: Id(0, 1, Empty),
+                        module: Id(0, 1),
                         entry_point: None,
                         constants: {},
                         zero_initialize_workgroup_memory: true,
@@ -84,7 +84,7 @@
             RunRenderPass(
                 base: (
                     commands: [
-                        SetPipeline(Id(0, 1, Empty)),
+                        SetPipeline(Id(0, 1)),
                         Draw(
                             vertex_count: 3,
                             instance_count: 1,
@@ -98,7 +98,7 @@
                 ),
                 target_colors: [
                     Some((
-                        view: Id(0, 1, Empty),
+                        view: Id(0, 1),
                         resolve_target: None,
                         channel: (
                             load_op: clear,
@@ -117,12 +117,12 @@
             ),
             CopyTextureToBuffer(
                 src: (
-                    texture: Id(0, 1, Empty),
+                    texture: Id(0, 1),
                     mip_level: 0,
                     array_layer: 0,
                 ),
                 dst:  (
-                    buffer: Id(0, 1, Empty),
+                    buffer: Id(0, 1),
                     layout: (
                         offset: 0,
                         bytes_per_row: Some(256),

player/tests/data/zero-init-buffer.ron

@@ -39,7 +39,7 @@
     ],
     actions: [
         CreateBuffer(
-            Id(0, 1, Empty),
+            Id(0, 1),
             (
                 label: Some("mapped_at_creation: false, with MAP_WRITE"),
                 size: 16,
@@ -48,7 +48,7 @@
             ),
         ),
         CreateBuffer(
-            Id(1, 1, Empty),
+            Id(1, 1),
             (
                 label: Some("mapped_at_creation: false, without MAP_WRITE"),
                 size: 16,
@@ -57,7 +57,7 @@
             ),
         ),
         CreateBuffer(
-            Id(2, 1, Empty),
+            Id(2, 1),
             (
                 label: Some("partially written"),
                 size: 24,
@@ -66,7 +66,7 @@
             ),
         ),
         WriteBuffer(
-            id: Id(2, 1, Empty),
+            id: Id(2, 1),
             data: "data1.bin",
             range: (
                 start: 4,
@@ -75,20 +75,20 @@
             queued: true,
         ),
         CreateShaderModule(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
                 flags: (bits: 3),
             ),
             data: "zero-init-buffer-for-binding.wgsl",
         ),
-        CreateBuffer(Id(3, 1, Empty), (
+        CreateBuffer(Id(3, 1), (
             label: Some("used in binding"),
             size: 16,
             usage: 129, // STORAGE + MAP_READ
             mapped_at_creation: false,
         )),
-        CreateBindGroupLayout(Id(0, 1, Empty), (
+        CreateBindGroupLayout(Id(0, 1), (
             label: None,
             entries: [
                 (
@@ -105,34 +105,34 @@
                 ),
             ],
         )),
-        CreateBindGroup(Id(0, 1, Empty), (
+        CreateBindGroup(Id(0, 1), (
             label: None,
-            layout: Id(0, 1, Empty),
+            layout: Id(0, 1),
             entries: [
                 (
                     binding: 0,
                     resource: Buffer((
-                        buffer_id: Id(3, 1, Empty),
+                        buffer_id: Id(3, 1),
                         offset: 0,
                         size: Some(16),
                     )),
                 ),
             ],
         )),
-        CreatePipelineLayout(Id(0, 1, Empty), (
+        CreatePipelineLayout(Id(0, 1), (
             label: None,
             bind_group_layouts: [
-                Id(0, 1, Empty),
+                Id(0, 1),
             ],
             push_constant_ranges: [],
         )),
         CreateComputePipeline(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
-                layout: Some(Id(0, 1, Empty)),
+                layout: Some(Id(0, 1)),
                 stage: (
-                    module: Id(0, 1, Empty),
+                    module: Id(0, 1),
                     entry_point: None,
                     constants: {},
                     zero_initialize_workgroup_memory: true,
@@ -145,11 +145,11 @@
                 base: (
                     label: None,
                     commands: [
-                        SetPipeline(Id(0, 1, Empty)),
+                        SetPipeline(Id(0, 1)),
                         SetBindGroup(
                             index: 0,
                             num_dynamic_offsets: 0,
-                            bind_group_id: Some(Id(0, 1, Empty)),
+                            bind_group_id: Some(Id(0, 1)),
                         ),
                         Dispatch((4, 1, 1)),
                     ],

player/tests/data/zero-init-texture-binding.ron

@@ -17,7 +17,7 @@
         // MISSING: Partial views
     ],
     actions: [
-        CreateTexture(Id(0, 1, Empty), (
+        CreateTexture(Id(0, 1), (
             label: Some("Sampled Texture"),
             size: (
                 width: 64,
@@ -31,12 +31,12 @@
             view_formats: [],
         )),
         CreateTextureView(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
-            parent_id: Id(0, 1, Empty),
+            parent_id: Id(0, 1),
             desc: (),
         ),
         CreateBuffer(
-            Id(0, 1, Empty),
+            Id(0, 1),
             (
                 label: Some("Sampled Texture Buffer"),
                 size: 16384,
@@ -44,7 +44,7 @@
                 mapped_at_creation: false,
             ),
         ),
-        CreateTexture(Id(1, 1, Empty), (
+        CreateTexture(Id(1, 1), (
             label: Some("Storage Texture"),
             size: (
                 width: 64,
@@ -58,12 +58,12 @@
             view_formats: [],
         )),
         CreateTextureView(
-            id: Id(1, 1, Empty),
+            id: Id(1, 1),
-            parent_id: Id(1, 1, Empty),
+            parent_id: Id(1, 1),
             desc: (),
         ),
         CreateBuffer(
-            Id(1, 1, Empty),
+            Id(1, 1),
             (
                 label: Some("Storage Texture Buffer"),
                 size: 16384,
@@ -73,7 +73,7 @@
         ),
 
