Enable ImageBitmap by default

[jdm]

The DOM interface is gated behind dom.imagebitmap.enabled, which is disabled by default.

Spec: https://html.spec.whatwg.org/multipage/imagebitmap-and-animations.html#imagebitmap

Known missing APIs:

• [x] close https://github.com/servo/servo/pull/34124
• [x] ImageOrientation default has been renamed from "none" to "from-image" https://github.com/servo/servo/pull/34149
• [ ] the interface should be serializable and transferrable

Test coverage:

• https://github.com/servo/servo/tree/main/tests/wpt/meta/html/canvas/element/manual/imagebitmap

We currently fail all tests because we never migrated the preference from the 2013 layout results.

[simonwuelker]

To add to the "known issues":

• window.createImageBitmap does not follow the spec. For example, we should crop to the source rectangle with formatting
• ImageBitmapSource is missing multiple variants because CanvasImageSource is incomplete

I don't think all of these should block enabling the interface by default, but it's worth noting them down anyways

[sagudev]

not done yet

[tharkum]

@jdm, @sagudev <

There is requirement to support optional scaling on image bitmap creation (Step 7).

I didn't find any scaling function out of box in Servo (did I miss something?). I am planning to use third-party library for it. Are there are some restrictions with LICENSE? Smth else?

Candidates:

1. Resize (https://crates.io/crates/resize) - single-threaded, simple
2. Fast Image Resize (https://crates.io/crates/fast_image_resize) - single/multi-threaded, SIMD
3. ????

[tharkum]

It's not yet done. NEED to implement the following parts:

1. Crop with formating
2. Bitmap queue
3. Remove from experimental feature
4. Some minor issues...

[jdm]

@jdm, @sagudev <

There is requirement to support optional scaling on image bitmap creation (Step 7).

I didn't find any scaling function out of box in Servo (did I miss something?). I am planning to use third-party library for it. Are there are some restrictions with LICENSE? Smth else?

Candidates:

1. Resize (https://crates.io/crates/resize) - single-threaded, simple

2. Fast Image Resize (https://crates.io/crates/fast_image_resize) - single/multi-threaded, SIMD

3. ????

Licensing is the only restriction. If it passes test-tidy's license check them it works.

[sagudev]

Maybe it's worth checking that library support all resizequality options.

[tharkum]

FYI < I looked at three packages (image/resize/fast_image_resize) and decided to implement the ImageBitmap resize functionality based on the "image" package (already in dependencies), even if the "fast_image_resize" package would have better performance on large images (multi-threading/SIMD).

Porting from "image" to "fast_image_resize" could be done as a separate task (needs to test on different platforms and confirm performance improvements).

[tharkum]

I propose to remove ImageBitmap from experimental feature list (dom.imagebitmap.enabled) because at current moment almost all major tests are passed except specific CanvasImageSource tests (vector HTMImageElement, bitmap/vector SVGImageElement) and EXIF image orientation.

WDYT?

[jdm]

You mean remove it from the experimental list and enable it by default? I agree!

[mrobinson]

Sounds good to me. I would also remove the preference entirely.