wgpu 0.14.0

Rusty WebGPU API wrapper
Documentation
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
613
614
615
616
617
618
619
620
621
622
623
624
625
626
use std::future::Future;
#[cfg(target_arch = "wasm32")]
use std::str::FromStr;
#[cfg(not(target_arch = "wasm32"))]
use std::time::Instant;
#[cfg(target_arch = "wasm32")]
use web_sys::{ImageBitmapRenderingContext, OffscreenCanvas};
use winit::{
    event::{self, WindowEvent},
    event_loop::{ControlFlow, EventLoop},
};

#[cfg(test)]
#[path = "../tests/common/mod.rs"]
pub mod test_common;

#[allow(dead_code)]
pub fn cast_slice<T>(data: &[T]) -> &[u8] {
    use std::{mem::size_of, slice::from_raw_parts};

    unsafe { from_raw_parts(data.as_ptr() as *const u8, data.len() * size_of::<T>()) }
}

#[allow(dead_code)]
pub enum ShaderStage {
    Vertex,
    Fragment,
    Compute,
}

pub trait Example: 'static + Sized {
    fn optional_features() -> wgpu::Features {
        wgpu::Features::empty()
    }
    fn required_features() -> wgpu::Features {
        wgpu::Features::empty()
    }
    fn required_downlevel_capabilities() -> wgpu::DownlevelCapabilities {
        wgpu::DownlevelCapabilities {
            flags: wgpu::DownlevelFlags::empty(),
            shader_model: wgpu::ShaderModel::Sm5,
            ..wgpu::DownlevelCapabilities::default()
        }
    }
    fn required_limits() -> wgpu::Limits {
        wgpu::Limits::downlevel_webgl2_defaults() // These downlevel limits will allow the code to run on all possible hardware
    }
    fn init(
        config: &wgpu::SurfaceConfiguration,
        adapter: &wgpu::Adapter,
        device: &wgpu::Device,
        queue: &wgpu::Queue,
    ) -> Self;
    fn resize(
        &mut self,
        config: &wgpu::SurfaceConfiguration,
        device: &wgpu::Device,
        queue: &wgpu::Queue,
    );
    fn update(&mut self, event: WindowEvent);
    fn render(
        &mut self,
        view: &wgpu::TextureView,
        device: &wgpu::Device,
        queue: &wgpu::Queue,
        spawner: &Spawner,
    );
}

struct Setup {
    window: winit::window::Window,
    event_loop: EventLoop<()>,
    instance: wgpu::Instance,
    size: winit::dpi::PhysicalSize<u32>,
    surface: wgpu::Surface,
    adapter: wgpu::Adapter,
    device: wgpu::Device,
    queue: wgpu::Queue,
    #[cfg(target_arch = "wasm32")]
    offscreen_canvas_setup: Option<OffscreenCanvasSetup>,
}

#[cfg(target_arch = "wasm32")]
struct OffscreenCanvasSetup {
    offscreen_canvas: OffscreenCanvas,
    bitmap_renderer: ImageBitmapRenderingContext,
}

async fn setup<E: Example>(title: &str) -> Setup {
    #[cfg(not(target_arch = "wasm32"))]
    {
        env_logger::init();
    };

    let event_loop = EventLoop::new();
    let mut builder = winit::window::WindowBuilder::new();
    builder = builder.with_title(title);
    #[cfg(windows_OFF)] // TODO
    {
        use winit::platform::windows::WindowBuilderExtWindows;
        builder = builder.with_no_redirection_bitmap(true);
    }
    let window = builder.build(&event_loop).unwrap();

    #[cfg(target_arch = "wasm32")]
    {
        use winit::platform::web::WindowExtWebSys;
        let query_string = web_sys::window().unwrap().location().search().unwrap();
        let level: log::Level = parse_url_query_string(&query_string, "RUST_LOG")
            .and_then(|x| x.parse().ok())
            .unwrap_or(log::Level::Error);
        console_log::init_with_level(level).expect("could not initialize logger");
        std::panic::set_hook(Box::new(console_error_panic_hook::hook));
        // On wasm, append the canvas to the document body
        web_sys::window()
            .and_then(|win| win.document())
            .and_then(|doc| doc.body())
            .and_then(|body| {
                body.append_child(&web_sys::Element::from(window.canvas()))
                    .ok()
            })
            .expect("couldn't append canvas to document body");
    }

