wgpu/
dispatch.rs

1//! Infrastructure for dispatching calls to the appropriate "backend". The "backends" are:
2//!
3//! - `wgpu_core`: An implementation of the the wgpu api on top of various native graphics APIs.
4//! - `webgpu`: An implementation of the wgpu api which calls WebGPU directly.
5//!
6//! The interface traits are all object safe and listed in the `InterfaceTypes` trait.
7//!
8//! The method for dispatching should optimize well if only one backend is
9//! compiled in, as-if there was no dispatching at all. See the comments on
10//! [`dispatch_types`] for details.
11//!
12//! [`dispatch_types`]: macro.dispatch_types.html
13
14#![allow(
15    drop_bounds,
16    reason = "This exists to remind implementors to impl drop."
17)]
18#![allow(clippy::too_many_arguments, reason = "It's fine.")]
19#![allow(
20    missing_docs,
21    clippy::missing_safety_doc,
22    reason = "Interfaces are not documented"
23)]
24#![allow(
25    clippy::len_without_is_empty,
26    reason = "trait is minimal, not ergonomic"
27)]
28
29use crate::{Blas, Tlas, WasmNotSend, WasmNotSendSync, WriteOnly};
30
31use alloc::{boxed::Box, string::String, sync::Arc, vec::Vec};
32use core::{any::Any, fmt::Debug, future::Future, hash::Hash, ops::Range, pin::Pin};
33
34#[cfg(custom)]
35use crate::backend::custom::*;
36#[cfg(webgpu)]
37use crate::backend::webgpu::*;
38#[cfg(wgpu_core)]
39use crate::backend::wgpu_core::*;
40
41/// Create a single trait with the given supertraits and a blanket impl for all types that implement them.
42///
43/// This is useful for creating a trait alias as a shorthand.
44macro_rules! trait_alias {
45    ($name:ident: $($bound:tt)+) => {
46        pub trait $name: $($bound)+ {}
47        impl<T: $($bound)+> $name for T {}
48    };
49}
50
51// Various return futures in the API.
52trait_alias!(RequestAdapterFuture: Future<Output = Result<DispatchAdapter, wgt::RequestAdapterError>> + WasmNotSend + 'static);
53trait_alias!(RequestDeviceFuture: Future<Output = Result<(DispatchDevice, DispatchQueue), crate::RequestDeviceError>> + WasmNotSend + 'static);
54trait_alias!(PopErrorScopeFuture: Future<Output = Option<crate::Error>> + WasmNotSend + 'static);
55trait_alias!(ShaderCompilationInfoFuture: Future<Output = crate::CompilationInfo> + WasmNotSend + 'static);
56trait_alias!(EnumerateAdapterFuture: Future<Output = Vec<DispatchAdapter>> + WasmNotSend + 'static);
57
58// We can't use trait aliases here, as you can't convert from a dyn Trait to dyn Supertrait _yet_.
59#[cfg(send_sync)]
60pub type BoxDeviceLostCallback = Box<dyn FnOnce(crate::DeviceLostReason, String) + Send + 'static>;
61#[cfg(not(send_sync))]
62pub type BoxDeviceLostCallback = Box<dyn FnOnce(crate::DeviceLostReason, String) + 'static>;
63#[cfg(send_sync)]
64pub type BoxSubmittedWorkDoneCallback = Box<dyn FnOnce() + Send + 'static>;
65#[cfg(not(send_sync))]
66pub type BoxSubmittedWorkDoneCallback = Box<dyn FnOnce() + 'static>;
67#[cfg(send_sync)]
68pub type BufferMapCallback = Box<dyn FnOnce(Result<(), crate::BufferAsyncError>) + Send + 'static>;
69#[cfg(not(send_sync))]
70pub type BufferMapCallback = Box<dyn FnOnce(Result<(), crate::BufferAsyncError>) + 'static>;
71
72#[cfg(send_sync)]
73pub type BlasCompactCallback = Box<dyn FnOnce(Result<(), crate::BlasAsyncError>) + Send + 'static>;
74#[cfg(not(send_sync))]
75pub type BlasCompactCallback = Box<dyn FnOnce(Result<(), crate::BlasAsyncError>) + 'static>;
76
77// remove when rust 1.86
78#[cfg_attr(not(custom), expect(dead_code))]
79pub trait AsAny {
80    fn as_any(&self) -> &dyn Any;
81}
82
83impl<T: 'static> AsAny for T {
84    fn as_any(&self) -> &dyn Any {
85        self
86    }
87}
88
89// Common traits on all the interface traits
90trait_alias!(CommonTraits: AsAny + Any + Debug + WasmNotSendSync);
91
92pub trait InstanceInterface: CommonTraits {
93    fn new(desc: crate::InstanceDescriptor) -> Self
94    where
95        Self: Sized;
96
97    unsafe fn create_surface(
98        &self,
99        target: crate::SurfaceTargetUnsafe,
100    ) -> Result<DispatchSurface, crate::CreateSurfaceError>;
101
102    fn request_adapter(
103        &self,