 
-        CreateBindGroupLayout(Id(0, 1, Empty), (
+        CreateBindGroupLayout(Id(0, 1), (
             label: None,
             entries: [
                 (
@@ -98,29 +98,29 @@
                 ),
             ],
         )),
-        CreateBindGroup(Id(0, 1, Empty), (
+        CreateBindGroup(Id(0, 1), (
             label: None,
-            layout: Id(0, 1, Empty),
+            layout: Id(0, 1),
             entries: [
                 (
                     binding: 0,
-                    resource: TextureView(Id(0, 1, Empty)),
+                    resource: TextureView(Id(0, 1)),
                 ),
                 (
                     binding: 1,
-                    resource: TextureView(Id(1, 1, Empty)),
+                    resource: TextureView(Id(1, 1)),
                 ),
             ],
         )),
-        CreatePipelineLayout(Id(0, 1, Empty), (
+        CreatePipelineLayout(Id(0, 1), (
             label: None,
             bind_group_layouts: [
-                Id(0, 1, Empty),
+                Id(0, 1),
             ],
             push_constant_ranges: [],
         )),
         CreateShaderModule(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
                 flags: (bits: 3),
@@ -128,12 +128,12 @@
             data: "zero-init-texture-binding.wgsl",
         ),
         CreateComputePipeline(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
             desc: (
                 label: None,
-                layout: Some(Id(0, 1, Empty)),
+                layout: Some(Id(0, 1)),
                 stage: (
-                    module: Id(0, 1, Empty),
+                    module: Id(0, 1),
                     entry_point: None,
                     constants: {},
                     zero_initialize_workgroup_memory: true,
@@ -146,11 +146,11 @@
             RunComputePass(
                 base: (
                     commands: [
-                        SetPipeline(Id(0, 1, Empty)),
+                        SetPipeline(Id(0, 1)),
                         SetBindGroup(
                             index: 0,
                             num_dynamic_offsets: 0,
-                            bind_group_id: Some(Id(0, 1, Empty)),
+                            bind_group_id: Some(Id(0, 1)),
                         ),
                         Dispatch((4, 1, 1)),
                     ],
@@ -161,12 +161,12 @@
             ),
             CopyTextureToBuffer(
                 src: (
-                    texture: Id(0, 1, Empty),
+                    texture: Id(0, 1),
                     mip_level: 0,
                     array_layer: 0,
                 ),
                 dst:  (
-                    buffer: Id(0, 1, Empty),
+                    buffer: Id(0, 1),
                     layout: (
                         offset: 0,
                         bytes_per_row: Some(256),
@@ -180,12 +180,12 @@
             ),
             CopyTextureToBuffer(
                 src: (
-                    texture: Id(1, 1, Empty),
+                    texture: Id(1, 1),
                     mip_level: 0,
                     array_layer: 0,
                 ),
                 dst:  (
-                    buffer: Id(1, 1, Empty),
+                    buffer: Id(1, 1),
                     layout: (
                         offset: 0,
                         bytes_per_row: Some(256),

player/tests/data/zero-init-texture-copytobuffer.ron

@@ -10,7 +10,7 @@
         // MISSING: Partial copies
     ],
     actions: [
-        CreateTexture(Id(0, 1, Empty), (
+        CreateTexture(Id(0, 1), (
             label: Some("Copy To Buffer Texture"),
             size: (
                 width: 64,
@@ -24,7 +24,7 @@
             view_formats: [],
         )),
         CreateBuffer(
-            Id(0, 1, Empty),
+            Id(0, 1),
             (
                 label: Some("Copy to Buffer Buffer"),
                 size: 16384,
@@ -35,12 +35,12 @@
         Submit(1, [
             CopyTextureToBuffer(
                 src: (
-                    texture: Id(0, 1, Empty),
+                    texture: Id(0, 1),
                     mip_level: 0,
                     array_layer: 0,
                 ),
                 dst:  (
-                    buffer: Id(0, 1, Empty),
+                    buffer: Id(0, 1),
                     layout: (
                         offset: 0,
                         bytes_per_row: Some(256),

player/tests/data/zero-init-texture-rendertarget.ron

@@ -10,7 +10,7 @@
         // MISSING: Partial view.
     ],
     actions: [
-        CreateTexture(Id(0, 1, Empty), (
+        CreateTexture(Id(0, 1), (
             label: Some("Render Target Texture"),
             size: (
                 width: 64,
@@ -24,12 +24,12 @@
             view_formats: [],
         )),
         CreateTextureView(
-            id: Id(0, 1, Empty),
+            id: Id(0, 1),
-            parent_id: Id(0, 1, Empty),
+            parent_id: Id(0, 1),
             desc: (),
         ),
         CreateBuffer(
-            Id(0, 1, Empty),
+            Id(0, 1),
             (
                 label: Some("Render Target Buffer"),
                 size: 16384,
@@ -48,7 +48,7 @@
                 ),
                 target_colors: [
                     Some((
-                        view: Id(0, 1, Empty),
+                        view: Id(0, 1),
                         resolve_target: None,
                         channel: (
                             load_op: load,
@@ -64,12 +64,12 @@
             ),
             CopyTextureToBuffer(
                 src: (
-                    texture: Id(0, 1, Empty),
+                    texture: Id(0, 1),
                     mip_level: 0,
                     array_layer: 0,
                 ),
                 dst:  (
-                    buffer: Id(0, 1, Empty),
+                    buffer: Id(0, 1),
                     layout: (
                         offset: 0,
                         bytes_per_row: Some(256),

player/tests/test.rs

@@ -105,9 +105,8 @@ impl Test<'_> {
         adapter: wgc::id::AdapterId,
         test_num: u32,
     ) {
-        let backend = adapter.backend();
+        let device_id = wgc::id::Id::zip(test_num, 1);
-        let device_id = wgc::id::Id::zip(test_num, 0, backend);
+        let queue_id = wgc::id::Id::zip(test_num, 1);
-        let queue_id = wgc::id::Id::zip(test_num, 0, backend);
         let res = global.adapter_request_device(
             adapter,
             &wgt::DeviceDescriptor {
@@ -137,7 +136,7 @@ impl Test<'_> {
         }
         println!("\t\t\tMapping...");
         for expect in &self.expectations {
-            let buffer = wgc::id::Id::zip(expect.buffer.index, expect.buffer.epoch, backend);
+            let buffer = wgc::id::Id::zip(expect.buffer.index, expect.buffer.epoch);
             global
                 .buffer_map_async(
                     buffer,
@@ -160,7 +159,7 @@ impl Test<'_> {
 
         for expect in self.expectations {
             println!("\t\t\tChecking {}", expect.name);
-            let buffer = wgc::id::Id::zip(expect.buffer.index, expect.buffer.epoch, backend);
+            let buffer = wgc::id::Id::zip(expect.buffer.index, expect.buffer.epoch);
             let (ptr, size) = global
                 .buffer_get_mapped_range(
                     buffer,
@@ -237,7 +236,8 @@ impl Corpus {
                         force_fallback_adapter: false,
                         compatible_surface: None,
                     },
-                    wgc::instance::AdapterInputs::IdSet(&[wgc::id::Id::zip(0, 0, backend)]),
+                    wgt::Backends::from(backend),
+                    Some(wgc::id::Id::zip(0, 1)),
                 ) {
                     Ok(adapter) => adapter,
                     Err(_) => continue,
@@ -247,7 +247,7 @@ impl Corpus {
                 let supported_features = global.adapter_features(adapter);
                 let downlevel_caps = global.adapter_downlevel_capabilities(adapter);
 