    #[cfg(target_arch = "wasm32")]
    let mut offscreen_canvas_setup: Option<OffscreenCanvasSetup> = None;
    #[cfg(target_arch = "wasm32")]
    {
        use wasm_bindgen::JsCast;
        use winit::platform::web::WindowExtWebSys;

        let query_string = web_sys::window().unwrap().location().search().unwrap();
        if let Some(offscreen_canvas_param) =
            parse_url_query_string(&query_string, "offscreen_canvas")
        {
            if FromStr::from_str(offscreen_canvas_param) == Ok(true) {
                log::info!("Creating OffscreenCanvasSetup");

                let offscreen_canvas =
                    OffscreenCanvas::new(1024, 768).expect("couldn't create OffscreenCanvas");

                let bitmap_renderer = window
                    .canvas()
                    .get_context("bitmaprenderer")
                    .expect("couldn't create ImageBitmapRenderingContext (Result)")
                    .expect("couldn't create ImageBitmapRenderingContext (Option)")
                    .dyn_into::<ImageBitmapRenderingContext>()
                    .expect("couldn't convert into ImageBitmapRenderingContext");

                offscreen_canvas_setup = Some(OffscreenCanvasSetup {
                    offscreen_canvas,
                    bitmap_renderer,
                })
            }
        }
    };

    log::info!("Initializing the surface...");

    let backend = wgpu::util::backend_bits_from_env().unwrap_or_else(wgpu::Backends::all);

    let instance = wgpu::Instance::new(backend);
    let (size, surface) = unsafe {
        let size = window.inner_size();

        #[cfg(not(target_arch = "wasm32"))]
        let surface = instance.create_surface(&window);
        #[cfg(target_arch = "wasm32")]
        let surface = {
            if let Some(offscreen_canvas_setup) = &offscreen_canvas_setup {
                log::info!("Creating surface from OffscreenCanvas");
                instance
                    .create_surface_from_offscreen_canvas(&offscreen_canvas_setup.offscreen_canvas)
            } else {
                instance.create_surface(&window)
            }
        };

        (size, surface)
    };
    let adapter =
        wgpu::util::initialize_adapter_from_env_or_default(&instance, backend, Some(&surface))
            .await
            .expect("No suitable GPU adapters found on the system!");

    #[cfg(not(target_arch = "wasm32"))]
    {
        let adapter_info = adapter.get_info();
        println!("Using {} ({:?})", adapter_info.name, adapter_info.backend);
    }

    let optional_features = E::optional_features();
    let required_features = E::required_features();
    let adapter_features = adapter.features();
    assert!(
        adapter_features.contains(required_features),
        "Adapter does not support required features for this example: {:?}",
        required_features - adapter_features
    );

    let required_downlevel_capabilities = E::required_downlevel_capabilities();
    let downlevel_capabilities = adapter.get_downlevel_capabilities();
    assert!(
        downlevel_capabilities.shader_model >= required_downlevel_capabilities.shader_model,
        "Adapter does not support the minimum shader model required to run this example: {:?}",
        required_downlevel_capabilities.shader_model
    );
    assert!(
        downlevel_capabilities
            .flags
            .contains(required_downlevel_capabilities.flags),
        "Adapter does not support the downlevel capabilities required to run this example: {:?}",
        required_downlevel_capabilities.flags - downlevel_capabilities.flags
    );

    // Make sure we use the texture resolution limits from the adapter, so we can support images the size of the surface.
    let needed_limits = E::required_limits().using_resolution(adapter.limits());

    let trace_dir = std::env::var("WGPU_TRACE");
    let (device, queue) = adapter
        .request_device(
            &wgpu::DeviceDescriptor {
                label: None,
                features: (optional_features & adapter_features) | required_features,
                limits: needed_limits,
            },
            trace_dir.ok().as_ref().map(std::path::Path::new),
        )
        .await
        .expect("Unable to find a suitable GPU adapter!");

