wgpu_examples/mipmap/
mod.rs

1use bytemuck::{Pod, Zeroable};
2use std::f32::consts;
3use wgpu::util::DeviceExt;
4
5const TEXTURE_FORMAT: wgpu::TextureFormat = wgpu::TextureFormat::Rgba8UnormSrgb;
6const MIP_LEVEL_COUNT: u32 = 10;
7const MIP_PASS_COUNT: u32 = MIP_LEVEL_COUNT - 1;
8
9const QUERY_FEATURES: wgpu::Features = {
10    wgpu::Features::TIMESTAMP_QUERY
11        .union(wgpu::Features::TIMESTAMP_QUERY_INSIDE_PASSES)
12        .union(wgpu::Features::PIPELINE_STATISTICS_QUERY)
13};
14
15fn create_texels(size: usize, cx: f32, cy: f32) -> Vec<u8> {
16    use std::iter;
17
18    (0..size * size)
19        .flat_map(|id| {
20            // get high five for recognizing this ;)
21            let mut x = 4.0 * (id % size) as f32 / (size - 1) as f32 - 2.0;
22            let mut y = 2.0 * (id / size) as f32 / (size - 1) as f32 - 1.0;
23            let mut count = 0;
24            while count < 0xFF && x * x + y * y < 4.0 {
25                let old_x = x;
26                x = x * x - y * y + cx;
27                y = 2.0 * old_x * y + cy;
28                count += 1;
29            }
30            iter::once(0xFF - (count * 2) as u8)
31                .chain(iter::once(0xFF - (count * 5) as u8))
32                .chain(iter::once(0xFF - (count * 13) as u8))
33                .chain(iter::once(u8::MAX))
34        })
35        .collect()
36}
37
38struct QuerySets {
39    timestamp: wgpu::QuerySet,
40    timestamp_period: f32,
41    pipeline_statistics: wgpu::QuerySet,
42    data_buffer: wgpu::Buffer,
43    mapping_buffer: wgpu::Buffer,
44}
45
46#[repr(C)]
47#[derive(Clone, Copy, Pod, Zeroable)]
48struct TimestampData {
49    start: u64,
50    end: u64,
51}
52
53type TimestampQueries = [TimestampData; MIP_PASS_COUNT as usize];
54type PipelineStatisticsQueries = [u64; MIP_PASS_COUNT as usize];
55
56fn pipeline_statistics_offset() -> wgpu::BufferAddress {
57    (size_of::<TimestampQueries>() as wgpu::BufferAddress).max(wgpu::QUERY_RESOLVE_BUFFER_ALIGNMENT)
58}
59
60struct Example {
61    bind_group: wgpu::BindGroup,
62    uniform_buf: wgpu::Buffer,
63    draw_pipeline: wgpu::RenderPipeline,
64}
65
66impl Example {
67    fn generate_matrix(aspect_ratio: f32) -> glam::Mat4 {
68        let projection = glam::Mat4::perspective_rh(consts::FRAC_PI_4, aspect_ratio, 1.0, 1000.0);
69        let view = glam::Mat4::look_at_rh(
70            glam::Vec3::new(0f32, 0.0, 10.0),
71            glam::Vec3::new(0f32, 50.0, 0.0),
72            glam::Vec3::Z,
73        );
74        projection * view
75    }
76
77    fn generate_mipmaps(
78        encoder: &mut wgpu::CommandEncoder,
79        device: &wgpu::Device,
80        texture: &wgpu::Texture,
81        query_sets: &Option<QuerySets>,
82        mip_count: u32,
83    ) {
84        let shader = device.create_shader_module(wgpu::include_wgsl!("blit.wgsl"));
85
86        let pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
87            label: Some("blit"),
88            layout: None,
89            vertex: wgpu::VertexState {
90                module: &shader,
91                entry_point: Some("vs_main"),
92                compilation_options: Default::default(),
93                buffers: &[],
94            },
95            fragment: Some(wgpu::FragmentState {
96                module: &shader,
97                entry_point: Some("fs_main"),
98                compilation_options: Default::default(),
99                targets: &[Some(TEXTURE_FORMAT.into())],
100            }),
101            primitive: wgpu::PrimitiveState {
102                topology: wgpu::PrimitiveTopology::TriangleList,
103                ..Default::default()
104            },
105            depth_stencil: None,
106            multisample: wgpu::MultisampleState::default(),
107            multiview_mask: None,
108            cache: None,
109        });
110
111        let bind_group_layout = pipeline.get_bind_group_layout(0);
112
113        let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
114            label: Some("mip"),
115            address_mode_u: wgpu::AddressMode::ClampToEdge,
116            address_mode_v: wgpu::AddressMode::ClampToEdge,
117            address_mode_w: wgpu::AddressMode::ClampToEdge,
118            mag_filter: wgpu::FilterMode::Linear,
119            min_filter: wgpu::FilterMode::Linear,
120            mipmap_filter: wgpu::MipmapFilterMode::Nearest,
121            ..Default::default()
122        });
123
124        let views = (0..mip_count)
125            .map(|mip| {
126                texture.create_view(&wgpu::TextureViewDescriptor {
127                    label: Some("mip"),
128                    format: None,
129                    dimension: None,
130                    usage: None,
131                    aspect: wgpu::TextureAspect::All,
