wgpu/
macros.rs

1//! Convenience macros
2
3#[cfg(doc)]
4use crate::{VertexAttribute, VertexBufferLayout, VertexFormat};
5
6/// Macro to produce an array of [`VertexAttribute`].
7///
8/// The input is a sequence of pairs of shader locations (expression of type [`u32`]) and
9/// variant names of [`VertexFormat`].
10///
11/// The return value has type `[VertexAttribute; N]`, where `N` is the number of inputs.
12///
13/// Offsets are calculated automatically,
14/// using the assumption that there is no padding or other data between attributes.
15///
16/// # Example
17///
18/// ```
19/// // Suppose that this is our vertex format:
20/// #[repr(C, packed)]
21/// struct Vertex {
22///     foo: [f32; 2],
23///     bar: f32,
24///     baz: [u16; 4],
25/// }
26///
27/// // Then these attributes match it:
28/// let attrs = wgpu::vertex_attr_array![
29///     0 => Float32x2,
30///     1 => Float32,
31///     2 => Uint16x4,
32/// ];
33///
34/// // Here's the full data structure the macro produced:
35/// use wgpu::{VertexAttribute as A, VertexFormat as F};
36/// assert_eq!(attrs, [
37///     A { format: F::Float32x2, offset:  0, shader_location: 0, },
38///     A { format: F::Float32,   offset:  8, shader_location: 1, },
39///     A { format: F::Uint16x4,  offset: 12, shader_location: 2, },
40/// ]);
41/// ```
42///
43/// See [`VertexBufferLayout`] for an example building on this one.
44#[macro_export]
45macro_rules! vertex_attr_array {
46    ($($location:expr => $format:ident),* $(,)?) => {
47        $crate::_vertex_attr_array_helper!([] ; 0; $($location => $format ,)*)
48    };
49}
50
51#[doc(hidden)]
52#[macro_export]
53macro_rules! _vertex_attr_array_helper {
54    ([$($t:expr,)*] ; $off:expr ;) => { [$($t,)*] };
55    ([$($t:expr,)*] ; $off:expr ; $location:expr => $format:ident, $($ll:expr => $ii:ident ,)*) => {
56        $crate::_vertex_attr_array_helper!(
57            [$($t,)*
58            $crate::VertexAttribute {
59                format: $crate::VertexFormat :: $format,
60                offset: $off,
61                shader_location: $location,
62            },];
63            $off + $crate::VertexFormat :: $format.size();
64            $($ll => $ii ,)*
65        )
66    };
67}
68
69#[test]
70fn test_vertex_attr_array() {
71    let attrs = vertex_attr_array![0 => Float32x2, 3 => Uint16x4];
72    // VertexAttribute does not support PartialEq, so we cannot test directly
73    assert_eq!(attrs.len(), 2);
74    assert_eq!(attrs[0].offset, 0);
75    assert_eq!(attrs[0].shader_location, 0);
76    assert_eq!(attrs[1].offset, size_of::<(f32, f32)>() as u64);
77    assert_eq!(attrs[1].shader_location, 3);
78}
79
80/// Macro to load a SPIR-V module statically.
81///
82/// It ensures the word alignment as well as the magic number.
83///
84/// Return type: [`crate::ShaderModuleDescriptor`]
85#[macro_export]
86#[cfg(feature = "spirv")]
87macro_rules! include_spirv {
88    ($($token:tt)*) => {
89        {
90            //log::info!("including '{}'", $($token)*);
91            $crate::ShaderModuleDescriptor {
92                label: Some($($token)*),
93                source: $crate::util::make_spirv(include_bytes!($($token)*)),
94            }
95        }
96    };
97}
98
99/// Macro to load raw SPIR-V data statically, for use with [`Features::SPIRV_SHADER_PASSTHROUGH`].
100///
101/// It ensures the word alignment as well as the magic number.
102///
103/// [`Features::SPIRV_SHADER_PASSTHROUGH`]: crate::Features::SPIRV_SHADER_PASSTHROUGH
104#[macro_export]
105macro_rules! include_spirv_raw {
106    ($($token:tt)*) => {
107        {
108            //log::info!("including '{}'", $($token)*);
109            $crate::ShaderModuleDescriptorPassthrough::SpirV(
110                $crate::ShaderModuleDescriptorSpirV {
111                    label: $crate::__macro_helpers::Some($($token)*),
112                    source: $crate::util::make_spirv_raw($crate::__macro_helpers::include_bytes!($($token)*)),
113                }
114            )
115        }
116    };
117}
118
119/// Load WGSL source code from a file at compile time.
120///
121/// The loaded path is relative to the path of the file containing the macro call, in the same way
122/// as [`include_str!`] operates.
123///
124/// ```ignore
125/// fn main() {
126///     let module: ShaderModuleDescriptor = include_wgsl!("shader.wgsl");
127/// }
128/// ```
129#[macro_export]
130macro_rules! include_wgsl {
131    ($($token:tt)*) => {
132        {
133            //log::info!("including '{}'", $($token)*);
134            $crate::ShaderModuleDescriptor {
135                label: $crate::__macro_helpers::Some($($token)*),
136                source: $crate::ShaderSource::Wgsl($crate::__macro_helpers::Cow::Borrowed($crate::__macro_helpers::include_str!($($token)*))),
137            }
138        }
139    };
140}
141
142#[doc(hidden)]
143pub mod helpers {
144    pub use alloc::borrow::Cow;
145    pub use core::{include_bytes, include_str};
146    pub use Some;
147}
wgpu/macros.rs

wgpu/
macros.rs
