wgpu_core/
pipeline.rs

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
pub use crate::pipeline_cache::PipelineCacheValidationError;
use crate::{
    binding_model::{CreateBindGroupLayoutError, CreatePipelineLayoutError, PipelineLayout},
    command::ColorAttachmentError,
    device::{Device, DeviceError, MissingDownlevelFlags, MissingFeatures, RenderPassContext},
    id::{PipelineCacheId, PipelineLayoutId, ShaderModuleId},
    resource::{InvalidResourceError, Labeled, TrackingData},
    resource_log, validation, Label,
};
use arrayvec::ArrayVec;
use naga::error::ShaderError;
use std::{borrow::Cow, marker::PhantomData, mem::ManuallyDrop, num::NonZeroU32, sync::Arc};
use thiserror::Error;

/// Information about buffer bindings, which
/// is validated against the shader (and pipeline)
/// at draw time as opposed to initialization time.
#[derive(Debug)]
pub(crate) struct LateSizedBufferGroup {
    // The order has to match `BindGroup::late_buffer_binding_sizes`.
    pub(crate) shader_sizes: Vec<wgt::BufferAddress>,
}

#[allow(clippy::large_enum_variant)]
pub enum ShaderModuleSource<'a> {
    #[cfg(feature = "wgsl")]
    Wgsl(Cow<'a, str>),
    #[cfg(feature = "glsl")]
    Glsl(Cow<'a, str>, naga::front::glsl::Options),
    #[cfg(feature = "spirv")]
    SpirV(Cow<'a, [u32]>, naga::front::spv::Options),
    Naga(Cow<'static, naga::Module>),
    /// Dummy variant because `Naga` doesn't have a lifetime and without enough active features it
    /// could be the last one active.
    #[doc(hidden)]
    Dummy(PhantomData<&'a ()>),
}

#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct ShaderModuleDescriptor<'a> {
    pub label: Label<'a>,
    #[cfg_attr(feature = "serde", serde(default))]
    pub shader_bound_checks: wgt::ShaderBoundChecks,
}

#[derive(Debug)]
pub struct ShaderModule {
    pub(crate) raw: ManuallyDrop<Box<dyn hal::DynShaderModule>>,
    pub(crate) device: Arc<Device>,
    pub(crate) interface: Option<validation::Interface>,
    /// The `label` from the descriptor used to create the resource.
    pub(crate) label: String,
}

impl Drop for ShaderModule {
    fn drop(&mut self) {
        resource_log!("Destroy raw {}", self.error_ident());
        // SAFETY: We are in the Drop impl and we don't use self.raw anymore after this point.
        let raw = unsafe { ManuallyDrop::take(&mut self.raw) };
        unsafe {
            self.device.raw().destroy_shader_module(raw);
        }
    }
}

crate::impl_resource_type!(ShaderModule);
crate::impl_labeled!(ShaderModule);
crate::impl_parent_device!(ShaderModule);
crate::impl_storage_item!(ShaderModule);

impl ShaderModule {
    pub(crate) fn raw(&self) -> &dyn hal::DynShaderModule {
        self.raw.as_ref()
    }

    pub(crate) fn finalize_entry_point_name(
        &self,
        stage_bit: wgt::ShaderStages,
        entry_point: Option<&str>,
    ) -> Result<String, validation::StageError> {
        match &self.interface {
            Some(interface) => interface.finalize_entry_point_name(stage_bit, entry_point),
            None => entry_point
                .map(|ep| ep.to_string())
                .ok_or(validation::StageError::NoEntryPointFound),
        }
    }
}

//Note: `Clone` would require `WithSpan: Clone`.
#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum CreateShaderModuleError {
    #[cfg(any(feature = "wgsl", feature = "indirect-validation"))]
    #[error(transparent)]
    Parsing(#[from] ShaderError<naga::front::wgsl::ParseError>),
    #[cfg(feature = "glsl")]
    #[error(transparent)]
    ParsingGlsl(#[from] ShaderError<naga::front::glsl::ParseErrors>),
    #[cfg(feature = "spirv")]
    #[error(transparent)]
    ParsingSpirV(#[from] ShaderError<naga::front::spv::Error>),
    #[error("Failed to generate the backend-specific code")]
    Generation,
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error(transparent)]
    Validation(#[from] ShaderError<naga::WithSpan<naga::valid::ValidationError>>),
    #[error(transparent)]
    MissingFeatures(#[from] MissingFeatures),
    #[error(
        "Shader global {bind:?} uses a group index {group} that exceeds the max_bind_groups limit of {limit}."
    )]
    InvalidGroupIndex {
        bind: naga::ResourceBinding,
        group: u32,
        limit: u32,
    },
}