132                    base_mip_level: mip,
133                    mip_level_count: Some(1),
134                    base_array_layer: 0,
135                    array_layer_count: None,
136                })
137            })
138            .collect::<Vec<_>>();
139
140        for target_mip in 1..mip_count as usize {
141            let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
142                layout: &bind_group_layout,
143                entries: &[
144                    wgpu::BindGroupEntry {
145                        binding: 0,
146                        resource: wgpu::BindingResource::TextureView(&views[target_mip - 1]),
147                    },
148                    wgpu::BindGroupEntry {
149                        binding: 1,
150                        resource: wgpu::BindingResource::Sampler(&sampler),
151                    },
152                ],
153                label: None,
154            });
155
156            let pipeline_query_index_base = target_mip as u32 - 1;
157            let timestamp_query_index_base = (target_mip as u32 - 1) * 2;
158
159            let mut rpass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
160                label: None,
161                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
162                    view: &views[target_mip],
163                    depth_slice: None,
164                    resolve_target: None,
165                    ops: wgpu::Operations {
166                        load: wgpu::LoadOp::Clear(wgpu::Color::WHITE),
167                        store: wgpu::StoreOp::Store,
168                    },
169                })],
170                depth_stencil_attachment: None,
171                timestamp_writes: None,
172                occlusion_query_set: None,
173                multiview_mask: None,
174            });
175            if let Some(ref query_sets) = query_sets {
176                rpass.write_timestamp(&query_sets.timestamp, timestamp_query_index_base);
177                rpass.begin_pipeline_statistics_query(
178                    &query_sets.pipeline_statistics,
179                    pipeline_query_index_base,
180                );
181            }
182            rpass.set_pipeline(&pipeline);
183            rpass.set_bind_group(0, &bind_group, &[]);
184            rpass.draw(0..3, 0..1);
185            if let Some(ref query_sets) = query_sets {
186                rpass.write_timestamp(&query_sets.timestamp, timestamp_query_index_base + 1);
187                rpass.end_pipeline_statistics_query();
188            }
189        }
190
191        if let Some(ref query_sets) = query_sets {
192            let timestamp_query_count = MIP_PASS_COUNT * 2;
193            encoder.resolve_query_set(
194                &query_sets.timestamp,
195                0..timestamp_query_count,
196                &query_sets.data_buffer,
197                0,
198            );
199            encoder.resolve_query_set(
200                &query_sets.pipeline_statistics,
201                0..MIP_PASS_COUNT,
202                &query_sets.data_buffer,
203                pipeline_statistics_offset(),
204            );
205        }
206    }
207}
208
209impl crate::framework::Example for Example {
210    fn optional_features() -> wgpu::Features {
211        QUERY_FEATURES
212    }
213
214    fn init(
215        config: &wgpu::SurfaceConfiguration,
216        _adapter: &wgpu::Adapter,
217        device: &wgpu::Device,
218        queue: &wgpu::Queue,
219    ) -> Self {
220        let mut init_encoder =
221            device.create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
222
223        // Create the texture
224        let size = 1 << MIP_PASS_COUNT;
225        let texels = create_texels(size as usize, -0.8, 0.156);
226        let texture_extent = wgpu::Extent3d {
227            width: size,
228            height: size,
229            depth_or_array_layers: 1,
230        };
231        let texture = device.create_texture(&wgpu::TextureDescriptor {
232            size: texture_extent,
233            mip_level_count: MIP_LEVEL_COUNT,
234            sample_count: 1,
235            dimension: wgpu::TextureDimension::D2,
236            format: TEXTURE_FORMAT,
237            usage: wgpu::TextureUsages::TEXTURE_BINDING
238                | wgpu::TextureUsages::RENDER_ATTACHMENT
239                | wgpu::TextureUsages::COPY_DST,
240            label: None,
241            view_formats: &[],
242        });
243        let texture_view = texture.create_view(&wgpu::TextureViewDescriptor::default());
244        //Note: we could use queue.write_texture instead, and this is what other
245        // examples do, but here we want to show another way to do this.