-                let test = Test::load(dir.join(test_path), adapter.backend());
+                let test = Test::load(dir.join(test_path), backend);
                 if !supported_features.contains(test.features) {
                     println!(
                         "\t\tSkipped due to missing features {:?}",

wgpu-core/src/device/global.rs

@@ -104,7 +104,7 @@ impl Global {
         profiling::scope!("Device::create_buffer");
 
         let hub = &self.hub;
-        let fid = hub.buffers.prepare(device_id.backend(), id_in);
+        let fid = hub.buffers.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -175,21 +175,19 @@ impl Global {
     /// [`wgpu_types::BufferUsages`]: wgt::BufferUsages
     pub fn create_buffer_error(
         &self,
-        backend: wgt::Backend,
         id_in: Option<id::BufferId>,
         desc: &resource::BufferDescriptor,
     ) {
-        let fid = self.hub.buffers.prepare(backend, id_in);
+        let fid = self.hub.buffers.prepare(id_in);
         fid.assign(Fallible::Invalid(Arc::new(desc.label.to_string())));
     }
 
     pub fn create_render_bundle_error(
         &self,
-        backend: wgt::Backend,
         id_in: Option<id::RenderBundleId>,
         desc: &command::RenderBundleDescriptor,
     ) {
-        let fid = self.hub.render_bundles.prepare(backend, id_in);
+        let fid = self.hub.render_bundles.prepare(id_in);
         fid.assign(Fallible::Invalid(Arc::new(desc.label.to_string())));
     }
 
@@ -198,11 +196,10 @@ impl Global {
     /// See `create_buffer_error` for more context and explanation.
     pub fn create_texture_error(
         &self,
-        backend: wgt::Backend,
         id_in: Option<id::TextureId>,
         desc: &resource::TextureDescriptor,
     ) {
-        let fid = self.hub.textures.prepare(backend, id_in);
+        let fid = self.hub.textures.prepare(id_in);
         fid.assign(Fallible::Invalid(Arc::new(desc.label.to_string())));
     }
 
@@ -311,7 +308,7 @@ impl Global {
 
         let hub = &self.hub;
 
-        let fid = hub.textures.prepare(device_id.backend(), id_in);
+        let fid = hub.textures.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -354,7 +351,7 @@ impl Global {
 
         let hub = &self.hub;
 
-        let fid = hub.textures.prepare(device_id.backend(), id_in);
+        let fid = hub.textures.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -398,7 +395,7 @@ impl Global {
         profiling::scope!("Device::create_buffer");
 
         let hub = &self.hub;
-        let fid = hub.buffers.prepare(A::VARIANT, id_in);
+        let fid = hub.buffers.prepare(id_in);
 
         let device = self.hub.devices.get(device_id);
 
@@ -458,7 +455,7 @@ impl Global {
 
         let hub = &self.hub;
 
-        let fid = hub.texture_views.prepare(texture_id.backend(), id_in);
+        let fid = hub.texture_views.prepare(id_in);
 
         let error = 'error: {
             let texture = match hub.textures.get(texture_id).get() {
@@ -522,7 +519,7 @@ impl Global {
         profiling::scope!("Device::create_sampler");
 
         let hub = &self.hub;
-        let fid = hub.samplers.prepare(device_id.backend(), id_in);
+        let fid = hub.samplers.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -575,7 +572,7 @@ impl Global {
         profiling::scope!("Device::create_bind_group_layout");
 
         let hub = &self.hub;
-        let fid = hub.bind_group_layouts.prepare(device_id.backend(), id_in);
+        let fid = hub.bind_group_layouts.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -647,7 +644,7 @@ impl Global {
         profiling::scope!("Device::create_pipeline_layout");
 
         let hub = &self.hub;
-        let fid = hub.pipeline_layouts.prepare(device_id.backend(), id_in);
+        let fid = hub.pipeline_layouts.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -715,7 +712,7 @@ impl Global {
         profiling::scope!("Device::create_bind_group");
 
         let hub = &self.hub;
-        let fid = hub.bind_groups.prepare(device_id.backend(), id_in);
+        let fid = hub.bind_groups.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -877,7 +874,7 @@ impl Global {
         profiling::scope!("Device::create_shader_module");
 
         let hub = &self.hub;
-        let fid = hub.shader_modules.prepare(device_id.backend(), id_in);
+        let fid = hub.shader_modules.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -949,7 +946,7 @@ impl Global {
         profiling::scope!("Device::create_shader_module");
 
         let hub = &self.hub;
-        let fid = hub.shader_modules.prepare(device_id.backend(), id_in);
+        let fid = hub.shader_modules.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -1006,10 +1003,9 @@ impl Global {
         profiling::scope!("Device::create_command_encoder");
 
         let hub = &self.hub;
-        let fid = hub.command_buffers.prepare(
+        let fid = hub
-            device_id.backend(),
+            .command_buffers
-            id_in.map(|id| id.into_command_buffer_id()),
+            .prepare(id_in.map(|id| id.into_command_buffer_id()));
-        );
 
         let device = self.hub.devices.get(device_id);
 
@@ -1072,9 +1068,7 @@ impl Global {
 
         let hub = &self.hub;
 
-        let fid = hub
+        let fid = hub.render_bundles.prepare(id_in);
-            .render_bundles
-            .prepare(bundle_encoder.parent().backend(), id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(bundle_encoder.parent());
@@ -1133,7 +1127,7 @@ impl Global {
         profiling::scope!("Device::create_query_set");
 
         let hub = &self.hub;
-        let fid = hub.query_sets.prepare(device_id.backend(), id_in);
+        let fid = hub.query_sets.prepare(id_in);
 
         let error = 'error: {
             let device = self.hub.devices.get(device_id);
@@ -1194,7 +1188,7 @@ impl Global {
         let missing_implicit_pipeline_ids =
             desc.layout.is_none() && id_in.is_some() && implicit_pipeline_ids.is_none();
 
-        let fid = hub.render_pipelines.prepare(device_id.backend(), id_in);
+        let fid = hub.render_pipelines.prepare(id_in);
         let implicit_context = implicit_pipeline_ids.map(|ipi| ipi.prepare(hub));
 
         let error = 'error: {
@@ -1378,7 +1372,7 @@ impl Global {
     ) {
         let hub = &self.hub;
 
-        let fid = hub.bind_group_layouts.prepare(pipeline_id.backend(), id_in);
+        let fid = hub.bind_group_layouts.prepare(id_in);
 
         let error = 'error: {
             let pipeline = match hub.render_pipelines.get(pipeline_id).get() {
@@ -1431,7 +1425,7 @@ impl Global {
         let missing_implicit_pipeline_ids =
             desc.layout.is_none() && id_in.is_some() && implicit_pipeline_ids.is_none();
 
-        let fid = hub.compute_pipelines.prepare(device_id.backend(), id_in);
+        let fid = hub.compute_pipelines.prepare(id_in);
         let implicit_context = implicit_pipeline_ids.map(|ipi| ipi.prepare(hub));
 
         let error = 'error: {
@@ -1562,7 +1556,7 @@ impl Global {
     ) {
         let hub = &self.hub;
 