104        options: &crate::RequestAdapterOptions<'_, '_>,
105    ) -> Pin<Box<dyn RequestAdapterFuture>>;
106
107    fn poll_all_devices(&self, force_wait: bool) -> bool;
108
109    #[cfg(feature = "wgsl")]
110    fn wgsl_language_features(&self) -> crate::WgslLanguageFeatures;
111
112    fn enumerate_adapters(&self, backends: crate::Backends)
113        -> Pin<Box<dyn EnumerateAdapterFuture>>;
114}
115
116pub trait AdapterInterface: CommonTraits {
117    fn request_device(
118        &self,
119        desc: &crate::DeviceDescriptor<'_>,
120    ) -> Pin<Box<dyn RequestDeviceFuture>>;
121
122    fn is_surface_supported(&self, surface: &DispatchSurface) -> bool;
123
124    fn features(&self) -> crate::Features;
125
126    fn limits(&self) -> crate::Limits;
127
128    fn downlevel_capabilities(&self) -> crate::DownlevelCapabilities;
129
130    fn get_info(&self) -> crate::AdapterInfo;
131
132    fn get_texture_format_features(
133        &self,
134        format: crate::TextureFormat,
135    ) -> crate::TextureFormatFeatures;
136
137    fn get_presentation_timestamp(&self) -> crate::PresentationTimestamp;
138
139    fn cooperative_matrix_properties(&self) -> Vec<crate::wgt::CooperativeMatrixProperties>;
140}
141
142pub trait DeviceInterface: CommonTraits {
143    fn features(&self) -> crate::Features;
144    fn limits(&self) -> crate::Limits;
145    fn adapter_info(&self) -> crate::AdapterInfo;
146
147    fn create_shader_module(
148        &self,
149        desc: crate::ShaderModuleDescriptor<'_>,
150        shader_bound_checks: crate::ShaderRuntimeChecks,
151    ) -> DispatchShaderModule;
152
153    unsafe fn create_shader_module_passthrough(
154        &self,
155        desc: &crate::ShaderModuleDescriptorPassthrough<'_>,
156    ) -> DispatchShaderModule;
157
158    fn create_bind_group_layout(
159        &self,
160        desc: &crate::BindGroupLayoutDescriptor<'_>,
161    ) -> DispatchBindGroupLayout;
162    fn create_bind_group(&self, desc: &crate::BindGroupDescriptor<'_>) -> DispatchBindGroup;
163    fn create_pipeline_layout(
164        &self,
165        desc: &crate::PipelineLayoutDescriptor<'_>,
166    ) -> DispatchPipelineLayout;
167    fn create_render_pipeline(
168        &self,
169        desc: &crate::RenderPipelineDescriptor<'_>,
170    ) -> DispatchRenderPipeline;
171    fn create_mesh_pipeline(
172        &self,
173        desc: &crate::MeshPipelineDescriptor<'_>,
174    ) -> DispatchRenderPipeline;
175    fn create_compute_pipeline(
176        &self,
177        desc: &crate::ComputePipelineDescriptor<'_>,
178    ) -> DispatchComputePipeline;
179    unsafe fn create_pipeline_cache(
180        &self,
181        desc: &crate::PipelineCacheDescriptor<'_>,
182    ) -> DispatchPipelineCache;
183    fn create_buffer(&self, desc: &crate::BufferDescriptor<'_>) -> DispatchBuffer;
184    fn create_texture(&self, desc: &crate::TextureDescriptor<'_>) -> DispatchTexture;
185    fn create_external_texture(
186        &self,
187        desc: &crate::ExternalTextureDescriptor<'_>,
188        planes: &[&crate::TextureView],
189    ) -> DispatchExternalTexture;
190    fn create_blas(
191        &self,
192        desc: &crate::CreateBlasDescriptor<'_>,
193        sizes: crate::BlasGeometrySizeDescriptors,
194    ) -> (Option<u64>, DispatchBlas);
195    fn create_tlas(&self, desc: &crate::CreateTlasDescriptor<'_>) -> DispatchTlas;
196    fn create_sampler(&self, desc: &crate::SamplerDescriptor<'_>) -> DispatchSampler;
197    fn create_query_set(&self, desc: &crate::QuerySetDescriptor<'_>) -> DispatchQuerySet;
198    fn create_command_encoder(
199        &self,
200        desc: &crate::CommandEncoderDescriptor<'_>,
201    ) -> DispatchCommandEncoder;
202    fn create_render_bundle_encoder(
203        &self,
204        desc: &crate::RenderBundleEncoderDescriptor<'_>,
205    ) -> DispatchRenderBundleEncoder;
206
207    fn set_device_lost_callback(&self, device_lost_callback: BoxDeviceLostCallback);
208
209    fn on_uncaptured_error(&self, handler: Arc<dyn crate::UncapturedErrorHandler>);
210    // Returns index on the stack of the pushed error scope.