246        let temp_buf = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
247            label: Some("Temporary Buffer"),
248            contents: texels.as_slice(),
249            usage: wgpu::BufferUsages::COPY_SRC,
250        });
251        init_encoder.copy_buffer_to_texture(
252            wgpu::TexelCopyBufferInfo {
253                buffer: &temp_buf,
254                layout: wgpu::TexelCopyBufferLayout {
255                    offset: 0,
256                    bytes_per_row: Some(4 * size),
257                    rows_per_image: None,
258                },
259            },
260            texture.as_image_copy(),
261            texture_extent,
262        );
263
264        // Create other resources
265        let sampler = device.create_sampler(&wgpu::SamplerDescriptor {
266            label: None,
267            address_mode_u: wgpu::AddressMode::Repeat,
268            address_mode_v: wgpu::AddressMode::Repeat,
269            address_mode_w: wgpu::AddressMode::Repeat,
270            mag_filter: wgpu::FilterMode::Linear,
271            min_filter: wgpu::FilterMode::Linear,
272            mipmap_filter: wgpu::MipmapFilterMode::Linear,
273            ..Default::default()
274        });
275        let mx_total = Self::generate_matrix(config.width as f32 / config.height as f32);
276        let mx_ref: &[f32; 16] = mx_total.as_ref();
277        let uniform_buf = device.create_buffer_init(&wgpu::util::BufferInitDescriptor {
278            label: Some("Uniform Buffer"),
279            contents: bytemuck::cast_slice(mx_ref),
280            usage: wgpu::BufferUsages::UNIFORM | wgpu::BufferUsages::COPY_DST,
281        });
282
283        // Create the render pipeline
284        let shader = device.create_shader_module(wgpu::include_wgsl!("draw.wgsl"));
285
286        let draw_pipeline = device.create_render_pipeline(&wgpu::RenderPipelineDescriptor {
287            label: Some("draw"),
288            layout: None,
289            vertex: wgpu::VertexState {
290                module: &shader,
291                entry_point: Some("vs_main"),
292                compilation_options: Default::default(),
293                buffers: &[],
294            },
295            fragment: Some(wgpu::FragmentState {
296                module: &shader,
297                entry_point: Some("fs_main"),
298                compilation_options: Default::default(),
299                targets: &[Some(config.view_formats[0].into())],
300            }),
301            primitive: wgpu::PrimitiveState {
302                topology: wgpu::PrimitiveTopology::TriangleStrip,
303                front_face: wgpu::FrontFace::Ccw,
304                cull_mode: Some(wgpu::Face::Back),
305                ..Default::default()
306            },
307            depth_stencil: None,
308            multisample: wgpu::MultisampleState::default(),
309            multiview_mask: None,
310            cache: None,
311        });
312
313        // Create bind group
314        let bind_group_layout = draw_pipeline.get_bind_group_layout(0);
315        let bind_group = device.create_bind_group(&wgpu::BindGroupDescriptor {
316            layout: &bind_group_layout,
317            entries: &[
318                wgpu::BindGroupEntry {
319                    binding: 0,
320                    resource: uniform_buf.as_entire_binding(),
321                },
322                wgpu::BindGroupEntry {
323                    binding: 1,
324                    resource: wgpu::BindingResource::TextureView(&texture_view),
325                },
326                wgpu::BindGroupEntry {
327                    binding: 2,
328                    resource: wgpu::BindingResource::Sampler(&sampler),
329                },
330            ],
331            label: None,
332        });
333
334        // If both kinds of query are supported, use queries
335        let query_sets = if device.features().contains(QUERY_FEATURES) {
336            // For N total mips, it takes N - 1 passes to generate them, and we're measuring those.