-        let fid = hub.bind_group_layouts.prepare(pipeline_id.backend(), id_in);
+        let fid = hub.bind_group_layouts.prepare(id_in);
 
         let error = 'error: {
             let pipeline = match hub.compute_pipelines.get(pipeline_id).get() {
@@ -1616,7 +1610,7 @@ impl Global {
 
         let hub = &self.hub;
 
-        let fid = hub.pipeline_caches.prepare(device_id.backend(), id_in);
+        let fid = hub.pipeline_caches.prepare(id_in);
         let error: pipeline::CreatePipelineCacheError = 'error: {
             let device = self.hub.devices.get(device_id);
 
@@ -1881,7 +1875,7 @@ impl Global {
                 //
                 // https://github.com/gfx-rs/wgpu/issues/4105
 
-                let surface_raw = surface.raw(device_id.backend()).unwrap();
+                let surface_raw = surface.raw(device.backend()).unwrap();
                 match unsafe { surface_raw.configure(device.raw(), &hal_config) } {
                     Ok(()) => (),
                     Err(error) => {
@@ -1963,7 +1957,6 @@ impl Global {
     /// submissions still in flight.
     fn poll_all_devices_of_api(
         &self,
-        backend: wgt::Backend,
         force_wait: bool,
         closures: &mut UserClosures,
     ) -> Result<bool, WaitIdleError> {
@@ -1974,7 +1967,7 @@ impl Global {
         {
             let device_guard = hub.devices.read();
 
-            for (_id, device) in device_guard.iter(backend) {
+            for (_id, device) in device_guard.iter() {
                 let maintain = if force_wait {
                     wgt::Maintain::Wait
                 } else {
@@ -2004,28 +1997,7 @@ impl Global {
     pub fn poll_all_devices(&self, force_wait: bool) -> Result<bool, WaitIdleError> {
         api_log!("poll_all_devices");
         let mut closures = UserClosures::default();
-        let mut all_queue_empty = true;
+        let all_queue_empty = self.poll_all_devices_of_api(force_wait, &mut closures)?;
-
-        #[cfg(vulkan)]
-        {
-            all_queue_empty &=
-                self.poll_all_devices_of_api(wgt::Backend::Vulkan, force_wait, &mut closures)?;
-        }
-        #[cfg(metal)]
-        {
-            all_queue_empty &=
-                self.poll_all_devices_of_api(wgt::Backend::Metal, force_wait, &mut closures)?;
-        }
-        #[cfg(dx12)]
-        {
-            all_queue_empty &=
-                self.poll_all_devices_of_api(wgt::Backend::Dx12, force_wait, &mut closures)?;
-        }
-        #[cfg(gles)]
-        {
-            all_queue_empty &=
-                self.poll_all_devices_of_api(wgt::Backend::Gl, force_wait, &mut closures)?;
-        }
 
         closures.fire();
 

wgpu-core/src/device/mod.rs

@@ -457,16 +457,12 @@ pub struct ImplicitPipelineIds<'a> {
 
 impl ImplicitPipelineIds<'_> {
     fn prepare(self, hub: &Hub) -> ImplicitPipelineContext {
-        let backend = self.root_id.backend();
         ImplicitPipelineContext {
-            root_id: hub
+            root_id: hub.pipeline_layouts.prepare(Some(self.root_id)).id(),
-                .pipeline_layouts
-                .prepare(backend, Some(self.root_id))
-                .id(),
             group_ids: self
                 .group_ids
                 .iter()
-                .map(|id_in| hub.bind_group_layouts.prepare(backend, Some(*id_in)).id())
+                .map(|id_in| hub.bind_group_layouts.prepare(Some(*id_in)).id())
                 .collect(),
         }
     }

wgpu-core/src/device/queue.rs

@@ -444,7 +444,7 @@ impl Global {
         let staging_buffer = StagingBuffer::new(device, buffer_size)?;
         let ptr = unsafe { staging_buffer.ptr() };
 
-        let fid = hub.staging_buffers.prepare(queue_id.backend(), id_in);
+        let fid = hub.staging_buffers.prepare(id_in);
         let id = fid.assign(staging_buffer);
         resource_log!("Queue::create_staging_buffer {id:?}");
 

wgpu-core/src/id.rs

@@ -4,18 +4,25 @@ use std::{
     fmt::{self, Debug},
     hash::Hash,
     marker::PhantomData,
+    num::NonZeroU64,
 };
-use wgt::{Backend, WasmNotSendSync};
+use wgt::WasmNotSendSync;
 
-type IdType = u64;
+const _: () = {
-type ZippedIndex = Index;
+    if std::mem::size_of::<Index>() != 4 {
-type NonZeroId = std::num::NonZeroU64;
+        panic!()
-
+    }
-const INDEX_BITS: usize = ZippedIndex::BITS as usize;
+};
-const EPOCH_BITS: usize = INDEX_BITS - BACKEND_BITS;
+const _: () = {
-const BACKEND_BITS: usize = 3;
+    if std::mem::size_of::<Epoch>() != 4 {
-const BACKEND_SHIFT: usize = INDEX_BITS * 2 - BACKEND_BITS;
+        panic!()
-pub const EPOCH_MASK: u32 = (1 << (EPOCH_BITS)) - 1;
+    }
+};
+const _: () = {
+    if std::mem::size_of::<RawId>() != 8 {
+        panic!()
+    }
+};
 
 /// The raw underlying representation of an identifier.
 #[repr(transparent)]
@@ -30,50 +37,18 @@ pub const EPOCH_MASK: u32 = (1 << (EPOCH_BITS)) - 1;
     serde(from = "SerialId")
 )]
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct RawId(NonZeroId);
+pub struct RawId(NonZeroU64);
 
 impl RawId {
-    #[doc(hidden)]
-    #[inline]
-    pub fn from_non_zero(non_zero: NonZeroId) -> Self {
-        Self(non_zero)
-    }
-
-    #[doc(hidden)]
-    #[inline]
-    pub fn into_non_zero(self) -> NonZeroId {
-        self.0
-    }
-
     /// Zip together an identifier and return its raw underlying representation.
-    pub fn zip(index: Index, epoch: Epoch, backend: Backend) -> RawId {
+    pub fn zip(index: Index, epoch: Epoch) -> RawId {
-        assert_eq!(0, epoch >> EPOCH_BITS);
+        let v = (index as u64) | ((epoch as u64) << 32);
-        assert_eq!(0, (index as IdType) >> INDEX_BITS);
+        Self(NonZeroU64::new(v).unwrap())
-        let v = index as IdType
-            | ((epoch as IdType) << INDEX_BITS)
-            | ((backend as IdType) << BACKEND_SHIFT);
-        Self(NonZeroId::new(v).unwrap())
     }
 
