EffectTiming.easing
Experimental
This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The EffectTiming
dictionary's
easing
property in the Web Animations API specifies the
timing function used to scale the time to produce easing effects, where easing
is the rate of the animation's change over time.
Element.animate()
,
KeyframeEffectReadOnly()
, and KeyframeEffect()
all accept an object of timing properties including
easing
. The value of easing corresponds directly
to AnimationEffectTimingReadOnly.easing
in
timing
objects returned by
AnimationEffectReadOnly
, KeyframeEffectReadOnly
, and
KeyframeEffect
.
Syntax
var timingProperties = {
easing: <single-transition-timing-function>
}
timingProperties.easing = <single-transition-timing-function>
Value
A string defining the timing function to use for easing transitions during the
animation process. Accepts several pre-defined DOMString
values, a
steps()
timing function like steps(5, end)
, or a custom
cubic-bezier
value like cubic-bezier(0.42, 0, 0.58, 1)
.
Defaults to linear
. Available values include:
linear
- A constant rate of change, neither accelerating nor deccelerating.
-
cubic-bezier(<number>, <number>, <number>, <number>)
Specifies a cubic Bézier timing function. The four numbers specify points P1 and P2 of the curve as (x1, y1, x2, y2). Both x values must be in the range [0, 1] or the definition is invalid.ease
- A decelerated rate of change, going from fast to slow. Equivalent to
cubic-bezier(0.25, 0.1, 0.25, 1)
. ease-in
- An accelerated rate of change, going from slow to fast. Equivalent to
cubic-bezier(0.42, 0, 1, 1)
. ease-out
- Another decelerated rate of change, going from fast to slow. Equivalent to
cubic-bezier(0, 0, 0.58, 1)
. ease-in-out
- This rate of change speeds up in the middle. Equivalent to
cubic-bezier(0.42, 0, 0.58, 1)
. frames(<integer>)
- Specifies a frames timing
function, which breaks the animation down into a number of equal time intervals
but also displays the start (0%) and end (100%) states for an equal amount of time to
the other intervals. The browser flips to a different static frame when each interval
is reached, rather than animating smoothly. See GitHub for a simple
example that illustrates the difference between
steps()
andframes()
. steps(<integer>[, [ start | end ] ]?)
Specifies a step timing function, which breaks the animation down into a number of equal time intervals. The browser flips to a different static frame when each interval is reached, rather than animating smoothly. The first parameter specifies the number of intervals in the function. It must be a positive integer (greater than 0). The second parameter, which is optional, specifies the point at which the change of values occur within the interval. If the second parameter is omitted, it is given the value end.step-start
- Equivalent to
steps(1, start)
step-end
- Equivalent to
steps(1, end)
.
Examples
In the Red Queen's
Race example, we animate Alice and the Red Queen by passing an easing
of steps(7, end)
to animate()
:
// Define the key frames
var spriteFrames = [
{ transform: 'translateY(0)' },
{ transform: 'translateY(-100%)' }
];
// Get the element that represents Alice and the Red Queen
var redQueen_alice_sprite = document.getElementById('red-queen_and_alice_sprite');
// Animate Alice and the Red Queen using steps()
var redQueen_alice = redQueen_alice_sprite.animate(
spriteFrames, {
easing: 'steps(7, end)',
direction: "reverse",
duration: 600,
playbackRate: 1,
iterations: Infinity
});
Specifications
Specification | Status | Comment |
---|---|---|
Web Animations The definition of 'easing' in that specification. |
Working Draft | Editor's draft. |
Browser compatibility
BCD tables only load in the browser
See also
- Web Animations API
Element.animate()
,KeyframeEffect()
, andAnimationEffect.updateTiming()
all accept an object of timing properties including this one.- The value of this property corresponds to the one in
EffectTiming
(which is returned fromAnimationEffect.getTiming()
andAnimationEffect.getComputedTiming()
). - CSS's
animation-timing-function
andtransition-timing-function
.