wgpu_types/
shader.rs

1use alloc::borrow::Cow;
2
3/// Describes how shader bound checks should be performed.
4#[derive(Copy, Clone, Debug)]
5#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
6pub struct ShaderRuntimeChecks {
7    /// Enforce bounds checks in shaders, even if the underlying driver doesn't
8    /// support doing so natively.
9    ///
10    /// When this is `true`, `wgpu` promises that shaders can only read or
11    /// write the accessible region of a bindgroup's buffer bindings. If
12    /// the underlying graphics platform cannot implement these bounds checks
13    /// itself, `wgpu` will inject bounds checks before presenting the
14    /// shader to the platform.
15    ///
16    /// When this is `false`, `wgpu` only enforces such bounds checks if the
17    /// underlying platform provides a way to do so itself. `wgpu` does not
18    /// itself add any bounds checks to generated shader code.
19    ///
20    /// Note that `wgpu` users may try to initialize only those portions of
21    /// buffers that they anticipate might be read from. Passing `false` here
22    /// may allow shaders to see wider regions of the buffers than expected,
23    /// making such deferred initialization visible to the application.
24    pub bounds_checks: bool,
25    ///
26    /// If false, the caller MUST ensure that all passed shaders do not contain any infinite loops.
27    ///
28    /// If it does, backend compilers MAY treat such a loop as unreachable code and draw
29    /// conclusions about other safety-critical code paths. This option SHOULD NOT be disabled
30    /// when running untrusted code.
31    pub force_loop_bounding: bool,
32    /// If false, the caller **MUST** ensure that in all passed shaders every function operating
33    /// on a ray query must obey these rules (functions using wgsl naming)
34    /// - `rayQueryInitialize` must have called before `rayQueryProceed`
35    /// - `rayQueryProceed` must have been called, returned true and have hit an AABB before
36    ///   `rayQueryGenerateIntersection` is called
37    /// - `rayQueryProceed` must have been called, returned true and have hit a triangle before
38    ///   `rayQueryConfirmIntersection` is called
39    /// - `rayQueryProceed` must have been called and have returned true before `rayQueryTerminate`,
40    ///   `getCandidateHitVertexPositions` or `rayQueryGetCandidateIntersection` is called
41    /// - `rayQueryProceed` must have been called and have returned false before `rayQueryGetCommittedIntersection`
42    ///   or `getCommittedHitVertexPositions` are called
43    ///
44    /// It is the aim that these cases will not cause UB if this is set to true, but currently this will still happen on DX12 and Metal.
45    pub ray_query_initialization_tracking: bool,
46
47    /// If false, task shaders will not validate that the mesh shader grid they dispatch is within legal limits.
48    pub task_shader_dispatch_tracking: bool,
49
50    /// If false, mesh shaders won't clamp the output primitives' vertex indices, which can lead to
51    /// undefined behavior and arbitrary memory access.
52    pub mesh_shader_primitive_indices_clamp: bool,
53}
54
55impl ShaderRuntimeChecks {
56    /// Creates a new configuration where the shader is fully checked.
57    #[must_use]
58    pub const fn checked() -> Self {
59        unsafe { Self::all(true) }
60    }
61
62    /// Creates a new configuration where none of the checks are performed.
63    ///
64    /// # Safety
65    ///
66    /// See the documentation for the `set_*` methods for the safety requirements
67    /// of each sub-configuration.
68    #[must_use]
69    pub const fn unchecked() -> Self {
70        unsafe { Self::all(false) }
71    }
72
73    /// Creates a new configuration where all checks are enabled or disabled. To safely
74    /// create a configuration with all checks enabled, use [`ShaderRuntimeChecks::checked`].
75    ///
76    /// # Safety
77    ///
78    /// See the documentation for the `set_*` methods for the safety requirements
79    /// of each sub-configuration.
80    #[must_use]
81    pub const unsafe fn all(all_checks: bool) -> Self {
82        Self {
83            bounds_checks: all_checks,
84            force_loop_bounding: all_checks,
85            ray_query_initialization_tracking: all_checks,
86            task_shader_dispatch_tracking: all_checks,
87            mesh_shader_primitive_indices_clamp: all_checks,
88        }
89    }
90}
91
92impl Default for ShaderRuntimeChecks {
93    fn default() -> Self {
94        Self::checked()
95    }
96}
97
98/// Descriptor for a shader module given by any of several sources.