     /// Unzip a raw identifier into its components.
-    #[allow(trivial_numeric_casts)]
+    pub fn unzip(self) -> (Index, Epoch) {
-    pub fn unzip(self) -> (Index, Epoch, Backend) {
+        (self.0.get() as Index, (self.0.get() >> 32) as Epoch)
-        (
-            (self.0.get() as ZippedIndex) as Index,
-            (((self.0.get() >> INDEX_BITS) as ZippedIndex) & (EPOCH_MASK as ZippedIndex)) as Index,
-            self.backend(),
-        )
-    }
-
-    pub fn backend(self) -> Backend {
-        match self.0.get() >> (BACKEND_SHIFT) as u8 {
-            0 => Backend::Empty,
-            1 => Backend::Vulkan,
-            2 => Backend::Metal,
-            3 => Backend::Dx12,
-            4 => Backend::Gl,
-            _ => unreachable!(),
-        }
     }
 }
 
@@ -116,20 +91,20 @@ pub struct Id<T: Marker>(RawId, PhantomData<T>);
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 enum SerialId {
     // The only variant forces RON to not ignore "Id"
-    Id(Index, Epoch, Backend),
+    Id(Index, Epoch),
 }
 
 impl From<RawId> for SerialId {
     fn from(id: RawId) -> Self {
-        let (index, epoch, backend) = id.unzip();
+        let (index, epoch) = id.unzip();
-        Self::Id(index, epoch, backend)
+        Self::Id(index, epoch)
     }
 }
 
 impl From<SerialId> for RawId {
     fn from(id: SerialId) -> Self {
         match id {
-            SerialId::Id(index, epoch, backend) => RawId::zip(index, epoch, backend),
+            SerialId::Id(index, epoch) => RawId::zip(index, epoch),
         }
     }
 }
@@ -150,29 +125,13 @@ where
         self.0
     }
 
-    #[allow(dead_code)]
-    pub(crate) fn dummy(index: u32) -> Self {
-        Id::zip(index, 1, Backend::Empty)
-    }
-
-    #[allow(dead_code)]
-    pub(crate) fn is_valid(&self) -> bool {
-        self.backend() != Backend::Empty
-    }
-
-    /// Get the backend this identifier corresponds to.
     #[inline]
-    pub fn backend(self) -> Backend {
+    pub fn zip(index: Index, epoch: Epoch) -> Self {
-        self.0.backend()
+        Id(RawId::zip(index, epoch), PhantomData)
     }
 
     #[inline]
-    pub fn zip(index: Index, epoch: Epoch, backend: Backend) -> Self {
+    pub fn unzip(self) -> (Index, Epoch) {
-        Id(RawId::zip(index, epoch, backend), PhantomData)
-    }
-
-    #[inline]
-    pub fn unzip(self) -> (Index, Epoch, Backend) {
         self.0.unzip()
     }
 }
@@ -194,16 +153,8 @@ where
     T: Marker,
 {
     fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
-        let (index, epoch, backend) = self.unzip();
+        let (index, epoch) = self.unzip();
-        let backend = match backend {
+        write!(formatter, "Id({index},{epoch})")?;
-            Backend::Empty => "_",
-            Backend::Vulkan => "vk",
-            Backend::Metal => "mtl",
-            Backend::Dx12 => "d3d12",
-            Backend::Gl => "gl",
-            Backend::BrowserWebGpu => "webgpu",
-        };
-        write!(formatter, "Id({index},{epoch},{backend})")?;
         Ok(())
     }
 }
@@ -326,43 +277,16 @@ impl CommandBufferId {
     }
 }
 
-#[test]
-fn test_id_backend() {
-    for &b in &[
-        Backend::Empty,
-        Backend::Vulkan,
-        Backend::Metal,
-        Backend::Dx12,
-        Backend::Gl,
-    ] {
-        let id = Id::<()>::zip(1, 0, b);
-        let (_id, _epoch, backend) = id.unzip();
-        assert_eq!(id.backend(), b);
-        assert_eq!(backend, b);
-    }
-}
-
 #[test]
 fn test_id() {
-    let last_index = ((1u64 << INDEX_BITS) - 1) as Index;
+    let indexes = [0, Index::MAX / 2 - 1, Index::MAX / 2 + 1, Index::MAX];
-    let indexes = [1, last_index / 2 - 1, last_index / 2 + 1, last_index];
+    let epochs = [1, Epoch::MAX / 2 - 1, Epoch::MAX / 2 + 1, Epoch::MAX];
-    let epochs = [1, EPOCH_MASK / 2 - 1, EPOCH_MASK / 2 + 1, EPOCH_MASK];
-    let backends = [
-        Backend::Empty,
-        Backend::Vulkan,
-        Backend::Metal,
-        Backend::Dx12,
-        Backend::Gl,
-    ];
     for &i in &indexes {
         for &e in &epochs {
-            for &b in &backends {
+            let id = Id::<()>::zip(i, e);
-                let id = Id::<()>::zip(i, e, b);
+            let (index, epoch) = id.unzip();
-                let (index, epoch, backend) = id.unzip();
+            assert_eq!(index, i);
-                assert_eq!(index, i);
+            assert_eq!(epoch, e);
-                assert_eq!(epoch, e);
-                assert_eq!(backend, b);
-            }
         }
     }
 }

wgpu-core/src/identity.rs

@@ -1,5 +1,3 @@
-use wgt::Backend;
-
 use crate::{
     id::{Id, Marker},
     lock::{rank, Mutex},
@@ -52,7 +50,7 @@ impl IdentityValues {
     ///
     /// The backend is incorporated into the id, so that ids allocated with
     /// different `backend` values are always distinct.
-    pub fn alloc<T: Marker>(&mut self, backend: Backend) -> Id<T> {
+    pub fn alloc<T: Marker>(&mut self) -> Id<T> {
         assert!(
             self.id_source != IdSource::External,
             "Mix of internally allocated and externally provided IDs"
@@ -61,12 +59,12 @@ impl IdentityValues {
 
         self.count += 1;
         match self.free.pop() {
-            Some((index, epoch)) => Id::zip(index, epoch + 1, backend),
+            Some((index, epoch)) => Id::zip(index, epoch + 1),
             None => {
                 let index = self.next_index;
                 self.next_index += 1;
                 let epoch = 1;
-                Id::zip(index, epoch, backend)
+                Id::zip(index, epoch)
             }
         }
     }
@@ -85,7 +83,7 @@ impl IdentityValues {
     /// Free `id`. It will never be returned from `alloc` again.
     pub fn release<T: Marker>(&mut self, id: Id<T>) {
         if let IdSource::Allocated = self.id_source {
-            let (index, epoch, _backend) = id.unzip();
+            let (index, epoch) = id.unzip();
             self.free.push((index, epoch));
         }
         self.count -= 1;
@@ -103,8 +101,8 @@ pub struct IdentityManager<T: Marker> {
 }
 
