wgpu/api/
adapter.rs

1use core::future::Future;
2#[cfg(wgpu_core)]
3use core::ops::Deref;
4
5use crate::*;
6
7/// Handle to a physical graphics and/or compute device.
8///
9/// Adapters can be created using [`Instance::request_adapter`]
10/// or other [`Instance`] methods.
11///
12/// Adapters can be used to open a connection to the corresponding [`Device`]
13/// on the host system by using [`Adapter::request_device`].
14///
15/// Does not have to be kept alive.
16///
17/// Corresponds to [WebGPU `GPUAdapter`](https://gpuweb.github.io/gpuweb/#gpu-adapter).
18#[derive(Debug, Clone)]
19pub struct Adapter {
20    pub(crate) inner: dispatch::DispatchAdapter,
21}
22#[cfg(send_sync)]
23static_assertions::assert_impl_all!(Adapter: Send, Sync);
24
25crate::cmp::impl_eq_ord_hash_proxy!(Adapter => .inner);
26
27pub use wgt::RequestAdapterOptions as RequestAdapterOptionsBase;
28/// Additional information required when requesting an adapter.
29///
30/// For use with [`Instance::request_adapter`].
31///
32/// Corresponds to [WebGPU `GPURequestAdapterOptions`](
33/// https://gpuweb.github.io/gpuweb/#dictdef-gpurequestadapteroptions).
34pub type RequestAdapterOptions<'a, 'b> = RequestAdapterOptionsBase<&'a Surface<'b>>;
35#[cfg(send_sync)]
36static_assertions::assert_impl_all!(RequestAdapterOptions<'_, '_>: Send, Sync);
37
38impl Adapter {
39    /// Requests a connection to a physical device, creating a logical device.
40    ///
41    /// Returns the [`Device`] together with a [`Queue`] that executes command buffers.
42    ///
43    /// [Per the WebGPU specification], an [`Adapter`] may only be used once to create a device.
44    /// If another device is wanted, call [`Instance::request_adapter()`] again to get a fresh
45    /// [`Adapter`].
46    /// However, `wgpu` does not currently enforce this restriction.
47    ///
48    /// # Panics
49    ///
50    /// - `request_device()` was already called on this `Adapter`.
51    /// - Features specified by `desc` are not supported by this adapter.
52    /// - Unsafe features were requested but not enabled when requesting the adapter.
53    /// - Limits requested exceed the values provided by the adapter.
54    /// - Adapter does not support all features wgpu requires to safely operate.
55    ///
56    /// [Per the WebGPU specification]: https://www.w3.org/TR/webgpu/#dom-gpuadapter-requestdevice
57    pub fn request_device(
58        &self,
59        desc: &DeviceDescriptor<'_>,
60    ) -> impl Future<Output = Result<(Device, Queue), RequestDeviceError>> + WasmNotSend {
61        let device = self.inner.request_device(desc);
62        async move {
63            device
64                .await
65                .map(|(device, queue)| (Device { inner: device }, Queue { inner: queue }))
66        }
67    }
68
69    /// Create a wgpu [`Device`] and [`Queue`] from a wgpu-hal [`hal::OpenDevice`].
70    ///
71    /// # Safety
72    ///
73    /// - `hal_device` must be created from this adapter internal handle.
74    /// - `desc.features` must be a subset of `hal_device`'s supported features.
75    #[cfg(wgpu_core)]
76    pub unsafe fn create_device_from_hal<A: hal::Api>(
77        &self,
78        hal_device: hal::OpenDevice<A>,
79        desc: &DeviceDescriptor<'_>,
80    ) -> Result<(Device, Queue), RequestDeviceError> {
81        let core_adapter = self.inner.as_core();
82        let (device, queue) = unsafe {
83            core_adapter
84                .context
85                .create_device_from_hal(core_adapter, hal_device, desc)
86        }?;
87
88        Ok((
89            Device {
90                inner: device.into(),
91            },
92            Queue {
93                inner: queue.into(),
94            },
95        ))
96    }
97
98    /// Get the [`wgpu_hal`] adapter from this `Adapter`.
99    ///
100    /// Find the Api struct corresponding to the active backend in [`wgpu_hal::api`],
101    /// and pass that struct to the to the `A` type parameter.
102    ///
103    /// Returns a guard that dereferences to the type of the hal backend
104    /// which implements [`A::Adapter`].
