wgpu/api/
render_bundle_encoder.rs

1use core::{marker::PhantomData, num::NonZeroU32, ops::Range};
2
3use crate::dispatch::RenderBundleEncoderInterface;
4use crate::*;
5
6/// Encodes a series of GPU operations into a reusable "render bundle".
7///
8/// It only supports a handful of render commands, but it makes them reusable.
9/// It can be created with [`Device::create_render_bundle_encoder`].
10/// It can be executed onto a [`CommandEncoder`] using [`RenderPass::execute_bundles`].
11///
12/// Executing a [`RenderBundle`] is often more efficient than issuing the underlying commands
13/// manually.
14///
15/// Corresponds to [WebGPU `GPURenderBundleEncoder`](
16/// https://gpuweb.github.io/gpuweb/#gpurenderbundleencoder).
17#[derive(Debug)]
18pub struct RenderBundleEncoder<'a> {
19    pub(crate) inner: dispatch::DispatchRenderBundleEncoder,
20    /// This type should be !Send !Sync, because it represents an allocation on this thread's
21    /// command buffer.
22    pub(crate) _p: PhantomData<(*const u8, &'a ())>,
23}
24static_assertions::assert_not_impl_any!(RenderBundleEncoder<'_>: Send, Sync);
25
26crate::cmp::impl_eq_ord_hash_proxy!(RenderBundleEncoder<'_> => .inner);
27
28/// Describes a [`RenderBundleEncoder`].
29///
30/// For use with [`Device::create_render_bundle_encoder`].
31///
32/// Corresponds to [WebGPU `GPURenderBundleEncoderDescriptor`](
33/// https://gpuweb.github.io/gpuweb/#dictdef-gpurenderbundleencoderdescriptor).
34#[derive(Clone, Debug, Default, PartialEq, Eq, Hash)]
35pub struct RenderBundleEncoderDescriptor<'a> {
36    /// Debug label of the render bundle encoder. This will show up in graphics debuggers for easy identification.
37    pub label: Label<'a>,
38    /// The formats of the color attachments that this render bundle is capable to rendering to. This
39    /// must match the formats of the color attachments in the render pass this render bundle is executed in.
40    pub color_formats: &'a [Option<TextureFormat>],
41    /// Information about the depth attachment that this render bundle is capable to rendering to. This
42    /// must match the format of the depth attachments in the render pass this render bundle is executed in.
43    pub depth_stencil: Option<RenderBundleDepthStencil>,
44    /// Sample count this render bundle is capable of rendering to. This must match the pipelines and
45    /// the render passes it is used in.
46    pub sample_count: u32,
47    /// If this render bundle will rendering to multiple array layers in the attachments at the same time.
48    pub multiview: Option<NonZeroU32>,
49}
50static_assertions::assert_impl_all!(RenderBundleEncoderDescriptor<'_>: Send, Sync);
51
52impl<'a> RenderBundleEncoder<'a> {
53    /// Finishes recording and returns a [`RenderBundle`] that can be executed in other render passes.
54    pub fn finish(self, desc: &RenderBundleDescriptor<'_>) -> RenderBundle {
55        let bundle = match self.inner {
56            #[cfg(wgpu_core)]
57            dispatch::DispatchRenderBundleEncoder::Core(b) => b.finish(desc),
58            #[cfg(webgpu)]
59            dispatch::DispatchRenderBundleEncoder::WebGPU(b) => b.finish(desc),
60            #[cfg(custom)]
61            dispatch::DispatchRenderBundleEncoder::Custom(_) => unimplemented!(),
62        };
63
64        RenderBundle { inner: bundle }
65    }
66
67    /// Sets the active bind group for a given bind group index. The bind group layout
68    /// in the active pipeline when any `draw()` function is called must match the layout of this bind group.
69    ///
70    /// If the bind group have dynamic offsets, provide them in the binding order.
71    pub fn set_bind_group<'b, BG>(&mut self, index: u32, bind_group: BG, offsets: &[DynamicOffset])
72    where
73        Option<&'b BindGroup>: From<BG>,
74    {
75        let bg: Option<&'b BindGroup> = bind_group.into();
76        let bg = bg.map(|x| &x.inner);
77        self.inner.set_bind_group(index, bg, offsets);
78    }
79
80    /// Sets the active render pipeline.
81    ///
82    /// Subsequent draw calls will exhibit the behavior defined by `pipeline`.
83    pub fn set_pipeline(&mut self, pipeline: &'a RenderPipeline) {
84        self.inner.set_pipeline(&pipeline.inner);
85    }
86
87    /// Sets the active index buffer.
88    ///
89    /// Subsequent calls to [`draw_indexed`](RenderBundleEncoder::draw_indexed) on this [`RenderBundleEncoder`] will
90    /// use `buffer` as the source index buffer.
91    pub fn set_index_buffer(&mut self, buffer_slice: BufferSlice<'a>, index_format: IndexFormat) {
92        self.inner.set_index_buffer(
93            &buffer_slice.buffer.inner,
94            index_format,
95            buffer_slice.offset,
96            Some(buffer_slice.size),
97        );
98    }
99
100    /// Assign a vertex buffer to a slot.
101    ///
102    /// Subsequent calls to [`draw`] and [`draw_indexed`] on this
103    /// [`RenderBundleEncoder`] will use `buffer` as one of the source vertex buffers.
104    ///
105    /// The `slot` refers to the index of the matching descriptor in
106    /// [`VertexState::buffers`].
107    ///
108    /// [`draw`]: RenderBundleEncoder::draw
109    /// [`draw_indexed`]: RenderBundleEncoder::draw_indexed
110    pub fn set_vertex_buffer(&mut self, slot: u32, buffer_slice: BufferSlice<'a>) {
111        self.inner.set_vertex_buffer(
112            slot,
113            &buffer_slice.buffer.inner,
114            buffer_slice.offset,
115            Some(buffer_slice.size),
116        );
117    }
118
119    /// Draws primitives from the active vertex buffer(s).
