[webkit-changes] [WebKit/WebKit] df87a5: [web-animations] animation with a non-invertible m...

[Antoine Quint]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: df87a56d78cc80fa3d314ac800addc4b6b18e340
      https://github.com/WebKit/WebKit/commit/df87a56d78cc80fa3d314ac800addc4b6b18e340
  Author: Antoine Quint <graouts at webkit.org>
  Date:   2024-06-28 (Fri, 28 Jun 2024)

  Changed paths:
    A LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-interpolation-007-expected.txt
    A LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-interpolation-007.html
    A LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-discrete-interpolation-expected.html
    A LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-discrete-interpolation-ref.html
    A LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-discrete-interpolation.html
    A LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-no-transition-expected.txt
    A LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-no-transition.html
    M Source/WebCore/animation/BlendingKeyframes.cpp
    M Source/WebCore/animation/BlendingKeyframes.h
    M Source/WebCore/animation/CSSPropertyAnimation.cpp
    M Source/WebCore/animation/KeyframeEffect.cpp
    M Source/WebCore/platform/graphics/transforms/TransformOperations.cpp
    M Source/WebCore/platform/graphics/transforms/TransformOperations.h

  Log Message:
  -----------
  [web-animations] animation with a non-invertible matrix should not interpolate
https://bugs.webkit.org/show_bug.cgi?id=275993
rdar://130704075

Reviewed by Matt Woodrow.

We had three separate issues that would lead us to visually animate when one of the values in a given interval
is a non-invertible matrix:

1. The method that determines whether it's possible to interpolate between two `transform` values would only
account for `matrix()` values and not `matrix3d()`.

2. The `transform` property animation wrapper would not implement the `canInterpolate()` method and would thus
always indicate that two `transform` values could be interpolated. This caused CSS Transitions to run even when
the values would not a discrete interpolation.

3. Even if we correctly determined that two `transform` values should yield discrete interpolation, we would
delegate an accelerated animation to Core Animation and that animation's behavior would differ an visibly
interpolate.

In this patch, we fill all three issues.

First, we introduce a new `TransformOperations::containsNonInvertibleMatrix()` method which will check whether
a `matrix()` or `matrix3d()` value that is not invertible is contained in the list of transform operations. We
now use this function in `TransformOperations::shouldFallBackToDiscreteAnimation()` to address issue #1.

Then, we add a `canInterpolate()` implementation to `AcceleratedTransformOperationsPropertyWrapper` which calls
in the now-correct `TransformOperations::shouldFallBackToDiscreteAnimation()` to address issue #2.

Finally, we add a new flag on `BlendingKeyframes` to determine whether a keyframe contains a `transform` value
with a non-invertible matrix and we consult that flag in `KeyframeEffect::canBeAccelerated()` to determine whether
an animation should be delegated to Core Animation, addressing issue #3.

We add new WPT tests to check the correct interpolation behavior of `transform` when a non-invertible `matrix3d()`
value is used, that no CSS Transition can be started with such a value, and finally that no animation is visibly
run to catch the Core Animation case.

* LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-interpolation-007-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-interpolation-007.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-discrete-interpolation-expected.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-discrete-interpolation-ref.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-discrete-interpolation.html: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-no-transition-expected.txt: Added.
* LayoutTests/imported/w3c/web-platform-tests/css/css-transforms/animation/transform-non-invertible-no-transition.html: Added.
* Source/WebCore/animation/BlendingKeyframes.cpp:
(WebCore::BlendingKeyframes::analyzeKeyframe):
* Source/WebCore/animation/BlendingKeyframes.h:
(WebCore::BlendingKeyframes::hasDiscreteTransformInterval const):
* Source/WebCore/animation/CSSPropertyAnimation.cpp:
* Source/WebCore/animation/KeyframeEffect.cpp:
(WebCore::KeyframeEffect::canBeAccelerated const):
* Source/WebCore/platform/graphics/transforms/TransformOperations.cpp:
(WebCore::TransformOperations::containsNonInvertibleMatrix const):
(WebCore::TransformOperations::shouldFallBackToDiscreteAnimation const):
* Source/WebCore/platform/graphics/transforms/TransformOperations.h:

Canonical link: https://commits.webkit.org/280466@main



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