211    fn push_error_scope(&self, filter: crate::ErrorFilter) -> u32;
212    fn pop_error_scope(&self, index: u32) -> Pin<Box<dyn PopErrorScopeFuture>>;
213
214    unsafe fn start_graphics_debugger_capture(&self);
215    unsafe fn stop_graphics_debugger_capture(&self);
216
217    fn poll(&self, poll_type: wgt::PollType<u64>) -> Result<crate::PollStatus, crate::PollError>;
218
219    fn get_internal_counters(&self) -> crate::InternalCounters;
220    fn generate_allocator_report(&self) -> Option<crate::AllocatorReport>;
221
222    fn destroy(&self);
223}
224
225pub trait QueueInterface: CommonTraits {
226    fn write_buffer(&self, buffer: &DispatchBuffer, offset: crate::BufferAddress, data: &[u8]);
227
228    fn create_staging_buffer(&self, size: crate::BufferSize) -> Option<DispatchQueueWriteBuffer>;
229    fn validate_write_buffer(
230        &self,
231        buffer: &DispatchBuffer,
232        offset: crate::BufferAddress,
233        size: crate::BufferSize,
234    ) -> Option<()>;
235    fn write_staging_buffer(
236        &self,
237        buffer: &DispatchBuffer,
238        offset: crate::BufferAddress,
239        staging_buffer: &DispatchQueueWriteBuffer,
240    );
241
242    fn write_texture(
243        &self,
244        texture: crate::TexelCopyTextureInfo<'_>,
245        data: &[u8],
246        data_layout: crate::TexelCopyBufferLayout,
247        size: crate::Extent3d,
248    );
249    #[cfg(web)]
250    fn copy_external_image_to_texture(
251        &self,
252        source: &crate::CopyExternalImageSourceInfo,
253        dest: crate::CopyExternalImageDestInfo<&crate::api::Texture>,
254        size: crate::Extent3d,
255    );
256
257    /// Submit must always drain the iterator, even in the case of error.
258    fn submit(&self, command_buffers: &mut dyn Iterator<Item = DispatchCommandBuffer>) -> u64;
259
260    fn get_timestamp_period(&self) -> f32;
261    fn on_submitted_work_done(&self, callback: BoxSubmittedWorkDoneCallback);
262
263    fn compact_blas(&self, blas: &DispatchBlas) -> (Option<u64>, DispatchBlas);
264}
265
266pub trait ShaderModuleInterface: CommonTraits {
267    fn get_compilation_info(&self) -> Pin<Box<dyn ShaderCompilationInfoFuture>>;
268}
269pub trait BindGroupLayoutInterface: CommonTraits {}
270pub trait BindGroupInterface: CommonTraits {}
271pub trait TextureViewInterface: CommonTraits {}
272pub trait SamplerInterface: CommonTraits {}
273pub trait BufferInterface: CommonTraits {
274    fn map_async(
275        &self,
276        mode: crate::MapMode,
277        range: Range<crate::BufferAddress>,
278        callback: BufferMapCallback,
279    );
280    fn get_mapped_range(&self, sub_range: Range<crate::BufferAddress>)
281        -> DispatchBufferMappedRange;
282
283    fn unmap(&self);
284
285    fn destroy(&self);
286}
287pub trait TextureInterface: CommonTraits {
288    fn create_view(&self, desc: &crate::TextureViewDescriptor<'_>) -> DispatchTextureView;
289
290    fn destroy(&self);
291}
292pub trait ExternalTextureInterface: CommonTraits {
293    fn destroy(&self);
294}
295pub trait BlasInterface: CommonTraits {
296    fn prepare_compact_async(&self, callback: BlasCompactCallback);
297    fn ready_for_compaction(&self) -> bool;
298}
299pub trait TlasInterface: CommonTraits {}
300pub trait QuerySetInterface: CommonTraits {}
301pub trait PipelineLayoutInterface: CommonTraits {}
302pub trait RenderPipelineInterface: CommonTraits {
303    fn get_bind_group_layout(&self, index: u32) -> DispatchBindGroupLayout;
304}
305pub trait ComputePipelineInterface: CommonTraits {
306    fn get_bind_group_layout(&self, index: u32) -> DispatchBindGroupLayout;
307}
308pub trait PipelineCacheInterface: CommonTraits {
309    fn get_data(&self) -> Option<Vec<u8>>;
310}
311pub trait CommandEncoderInterface: CommonTraits {
312    fn copy_buffer_to_buffer(
313        &self,
314        source: &DispatchBuffer,
315        source_offset: crate::BufferAddress,
316        destination: &DispatchBuffer,
317        destination_offset: crate::BufferAddress,
318        copy_size: Option<crate::BufferAddress>,
319    );
320    fn copy_buffer_to_texture(
321        &self,
322        source: crate::TexelCopyBufferInfo<'_>,
323        destination: crate::TexelCopyTextureInfo<'_>,
324        copy_size: crate::Extent3d,
325    );
326    fn copy_texture_to_buffer(
327        &self,
328        source: crate::TexelCopyTextureInfo<'_>,
329        destination: crate::TexelCopyBufferInfo<'_>,
330        copy_size: crate::Extent3d,
331    );
332    fn copy_texture_to_texture(
333        &self,
334        source: crate::TexelCopyTextureInfo<'_>,
335        destination: crate::TexelCopyTextureInfo<'_>,
336        copy_size: crate::Extent3d,
337    );
338
339    fn begin_compute_pass(&self, desc: &crate::ComputePassDescriptor<'_>) -> DispatchComputePass;
340    fn begin_render_pass(&self, desc: &crate::RenderPassDescriptor<'_>) -> DispatchRenderPass;
