Easing模块实现了常见的动画缓动函数。 This module is used by Animated.timing() to convey physically believable motion in animations.
You can find a visualization of some common easing functions at http://easings.net/
backprovides a simple animation where the object goes slightly back before moving forward
bounceprovides a bouncing animation
easeprovides a simple inertial animation
elasticprovides a simple spring interaction
poly function can be used to implement quartic, quintic, and other higher power functions.
bezierprovides a cubic bezier curve
circleprovides a circular function
sinprovides a sinusoidal function
expprovides an exponential function
The following helpers are used to modify other easing functions.
inruns an easing function forwards
inOutmakes any easing function symmetrical
outruns an easing function backwards
A stepping function, returns 1 for any positive value of
A stepping function, returns 1 if
n is greater than or equal to 1.
A linear function,
f(t) = t. Position correlates to elapsed time one to one.
A simple inertial interaction, similar to an object slowly accelerating to speed.
A quadratic function,
f(t) = t * t. Position equals the square of elapsed time.
A cubic function,
f(t) = t * t * t. Position equals the cube of elapsed time.
A power function. Position is equal to the Nth power of elapsed time.
n = 4: http://easings.net/#easeInQuart n = 5: http://easings.net/#easeInQuint
A sinusoidal function.
A circular function.
An exponential function.
A simple elastic interaction, similar to a spring oscillating back and forth.
Default bounciness is 1, which overshoots a little bit once. 0 bounciness doesn't overshoot at all, and bounciness of N > 1 will overshoot about N times.
Animated.parallel() to create a simple effect where the object animates back slightly as the animation starts.
Provides a simple bouncing effect.
static bezier(x1, y1, x2, y2)
Provides a cubic bezier curve, equivalent to CSS Transitions'
A useful tool to visualize cubic bezier curves can be found at http://cubic-bezier.com/
Runs an easing function forwards.
Runs an easing function backwards.
Makes any easing function symmetrical. The easing function will run forwards for half of the duration, then backwards for the rest of the duration.