 impl<T: Marker> IdentityManager<T> {
-    pub fn process(&self, backend: Backend) -> Id<T> {
+    pub fn process(&self) -> Id<T> {
-        self.values.lock().alloc(backend)
+        self.values.lock().alloc()
     }
     pub fn mark_as_used(&self, id: Id<T>) -> Id<T> {
         self.values.lock().mark_as_used(id)
@@ -135,10 +133,10 @@ impl<T: Marker> IdentityManager<T> {
 fn test_epoch_end_of_life() {
     use crate::id;
     let man = IdentityManager::<id::markers::Buffer>::new();
-    let id1 = man.process(Backend::Empty);
+    let id1 = man.process();
-    assert_eq!(id1.unzip(), (0, 1, Backend::Empty));
+    assert_eq!(id1.unzip(), (0, 1));
     man.free(id1);
-    let id2 = man.process(Backend::Empty);
+    let id2 = man.process();
     // confirm that the epoch 1 is no longer re-used
-    assert_eq!(id2.unzip(), (0, 2, Backend::Empty));
+    assert_eq!(id2.unzip(), (0, 2));
 }

wgpu-core/src/instance.rs

@@ -1,13 +1,12 @@
 use std::sync::Arc;
 use std::{borrow::Cow, collections::HashMap};
 
-use crate::hub::Hub;
 use crate::{
     api_log,
     device::{queue::Queue, resource::Device, DeviceDescriptor, DeviceError},
     global::Global,
     hal_api::HalApi,
-    id::{markers, AdapterId, DeviceId, Id, Marker, QueueId, SurfaceId},
+    id::{markers, AdapterId, DeviceId, QueueId, SurfaceId},
     lock::{rank, Mutex},
     present::Presentation,
     resource::ResourceType,
@@ -368,26 +367,6 @@ pub enum RequestDeviceError {
     UnsupportedFeature(wgt::Features),
 }
 
-pub enum AdapterInputs<'a, M: Marker> {
-    IdSet(&'a [Id<M>]),
-    Mask(Backends, fn(Backend) -> Option<Id<M>>),
-}
-
-impl<M: Marker> AdapterInputs<'_, M> {
-    fn find(&self, b: Backend) -> Option<Option<Id<M>>> {
-        match *self {
-            Self::IdSet(ids) => Some(Some(ids.iter().find(|id| id.backend() == b).copied()?)),
-            Self::Mask(bits, ref fun) => {
-                if bits.contains(b.into()) {
-                    Some(fun(b))
-                } else {
-                    None
-                }
-            }
-        }
-    }
-}
-
 #[derive(Clone, Debug, Error)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 #[non_exhaustive]
@@ -467,7 +446,7 @@ impl Global {
 
             let id = self
                 .surfaces
-                .prepare(Backend::Empty, id_in) // No specific backend for Surface, since it's not specific.
+                .prepare(id_in) // No specific backend for Surface, since it's not specific.
                 .assign(Arc::new(surface));
             Ok(id)
         }
@@ -511,10 +490,7 @@ impl Global {
             surface_per_backend: std::iter::once((Backend::Metal, raw_surface)).collect(),
         };
 
-        let id = self
+        let id = self.surfaces.prepare(id_in).assign(Arc::new(surface));
-            .surfaces
-            .prepare(Backend::Metal, id_in)
-            .assign(Arc::new(surface));
         Ok(id)
     }
 
@@ -536,10 +512,7 @@ impl Global {
             surface_per_backend: std::iter::once((Backend::Dx12, surface)).collect(),
         };
 
-        let id = self
+        let id = self.surfaces.prepare(id_in).assign(Arc::new(surface));
-            .surfaces
-            .prepare(Backend::Dx12, id_in)
-            .assign(Arc::new(surface));
         Ok(id)
     }
 
@@ -607,178 +580,81 @@ impl Global {
         drop(surface)
     }
 
-    pub fn enumerate_adapters(&self, inputs: AdapterInputs<markers::Adapter>) -> Vec<AdapterId> {
+    pub fn enumerate_adapters(&self, backends: Backends) -> Vec<AdapterId> {
         profiling::scope!("Instance::enumerate_adapters");
         api_log!("Instance::enumerate_adapters");
 
-        fn enumerate(
+        let mut adapters = Vec::new();
-            hub: &Hub,
+        for (_, instance) in self
-            backend: Backend,
+            .instance
-            instance: &dyn hal::DynInstance,
+            .instance_per_backend
-            inputs: &AdapterInputs<markers::Adapter>,
+            .iter()
-            list: &mut Vec<AdapterId>,
+            .filter(|(backend, _)| backends.contains(Backends::from(*backend)))
-        ) {
+        {
-            let Some(id_backend) = inputs.find(backend) else {
-                return;
-            };
-
             profiling::scope!("enumerating", &*format!("{:?}", backend));
 
             let hal_adapters = unsafe { instance.enumerate_adapters(None) };
             for raw in hal_adapters {
                 let adapter = Adapter::new(raw);
                 log::info!("Adapter {:?}", adapter.raw.info);
-                let id = hub
+                let id = self.hub.adapters.prepare(None).assign(Arc::new(adapter));
-                    .adapters
+                adapters.push(id);
-                    .prepare(backend, id_backend)
-                    .assign(Arc::new(adapter));
-                list.push(id);
             }
         }
-
-        let mut adapters = Vec::new();
-        for (backend, instance) in &self.instance.instance_per_backend {
-            enumerate(
-                &self.hub,
-                *backend,
-                instance.as_ref(),
-                &inputs,
-                &mut adapters,
-            );
-        }
         adapters
     }
 
-    fn select(
-        &self,
-        backend: Backend,
-        selected: &mut usize,
-        new_id: Option<AdapterId>,
-        mut list: Vec<hal::DynExposedAdapter>,
-    ) -> Option<AdapterId> {
-        match selected.checked_sub(list.len()) {
-            Some(left) => {
-                *selected = left;
-                None
-            }
-            None => {
-                let adapter = Adapter::new(list.swap_remove(*selected));
-                log::info!("Adapter {:?}", adapter.raw.info);
-                let id = self
-                    .hub
-                    .adapters
-                    .prepare(backend, new_id)
-                    .assign(Arc::new(adapter));
-                Some(id)
-            }
-        }
-    }
-
     pub fn request_adapter(
         &self,
         desc: &RequestAdapterOptions,
-        inputs: AdapterInputs<markers::Adapter>,
+        backends: Backends,
+        id_in: Option<AdapterId>,
     ) -> Result<AdapterId, RequestAdapterError> {
         profiling::scope!("Instance::request_adapter");
         api_log!("Instance::request_adapter");
 