341    fn finish(&mut self) -> DispatchCommandBuffer;
342
343    fn clear_texture(
344        &self,
345        texture: &DispatchTexture,
346        subresource_range: &crate::ImageSubresourceRange,
347    );
348    fn clear_buffer(
349        &self,
350        buffer: &DispatchBuffer,
351        offset: crate::BufferAddress,
352        size: Option<crate::BufferAddress>,
353    );
354
355    fn insert_debug_marker(&self, label: &str);
356    fn push_debug_group(&self, label: &str);
357    fn pop_debug_group(&self);
358
359    fn write_timestamp(&self, query_set: &DispatchQuerySet, query_index: u32);
360    fn resolve_query_set(
361        &self,
362        query_set: &DispatchQuerySet,
363        first_query: u32,
364        query_count: u32,
365        destination: &DispatchBuffer,
366        destination_offset: crate::BufferAddress,
367    );
368    fn mark_acceleration_structures_built<'a>(
369        &self,
370        blas: &mut dyn Iterator<Item = &'a Blas>,
371        tlas: &mut dyn Iterator<Item = &'a Tlas>,
372    );
373
374    fn build_acceleration_structures<'a>(
375        &self,
376        blas: &mut dyn Iterator<Item = &'a crate::BlasBuildEntry<'a>>,
377        tlas: &mut dyn Iterator<Item = &'a crate::Tlas>,
378    );
379
380    fn transition_resources<'a>(
381        &mut self,
382        buffer_transitions: &mut dyn Iterator<Item = wgt::BufferTransition<&'a DispatchBuffer>>,
383        texture_transitions: &mut dyn Iterator<Item = wgt::TextureTransition<&'a DispatchTexture>>,
384    );
385}
386pub trait ComputePassInterface: CommonTraits + Drop {
387    fn set_pipeline(&mut self, pipeline: &DispatchComputePipeline);
388    fn set_bind_group(
389        &mut self,
390        index: u32,
391        bind_group: Option<&DispatchBindGroup>,
392        offsets: &[crate::DynamicOffset],
393    );
394    fn set_immediates(&mut self, offset: u32, data: &[u8]);
395
396    fn insert_debug_marker(&mut self, label: &str);
397    fn push_debug_group(&mut self, group_label: &str);
398    fn pop_debug_group(&mut self);
399
400    fn write_timestamp(&mut self, query_set: &DispatchQuerySet, query_index: u32);
401    fn begin_pipeline_statistics_query(&mut self, query_set: &DispatchQuerySet, query_index: u32);
402    fn end_pipeline_statistics_query(&mut self);
403
404    fn dispatch_workgroups(&mut self, x: u32, y: u32, z: u32);
405    fn dispatch_workgroups_indirect(
406        &mut self,
407        indirect_buffer: &DispatchBuffer,
408        indirect_offset: crate::BufferAddress,
409    );
410}
411pub trait RenderPassInterface: CommonTraits + Drop {
412    fn set_pipeline(&mut self, pipeline: &DispatchRenderPipeline);
413    fn set_bind_group(
414        &mut self,
415        index: u32,
416        bind_group: Option<&DispatchBindGroup>,
417        offsets: &[crate::DynamicOffset],
418    );
419    fn set_index_buffer(
420        &mut self,
421        buffer: &DispatchBuffer,
422        index_format: crate::IndexFormat,
423        offset: crate::BufferAddress,
424        size: Option<crate::BufferSize>,
425    );
426    fn set_vertex_buffer(
427        &mut self,
428        slot: u32,
429        buffer: &DispatchBuffer,
430        offset: crate::BufferAddress,
431        size: Option<crate::BufferSize>,
432    );
433    fn set_immediates(&mut self, offset: u32, data: &[u8]);
434    fn set_blend_constant(&mut self, color: crate::Color);
435    fn set_scissor_rect(&mut self, x: u32, y: u32, width: u32, height: u32);
436    fn set_viewport(
437        &mut self,
438        x: f32,
439        y: f32,
440        width: f32,
441        height: f32,
442        min_depth: f32,
443        max_depth: f32,
444    );
445    fn set_stencil_reference(&mut self, reference: u32);
446
447    fn draw(&mut self, vertices: Range<u32>, instances: Range<u32>);
448    fn draw_indexed(&mut self, indices: Range<u32>, base_vertex: i32, instances: Range<u32>);
449    fn draw_mesh_tasks(&mut self, group_count_x: u32, group_count_y: u32, group_count_z: u32);
450    fn draw_indirect(
451        &mut self,
452        indirect_buffer: &DispatchBuffer,
453        indirect_offset: crate::BufferAddress,
454    );
455    fn draw_indexed_indirect(
456        &mut self,
457        indirect_buffer: &DispatchBuffer,
458        indirect_offset: crate::BufferAddress,
459    );
460    fn draw_mesh_tasks_indirect(
461        &mut self,
462        indirect_buffer: &DispatchBuffer,
463        indirect_offset: crate::BufferAddress,
464    );
465
466    fn multi_draw_indirect(
467        &mut self,
468        indirect_buffer: &DispatchBuffer,
469        indirect_offset: crate::BufferAddress,
470        count: u32,
471    );
472    fn multi_draw_indexed_indirect(
473        &mut self,
474        indirect_buffer: &DispatchBuffer,
475        indirect_offset: crate::BufferAddress,
476        count: u32,
477    );
478    fn multi_draw_indirect_count(
479        &mut self,
