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
//! Producing the WGSL forms of types, for use in error messages.

use crate::proc::GlobalCtx;
use crate::Handle;

impl crate::proc::TypeResolution {
    pub fn to_wgsl(&self, gctx: &GlobalCtx) -> String {
        match *self {
            crate::proc::TypeResolution::Handle(handle) => handle.to_wgsl(gctx),
            crate::proc::TypeResolution::Value(ref inner) => inner.to_wgsl(gctx),
        }
    }
}

impl Handle<crate::Type> {
    /// Formats the type as it is written in wgsl.
    ///
    /// For example `vec3<f32>`.
    pub fn to_wgsl(self, gctx: &GlobalCtx) -> String {
        let ty = &gctx.types[self];
        match ty.name {
            Some(ref name) => name.clone(),
            None => ty.inner.to_wgsl(gctx),
        }
    }
}

impl crate::TypeInner {
    /// Formats the type as it is written in wgsl.
    ///
    /// For example `vec3<f32>`.
    ///
    /// Note: `TypeInner::Struct` doesn't include the name of the
    /// struct type. Therefore this method will simply return "struct"
    /// for them.
    pub fn to_wgsl(&self, gctx: &GlobalCtx) -> String {
        use crate::TypeInner as Ti;

        match *self {
            Ti::Scalar(scalar) => scalar.to_wgsl(),
            Ti::Vector { size, scalar } => {
                format!("vec{}<{}>", size as u32, scalar.to_wgsl())
            }
            Ti::Matrix {
                columns,
                rows,
                scalar,
            } => {
                format!(
                    "mat{}x{}<{}>",
                    columns as u32,
                    rows as u32,
                    scalar.to_wgsl(),
                )
            }
            Ti::Atomic(scalar) => {
                format!("atomic<{}>", scalar.to_wgsl())
            }
            Ti::Pointer { base, .. } => {
                let name = base.to_wgsl(gctx);
                format!("ptr<{name}>")
            }
            Ti::ValuePointer { scalar, .. } => {
                format!("ptr<{}>", scalar.to_wgsl())
            }
            Ti::Array { base, size, .. } => {
                let base = base.to_wgsl(gctx);
                match size {
                    crate::ArraySize::Constant(size) => format!("array<{base}, {size}>"),
                    crate::ArraySize::Dynamic => format!("array<{base}>"),
                }
            }
            Ti::Struct { .. } => {
                // TODO: Actually output the struct?
                "struct".to_string()
            }
            Ti::Image {
                dim,
                arrayed,
                class,
            } => {
                let dim_suffix = match dim {
                    crate::ImageDimension::D1 => "_1d",
                    crate::ImageDimension::D2 => "_2d",
                    crate::ImageDimension::D3 => "_3d",
                    crate::ImageDimension::Cube => "_cube",
                };
                let array_suffix = if arrayed { "_array" } else { "" };

                let class_suffix = match class {
                    crate::ImageClass::Sampled { multi: true, .. } => "_multisampled",
                    crate::ImageClass::Depth { multi: false } => "_depth",
                    crate::ImageClass::Depth { multi: true } => "_depth_multisampled",
                    crate::ImageClass::Sampled { multi: false, .. }
                    | crate::ImageClass::Storage { .. } => "",
                };

                let type_in_brackets = match class {
                    crate::ImageClass::Sampled { kind, .. } => {
                        // Note: The only valid widths are 4 bytes wide.
                        // The lexer has already verified this, so we can safely assume it here.
                        // https://gpuweb.github.io/gpuweb/wgsl/#sampled-texture-type
                        let element_type = crate::Scalar { kind, width: 4 }.to_wgsl();
                        format!("<{element_type}>")
                    }
                    crate::ImageClass::Depth { multi: _ } => String::new(),
                    crate::ImageClass::Storage { format, access } => {
                        if access.contains(crate::StorageAccess::STORE) {
                            format!("<{},write>", format.to_wgsl())
                        } else {
                            format!("<{}>", format.to_wgsl())
                        }
                    }
                };

                format!("texture{class_suffix}{dim_suffix}{array_suffix}{type_in_brackets}")
            }
            Ti::Sampler { .. } => "sampler".to_string(),
            Ti::AccelerationStructure => "acceleration_structure".to_string(),
            Ti::RayQuery => "ray_query".to_string(),
            Ti::BindingArray { base, size, .. } => {
                let member_type = &gctx.types[base];
                let base = member_type.name.as_deref().unwrap_or("unknown");
                match size {
                    crate::ArraySize::Constant(size) => format!("binding_array<{base}, {size}>"),
                    crate::ArraySize::Dynamic => format!("binding_array<{base}>"),
                }
            }
        }
    }
}

impl crate::Scalar {
    /// Format a scalar kind+width as a type is written in wgsl.
    ///
    /// Examples: `f32`, `u64`, `bool`.
    pub fn to_wgsl(self) -> String {
        let prefix = match self.kind {
            crate::ScalarKind::Sint => "i",
            crate::ScalarKind::Uint => "u",
            crate::ScalarKind::Float => "f",
            crate::ScalarKind::Bool => return "bool".to_string(),
            crate::ScalarKind::AbstractInt => return "{AbstractInt}".to_string(),
            crate::ScalarKind::AbstractFloat => return "{AbstractFloat}".to_string(),
        };
        format!("{}{}", prefix, self.width * 8)
    }
}