/// Describes a programmable pipeline stage.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct ProgrammableStageDescriptor<'a> {
    /// The compiled shader module for this stage.
    pub module: ShaderModuleId,
    /// The name of the entry point in the compiled shader. The name is selected using the
    /// following logic:
    ///
    /// * If `Some(name)` is specified, there must be a function with this name in the shader.
    /// * If a single entry point associated with this stage must be in the shader, then proceed as
    ///   if `Some(…)` was specified with that entry point's name.
    pub entry_point: Option<Cow<'a, str>>,
    /// Specifies the values of pipeline-overridable constants in the shader module.
    ///
    /// If an `@id` attribute was specified on the declaration,
    /// the key must be the pipeline constant ID as a decimal ASCII number; if not,
    /// the key must be the constant's identifier name.
    ///
    /// The value may represent any of WGSL's concrete scalar types.
    pub constants: Cow<'a, naga::back::PipelineConstants>,
    /// Whether workgroup scoped memory will be initialized with zero values for this stage.
    ///
    /// This is required by the WebGPU spec, but may have overhead which can be avoided
    /// for cross-platform applications
    pub zero_initialize_workgroup_memory: bool,
}

/// Describes a programmable pipeline stage.
#[derive(Clone, Debug)]
pub struct ResolvedProgrammableStageDescriptor<'a> {
    /// The compiled shader module for this stage.
    pub module: Arc<ShaderModule>,
    /// The name of the entry point in the compiled shader. The name is selected using the
    /// following logic:
    ///
    /// * If `Some(name)` is specified, there must be a function with this name in the shader.
    /// * If a single entry point associated with this stage must be in the shader, then proceed as
    ///   if `Some(…)` was specified with that entry point's name.
    pub entry_point: Option<Cow<'a, str>>,
    /// Specifies the values of pipeline-overridable constants in the shader module.
    ///
    /// If an `@id` attribute was specified on the declaration,
    /// the key must be the pipeline constant ID as a decimal ASCII number; if not,
    /// the key must be the constant's identifier name.
    ///
    /// The value may represent any of WGSL's concrete scalar types.
    pub constants: Cow<'a, naga::back::PipelineConstants>,
    /// Whether workgroup scoped memory will be initialized with zero values for this stage.
    ///
    /// This is required by the WebGPU spec, but may have overhead which can be avoided
    /// for cross-platform applications
    pub zero_initialize_workgroup_memory: bool,
}

/// Number of implicit bind groups derived at pipeline creation.
pub type ImplicitBindGroupCount = u8;

#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum ImplicitLayoutError {
    #[error("The implicit_pipeline_ids arg is required")]
    MissingImplicitPipelineIds,
    #[error("Missing IDs for deriving {0} bind groups")]
    MissingIds(ImplicitBindGroupCount),
    #[error("Unable to reflect the shader {0:?} interface")]
    ReflectionError(wgt::ShaderStages),
    #[error(transparent)]
    BindGroup(#[from] CreateBindGroupLayoutError),
    #[error(transparent)]
    Pipeline(#[from] CreatePipelineLayoutError),
}

/// Describes a compute pipeline.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct ComputePipelineDescriptor<'a> {
    pub label: Label<'a>,
    /// The layout of bind groups for this pipeline.
    pub layout: Option<PipelineLayoutId>,
    /// The compiled compute stage and its entry point.
    pub stage: ProgrammableStageDescriptor<'a>,
    /// The pipeline cache to use when creating this pipeline.
    pub cache: Option<PipelineCacheId>,
}