-        fn gather(
-            backend: Backend,
-            instance: &Instance,
-            inputs: &AdapterInputs<markers::Adapter>,
-            compatible_surface: Option<&Surface>,
-            force_software: bool,
-            device_types: &mut Vec<wgt::DeviceType>,
-        ) -> (Option<Id<markers::Adapter>>, Vec<hal::DynExposedAdapter>) {
-            let id = inputs.find(backend);
-            match (id, instance.raw(backend)) {
-                (Some(id), Some(inst)) => {
-                    let compatible_hal_surface =
-                        compatible_surface.and_then(|surface| surface.raw(backend));
-                    let mut adapters = unsafe { inst.enumerate_adapters(compatible_hal_surface) };
-                    if force_software {
-                        adapters.retain(|exposed| exposed.info.device_type == wgt::DeviceType::Cpu);
-                    }
-                    if let Some(surface) = compatible_surface {
-                        adapters
-                            .retain(|exposed| surface.get_capabilities_with_raw(exposed).is_ok());
-                    }
-                    device_types.extend(adapters.iter().map(|ad| ad.info.device_type));
-                    (id, adapters)
-                }
-                _ => (None, Vec::new()),
-            }
-        }
-
         let compatible_surface = desc.compatible_surface.map(|id| self.surfaces.get(id));
         let compatible_surface = compatible_surface.as_ref().map(|surface| surface.as_ref());
-        let mut device_types = Vec::new();
+        let mut adapters = Vec::new();
 
-        #[cfg(vulkan)]
+        for (backend, instance) in self
-        let (id_vulkan, adapters_vk) = gather(
+            .instance
-            Backend::Vulkan,
+            .instance_per_backend
-            &self.instance,
+            .iter()
-            &inputs,
+            .filter(|(backend, _)| backends.contains(Backends::from(*backend)))
-            compatible_surface,
+        {
-            desc.force_fallback_adapter,
+            let compatible_hal_surface =
-            &mut device_types,
+                compatible_surface.and_then(|surface| surface.raw(*backend));
-        );
+            let mut backend_adapters =
-        #[cfg(metal)]
+                unsafe { instance.enumerate_adapters(compatible_hal_surface) };
-        let (id_metal, adapters_metal) = gather(
+            if desc.force_fallback_adapter {
-            Backend::Metal,
+                backend_adapters.retain(|exposed| exposed.info.device_type == wgt::DeviceType::Cpu);
-            &self.instance,
-            &inputs,
-            compatible_surface,
-            desc.force_fallback_adapter,
-            &mut device_types,
-        );
-        #[cfg(dx12)]
-        let (id_dx12, adapters_dx12) = gather(
-            Backend::Dx12,
-            &self.instance,
-            &inputs,
-            compatible_surface,
-            desc.force_fallback_adapter,
-            &mut device_types,
-        );
-        #[cfg(gles)]
-        let (id_gl, adapters_gl) = gather(
-            Backend::Gl,
-            &self.instance,
-            &inputs,
-            compatible_surface,
-            desc.force_fallback_adapter,
-            &mut device_types,
-        );
-
-        if device_types.is_empty() {
-            return Err(RequestAdapterError::NotFound);
-        }
-
-        let (mut integrated, mut discrete, mut virt, mut cpu, mut other) =
-            (None, None, None, None, None);
-
-        for (i, ty) in device_types.into_iter().enumerate() {
-            match ty {
-                wgt::DeviceType::IntegratedGpu => {
-                    integrated = integrated.or(Some(i));
-                }
-                wgt::DeviceType::DiscreteGpu => {
-                    discrete = discrete.or(Some(i));
-                }
-                wgt::DeviceType::VirtualGpu => {
-                    virt = virt.or(Some(i));
-                }
-                wgt::DeviceType::Cpu => {
-                    cpu = cpu.or(Some(i));
-                }
-                wgt::DeviceType::Other => {
-                    other = other.or(Some(i));
-                }
             }
+            if let Some(surface) = compatible_surface {
+                backend_adapters
+                    .retain(|exposed| surface.get_capabilities_with_raw(exposed).is_ok());
+            }
+            adapters.extend(backend_adapters);
         }
 
-        let preferred_gpu = match desc.power_preference {
+        match desc.power_preference {
+            PowerPreference::LowPower => {
+                sort(&mut adapters, true);
+            }
+            PowerPreference::HighPerformance => {
+                sort(&mut adapters, false);
+            }
+            PowerPreference::None => {}
+        };
+
+        fn sort(adapters: &mut [hal::DynExposedAdapter], prefer_integrated_gpu: bool) {
+            adapters.sort_by(|a, b| {
+                get_order(a.info.device_type, prefer_integrated_gpu)
+                    .cmp(&get_order(b.info.device_type, prefer_integrated_gpu))
+            });
+        }
+
+        fn get_order(device_type: wgt::DeviceType, prefer_integrated_gpu: bool) -> u8 {
             // Since devices of type "Other" might really be "Unknown" and come
             // from APIs like OpenGL that don't specify device type, Prefer more
             // Specific types over Other.
@@ -786,42 +662,28 @@ impl Global {
             // This means that backends which do provide accurate device types
             // will be preferred if their device type indicates an actual
             // hardware GPU (integrated or discrete).
-            PowerPreference::LowPower => integrated.or(discrete).or(other).or(virt).or(cpu),
+            match device_type {
-            PowerPreference::HighPerformance => discrete.or(integrated).or(other).or(virt).or(cpu),
+                wgt::DeviceType::DiscreteGpu if prefer_integrated_gpu => 2,
-            PowerPreference::None => {
+                wgt::DeviceType::IntegratedGpu if prefer_integrated_gpu => 1,
-                let option_min = |a: Option<usize>, b: Option<usize>| {
+                wgt::DeviceType::DiscreteGpu => 1,
-                    if let (Some(a), Some(b)) = (a, b) {
+                wgt::DeviceType::IntegratedGpu => 2,
-                        Some(a.min(b))
+                wgt::DeviceType::Other => 3,
-                    } else {
+                wgt::DeviceType::VirtualGpu => 4,
-                        a.or(b)
+                wgt::DeviceType::Cpu => 5,
-                    }
-                };
-                // Pick the lowest id of these types
-                option_min(option_min(discrete, integrated), other)
             }
-        };
+        }
 
-        let mut selected = preferred_gpu.unwrap_or(0);
+        if let Some(adapter) = adapters.into_iter().next() {
-        #[cfg(vulkan)]
+            log::info!("Adapter {:?}", adapter.info);
-        if let Some(id) = self.select(Backend::Vulkan, &mut selected, id_vulkan, adapters_vk) {
+            let id = self
-            return Ok(id);
+                .hub
+                .adapters
+                .prepare(id_in)
+                .assign(Arc::new(Adapter::new(adapter)));
+            Ok(id)
+        } else {
+            Err(RequestAdapterError::NotFound)
         }
-        #[cfg(metal)]
-        if let Some(id) = self.select(Backend::Metal, &mut selected, id_metal, adapters_metal) {
-            return Ok(id);
-        }
-        #[cfg(dx12)]
-        if let Some(id) = self.select(Backend::Dx12, &mut selected, id_dx12, adapters_dx12) {
-            return Ok(id);
-        }
-        #[cfg(gles)]
-        if let Some(id) = self.select(Backend::Gl, &mut selected, id_gl, adapters_gl) {
-            return Ok(id);
-        }
-        let _ = selected;
-
-        log::warn!("Some adapters are present, but enumerating them failed!");
-        Err(RequestAdapterError::NotFound)
     }
 