    Setup {
        window,
        event_loop,
        instance,
        size,
        surface,
        adapter,
        device,
        queue,
        #[cfg(target_arch = "wasm32")]
        offscreen_canvas_setup,
    }
}

fn start<E: Example>(
    #[cfg(not(target_arch = "wasm32"))] Setup {
        window,
        event_loop,
        instance,
        size,
        surface,
        adapter,
        device,
        queue,
    }: Setup,
    #[cfg(target_arch = "wasm32")] Setup {
        window,
        event_loop,
        instance,
        size,
        surface,
        adapter,
        device,
        queue,
        offscreen_canvas_setup,
    }: Setup,
) {
    let spawner = Spawner::new();
    let mut config = wgpu::SurfaceConfiguration {
        usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
        format: surface.get_supported_formats(&adapter)[0],
        width: size.width,
        height: size.height,
        present_mode: wgpu::PresentMode::Fifo,
        alpha_mode: surface.get_supported_alpha_modes(&adapter)[0],
    };
    surface.configure(&device, &config);

    log::info!("Initializing the example...");
    let mut example = E::init(&config, &adapter, &device, &queue);

    #[cfg(not(target_arch = "wasm32"))]
    let mut last_frame_inst = Instant::now();
    #[cfg(not(target_arch = "wasm32"))]
    let (mut frame_count, mut accum_time) = (0, 0.0);

    log::info!("Entering render loop...");
    event_loop.run(move |event, _, control_flow| {
        let _ = (&instance, &adapter); // force ownership by the closure
        *control_flow = if cfg!(feature = "metal-auto-capture") {
            ControlFlow::Exit
        } else {
            ControlFlow::Poll
        };
        match event {
            event::Event::RedrawEventsCleared => {
                #[cfg(not(target_arch = "wasm32"))]
                spawner.run_until_stalled();

                window.request_redraw();
            }
            event::Event::WindowEvent {
                event:
                    WindowEvent::Resized(size)
                    | WindowEvent::ScaleFactorChanged {
                        new_inner_size: &mut size,
                        ..
                    },
                ..
            } => {
                log::info!("Resizing to {:?}", size);
                config.width = size.width.max(1);
                config.height = size.height.max(1);
                example.resize(&config, &device, &queue);
                surface.configure(&device, &config);
            }
            event::Event::WindowEvent { event, .. } => match event {
                WindowEvent::KeyboardInput {
                    input:
                        event::KeyboardInput {
                            virtual_keycode: Some(event::VirtualKeyCode::Escape),
                            state: event::ElementState::Pressed,
                            ..
                        },
                    ..
                }
                | WindowEvent::CloseRequested => {
                    *control_flow = ControlFlow::Exit;
                }
                #[cfg(not(target_arch = "wasm32"))]
                WindowEvent::KeyboardInput {
                    input:
                        event::KeyboardInput {
                            virtual_keycode: Some(event::VirtualKeyCode::R),
                            state: event::ElementState::Pressed,
                            ..
                        },
                    ..
                } => {
                    println!("{:#?}", instance.generate_report());
                }
                _ => {
                    example.update(event);
                }
            },
            event::Event::RedrawRequested(_) => {
                #[cfg(not(target_arch = "wasm32"))]
                {
                    accum_time += last_frame_inst.elapsed().as_secs_f32();
                    last_frame_inst = Instant::now();
                    frame_count += 1;
                    if frame_count == 100 {
                        println!(
                            "Avg frame time {}ms",
                            accum_time * 1000.0 / frame_count as f32
                        );
                        accum_time = 0.0;
                        frame_count = 0;
                    }
                }

                let frame = match surface.get_current_texture() {
                    Ok(frame) => frame,
                    Err(_) => {
                        surface.configure(&device, &config);
                        surface
                            .get_current_texture()
                            .expect("Failed to acquire next surface texture!")
                    }
                };
                let view = frame
                    .texture
                    .create_view(&wgpu::TextureViewDescriptor::default());

                example.render(&view, &device, &queue, &spawner);

                frame.present();