/// Describes a compute pipeline.
#[derive(Clone, Debug)]
pub struct ResolvedComputePipelineDescriptor<'a> {
    pub label: Label<'a>,
    /// The layout of bind groups for this pipeline.
    pub layout: Option<Arc<PipelineLayout>>,
    /// The compiled compute stage and its entry point.
    pub stage: ResolvedProgrammableStageDescriptor<'a>,
    /// The pipeline cache to use when creating this pipeline.
    pub cache: Option<Arc<PipelineCache>>,
}

#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum CreateComputePipelineError {
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error("Unable to derive an implicit layout")]
    Implicit(#[from] ImplicitLayoutError),
    #[error("Error matching shader requirements against the pipeline")]
    Stage(#[from] validation::StageError),
    #[error("Internal error: {0}")]
    Internal(String),
    #[error("Pipeline constant error: {0}")]
    PipelineConstants(String),
    #[error(transparent)]
    MissingDownlevelFlags(#[from] MissingDownlevelFlags),
    #[error(transparent)]
    InvalidResource(#[from] InvalidResourceError),
}

#[derive(Debug)]
pub struct ComputePipeline {
    pub(crate) raw: ManuallyDrop<Box<dyn hal::DynComputePipeline>>,
    pub(crate) layout: Arc<PipelineLayout>,
    pub(crate) device: Arc<Device>,
    pub(crate) _shader_module: Arc<ShaderModule>,
    pub(crate) late_sized_buffer_groups: ArrayVec<LateSizedBufferGroup, { hal::MAX_BIND_GROUPS }>,
    /// The `label` from the descriptor used to create the resource.
    pub(crate) label: String,
    pub(crate) tracking_data: TrackingData,
}

impl Drop for ComputePipeline {
    fn drop(&mut self) {
        resource_log!("Destroy raw {}", self.error_ident());
        // SAFETY: We are in the Drop impl and we don't use self.raw anymore after this point.
        let raw = unsafe { ManuallyDrop::take(&mut self.raw) };
        unsafe {
            self.device.raw().destroy_compute_pipeline(raw);
        }
    }
}

crate::impl_resource_type!(ComputePipeline);
crate::impl_labeled!(ComputePipeline);
crate::impl_parent_device!(ComputePipeline);
crate::impl_storage_item!(ComputePipeline);
crate::impl_trackable!(ComputePipeline);

impl ComputePipeline {
    pub(crate) fn raw(&self) -> &dyn hal::DynComputePipeline {
        self.raw.as_ref()
    }
}

#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum CreatePipelineCacheError {
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error("Pipeline cache validation failed")]
    Validation(#[from] PipelineCacheValidationError),
    #[error(transparent)]
    MissingFeatures(#[from] MissingFeatures),
    #[error("Internal error: {0}")]
    Internal(String),
}

#[derive(Debug)]
pub struct PipelineCache {
    pub(crate) raw: ManuallyDrop<Box<dyn hal::DynPipelineCache>>,
    pub(crate) device: Arc<Device>,
    /// The `label` from the descriptor used to create the resource.
    pub(crate) label: String,
}

impl Drop for PipelineCache {
    fn drop(&mut self) {
        resource_log!("Destroy raw {}", self.error_ident());
        // SAFETY: We are in the Drop impl and we don't use self.raw anymore after this point.
        let raw = unsafe { ManuallyDrop::take(&mut self.raw) };
        unsafe {
            self.device.raw().destroy_pipeline_cache(raw);
        }
    }
}

crate::impl_resource_type!(PipelineCache);
crate::impl_labeled!(PipelineCache);
crate::impl_parent_device!(PipelineCache);
crate::impl_storage_item!(PipelineCache);

impl PipelineCache {
    pub(crate) fn raw(&self) -> &dyn hal::DynPipelineCache {
        self.raw.as_ref()
    }
}

/// Describes how the vertex buffer is interpreted.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
#[cfg_attr(feature = "serde", serde(rename_all = "camelCase"))]
pub struct VertexBufferLayout<'a> {
    /// The stride, in bytes, between elements of this buffer.
    pub array_stride: wgt::BufferAddress,
    /// How often this vertex buffer is "stepped" forward.
    pub step_mode: wgt::VertexStepMode,
    /// The list of attributes which comprise a single vertex.
    pub attributes: Cow<'a, [wgt::VertexAttribute]>,
}