337            let mip_passes = MIP_LEVEL_COUNT - 1;
338
339            // Create the timestamp query set. We need twice as many queries as we have passes,
340            // as we need a query at the beginning and at the end of the operation.
341            let timestamp = device.create_query_set(&wgpu::QuerySetDescriptor {
342                label: None,
343                count: mip_passes * 2,
344                ty: wgpu::QueryType::Timestamp,
345            });
346            // Timestamp queries use an device-specific timestamp unit. We need to figure out how many
347            // nanoseconds go by for the timestamp to be incremented by one. The period is this value.
348            let timestamp_period = queue.get_timestamp_period();
349
350            // We only need one pipeline statistics query per pass.
351            let pipeline_statistics = device.create_query_set(&wgpu::QuerySetDescriptor {
352                label: None,
353                count: mip_passes,
354                ty: wgpu::QueryType::PipelineStatistics(
355                    wgpu::PipelineStatisticsTypes::FRAGMENT_SHADER_INVOCATIONS,
356                ),
357            });
358
359            // This databuffer has to store all of the query results, 2 * passes timestamp queries
360            // and 1 * passes statistics queries. Each query returns a u64 value.
361            let buffer_size = pipeline_statistics_offset()
362                + size_of::<PipelineStatisticsQueries>() as wgpu::BufferAddress;
363            let data_buffer = device.create_buffer(&wgpu::BufferDescriptor {
364                label: Some("query buffer"),
365                size: buffer_size,
366                usage: wgpu::BufferUsages::QUERY_RESOLVE | wgpu::BufferUsages::COPY_SRC,
367                mapped_at_creation: false,
368            });
369
370            // Mapping buffer
371            let mapping_buffer = device.create_buffer(&wgpu::BufferDescriptor {
372                label: Some("query buffer"),
373                size: buffer_size,
374                usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::MAP_READ,
375                mapped_at_creation: false,
376            });
377
378            Some(QuerySets {
379                timestamp,
380                timestamp_period,
381                pipeline_statistics,
382                data_buffer,
383                mapping_buffer,
384            })
385        } else {
386            None
387        };
388
389        Self::generate_mipmaps(
390            &mut init_encoder,
391            device,
392            &texture,
393            &query_sets,
394            MIP_LEVEL_COUNT,
395        );
396
397        if let Some(ref query_sets) = query_sets {
398            init_encoder.copy_buffer_to_buffer(
399                &query_sets.data_buffer,
400                0,
401                &query_sets.mapping_buffer,
402                0,
403                query_sets.data_buffer.size(),
404            );
405        }
406
407        queue.submit(Some(init_encoder.finish()));
408        if let Some(ref query_sets) = query_sets {
409            // We can ignore the callback as we're about to wait for the device.
410            query_sets
411                .mapping_buffer
412                .slice(..)
413                .map_async(wgpu::MapMode::Read, |_| ());
414            // Wait for device to be done rendering mipmaps
415            device.poll(wgpu::PollType::wait_indefinitely()).unwrap();
416            // This is guaranteed to be ready.
417            let timestamp_view = query_sets
418                .mapping_buffer
419                .slice(..size_of::<TimestampQueries>() as wgpu::BufferAddress)
420                .get_mapped_range();
421            let pipeline_stats_view = query_sets
422                .mapping_buffer
423                .slice(pipeline_statistics_offset()..)
424                .get_mapped_range();
425            // Convert the raw data into a useful structure
426            let timestamp_data: &TimestampQueries = bytemuck::from_bytes(&timestamp_view);
427            let pipeline_stats_data: &PipelineStatisticsQueries =
428                bytemuck::from_bytes(&pipeline_stats_view);
429            // Iterate over the data
430            for (idx, (timestamp, pipeline)) in timestamp_data
431                .iter()
432                .zip(pipeline_stats_data.iter())
433                .enumerate()
434            {
435                // Figure out the timestamp differences and multiply by the period to get nanoseconds
436                let nanoseconds =
437                    (timestamp.end - timestamp.start) as f32 * query_sets.timestamp_period;
438                // Nanoseconds is a bit small, so lets use microseconds.