480        indirect_buffer: &DispatchBuffer,
481        indirect_offset: crate::BufferAddress,
482        count_buffer: &DispatchBuffer,
483        count_buffer_offset: crate::BufferAddress,
484        max_count: u32,
485    );
486    fn multi_draw_mesh_tasks_indirect(
487        &mut self,
488        indirect_buffer: &DispatchBuffer,
489        indirect_offset: crate::BufferAddress,
490        count: u32,
491    );
492    fn multi_draw_indexed_indirect_count(
493        &mut self,
494        indirect_buffer: &DispatchBuffer,
495        indirect_offset: crate::BufferAddress,
496        count_buffer: &DispatchBuffer,
497        count_buffer_offset: crate::BufferAddress,
498        max_count: u32,
499    );
500    fn multi_draw_mesh_tasks_indirect_count(
501        &mut self,
502        indirect_buffer: &DispatchBuffer,
503        indirect_offset: crate::BufferAddress,
504        count_buffer: &DispatchBuffer,
505        count_buffer_offset: crate::BufferAddress,
506        max_count: u32,
507    );
508
509    fn insert_debug_marker(&mut self, label: &str);
510    fn push_debug_group(&mut self, group_label: &str);
511    fn pop_debug_group(&mut self);
512
513    fn write_timestamp(&mut self, query_set: &DispatchQuerySet, query_index: u32);
514    fn begin_occlusion_query(&mut self, query_index: u32);
515    fn end_occlusion_query(&mut self);
516    fn begin_pipeline_statistics_query(&mut self, query_set: &DispatchQuerySet, query_index: u32);
517    fn end_pipeline_statistics_query(&mut self);
518
519    fn execute_bundles(&mut self, render_bundles: &mut dyn Iterator<Item = &DispatchRenderBundle>);
520}
521
522pub trait RenderBundleEncoderInterface: CommonTraits {
523    fn set_pipeline(&mut self, pipeline: &DispatchRenderPipeline);
524    fn set_bind_group(
525        &mut self,
526        index: u32,
527        bind_group: Option<&DispatchBindGroup>,
528        offsets: &[crate::DynamicOffset],
529    );
530    fn set_index_buffer(
531        &mut self,
532        buffer: &DispatchBuffer,
533        index_format: crate::IndexFormat,
534        offset: crate::BufferAddress,
535        size: Option<crate::BufferSize>,
536    );
537    fn set_vertex_buffer(
538        &mut self,
539        slot: u32,
540        buffer: &DispatchBuffer,
541        offset: crate::BufferAddress,
542        size: Option<crate::BufferSize>,
543    );
544    fn set_immediates(&mut self, offset: u32, data: &[u8]);
545
546    fn draw(&mut self, vertices: Range<u32>, instances: Range<u32>);
547    fn draw_indexed(&mut self, indices: Range<u32>, base_vertex: i32, instances: Range<u32>);
548    fn draw_indirect(
549        &mut self,
550        indirect_buffer: &DispatchBuffer,
551        indirect_offset: crate::BufferAddress,
552    );
553    fn draw_indexed_indirect(
554        &mut self,
555        indirect_buffer: &DispatchBuffer,
556        indirect_offset: crate::BufferAddress,
557    );
558
559    fn finish(self, desc: &crate::RenderBundleDescriptor<'_>) -> DispatchRenderBundle
560    where
561        Self: Sized;
562}
563
564pub trait CommandBufferInterface: CommonTraits {}
565pub trait RenderBundleInterface: CommonTraits {}
566
567pub trait SurfaceInterface: CommonTraits {
568    fn get_capabilities(&self, adapter: &DispatchAdapter) -> crate::SurfaceCapabilities;
569
570    fn configure(&self, device: &DispatchDevice, config: &crate::SurfaceConfiguration);
571    fn get_current_texture(
572        &self,
573    ) -> (
574        Option<DispatchTexture>,
575        crate::SurfaceStatus,
576        DispatchSurfaceOutputDetail,
577    );
578}
579
580pub trait SurfaceOutputDetailInterface: CommonTraits {
581    fn present(&self);
582    fn texture_discard(&self);
583}
584
585pub trait QueueWriteBufferInterface: CommonTraits {
586    fn len(&self) -> usize;
587
588    /// # Safety
589    ///
590    /// Must only be used on write, not read, mappings.
591    unsafe fn write_slice(&mut self) -> WriteOnly<'_, [u8]>;
592}
593
594pub trait BufferMappedRangeInterface: CommonTraits {
595    fn len(&self) -> usize;
596
597    /// # Safety
598    ///
599    /// Must only be used on read, not write, mappings.
600    unsafe fn read_slice(&self) -> &[u8];
601
602    /// # Safety
603    ///
604    /// Must only be used on write, not read, mappings.
605    unsafe fn write_slice(&mut self) -> WriteOnly<'_, [u8]>;
606
607    #[cfg(webgpu)]
608    fn as_uint8array(&self) -> &js_sys::Uint8Array;
609}
610
611/// Generates a dispatch type for some `wgpu` API type.
612///
613/// Invocations of this macro take one of the following forms:
614///
615/// ```ignore
616/// dispatch_types! {mut type D: I = Core, Web, Dyn }
617/// dispatch_types! {ref type D: I = Core, Web, Dyn }
618/// ```
619///
620/// This defines `D` as a type that dereferences to a `dyn I` trait object. Most uses of
621/// `D` in the rest of this crate just call the methods from the `dyn I` object, not from
622/// `D` itself.