99/// These shaders are passed through directly to the underlying api.
100/// At least one shader type that may be used by the backend must be `Some` or a panic is raised.
101#[derive(Debug, Clone)]
102#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
103pub struct CreateShaderModuleDescriptorPassthrough<'a, L> {
104    /// Debug label of the shader module. This will show up in graphics debuggers for easy identification.
105    pub label: L,
106    /// Number of workgroups in each dimension x, y and z. Unused for Spir-V.
107    pub num_workgroups: (u32, u32, u32),
108
109    /// Binary SPIR-V data, in 4-byte words.
110    pub spirv: Option<Cow<'a, [u32]>>,
111    /// Shader DXIL source.
112    pub dxil: Option<Cow<'a, [u8]>>,
113    /// Shader HLSL source.
114    pub hlsl: Option<Cow<'a, str>>,
115    /// Shader MetalLib source.
116    pub metallib: Option<Cow<'a, [u8]>>,
117    /// Shader MSL source.
118    pub msl: Option<Cow<'a, str>>,
119    /// Shader GLSL source (currently unused).
120    pub glsl: Option<Cow<'a, str>>,
121    /// Shader WGSL source.
122    pub wgsl: Option<Cow<'a, str>>,
123}
124
125// This is so people don't have to fill in fields they don't use, like num_workgroups,
126// entry_point, or other shader languages they didn't compile for
127impl<'a, L: Default> Default for CreateShaderModuleDescriptorPassthrough<'a, L> {
128    fn default() -> Self {
129        Self {
130            label: Default::default(),
131            num_workgroups: (0, 0, 0),
132            spirv: None,
133            dxil: None,
134            metallib: None,
135            msl: None,
136            hlsl: None,
137            glsl: None,
138            wgsl: None,
139        }
140    }
141}
142
143impl<'a, L> CreateShaderModuleDescriptorPassthrough<'a, L> {
144    /// Takes a closure and maps the label of the shader module descriptor into another.
145    pub fn map_label<K>(
146        &self,
147        fun: impl FnOnce(&L) -> K,
148    ) -> CreateShaderModuleDescriptorPassthrough<'a, K> {
149        CreateShaderModuleDescriptorPassthrough {
150            label: fun(&self.label),
151            num_workgroups: self.num_workgroups,
152            spirv: self.spirv.clone(),
153            metallib: self.metallib.clone(),
154            dxil: self.dxil.clone(),
155            msl: self.msl.clone(),
156            hlsl: self.hlsl.clone(),
157            glsl: self.glsl.clone(),
158            wgsl: self.wgsl.clone(),
159        }
160    }
161
162    #[cfg(feature = "trace")]
163    /// Returns the source data for tracing purpose.
164    pub fn trace_data(&self) -> &[u8] {
165        if let Some(spirv) = &self.spirv {
166            bytemuck::cast_slice(spirv)
167        } else if let Some(metallib) = &self.metallib {
168            metallib
169        } else if let Some(msl) = &self.msl {
170            msl.as_bytes()
171        } else if let Some(dxil) = &self.dxil {
172            dxil
173        } else if let Some(hlsl) = &self.hlsl {
174            hlsl.as_bytes()
175        } else if let Some(glsl) = &self.glsl {
176            glsl.as_bytes()
177        } else if let Some(wgsl) = &self.wgsl {
178            wgsl.as_bytes()
179        } else {
180            panic!("No binary data provided to `ShaderModuleDescriptorGeneric`")
181        }
182    }
183
184    #[cfg(feature = "trace")]
185    /// Returns the binary file extension for tracing purpose.
186    pub fn trace_binary_ext(&self) -> &'static str {
187        if self.spirv.is_some() {
188            "spv"
189        } else if self.metallib.is_some() {
190            "metallib"
191        } else if self.msl.is_some() {
192            "metal"
193        } else if self.dxil.is_some() {
194            "dxil"
195        } else if self.hlsl.is_some() {
196            "hlsl"
197        } else if self.glsl.is_some() {
198            "glsl"
199        } else if self.wgsl.is_some() {
200            "wgsl"
201        } else {
202            panic!("No binary data provided to `ShaderModuleDescriptorGeneric`")
203        }
204    }
205}