439                let microseconds = nanoseconds / 1000.0;
440                // Print the data!
441                println!(
442                    "Generating mip level {} took {:.3} μs and called the fragment shader {} times",
443                    idx + 1,
444                    microseconds,
445                    pipeline
446                );
447            }
448        }
449
450        Example {
451            bind_group,
452            uniform_buf,
453            draw_pipeline,
454        }
455    }
456
457    fn update(&mut self, _event: winit::event::WindowEvent) {
458        //empty
459    }
460
461    fn resize(
462        &mut self,
463        config: &wgpu::SurfaceConfiguration,
464        _device: &wgpu::Device,
465        queue: &wgpu::Queue,
466    ) {
467        let mx_total = Self::generate_matrix(config.width as f32 / config.height as f32);
468        let mx_ref: &[f32; 16] = mx_total.as_ref();
469        queue.write_buffer(&self.uniform_buf, 0, bytemuck::cast_slice(mx_ref));
470    }
471
472    fn render(&mut self, view: &wgpu::TextureView, device: &wgpu::Device, queue: &wgpu::Queue) {
473        let mut encoder =
474            device.create_command_encoder(&wgpu::CommandEncoderDescriptor { label: None });
475        {
476            let clear_color = wgpu::Color {
477                r: 0.1,
478                g: 0.2,
479                b: 0.3,
480                a: 1.0,
481            };
482            let mut rpass = encoder.begin_render_pass(&wgpu::RenderPassDescriptor {
483                label: None,
484                color_attachments: &[Some(wgpu::RenderPassColorAttachment {
485                    view,
486                    depth_slice: None,
487                    resolve_target: None,
488                    ops: wgpu::Operations {
489                        load: wgpu::LoadOp::Clear(clear_color),
490                        store: wgpu::StoreOp::Store,
491                    },
492                })],
493                depth_stencil_attachment: None,
494                timestamp_writes: None,
495                occlusion_query_set: None,
496                multiview_mask: None,
497            });
498            rpass.set_pipeline(&self.draw_pipeline);
499            rpass.set_bind_group(0, &self.bind_group, &[]);
500            rpass.draw(0..4, 0..1);
501        }
502
503        queue.submit(Some(encoder.finish()));
504    }
505}
506
507pub fn main() {
508    crate::framework::run::<Example>("mipmap");
509}
510
511#[cfg(test)]
512#[wgpu_test::gpu_test]
513pub static TEST: crate::framework::ExampleTestParams = crate::framework::ExampleTestParams {
514    name: "mipmap",
515    image_path: "/examples/features/src/mipmap/screenshot.png",
516    width: 1024,
517    height: 768,
518    optional_features: wgpu::Features::default(),
519    base_test_parameters: wgpu_test::TestParameters::default(),
520    comparisons: &[wgpu_test::ComparisonType::Mean(0.02)],
521    _phantom: std::marker::PhantomData::<Example>,
522};
523
524#[cfg(test)]
525#[wgpu_test::gpu_test]
526pub static TEST_QUERY: crate::framework::ExampleTestParams = crate::framework::ExampleTestParams {
527    name: "mipmap-query",
528    image_path: "/examples/features/src/mipmap/screenshot_query.png",
529    width: 1024,
530    height: 768,
531    optional_features: QUERY_FEATURES,
532    base_test_parameters: wgpu_test::TestParameters::default(),
533    // Somehow, this test on CI lavapipe reasonably often gets error of 0.025341, significantly higher
534    // than the comparison we usually do with mean 0.005. This only happens when the query is used.
535    comparisons: &[
536        wgpu_test::ComparisonType::Mean(0.03),
537        wgpu_test::ComparisonType::Percentile {
538            percentile: 0.99,
539            threshold: 0.1,
540        },
541    ],
542    _phantom: std::marker::PhantomData::<Example>,
543};
wgpu_examples/mipmap/mod.rs

wgpu_examples/mipmap/
mod.rs