     /// # Safety
@@ -834,7 +696,7 @@ impl Global {
     ) -> AdapterId {
         profiling::scope!("Instance::create_adapter_from_hal");
 
-        let fid = self.hub.adapters.prepare(hal_adapter.backend(), input);
+        let fid = self.hub.adapters.prepare(input);
         let id = fid.assign(Arc::new(Adapter::new(hal_adapter)));
 
         resource_log!("Created Adapter {:?}", id);
@@ -901,9 +763,8 @@ impl Global {
         profiling::scope!("Adapter::request_device");
         api_log!("Adapter::request_device");
 
-        let backend = adapter_id.backend();
+        let device_fid = self.hub.devices.prepare(device_id_in);
-        let device_fid = self.hub.devices.prepare(backend, device_id_in);
+        let queue_fid = self.hub.queues.prepare(queue_id_in);
-        let queue_fid = self.hub.queues.prepare(backend, queue_id_in);
 
         let adapter = self.hub.adapters.get(adapter_id);
         let (device, queue) =
@@ -933,9 +794,8 @@ impl Global {
     ) -> Result<(DeviceId, QueueId), RequestDeviceError> {
         profiling::scope!("Global::create_device_from_hal");
 
-        let backend = adapter_id.backend();
+        let devices_fid = self.hub.devices.prepare(device_id_in);
-        let devices_fid = self.hub.devices.prepare(backend, device_id_in);
+        let queues_fid = self.hub.queues.prepare(queue_id_in);
-        let queues_fid = self.hub.queues.prepare(backend, queue_id_in);
 
         let adapter = self.hub.adapters.get(adapter_id);
         let (device, queue) = adapter.create_device_and_queue_from_hal(

wgpu-core/src/present.rs

@@ -131,7 +131,7 @@ impl Global {
             return Err(SurfaceError::NotConfigured);
         };
 
-        let fid = hub.textures.prepare(device.backend(), texture_id_in);
+        let fid = hub.textures.prepare(texture_id_in);
 
         #[cfg(feature = "trace")]
         if let Some(ref mut trace) = *device.trace.lock() {

wgpu-core/src/registry.rs

@@ -70,18 +70,14 @@ impl<T: StorageItem> FutureId<'_, T> {
 }
 
 impl<T: StorageItem> Registry<T> {
-    pub(crate) fn prepare(
+    pub(crate) fn prepare(&self, id_in: Option<Id<T::Marker>>) -> FutureId<T> {
-        &self,
-        backend: wgt::Backend,
-        id_in: Option<Id<T::Marker>>,
-    ) -> FutureId<T> {
         FutureId {
             id: match id_in {
                 Some(id_in) => {
                     self.identity.mark_as_used(id_in);
                     id_in
                 }
-                None => self.identity.process(backend),
+                None => self.identity.process(),
             },
             data: &self.storage,
         }
@@ -154,7 +150,7 @@ mod tests {
                 s.spawn(|| {
                     for _ in 0..1000 {
                         let value = Arc::new(TestData);
-                        let new_id = registry.prepare(wgt::Backend::Empty, None);
+                        let new_id = registry.prepare(None);
                         let id = new_id.assign(value);
                         registry.remove(id);
                     }

wgpu-core/src/storage.rs

@@ -1,7 +1,5 @@
 use std::sync::Arc;
 
-use wgt::Backend;
-
 use crate::id::{Id, Marker};
 use crate::resource::ResourceType;
 use crate::{Epoch, Index};
@@ -75,7 +73,7 @@ where
     T: StorageItem,
 {
     pub(crate) fn insert(&mut self, id: Id<T::Marker>, value: T) {
-        let (index, epoch, _) = id.unzip();
+        let (index, epoch) = id.unzip();
         let index = index as usize;
         if index >= self.map.len() {
             self.map.resize_with(index + 1, || Element::Vacant);
@@ -94,7 +92,7 @@ where
     }
 
     pub(crate) fn remove(&mut self, id: Id<T::Marker>) -> T {
-        let (index, epoch, _) = id.unzip();
+        let (index, epoch) = id.unzip();
         match std::mem::replace(&mut self.map[index as usize], Element::Vacant) {
             Element::Occupied(value, storage_epoch) => {
                 assert_eq!(epoch, storage_epoch);
@@ -104,13 +102,13 @@ where
         }
     }
 
-    pub(crate) fn iter(&self, backend: Backend) -> impl Iterator<Item = (Id<T::Marker>, &T)> {
+    pub(crate) fn iter(&self) -> impl Iterator<Item = (Id<T::Marker>, &T)> {
         self.map
             .iter()
             .enumerate()
             .filter_map(move |(index, x)| match *x {
                 Element::Occupied(ref value, storage_epoch) => {
-                    Some((Id::zip(index as Index, storage_epoch, backend), value))
+                    Some((Id::zip(index as Index, storage_epoch), value))
                 }
                 _ => None,
             })
@@ -128,7 +126,7 @@ where
     /// Get an owned reference to an item.
     /// Panics if there is an epoch mismatch, the entry is empty or in error.
     pub(crate) fn get(&self, id: Id<T::Marker>) -> T {
-        let (index, epoch, _) = id.unzip();
+        let (index, epoch) = id.unzip();
         let (result, storage_epoch) = match self.map.get(index as usize) {
             Some(&Element::Occupied(ref v, epoch)) => (v.clone(), epoch),
             None | Some(&Element::Vacant) => panic!("{}[{:?}] does not exist", self.kind, id),

wgpu/src/backend/wgpu_core.rs

@@ -61,8 +61,7 @@ impl ContextWgpuCore {
 
     #[cfg(native)]
     pub fn enumerate_adapters(&self, backends: wgt::Backends) -> Vec<wgc::id::AdapterId> {
-        self.0
+        self.0.enumerate_adapters(backends)
-            .enumerate_adapters(wgc::instance::AdapterInputs::Mask(backends, |_| None))
     }
 
     pub unsafe fn create_adapter_from_hal<A: wgc::hal_api::HalApi>(
@@ -589,7 +588,8 @@ impl crate::Context for ContextWgpuCore {
                     surface.id
                 }),
             },
-            wgc::instance::AdapterInputs::Mask(wgt::Backends::all(), |_| None),
+            wgt::Backends::all(),
+            None,
         );
         ready(id.ok())
     }