Add vello backend by implementing Backend traits in canvas crate (so
this lives in canvas_paint_thread - embedded process). Current
implementation uses normal wgpu, so we block on GPU work. Vello backend
is gated behind `vello` feature and `dom_canvas_vello_enabled` pref.
Feature-wise this backend is on on par with raqote (sometimes better
sometimes worse), but performance wise it's worse.
## Known vello problems:
- image roundtrip does not work (fixed in
https://github.com/linebender/vello/pull/974)
- https://github.com/linebender/vello/issues/1066 (fixed)
- clip layers are not working properly:
https://github.com/linebender/vello/issues/1061
- `/html/canvas/element/pixel-manipulation/2d.imageData.put.*`
- `/html/canvas/element/path-objects/2d.path.clip.intersect.html`
- https://github.com/linebender/vello/issues/1056
-
`/html/canvas/element/fill-and-stroke-styles/2d.gradient.interpolate.coloralpha.html`
- `kurbo::Cap::Butt` is defect (only visible with big lineWidth)
https://github.com/linebender/vello/issues/1063
- `/html/canvas/element/line-styles/2d.line.cross.html`
- `/html/canvas/element/line-styles/2d.line.miter.acute.html`
- other lack of strong correct problems
(https://github.com/linebender/vello/issues/1063#issuecomment-2998084736):
- `/html/canvas/element/path-objects/2d.path.rect.selfintersect.html`
- There is currently no way to do put image properly in vello as we
would need to ignore all clips and other stuff (we try to work around
this on best effort basis)
https://github.com/linebender/vello/issues/1088
- `/html/canvas/element/pixel-manipulation/2d.imageData.put.*`
- precision problems
- `/html/canvas/element/path-objects/2d.path.stroke.scale2.html`
- `/html/canvas/element/path-objects/2d.path.arc.scale.1.html`
## Known servo problems
- bad performance due to blocking on GPU work
- some get/put intensive tests `TIMEOUT`
- proper shadow support (non-blocker as we already are living without it
now)
- support for rect shadow is there but unimplemented currently as that's
the state in raqote
Testing: `mach try vello` will run normal WPT (with raqote) +
vello_canvas subsuite that runs only on `/html/canvas/element`. All
subsuite expectations are stored separately.
Fixes: #36823Fixes: #35230
---------
Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>
This removes assumption about pixel format from backend abstraction to
actual backend implementation. This is important for vello.
Testing: WPT tests
---------
Signed-off-by: sagudev <16504129+sagudev@users.noreply.github.com>
Follow to the HTML specification and support of Blob as
ImageBitmapSource
to able use it as intermediate instance in "fetch() -> Blob ->
ImageBitmap" execution sequence.
https://html.spec.whatwg.org/multipage/#imagebitmapsource
The specification says what these steps must run in parallel
(outside the createImageBitmap task), but currently loading bytes from
Blob
and later image decoding happen in synchronous order while
promise is fullfilled or rejected on bitmap task source.
https://html.spec.whatwg.org/multipage/#the-imagebitmap-interface:blob-4
Testing: Improvements in the following WPT tests
- html/canvas/element/compositing/2d.composite*
- html/canvas/element/drawing-images-to-the-canvas/2d.drawImage*
- html/canvas/element/manual/imagebitmap/createImageBitmap*
- html/canvas/offscreen/compositing/2d.composite
- html/canvas/offscreen/drawing-images-to-the-canvas/2d.drawImage
- webgl/tests/conformance/textures/image_bitmap_from_blob/*
Fixes (partially): #34112
Signed-off-by: Andrei Volykhin <andrei.volykhin@gmail.com>
This change adds support for rendering static SVG images using the
`resvg` crate, allowing svg sources in the `img` tag and in CSS
`background` and `content` properties. There are some limitations in
using resvg:
1. There is no support for animations or interactivity as these would
require implementing the full DOM layer of SVG specification.
2. Only system fonts can be used for text rendering. There is some
mechanism to provide a custom font resolver to usvg, but that is not
explored in this change.
3. resvg's handling of certain edge cases involving lack of explicit
`width` and `height` on the root svg element deviates from what the
specification expects from browsers. For example, resvg uses the values
in `viewBox` to derive the missing width or height dimension, but
without scaling that dimension to preserve the aspect ratio. It also
doesn't allow overriding this behavior.
Demo screenshot:

<details>
<summary>Source</summary>
```
<style>
#svg1 {
border: 1px solid red;
}
#svg2 {
border: 1px solid red;
width: 300px;
}
#svg3 {
border: 1px solid red;
width: 300px;
height: 200px;
object-fit: contain;
}
#svg4 {
border: 1px solid red;
width: 300px;
height: 200px;
object-fit: cover;
}
#svg5 {
border: 1px solid red;
width: 300px;
height: 200px;
object-fit: fill;
}
#svg6 {
border: 1px solid red;
width: 300px;
height: 200px;
object-fit: none;
}
</style>
</head>
<body>
<div>
<img id="svg1" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
</div>
<div>
<img id="svg2" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
<img id="svg3" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
<img id="svg4" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
</div>
<div>
<img id="svg5" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
<img id="svg6" src="https://raw.githubusercontent.com/servo/servo/refs/heads/main/resources/servo.svg" alt="Servo logo">
</div>
</body>
```
</details>
---------
Signed-off-by: Mukilan Thiyagarajan <mukilan@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>
Most tests were only being run for layout-2013, not for layout-2020.
This wasn't great since layout-2020 is now the default.
So this patch unifies the lists of included tests for both layouts.
For layout-2013 this implies adding css/css-content/, css/css-logical/
and css/css-masking/clip/.
For layout-2020 this implies adding several additional css tests, and
also tests like dom/, js/, html/, etc.