623///
624/// Internally, `D` is an enum with up to three variants holding values of type `Core`,
625/// `Web`, and `Dyn`, all of which must implement `I`. `Core`, `Web` and `Dyn` are the
626/// types from the `wgpu_core`, `webgpu`, and `custom` submodules of `wgpu::backend` that
627/// correspond to `D`. The macro generates `Deref` and `DerefMut` implementations that
628/// match on this enum and produce a `dyn I` reference for each variant.
629///
630/// The macro's `mut type` form defines `D` as the unique owner of the backend type, with
631/// a `DerefMut` implementation, and `as_*_mut` methods that return `&mut` references.
632/// This `D` does not implement `Clone`.
633///
634/// The macro's `ref type` form defines `D` to hold an `Arc` pointing to the backend type,
635/// permitting `Clone` and `Deref`, but losing exclusive, mutable access.
636///
637/// For example:
638///
639/// ```ignore
640/// dispatch_types! {ref type DispatchBuffer: BufferInterface =
641///                  CoreBuffer, WebBuffer, DynBuffer}
642/// ```
643///
644/// This defines `DispatchBuffer` as a type that dereferences to `&dyn BufferInterface`,
645/// which has methods like `map_async` and `destroy`. The enum would be:
646///
647/// ```ignore
648/// pub enum DispatchBuffer {
649///     #[cfg(wgpu_core)]
650///     Core(Arc<CoreBuffer>),
651///     #[cfg(webgpu)]
652///     WebGPU(WebBuffer),
653///     #[cfg(custom)]
654///     Custom(DynBuffer),
655/// }
656/// ```
657///
658/// This macro also defines `as_*` methods so that the backend implementations can
659/// dereference other arguments.
660///
661/// ## Devirtualization
662///
663/// The dispatch types generated by this macro are carefully designed to allow the
664/// compiler to completely devirtualize calls in most circumstances.
665///
666/// Note that every variant of the enum generated by this macro is under a `#[cfg]`.
667/// Naturally, the `match` expressions in the `Deref` and `DerefMut` implementations have
668/// matching `#[cfg]` attributes on each match arm.
669///
670/// In practice, when `wgpu`'s `"custom"` feature is not enabled, there is usually only
671/// one variant in the `enum`, making it effectively a newtype around the sole variant's
672/// data: it has no discriminant to branch on, and the `match` expressions are removed
673/// entirely by the compiler.
674///
675/// In this case, when we invoke a method from the interface trait `I` on a dispatch type,
676/// the `Deref` and `DerefMut` implementations' `match` statements build a `&dyn I` for
677/// the data, on which we immediately invoke a method. The vtable is a constant, allowing
678/// the Rust compiler to turn the `dyn` method call into an ordinary method call. This
679/// creates opportunities for inlining.
680///
681/// Similarly, the `as_*` methods are free when there is only one backend.
682macro_rules! dispatch_types {
683    (
684        ref type $name:ident: $interface:ident = $core_type:ident,$webgpu_type:ident,$custom_type:ident
685    ) => {
686        #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash, Clone)]
687        pub enum $name {
688            #[cfg(wgpu_core)]
689            Core(Arc<$core_type>),
690            #[cfg(webgpu)]
691            WebGPU($webgpu_type),
692            #[allow(clippy::allow_attributes, private_interfaces)]
693            #[cfg(custom)]
694            Custom($custom_type),
695        }
696
697        impl $name {
698            #[cfg(wgpu_core)]
699            #[inline]
700            #[allow(clippy::allow_attributes, unused)]
701            pub fn as_core(&self) -> &$core_type {
702                match self {
703                    Self::Core(value) => value,
704                    _ => panic!(concat!(stringify!($name), " is not core")),
705                }
706            }
707
708            #[cfg(wgpu_core)]
709            #[inline]
710            #[allow(clippy::allow_attributes, unused)]
711            pub fn as_core_opt(&self) -> Option<&$core_type> {
712                match self {
713                    Self::Core(value) => Some(value),
714                    _ => None,
715                }
716            }
717
718            #[cfg(custom)]
719            #[inline]
720            #[allow(clippy::allow_attributes, unused)]
721            pub fn as_custom<T: $interface>(&self) -> Option<&T> {
722                match self {
723                    Self::Custom(value) => value.downcast(),
724                    _ => None,
725                }
726            }
727
728            #[cfg(webgpu)]
729            #[inline]
730            #[allow(clippy::allow_attributes, unused)]
731            pub fn as_webgpu(&self) -> &$webgpu_type {
732                match self {
733                    Self::WebGPU(value) => value,
734                    _ => panic!(concat!(stringify!($name), " is not webgpu")),
735                }
736            }
737
738            #[cfg(webgpu)]
739            #[inline]
740            #[allow(clippy::allow_attributes, unused)]
741            pub fn as_webgpu_opt(&self) -> Option<&$webgpu_type> {
742                match self {
743                    Self::WebGPU(value) => Some(value),
744                    _ => None,
745                }
746            }
747
748            #[cfg(custom)]
749            #[inline]
750            pub fn custom<T: $interface>(t: T) -> Self {
751                Self::Custom($custom_type::new(t))
