[webkit-changes] [WebKit/WebKit] 5dfffd: [web-animations] interpolating keyframes should be...

[Antoine Quint]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 5dfffd1d9c0cdf683b9302cd72303bf9e6700921
      https://github.com/WebKit/WebKit/commit/5dfffd1d9c0cdf683b9302cd72303bf9e6700921
  Author: Antoine Quint <graouts at webkit.org>
  Date:   2023-11-14 (Tue, 14 Nov 2023)

  Changed paths:
    M Source/WebCore/animation/KeyframeEffect.cpp
    M Source/WebCore/animation/KeyframeEffect.h
    M Source/WebCore/animation/KeyframeInterpolation.cpp
    M Source/WebCore/animation/KeyframeInterpolation.h
    M Source/WebCore/platform/animation/AcceleratedEffect.cpp
    M Source/WebCore/platform/animation/AcceleratedEffect.h

  Log Message:
  -----------
  [web-animations] interpolating keyframes should be shared in `KeyframeInterpolation`
https://bugs.webkit.org/show_bug.cgi?id=264796

Reviewed by Dean Jackson.

Until now, the code to interpolate keyframes was contained within `KeyframeEffect::setAnimatedPropertiesInStyle()`.
As part of the work on threaded animation resolution (see bug 250970), we will need to share this logic with
`AcceleratedEffect` as well. Now that we have a shared concept of a keyframe (see bug 264747) and shared code to
determine the interpolation interval (see bug 264756), we add a method to `KeyframeInterpolation` for the
purpose of interpolation and whatever virtual methods are required to support it.

During interpolation, we need additional information from the `KeyframeInterpolation` subclasses such that we can
determine what composite operation to use and how to apply it, as well as the timing function to use to compute
the final interpolation progress:

    CompositeOperation compositeOperation() const;
    bool isPropertyAdditiveOrCumulative(Property) const;
    IterationCompositeOperation iterationCompositeOperation() const;
    const TimingFunction* timingFunctionForKeyframe(const Keyframe&) const;

With that information, we can add a new `interpolateKeyframes()` method which will take several callbacks as parameters
to let the `KeyframeInterpolation` subclass perform the actual interpolation based on the value types it manipulates
(`RenderStyle` objects for `KeyframeEffect` and `AcceleratedEffectValues` for `AcceleratedEffect`):

    using CompositionCallback = Function<void(const Keyframe&, CompositeOperation)>;
    using AccumulationCallback = Function<void(const Keyframe&)>;
    using InterpolationCallback = Function<void(double intervalProgress, double currentIteration, IterationCompositeOperation)>;
    using RequiresBlendingForAccumulativeIterationCallback = Function<bool()>;
    void interpolateKeyframes(Property, const KeyframeInterval&, double iterationProgress, double currentIteration, Seconds iterationDuration, const CompositionCallback&, const AccumulationCallback&, const InterpolationCallback&, const RequiresBlendingForAccumulativeIterationCallback&) const;

Finally, we move much of the remaining code from `KeyframeEffect::setAnimatedPropertiesInStyle` into the new
`KeyframeInterpolation::interpolateKeyframes()` method.

* Source/WebCore/animation/KeyframeEffect.cpp:
(WebCore::KeyframeEffect::setAnimatedPropertiesInStyle):
(WebCore::KeyframeEffect::timingFunctionForBlendingKeyframe const):
(WebCore::KeyframeEffect::timingFunctionForKeyframeAtIndex const):
(WebCore::KeyframeEffect::progressUntilNextStep const):
(WebCore::KeyframeEffect::timingFunctionForKeyframe const):
(WebCore::KeyframeEffect::isPropertyAdditiveOrCumulative const):
* Source/WebCore/animation/KeyframeEffect.h:
* Source/WebCore/animation/KeyframeInterpolation.cpp:
(WebCore::KeyframeInterpolation::interpolateKeyframes const):
* Source/WebCore/animation/KeyframeInterpolation.h:
(WebCore::KeyframeInterpolation::iterationCompositeOperation const):
* Source/WebCore/platform/animation/AcceleratedEffect.cpp:
(WebCore::cssPropertyFromAcceleratedProperty):
(WebCore::AcceleratedEffect::timingFunctionForKeyframe const):
(WebCore::AcceleratedEffect::isPropertyAdditiveOrCumulative const):
* Source/WebCore/platform/animation/AcceleratedEffect.h:
(WebCore::AcceleratedEffect::compositeOperation const): Deleted.

Canonical link: https://commits.webkit.org/270700@main