impl crate::StorageFormat {
    pub const fn to_wgsl(self) -> &'static str {
        use crate::StorageFormat as Sf;
        match self {
            Sf::R8Unorm => "r8unorm",
            Sf::R8Snorm => "r8snorm",
            Sf::R8Uint => "r8uint",
            Sf::R8Sint => "r8sint",
            Sf::R16Uint => "r16uint",
            Sf::R16Sint => "r16sint",
            Sf::R16Float => "r16float",
            Sf::Rg8Unorm => "rg8unorm",
            Sf::Rg8Snorm => "rg8snorm",
            Sf::Rg8Uint => "rg8uint",
            Sf::Rg8Sint => "rg8sint",
            Sf::R32Uint => "r32uint",
            Sf::R32Sint => "r32sint",
            Sf::R32Float => "r32float",
            Sf::Rg16Uint => "rg16uint",
            Sf::Rg16Sint => "rg16sint",
            Sf::Rg16Float => "rg16float",
            Sf::Rgba8Unorm => "rgba8unorm",
            Sf::Rgba8Snorm => "rgba8snorm",
            Sf::Rgba8Uint => "rgba8uint",
            Sf::Rgba8Sint => "rgba8sint",
            Sf::Bgra8Unorm => "bgra8unorm",
            Sf::Rgb10a2Uint => "rgb10a2uint",
            Sf::Rgb10a2Unorm => "rgb10a2unorm",
            Sf::Rg11b10Ufloat => "rg11b10float",
            Sf::Rg32Uint => "rg32uint",
            Sf::Rg32Sint => "rg32sint",
            Sf::Rg32Float => "rg32float",
            Sf::Rgba16Uint => "rgba16uint",
            Sf::Rgba16Sint => "rgba16sint",
            Sf::Rgba16Float => "rgba16float",
            Sf::Rgba32Uint => "rgba32uint",
            Sf::Rgba32Sint => "rgba32sint",
            Sf::Rgba32Float => "rgba32float",
            Sf::R16Unorm => "r16unorm",
            Sf::R16Snorm => "r16snorm",
            Sf::Rg16Unorm => "rg16unorm",
            Sf::Rg16Snorm => "rg16snorm",
            Sf::Rgba16Unorm => "rgba16unorm",
            Sf::Rgba16Snorm => "rgba16snorm",
        }
    }
}

mod tests {
    #[test]
    fn to_wgsl() {
        use std::num::NonZeroU32;

        let mut types = crate::UniqueArena::new();

        let mytype1 = types.insert(
            crate::Type {
                name: Some("MyType1".to_string()),
                inner: crate::TypeInner::Struct {
                    members: vec![],
                    span: 0,
                },
            },
            Default::default(),
        );
        let mytype2 = types.insert(
            crate::Type {
                name: Some("MyType2".to_string()),
                inner: crate::TypeInner::Struct {
                    members: vec![],
                    span: 0,
                },
            },
            Default::default(),
        );

        let gctx = crate::proc::GlobalCtx {
            types: &types,
            constants: &crate::Arena::new(),
            overrides: &crate::Arena::new(),
            global_expressions: &crate::Arena::new(),
        };
        let array = crate::TypeInner::Array {
            base: mytype1,
            stride: 4,
            size: crate::ArraySize::Constant(unsafe { NonZeroU32::new_unchecked(32) }),
        };
        assert_eq!(array.to_wgsl(&gctx), "array<MyType1, 32>");

        let mat = crate::TypeInner::Matrix {
            rows: crate::VectorSize::Quad,
            columns: crate::VectorSize::Bi,
            scalar: crate::Scalar::F64,
        };
        assert_eq!(mat.to_wgsl(&gctx), "mat2x4<f64>");

        let ptr = crate::TypeInner::Pointer {
            base: mytype2,
            space: crate::AddressSpace::Storage {
                access: crate::StorageAccess::default(),
            },
        };
        assert_eq!(ptr.to_wgsl(&gctx), "ptr<MyType2>");

        let img1 = crate::TypeInner::Image {
            dim: crate::ImageDimension::D2,
            arrayed: false,
            class: crate::ImageClass::Sampled {
                kind: crate::ScalarKind::Float,
                multi: true,
            },
        };
        assert_eq!(img1.to_wgsl(&gctx), "texture_multisampled_2d<f32>");

        let img2 = crate::TypeInner::Image {
            dim: crate::ImageDimension::Cube,
            arrayed: true,
            class: crate::ImageClass::Depth { multi: false },
        };
        assert_eq!(img2.to_wgsl(&gctx), "texture_depth_cube_array");

        let img3 = crate::TypeInner::Image {
            dim: crate::ImageDimension::D2,
            arrayed: false,
            class: crate::ImageClass::Depth { multi: true },
        };
        assert_eq!(img3.to_wgsl(&gctx), "texture_depth_multisampled_2d");

        let array = crate::TypeInner::BindingArray {
            base: mytype1,
            size: crate::ArraySize::Constant(unsafe { NonZeroU32::new_unchecked(32) }),
        };
        assert_eq!(array.to_wgsl(&gctx), "binding_array<MyType1, 32>");
    }
}