752            }
753        }
754
755        #[cfg(wgpu_core)]
756        impl From<$core_type> for $name {
757            #[inline]
758            fn from(value: $core_type) -> Self {
759                Self::Core(Arc::new(value))
760            }
761        }
762
763        #[cfg(webgpu)]
764        impl From<$webgpu_type> for $name {
765            #[inline]
766            fn from(value: $webgpu_type) -> Self {
767                Self::WebGPU(value)
768            }
769        }
770
771        impl core::ops::Deref for $name {
772            type Target = dyn $interface;
773
774            #[inline]
775            fn deref(&self) -> &Self::Target {
776                match self {
777                    #[cfg(wgpu_core)]
778                    Self::Core(value) => value.as_ref(),
779                    #[cfg(webgpu)]
780                    Self::WebGPU(value) => value,
781                    #[cfg(custom)]
782                    Self::Custom(value) => value.deref(),
783                    #[cfg(not(any(wgpu_core, webgpu)))]
784                    _ => panic!("No context available. You need to enable one of wgpu's backend feature build flags."),
785                }
786            }
787        }
788    };
789    (
790        mut type $name:ident: $interface:ident = $core_type:ident,$webgpu_type:ident,$custom_type:ident
791    ) => {
792        #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
793        pub enum $name {
794            #[cfg(wgpu_core)]
795            Core($core_type),
796            #[cfg(webgpu)]
797            WebGPU($webgpu_type),
798            #[allow(clippy::allow_attributes, private_interfaces)]
799            #[cfg(custom)]
800            Custom($custom_type),
801        }
802
803        impl $name {
804            #[cfg(wgpu_core)]
805            #[inline]
806            #[allow(clippy::allow_attributes, unused)]
807            pub fn as_core(&self) -> &$core_type {
808                match self {
809                    Self::Core(value) => value,
810                    _ => panic!(concat!(stringify!($name), " is not core")),
811                }
812            }
813
814            #[cfg(wgpu_core)]
815            #[inline]
816            #[allow(clippy::allow_attributes, unused)]
817            pub fn as_core_mut(&mut self) -> &mut $core_type {
818                match self {
819                    Self::Core(value) => value,
820                    _ => panic!(concat!(stringify!($name), " is not core")),
821                }
822            }
823
824            #[cfg(wgpu_core)]
825            #[inline]
826            #[allow(clippy::allow_attributes, unused)]
827            pub fn as_core_opt(&self) -> Option<&$core_type> {
828                match self {
829                    Self::Core(value) => Some(value),
830                    _ => None,
831                }
832            }
833
834            #[cfg(wgpu_core)]
835            #[inline]
836            #[allow(clippy::allow_attributes, unused)]
837            pub fn as_core_mut_opt(
838                &mut self,
839            ) -> Option<&mut $core_type> {
840                match self {
841                    Self::Core(value) => Some(value),
842                    _ => None,
843                }
844            }
845
846            #[cfg(custom)]
847            #[inline]
848            #[allow(clippy::allow_attributes, unused)]
849            pub fn as_custom<T: $interface>(&self) -> Option<&T> {
850                match self {
851                    Self::Custom(value) => value.downcast(),
852                    _ => None,
853                }
854            }
855
856            #[cfg(webgpu)]
857            #[inline]
858            #[allow(clippy::allow_attributes, unused)]
859            pub fn as_webgpu(&self) -> &$webgpu_type {
860                match self {
861                    Self::WebGPU(value) => value,
862                    _ => panic!(concat!(stringify!($name), " is not webgpu")),
863                }
864            }
865
866            #[cfg(webgpu)]
867            #[inline]
868            #[allow(clippy::allow_attributes, unused)]
869            pub fn as_webgpu_mut(&mut self) -> &mut $webgpu_type {
870                match self {
871                    Self::WebGPU(value) => value,
872                    _ => panic!(concat!(stringify!($name), " is not webgpu")),
873                }
874            }
875
876            #[cfg(webgpu)]
877            #[inline]
878            #[allow(clippy::allow_attributes, unused)]
879            pub fn as_webgpu_opt(&self) -> Option<&$webgpu_type> {
880                match self {
881                    Self::WebGPU(value) => Some(value),
882                    _ => None,
883                }
884            }
885
886            #[cfg(webgpu)]
887            #[inline]
888            #[allow(clippy::allow_attributes, unused)]
889            pub fn as_webgpu_mut_opt(
890                &mut self,
891            ) -> Option<&mut $webgpu_type> {
892                match self {
893                    Self::WebGPU(value) => Some(value),
894                    _ => None,
895                }
896            }
897
898            #[cfg(custom)]
899            #[inline]
900            pub fn custom<T: $interface>(t: T) -> Self {
901                Self::Custom($custom_type::new(t))
902            }
903        }
904
905        #[cfg(wgpu_core)]