105    ///
106    /// # Types
107    ///
108    /// The returned type depends on the backend:
109    ///
110    #[doc = crate::hal_type_vulkan!("Adapter")]
111    #[doc = crate::hal_type_metal!("Adapter")]
112    #[doc = crate::hal_type_dx12!("Adapter")]
113    #[doc = crate::hal_type_gles!("Adapter")]
114    ///
115    /// # Errors
116    ///
117    /// This method will return None if:
118    /// - The adapter is not from the backend specified by `A`.
119    /// - The adapter is from the `webgpu` or `custom` backend.
120    ///
121    /// # Safety
122    ///
123    /// - The returned resource must not be destroyed unless the guard
124    ///   is the last reference to it and it is not in use by the GPU.
125    ///   The guard and handle may be dropped at any time however.
126    /// - All the safety requirements of wgpu-hal must be upheld.
127    ///
128    /// [`A::Adapter`]: hal::Api::Adapter
129    #[cfg(wgpu_core)]
130    pub unsafe fn as_hal<A: hal::Api>(
131        &self,
132    ) -> Option<impl Deref<Target = A::Adapter> + WasmNotSendSync> {
133        let adapter = self.inner.as_core_opt()?;
134
135        unsafe { adapter.context.adapter_as_hal::<A>(adapter) }
136    }
137
138    #[cfg(custom)]
139    /// Returns custom implementation of adapter (if custom backend and is internally T)
140    pub fn as_custom<T: custom::AdapterInterface>(&self) -> Option<&T> {
141        self.inner.as_custom()
142    }
143
144    #[cfg(custom)]
145    /// Creates Adapter from custom implementation
146    pub fn from_custom<T: custom::AdapterInterface>(adapter: T) -> Self {
147        Self {
148            inner: dispatch::DispatchAdapter::custom(adapter),
149        }
150    }
151
152    /// Returns whether this adapter may present to the passed surface.
153    pub fn is_surface_supported(&self, surface: &Surface<'_>) -> bool {
154        self.inner.is_surface_supported(&surface.inner)
155    }
156
157    /// The features which can be used to create devices on this adapter.
158    pub fn features(&self) -> Features {
159        self.inner.features()
160    }
161
162    /// The best limits which can be used to create devices on this adapter.
163    pub fn limits(&self) -> Limits {
164        self.inner.limits()
165    }
166
167    /// Get info about the adapter itself.
168    pub fn get_info(&self) -> AdapterInfo {
169        self.inner.get_info()
170    }
171
172    /// Get info about the adapter itself.
173    pub fn get_downlevel_capabilities(&self) -> DownlevelCapabilities {
174        self.inner.downlevel_capabilities()
175    }
176
177    /// Returns the features supported for a given texture format by this adapter.
178    ///
179    /// Note that the WebGPU spec further restricts the available usages/features.
180    /// To disable these restrictions on a device, request the [`Features::TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES`] feature.
181    pub fn get_texture_format_features(&self, format: TextureFormat) -> TextureFormatFeatures {
182        self.inner.get_texture_format_features(format)
183    }
184
185    /// Generates a timestamp using the clock used by the presentation engine.
186    ///
187    /// When comparing completely opaque timestamp systems, we need a way of generating timestamps that signal
188    /// the exact same time. You can do this by calling your own timestamp function immediately after a call to
189    /// this function. This should result in timestamps that are 0.5 to 5 microseconds apart. There are locks
190    /// that must be taken during the call, so don't call your function before.
191    ///
192    /// ```no_run
193    /// # let adapter: wgpu::Adapter = panic!();
194    /// # let some_code = || wgpu::PresentationTimestamp::INVALID_TIMESTAMP;
195    /// use std::time::{Duration, Instant};
196    /// let presentation = adapter.get_presentation_timestamp();
197    /// let instant = Instant::now();
198    ///
199    /// // We can now turn a new presentation timestamp into an Instant.
200    /// let some_pres_timestamp = some_code();
201    /// let duration = Duration::from_nanos((some_pres_timestamp.0 - presentation.0) as u64);
202    /// let new_instant: Instant = instant + duration;
203    /// ```
204    //
205    /// [Instant]: std::time::Instant
206    pub fn get_presentation_timestamp(&self) -> PresentationTimestamp {
207        self.inner.get_presentation_timestamp()
208    }
209}