/// Describes the vertex process in a render pipeline.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct VertexState<'a> {
    /// The compiled vertex stage and its entry point.
    pub stage: ProgrammableStageDescriptor<'a>,
    /// The format of any vertex buffers used with this pipeline.
    pub buffers: Cow<'a, [VertexBufferLayout<'a>]>,
}

/// Describes the vertex process in a render pipeline.
#[derive(Clone, Debug)]
pub struct ResolvedVertexState<'a> {
    /// The compiled vertex stage and its entry point.
    pub stage: ResolvedProgrammableStageDescriptor<'a>,
    /// The format of any vertex buffers used with this pipeline.
    pub buffers: Cow<'a, [VertexBufferLayout<'a>]>,
}

/// Describes fragment processing in a render pipeline.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct FragmentState<'a> {
    /// The compiled fragment stage and its entry point.
    pub stage: ProgrammableStageDescriptor<'a>,
    /// The effect of draw calls on the color aspect of the output target.
    pub targets: Cow<'a, [Option<wgt::ColorTargetState>]>,
}

/// Describes fragment processing in a render pipeline.
#[derive(Clone, Debug)]
pub struct ResolvedFragmentState<'a> {
    /// The compiled fragment stage and its entry point.
    pub stage: ResolvedProgrammableStageDescriptor<'a>,
    /// The effect of draw calls on the color aspect of the output target.
    pub targets: Cow<'a, [Option<wgt::ColorTargetState>]>,
}

/// Describes a render (graphics) pipeline.
#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct RenderPipelineDescriptor<'a> {
    pub label: Label<'a>,
    /// The layout of bind groups for this pipeline.
    pub layout: Option<PipelineLayoutId>,
    /// The vertex processing state for this pipeline.
    pub vertex: VertexState<'a>,
    /// The properties of the pipeline at the primitive assembly and rasterization level.
    #[cfg_attr(feature = "serde", serde(default))]
    pub primitive: wgt::PrimitiveState,
    /// The effect of draw calls on the depth and stencil aspects of the output target, if any.
    #[cfg_attr(feature = "serde", serde(default))]
    pub depth_stencil: Option<wgt::DepthStencilState>,
    /// The multi-sampling properties of the pipeline.
    #[cfg_attr(feature = "serde", serde(default))]
    pub multisample: wgt::MultisampleState,
    /// The fragment processing state for this pipeline.
    pub fragment: Option<FragmentState<'a>>,
    /// If the pipeline will be used with a multiview render pass, this indicates how many array
    /// layers the attachments will have.
    pub multiview: Option<NonZeroU32>,
    /// The pipeline cache to use when creating this pipeline.
    pub cache: Option<PipelineCacheId>,
}

/// Describes a render (graphics) pipeline.
#[derive(Clone, Debug)]
pub struct ResolvedRenderPipelineDescriptor<'a> {
    pub label: Label<'a>,
    /// The layout of bind groups for this pipeline.
    pub layout: Option<Arc<PipelineLayout>>,
    /// The vertex processing state for this pipeline.
    pub vertex: ResolvedVertexState<'a>,
    /// The properties of the pipeline at the primitive assembly and rasterization level.
    pub primitive: wgt::PrimitiveState,
    /// The effect of draw calls on the depth and stencil aspects of the output target, if any.
    pub depth_stencil: Option<wgt::DepthStencilState>,
    /// The multi-sampling properties of the pipeline.
    pub multisample: wgt::MultisampleState,
    /// The fragment processing state for this pipeline.
    pub fragment: Option<ResolvedFragmentState<'a>>,
    /// If the pipeline will be used with a multiview render pass, this indicates how many array
    /// layers the attachments will have.
    pub multiview: Option<NonZeroU32>,
    /// The pipeline cache to use when creating this pipeline.
    pub cache: Option<Arc<PipelineCache>>,
}

#[derive(Clone, Debug)]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct PipelineCacheDescriptor<'a> {
    pub label: Label<'a>,
    pub data: Option<Cow<'a, [u8]>>,
    pub fallback: bool,
}

