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- This WPT test may be referenced by the following Test IDs:
- /css/css-easing/cubic-bezier-timing-functions-output.html - WPT Dashboard Interop Dashboard
<!DOCTYPE html>
<meta charset=utf-8>
<meta name="assert"
content="This test checks the output of Cubic Bézier functions" />
<title>Tests for the output of Cubic Bézier timing functions</title>
<link rel="help"
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="testcommon.js"></script>
<body>
<div id="log"></div>
<script>
'use strict';
// Precision of major rendering engines' layout systems.
const epsilon = 0.02;
function assert_style_left_at(animation, time, easingFunction) {
animation.currentTime = time;
var portion = time / animation.effect.getTiming()['duration'];
assert_approx_equals(pxToNum(getComputedStyle(animation.effect.target).left),
easingFunction(portion) * 100,
epsilon,
'The left of the animation should be approximately ' +
easingFunction(portion) * 100 + ' at ' + time + 'ms');
}
test(function(t) {
var target = createDiv(t);
target.style.position = 'absolute';
var anim = target.animate(
[ { left: '0px', easing: 'cubic-bezier(0.5, 1, 0.5, 0)' },
{ left: '100px' } ],
{ duration: 1000,
fill: 'forwards',
easing: 'cubic-bezier(0, 1.5, 1, 1.5)' });
var keyframeEasing = function(x) {
assert_greater_than_equal(x, 0.0,
'This function should be called in [0, 1.0] range');
assert_less_than_equal(x, 1.0,
'This function should be called in [0, 1.0] range');
return cubicBezier(0.5, 1, 0.5, 0)(x);
}
var keyframeEasingExtrapolated = function(x) {
assert_greater_than(x, 1.0,
'This function should be called in (1.0, infinity) range');
// p3x + (p2y - p3y) / (p2x - p3x) * (x - p3x)
return 1.0 + (0 - 1) / (0.5 - 1) * (x - 1.0);
}
var effectEasing = function(x) {
return cubicBezier(0, 1.5, 1, 1.5)(x);
}
// The effect-easing produces values greater than 1 in (0.23368794, 1)
assert_style_left_at(anim, 0, function(x) {
return keyframeEasing(effectEasing(x));
});
assert_style_left_at(anim, 230, function(x) {
return keyframeEasing(effectEasing(x));
});
assert_style_left_at(anim, 240, function(x) {
return keyframeEasingExtrapolated(effectEasing(x));
});
// Near the extreme point of the effect-easing function
assert_style_left_at(anim, 700, function(x) {
return keyframeEasingExtrapolated(effectEasing(x));
});
assert_style_left_at(anim, 990, function(x) {
return keyframeEasingExtrapolated(effectEasing(x));
});
assert_style_left_at(anim, 1000, function(x) {
return keyframeEasing(effectEasing(x));
});
}, 'cubic-bezier easing with input progress greater than 1');
test(function(t) {
var target = createDiv(t);
target.style.position = 'absolute';
var anim = target.animate(
[ { left: '0px', easing: 'cubic-bezier(0, 1.5, 1, 1.5)' },
{ left: '100px' } ],
{ duration: 1000,
fill: 'forwards',
easing: 'cubic-bezier(0, 1.5, 1, 1.5)' });
var easing = function(x) {
assert_greater_than_equal(x, 0.0,
'This function should be called in [0, 1.0] range');
assert_less_than_equal(x, 1.0,
'This function should be called in [0, 1.0] range');
return cubicBezier(0, 1.5, 1, 1.5)(x);
}
var easingExtrapolated = function(x) {
assert_greater_than(x, 1.0,
'This function should be called in negative range');
// For cubic-bezier(0, 1.5, 1, 1.5), the tangent at the
// endpoint (x = 1.0) is infinity so we should just return 1.0.