120    ///
121    /// The active vertex buffers can be set with [`RenderBundleEncoder::set_vertex_buffer`].
122    /// Does not use an Index Buffer. If you need this see [`RenderBundleEncoder::draw_indexed`]
123    ///
124    /// Panics if vertices Range is outside of the range of the vertices range of any set vertex buffer.
125    ///
126    /// vertices: The range of vertices to draw.
127    /// instances: Range of Instances to draw. Use 0..1 if instance buffers are not used.
128    /// E.g.of how its used internally
129    /// ```rust ignore
130    /// for instance_id in instance_range {
131    ///     for vertex_id in vertex_range {
132    ///         let vertex = vertex[vertex_id];
133    ///         vertex_shader(vertex, vertex_id, instance_id);
134    ///     }
135    /// }
136    /// ```
137    pub fn draw(&mut self, vertices: Range<u32>, instances: Range<u32>) {
138        self.inner.draw(vertices, instances);
139    }
140
141    /// Draws indexed primitives using the active index buffer and the active vertex buffer(s).
142    ///
143    /// The active index buffer can be set with [`RenderBundleEncoder::set_index_buffer`].
144    /// The active vertex buffer(s) can be set with [`RenderBundleEncoder::set_vertex_buffer`].
145    ///
146    /// Panics if indices Range is outside of the range of the indices range of any set index buffer.
147    ///
148    /// indices: The range of indices to draw.
149    /// base_vertex: value added to each index value before indexing into the vertex buffers.
150    /// instances: Range of Instances to draw. Use 0..1 if instance buffers are not used.
151    /// E.g.of how its used internally
152    /// ```rust ignore
153    /// for instance_id in instance_range {
154    ///     for index_index in index_range {
155    ///         let vertex_id = index_buffer[index_index];
156    ///         let adjusted_vertex_id = vertex_id + base_vertex;
157    ///         let vertex = vertex[adjusted_vertex_id];
158    ///         vertex_shader(vertex, adjusted_vertex_id, instance_id);
159    ///     }
160    /// }
161    /// ```
162    pub fn draw_indexed(&mut self, indices: Range<u32>, base_vertex: i32, instances: Range<u32>) {
163        self.inner.draw_indexed(indices, base_vertex, instances);
164    }
165
166    /// Draws primitives from the active vertex buffer(s) based on the contents of the `indirect_buffer`.
167    ///
168    /// The active vertex buffers can be set with [`RenderBundleEncoder::set_vertex_buffer`].
169    ///
170    /// The structure expected in `indirect_buffer` must conform to [`DrawIndirectArgs`](crate::util::DrawIndirectArgs).
171    pub fn draw_indirect(&mut self, indirect_buffer: &'a Buffer, indirect_offset: BufferAddress) {
172        self.inner
173            .draw_indirect(&indirect_buffer.inner, indirect_offset);
174    }
175
176    /// Draws indexed primitives using the active index buffer and the active vertex buffers,
177    /// based on the contents of the `indirect_buffer`.
178    ///
179    /// The active index buffer can be set with [`RenderBundleEncoder::set_index_buffer`], while the active
180    /// vertex buffers can be set with [`RenderBundleEncoder::set_vertex_buffer`].
181    ///
182    /// The structure expected in `indirect_buffer` must conform to [`DrawIndexedIndirectArgs`](crate::util::DrawIndexedIndirectArgs).
183    pub fn draw_indexed_indirect(
184        &mut self,
185        indirect_buffer: &'a Buffer,
186        indirect_offset: BufferAddress,
187    ) {
188        self.inner
189            .draw_indexed_indirect(&indirect_buffer.inner, indirect_offset);
190    }
191
192    #[cfg(custom)]
193    /// Returns custom implementation of RenderBundleEncoder (if custom backend and is internally T)
194    pub fn as_custom<T: custom::RenderBundleEncoderInterface>(&self) -> Option<&T> {
195        self.inner.as_custom()
196    }
197}
198
199/// [`Features::PUSH_CONSTANTS`] must be enabled on the device in order to call these functions.
200impl RenderBundleEncoder<'_> {
201    /// Set push constant data.
202    ///
203    /// Offset is measured in bytes, but must be a multiple of [`PUSH_CONSTANT_ALIGNMENT`].
204    ///
205    /// Data size must be a multiple of 4 and must have an alignment of 4.
206    /// For example, with an offset of 4 and an array of `[u8; 8]`, that will write to the range
207    /// of 4..12.
208    ///
209    /// For each byte in the range of push constant data written, the union of the stages of all push constant
210    /// ranges that covers that byte must be exactly `stages`. There's no good way of explaining this simply,
211    /// so here are some examples:
212    ///
213    /// ```text
214    /// For the given ranges:
215    /// - 0..4 Vertex
216    /// - 4..8 Fragment
217    /// ```
218    ///
219    /// You would need to upload this in two set_push_constants calls. First for the `Vertex` range, second for the `Fragment` range.
220    ///
221    /// ```text
222    /// For the given ranges:
223    /// - 0..8  Vertex
224    /// - 4..12 Fragment
225    /// ```
226    ///
227    /// You would need to upload this in three set_push_constants calls. First for the `Vertex` only range 0..4, second
228    /// for the `Vertex | Fragment` range 4..8, third for the `Fragment` range 8..12.
229    pub fn set_push_constants(&mut self, stages: ShaderStages, offset: u32, data: &[u8]) {
230        self.inner.set_push_constants(stages, offset, data);
231    }
232}