#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum ColorStateError {
    #[error("Format {0:?} is not renderable")]
    FormatNotRenderable(wgt::TextureFormat),
    #[error("Format {0:?} is not blendable")]
    FormatNotBlendable(wgt::TextureFormat),
    #[error("Format {0:?} does not have a color aspect")]
    FormatNotColor(wgt::TextureFormat),
    #[error("Sample count {0} is not supported by format {1:?} on this device. The WebGPU spec guarantees {2:?} samples are supported by this format. With the TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES feature your device supports {3:?}.")]
    InvalidSampleCount(u32, wgt::TextureFormat, Vec<u32>, Vec<u32>),
    #[error("Output format {pipeline} is incompatible with the shader {shader}")]
    IncompatibleFormat {
        pipeline: validation::NumericType,
        shader: validation::NumericType,
    },
    #[error("Blend factors for {0:?} must be `One`")]
    InvalidMinMaxBlendFactors(wgt::BlendComponent),
    #[error("Invalid write mask {0:?}")]
    InvalidWriteMask(wgt::ColorWrites),
}

#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum DepthStencilStateError {
    #[error("Format {0:?} is not renderable")]
    FormatNotRenderable(wgt::TextureFormat),
    #[error("Format {0:?} does not have a depth aspect, but depth test/write is enabled")]
    FormatNotDepth(wgt::TextureFormat),
    #[error("Format {0:?} does not have a stencil aspect, but stencil test/write is enabled")]
    FormatNotStencil(wgt::TextureFormat),
    #[error("Sample count {0} is not supported by format {1:?} on this device. The WebGPU spec guarantees {2:?} samples are supported by this format. With the TEXTURE_ADAPTER_SPECIFIC_FORMAT_FEATURES feature your device supports {3:?}.")]
    InvalidSampleCount(u32, wgt::TextureFormat, Vec<u32>, Vec<u32>),
}

#[derive(Clone, Debug, Error)]
#[non_exhaustive]
pub enum CreateRenderPipelineError {
    #[error(transparent)]
    ColorAttachment(#[from] ColorAttachmentError),
    #[error(transparent)]
    Device(#[from] DeviceError),
    #[error("Unable to derive an implicit layout")]
    Implicit(#[from] ImplicitLayoutError),
    #[error("Color state [{0}] is invalid")]
    ColorState(u8, #[source] ColorStateError),
    #[error("Depth/stencil state is invalid")]
    DepthStencilState(#[from] DepthStencilStateError),
    #[error("Invalid sample count {0}")]
    InvalidSampleCount(u32),
    #[error("The number of vertex buffers {given} exceeds the limit {limit}")]
    TooManyVertexBuffers { given: u32, limit: u32 },
    #[error("The total number of vertex attributes {given} exceeds the limit {limit}")]
    TooManyVertexAttributes { given: u32, limit: u32 },
    #[error("Vertex buffer {index} stride {given} exceeds the limit {limit}")]
    VertexStrideTooLarge { index: u32, given: u32, limit: u32 },
    #[error("Vertex buffer {index} stride {stride} does not respect `VERTEX_STRIDE_ALIGNMENT`")]
    UnalignedVertexStride {
        index: u32,
        stride: wgt::BufferAddress,
    },
    #[error("Vertex attribute at location {location} has invalid offset {offset}")]
    InvalidVertexAttributeOffset {
        location: wgt::ShaderLocation,
        offset: wgt::BufferAddress,
    },
    #[error("Two or more vertex attributes were assigned to the same location in the shader: {0}")]
    ShaderLocationClash(u32),
    #[error("Strip index format was not set to None but to {strip_index_format:?} while using the non-strip topology {topology:?}")]
    StripIndexFormatForNonStripTopology {
        strip_index_format: Option<wgt::IndexFormat>,
        topology: wgt::PrimitiveTopology,
    },
    #[error("Conservative Rasterization is only supported for wgt::PolygonMode::Fill")]
    ConservativeRasterizationNonFillPolygonMode,
    #[error(transparent)]
    MissingFeatures(#[from] MissingFeatures),
    #[error(transparent)]
    MissingDownlevelFlags(#[from] MissingDownlevelFlags),
    #[error("Error matching {stage:?} shader requirements against the pipeline")]
    Stage {
        stage: wgt::ShaderStages,
        #[source]
        error: validation::StageError,
    },
    #[error("Internal error in {stage:?} shader: {error}")]
    Internal {
        stage: wgt::ShaderStages,
        error: String,
    },
    #[error("Pipeline constant error in {stage:?} shader: {error}")]
    PipelineConstants {
        stage: wgt::ShaderStages,
        error: String,
    },
    #[error("In the provided shader, the type given for group {group} binding {binding} has a size of {size}. As the device does not support `DownlevelFlags::BUFFER_BINDINGS_NOT_16_BYTE_ALIGNED`, the type must have a size that is a multiple of 16 bytes.")]
    UnalignedShader { group: u32, binding: u32, size: u64 },
    #[error("Using the blend factor {factor:?} for render target {target} is not possible. Only the first render target may be used when dual-source blending.")]
    BlendFactorOnUnsupportedTarget {
        factor: wgt::BlendFactor,
        target: u32,
    },
    #[error("Pipeline expects the shader entry point to make use of dual-source blending.")]
    PipelineExpectsShaderToUseDualSourceBlending,
    #[error("Shader entry point expects the pipeline to make use of dual-source blending.")]
    ShaderExpectsPipelineToUseDualSourceBlending,
    #[error("{}", concat!(
        "At least one color attachment or depth-stencil attachment was expected, ",
        "but no render target for the pipeline was specified."
    ))]
    NoTargetSpecified,
    #[error(transparent)]
    InvalidResource(#[from] InvalidResourceError),
}