906        impl From<$core_type> for $name {
907            #[inline]
908            fn from(value: $core_type) -> Self {
909                Self::Core(value)
910            }
911        }
912
913        #[cfg(webgpu)]
914        impl From<$webgpu_type> for $name {
915            #[inline]
916            fn from(value: $webgpu_type) -> Self {
917                Self::WebGPU(value)
918            }
919        }
920
921        impl core::ops::Deref for $name {
922            type Target = dyn $interface;
923
924            #[inline]
925            fn deref(&self) -> &Self::Target {
926                match self {
927                    #[cfg(wgpu_core)]
928                    Self::Core(value) => value,
929                    #[cfg(webgpu)]
930                    Self::WebGPU(value) => value,
931                    #[cfg(custom)]
932                    Self::Custom(value) => value.deref(),
933                    #[cfg(not(any(wgpu_core, webgpu)))]
934                    _ => panic!("No context available. You need to enable one of wgpu's backend feature build flags."),
935                }
936            }
937        }
938
939        impl core::ops::DerefMut for $name {
940            #[inline]
941            fn deref_mut(&mut self) -> &mut Self::Target {
942                match self {
943                    #[cfg(wgpu_core)]
944                    Self::Core(value) => value,
945                    #[cfg(webgpu)]
946                    Self::WebGPU(value) => value,
947                    #[cfg(custom)]
948                    Self::Custom(value) => value.deref_mut(),
949                    #[cfg(not(any(wgpu_core, webgpu)))]
950                    _ => panic!("No context available. You need to enable one of wgpu's backend feature build flags."),
951                }
952            }
953        }
954    };
955}
956
957dispatch_types! {ref type DispatchInstance: InstanceInterface = ContextWgpuCore, ContextWebGpu, DynContext}
958dispatch_types! {ref type DispatchAdapter: AdapterInterface = CoreAdapter, WebAdapter, DynAdapter}
959dispatch_types! {ref type DispatchDevice: DeviceInterface = CoreDevice, WebDevice, DynDevice}
960dispatch_types! {ref type DispatchQueue: QueueInterface = CoreQueue, WebQueue, DynQueue}
961dispatch_types! {ref type DispatchShaderModule: ShaderModuleInterface = CoreShaderModule, WebShaderModule, DynShaderModule}
962dispatch_types! {ref type DispatchBindGroupLayout: BindGroupLayoutInterface = CoreBindGroupLayout, WebBindGroupLayout, DynBindGroupLayout}
963dispatch_types! {ref type DispatchBindGroup: BindGroupInterface = CoreBindGroup, WebBindGroup, DynBindGroup}
964dispatch_types! {ref type DispatchTextureView: TextureViewInterface = CoreTextureView, WebTextureView, DynTextureView}
965dispatch_types! {ref type DispatchSampler: SamplerInterface = CoreSampler, WebSampler, DynSampler}
966dispatch_types! {ref type DispatchBuffer: BufferInterface = CoreBuffer, WebBuffer, DynBuffer}
967dispatch_types! {ref type DispatchTexture: TextureInterface = CoreTexture, WebTexture, DynTexture}
968dispatch_types! {ref type DispatchExternalTexture: ExternalTextureInterface = CoreExternalTexture, WebExternalTexture, DynExternalTexture}
969dispatch_types! {ref type DispatchBlas: BlasInterface = CoreBlas, WebBlas, DynBlas}
970dispatch_types! {ref type DispatchTlas: TlasInterface = CoreTlas, WebTlas, DynTlas}
971dispatch_types! {ref type DispatchQuerySet: QuerySetInterface = CoreQuerySet, WebQuerySet, DynQuerySet}
972dispatch_types! {ref type DispatchPipelineLayout: PipelineLayoutInterface = CorePipelineLayout, WebPipelineLayout, DynPipelineLayout}
973dispatch_types! {ref type DispatchRenderPipeline: RenderPipelineInterface = CoreRenderPipeline, WebRenderPipeline, DynRenderPipeline}
974dispatch_types! {ref type DispatchComputePipeline: ComputePipelineInterface = CoreComputePipeline, WebComputePipeline, DynComputePipeline}
975dispatch_types! {ref type DispatchPipelineCache: PipelineCacheInterface = CorePipelineCache, WebPipelineCache, DynPipelineCache}
976dispatch_types! {mut type DispatchCommandEncoder: CommandEncoderInterface = CoreCommandEncoder, WebCommandEncoder, DynCommandEncoder}
977dispatch_types! {mut type DispatchComputePass: ComputePassInterface = CoreComputePass, WebComputePassEncoder, DynComputePass}
978dispatch_types! {mut type DispatchRenderPass: RenderPassInterface = CoreRenderPass, WebRenderPassEncoder, DynRenderPass}
979dispatch_types! {mut type DispatchCommandBuffer: CommandBufferInterface = CoreCommandBuffer, WebCommandBuffer, DynCommandBuffer}
980dispatch_types! {mut type DispatchRenderBundleEncoder: RenderBundleEncoderInterface = CoreRenderBundleEncoder, WebRenderBundleEncoder, DynRenderBundleEncoder}
981dispatch_types! {ref type DispatchRenderBundle: RenderBundleInterface = CoreRenderBundle, WebRenderBundle, DynRenderBundle}
982dispatch_types! {ref type DispatchSurface: SurfaceInterface = CoreSurface, WebSurface, DynSurface}
983dispatch_types! {ref type DispatchSurfaceOutputDetail: SurfaceOutputDetailInterface = CoreSurfaceOutputDetail, WebSurfaceOutputDetail, DynSurfaceOutputDetail}
984dispatch_types! {mut type DispatchQueueWriteBuffer: QueueWriteBufferInterface = CoreQueueWriteBuffer, WebQueueWriteBuffer, DynQueueWriteBuffer}
985dispatch_types! {mut type DispatchBufferMappedRange: BufferMappedRangeInterface = CoreBufferMappedRange, WebBufferMappedRange, DynBufferMappedRange}
wgpu/dispatch.rs

wgpu/
dispatch.rs