return 1.0;
}
// The effect-easing produces values greater than 1 in (0.23368794, 1)
assert_style_left_at(anim, 0, function(x) {
return easing(easing(x))
});
assert_style_left_at(anim, 230, function(x) {
return easing(easing(x))
});
assert_style_left_at(anim, 240, function(x) {
return easingExtrapolated(easing(x));
});
// Near the extreme point of the effect-easing function
assert_style_left_at(anim, 700, function(x) {
return easingExtrapolated(easing(x));
});
assert_style_left_at(anim, 990, function(x) {
return easingExtrapolated(easing(x));
});
assert_style_left_at(anim, 1000, function(x) {
return easing(easing(x))
});
}, 'cubic-bezier easing with input progress greater than 1 and where the ' +
'tangent on the upper boundary is infinity');
test(function(t) {
var target = createDiv(t);
target.style.position = 'absolute';
var anim = target.animate(
[ { left: '0px', easing: 'cubic-bezier(0.5, 1, 0.5, 0)' },
{ left: '100px' } ],
{ duration: 1000,
fill: 'forwards',
easing: 'cubic-bezier(0, -0.5, 1, -0.5)' });
var keyframeEasing = function(x) {
assert_greater_than_equal(x, 0.0,
'This function should be called in [0, 1.0] range');
assert_less_than_equal(x, 1.0,
'This function should be called in [0, 1.0] range');
return cubicBezier(0.5, 1, 0.5, 0)(x);
}
var keyframeEasingExtrapolated = function(x) {
assert_less_than(x, 0.0,
'This function should be called in negative range');
// p0x + (p1y - p0y) / (p1x - p0x) * (x - p0x)
return (1 / 0.5) * x;
}
var effectEasing = function(x) {
return cubicBezier(0, -0.5, 1, -0.5)(x);
}
// The effect-easing produces negative values in (0, 0.766312060)
assert_style_left_at(anim, 0, function(x) {
return keyframeEasing(effectEasing(x));
});
assert_style_left_at(anim, 10, function(x) {
return keyframeEasingExtrapolated(effectEasing(x));
});
// Near the extreme point of the effect-easing function
assert_style_left_at(anim, 300, function(x) {
return keyframeEasingExtrapolated(effectEasing(x));
});
assert_style_left_at(anim, 750, function(x) {
return keyframeEasingExtrapolated(effectEasing(x));
});
assert_style_left_at(anim, 770, function(x) {
return keyframeEasing(effectEasing(x));
});
assert_style_left_at(anim, 1000, function(x) {
return keyframeEasing(effectEasing(x));
});
}, 'cubic-bezier easing with input progress less than 0');
test(function(t) {
var target = createDiv(t);
target.style.position = 'absolute';
var anim = target.animate(
[ { left: '0px', easing: 'cubic-bezier(0, -0.5, 1, -0.5)' },
{ left: '100px' } ],
{ duration: 1000,
fill: 'forwards',
easing: 'cubic-bezier(0, -0.5, 1, -0.5)' });
var easing = function(x) {
assert_greater_than_equal(x, 0.0,
'This function should be called in [0, 1.0] range');
assert_less_than_equal(x, 1.0,
'This function should be called in [0, 1.0] range');
return cubicBezier(0, -0.5, 1, -0.5)(x);
}
var easingExtrapolated = function(x) {
assert_less_than(x, 0.0,
'This function should be called in negative range');
// For cubic-bezier(0, -0.5, 1, -0.5), the tangent at the
// endpoint (x = 0.0) is infinity so we should just return 0.0.
return 0.0;
}
// The effect-easing produces negative values in (0, 0.766312060)
assert_style_left_at(anim, 0, function(x) {
return easing(easing(x))
});
assert_style_left_at(anim, 10, function(x) {
return easingExtrapolated(easing(x));
});
// Near the extreme point of the effect-easing function
assert_style_left_at(anim, 300, function(x) {
return easingExtrapolated(easing(x));
});
assert_style_left_at(anim, 750, function(x) {
return easingExtrapolated(easing(x));
});
assert_style_left_at(anim, 770, function(x) {
return easing(easing(x))
});
assert_style_left_at(anim, 1000, function(x) {
return easing(easing(x))
});
}, 'cubic-bezier easing with input progress less than 0 and where the ' +
'tangent on the lower boundary is infinity');
</script>
</body>