bitflags::bitflags! {
    #[repr(transparent)]
    #[derive(Debug, Copy, Clone, PartialEq, Eq, Hash)]
    pub struct PipelineFlags: u32 {
        const BLEND_CONSTANT = 1 << 0;
        const STENCIL_REFERENCE = 1 << 1;
        const WRITES_DEPTH = 1 << 2;
        const WRITES_STENCIL = 1 << 3;
    }
}

/// How a render pipeline will retrieve attributes from a particular vertex buffer.
#[derive(Clone, Copy, Debug)]
pub struct VertexStep {
    /// The byte stride in the buffer between one attribute value and the next.
    pub stride: wgt::BufferAddress,

    /// The byte size required to fit the last vertex in the stream.
    pub last_stride: wgt::BufferAddress,

    /// Whether the buffer is indexed by vertex number or instance number.
    pub mode: wgt::VertexStepMode,
}

impl Default for VertexStep {
    fn default() -> Self {
        Self {
            stride: 0,
            last_stride: 0,
            mode: wgt::VertexStepMode::Vertex,
        }
    }
}

#[derive(Debug)]
pub struct RenderPipeline {
    pub(crate) raw: ManuallyDrop<Box<dyn hal::DynRenderPipeline>>,
    pub(crate) device: Arc<Device>,
    pub(crate) layout: Arc<PipelineLayout>,
    pub(crate) _shader_modules: ArrayVec<Arc<ShaderModule>, { hal::MAX_CONCURRENT_SHADER_STAGES }>,
    pub(crate) pass_context: RenderPassContext,
    pub(crate) flags: PipelineFlags,
    pub(crate) strip_index_format: Option<wgt::IndexFormat>,
    pub(crate) vertex_steps: Vec<VertexStep>,
    pub(crate) late_sized_buffer_groups: ArrayVec<LateSizedBufferGroup, { hal::MAX_BIND_GROUPS }>,
    /// The `label` from the descriptor used to create the resource.
    pub(crate) label: String,
    pub(crate) tracking_data: TrackingData,
}

impl Drop for RenderPipeline {
    fn drop(&mut self) {
        resource_log!("Destroy raw {}", self.error_ident());
        // SAFETY: We are in the Drop impl and we don't use self.raw anymore after this point.
        let raw = unsafe { ManuallyDrop::take(&mut self.raw) };
        unsafe {
            self.device.raw().destroy_render_pipeline(raw);
        }
    }
}

crate::impl_resource_type!(RenderPipeline);
crate::impl_labeled!(RenderPipeline);
crate::impl_parent_device!(RenderPipeline);
crate::impl_storage_item!(RenderPipeline);
crate::impl_trackable!(RenderPipeline);

impl RenderPipeline {
    pub(crate) fn raw(&self) -> &dyn hal::DynRenderPipeline {
        self.raw.as_ref()
    }
}