                #[cfg(target_arch = "wasm32")]
                {
                    if let Some(offscreen_canvas_setup) = &offscreen_canvas_setup {
                        let image_bitmap = offscreen_canvas_setup
                            .offscreen_canvas
                            .transfer_to_image_bitmap()
                            .expect("couldn't transfer offscreen canvas to image bitmap.");
                        offscreen_canvas_setup
                            .bitmap_renderer
                            .transfer_from_image_bitmap(&image_bitmap);

                        log::info!("Transferring OffscreenCanvas to ImageBitmapRenderer");
                    }
                }
            }
            _ => {}
        }
    });
}

#[cfg(not(target_arch = "wasm32"))]
pub struct Spawner<'a> {
    executor: async_executor::LocalExecutor<'a>,
}

#[cfg(not(target_arch = "wasm32"))]
impl<'a> Spawner<'a> {
    fn new() -> Self {
        Self {
            executor: async_executor::LocalExecutor::new(),
        }
    }

    #[allow(dead_code)]
    pub fn spawn_local(&self, future: impl Future<Output = ()> + 'a) {
        self.executor.spawn(future).detach();
    }

    fn run_until_stalled(&self) {
        while self.executor.try_tick() {}
    }
}

#[cfg(target_arch = "wasm32")]
pub struct Spawner {}

#[cfg(target_arch = "wasm32")]
impl Spawner {
    fn new() -> Self {
        Self {}
    }

    #[allow(dead_code)]
    pub fn spawn_local(&self, future: impl Future<Output = ()> + 'static) {
        wasm_bindgen_futures::spawn_local(future);
    }
}

#[cfg(not(target_arch = "wasm32"))]
pub fn run<E: Example>(title: &str) {
    let setup = pollster::block_on(setup::<E>(title));
    start::<E>(setup);
}

#[cfg(target_arch = "wasm32")]
pub fn run<E: Example>(title: &str) {
    use wasm_bindgen::{prelude::*, JsCast};

    let title = title.to_owned();
    wasm_bindgen_futures::spawn_local(async move {
        let setup = setup::<E>(&title).await;
        let start_closure = Closure::once_into_js(move || start::<E>(setup));

        // make sure to handle JS exceptions thrown inside start.
        // Otherwise wasm_bindgen_futures Queue would break and never handle any tasks again.
        // This is required, because winit uses JS exception for control flow to escape from `run`.
        if let Err(error) = call_catch(&start_closure) {
            let is_control_flow_exception = error.dyn_ref::<js_sys::Error>().map_or(false, |e| {
                e.message().includes("Using exceptions for control flow", 0)
            });

            if !is_control_flow_exception {
                web_sys::console::error_1(&error);
            }
        }

        #[wasm_bindgen]
        extern "C" {
            #[wasm_bindgen(catch, js_namespace = Function, js_name = "prototype.call.call")]
            fn call_catch(this: &JsValue) -> Result<(), JsValue>;
        }
    });
}

#[cfg(target_arch = "wasm32")]
/// Parse the query string as returned by `web_sys::window()?.location().search()?` and get a
/// specific key out of it.
pub fn parse_url_query_string<'a>(query: &'a str, search_key: &str) -> Option<&'a str> {
    let query_string = query.strip_prefix('?')?;

    for pair in query_string.split('&') {
        let mut pair = pair.split('=');
        let key = pair.next()?;
        let value = pair.next()?;

        if key == search_key {
            return Some(value);
        }
    }

    None
}

#[cfg(test)]
pub struct FrameworkRefTest {
    pub image_path: &'static str,
    pub width: u32,
    pub height: u32,
    pub optional_features: wgpu::Features,
    pub base_test_parameters: test_common::TestParameters,
    pub tolerance: u8,
    pub max_outliers: usize,
}

