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'use strict';
function registerPassthroughAnimator() {
return runInAnimationWorklet(`
registerAnimator('passthrough', class {
animate(currentTime, effect) {
effect.localTime = currentTime;
}
});
`);
}
function registerConstantLocalTimeAnimator(localTime) {
return runInAnimationWorklet(`
registerAnimator('constant_time', class {
animate(currentTime, effect) { effect.localTime = ${localTime}; }
});
`);
}
function runInAnimationWorklet(code) {
return CSS.animationWorklet.addModule(
URL.createObjectURL(new Blob([code], {type: 'text/javascript'}))
);
}
function approxEquals(actual, expected){
// precision in ms
const epsilon = 0.005;
const lowerBound = (expected - epsilon) < actual;
const upperBound = (expected + epsilon) > actual;
return lowerBound && upperBound;
}
function waitForAsyncAnimationFrames(count) {
// In Chrome, waiting for N+1 main thread frames guarantees that compositor has produced
// at least N frames.
// TODO(majidvp): re-evaluate this choice once other browsers have implemented
// AnimationWorklet.
return waitForAnimationFrames(count + 1);
}
async function waitForAnimationFrameWithCondition(condition) {
do {
await new Promise(window.requestAnimationFrame);
} while (!condition())
}
async function waitForDocumentTimelineAdvance() {
const timeAtStart = document.timeline.currentTime;
do {
await new Promise(window.requestAnimationFrame);
} while (timeAtStart === document.timeline.currentTime)
}
// Wait until animation's effect has a non-null localTime.
async function waitForNotNullLocalTime(animation) {
await waitForAnimationFrameWithCondition(_ => {
return animation.effect.getComputedTiming().localTime !== null;
});
}