#[cfg(test)]
#[allow(dead_code)]
pub fn test<E: Example>(mut params: FrameworkRefTest) {
    use std::{mem, num::NonZeroU32};

    assert_eq!(params.width % 64, 0, "width needs to be aligned 64");

    let features = E::required_features() | params.optional_features;

    test_common::initialize_test(
        mem::take(&mut params.base_test_parameters).features(features),
        |ctx| {
            let spawner = Spawner::new();

            let dst_texture = ctx.device.create_texture(&wgpu::TextureDescriptor {
                label: Some("destination"),
                size: wgpu::Extent3d {
                    width: params.width,
                    height: params.height,
                    depth_or_array_layers: 1,
                },
                mip_level_count: 1,
                sample_count: 1,
                dimension: wgpu::TextureDimension::D2,
                format: wgpu::TextureFormat::Rgba8UnormSrgb,
                usage: wgpu::TextureUsages::RENDER_ATTACHMENT | wgpu::TextureUsages::COPY_SRC,
            });

            let dst_view = dst_texture.create_view(&wgpu::TextureViewDescriptor::default());

            let dst_buffer = ctx.device.create_buffer(&wgpu::BufferDescriptor {
                label: Some("image map buffer"),
                size: params.width as u64 * params.height as u64 * 4,
                usage: wgpu::BufferUsages::COPY_DST | wgpu::BufferUsages::MAP_READ,
                mapped_at_creation: false,
            });

            let mut example = E::init(
                &wgpu::SurfaceConfiguration {
                    usage: wgpu::TextureUsages::RENDER_ATTACHMENT,
                    format: wgpu::TextureFormat::Rgba8UnormSrgb,
                    width: params.width,
                    height: params.height,
                    present_mode: wgpu::PresentMode::Fifo,
                    alpha_mode: wgpu::CompositeAlphaMode::Auto,
                },
                &ctx.adapter,
                &ctx.device,
                &ctx.queue,
            );

            example.render(&dst_view, &ctx.device, &ctx.queue, &spawner);

            // Handle specific case for bunnymark
            #[allow(deprecated)]
            if params.image_path == "/examples/bunnymark/screenshot.png" {
                // Press spacebar to spawn bunnies
                example.update(winit::event::WindowEvent::KeyboardInput {
                    input: winit::event::KeyboardInput {
                        scancode: 0,
                        state: winit::event::ElementState::Pressed,
                        virtual_keycode: Some(winit::event::VirtualKeyCode::Space),
                        modifiers: winit::event::ModifiersState::empty(),
                    },
                    device_id: unsafe { winit::event::DeviceId::dummy() },
                    is_synthetic: false,
                });

                // Step 3 extra frames
                for _ in 0..3 {
                    example.render(&dst_view, &ctx.device, &ctx.queue, &spawner);
                }
            }

            let mut cmd_buf = ctx
                .device
                .create_command_encoder(&wgpu::CommandEncoderDescriptor::default());

            cmd_buf.copy_texture_to_buffer(
                wgpu::ImageCopyTexture {
                    texture: &dst_texture,
                    mip_level: 0,
                    origin: wgpu::Origin3d::ZERO,
                    aspect: wgpu::TextureAspect::All,
                },
                wgpu::ImageCopyBuffer {
                    buffer: &dst_buffer,
                    layout: wgpu::ImageDataLayout {
                        offset: 0,
                        bytes_per_row: NonZeroU32::new(params.width * 4),
                        rows_per_image: None,
                    },
                },
                wgpu::Extent3d {
                    width: params.width,
                    height: params.height,
                    depth_or_array_layers: 1,
                },
            );

            ctx.queue.submit(Some(cmd_buf.finish()));

            let dst_buffer_slice = dst_buffer.slice(..);
            dst_buffer_slice.map_async(wgpu::MapMode::Read, |_| ());
            ctx.device.poll(wgpu::Maintain::Wait);
            let bytes = dst_buffer_slice.get_mapped_range().to_vec();

            test_common::image::compare_image_output(
                env!("CARGO_MANIFEST_DIR").to_string() + params.image_path,
                params.width,
                params.height,
                &bytes,
                params.tolerance,
                params.max_outliers,
            );
        },
    );
}

// This allows treating the framework as a standalone example,
// thus avoiding listing the example names in `Cargo.toml`.
#[allow(dead_code)]
fn main() {}