# Easing

Analog of the `Easing`

module from React Native.

#### API

**step0()**

A stepping function, returns 1 for any positive value of `n`

.

**step1()**

A stepping function, returns 1 if `n`

is greater than or equal to 1.

**linear()**

A linear function, `f(t) = t`

. Position correlates to elapsed time one to one.

http://cubic-bezier.com/#0,0,1,1

**ease()**

A basic inertial interaction, similar to an object slowly accelerating to speed.

http://cubic-bezier.com/#.42,0,1,1

**quad()**

A quadratic function, `f(t) = t * t`

. Position equals the square of elapsed time.

http://easings.net/#easeInQuad

**cubic()**

A cubic function, `f(t) = t * t * t`

. Position equals the cube of elapsed time.

http://easings.net/#easeInCubic

**poly()**

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

**sin()**

A sinusoidal function.

http://easings.net/#easeInSine

**circle()**

A circular function.

http://easings.net/#easeInCirc

**exp()**

An exponential function.

http://easings.net/#easeInExpo

**elastic()**

A basic 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.

http://easings.net/#easeInElastic

**back()**

Use with `Animated.parallel()`

to create a basic effect where the object animates back slightly as the animation starts.

**bounce()**

Provides a basic bouncing effect.

http://easings.net/#easeInBounce

**bezier()**

Provides a cubic bezier curve, equivalent to CSS Transitions' `transition-timing-function`

.

A useful tool to visualize cubic bezier curves can be found at http://cubic-bezier.com/

**in()**

Runs an easing function forwards.

**out()**

Runs an easing function backwards.

**inOut()**

Makes any easing function symmetrical. The easing function will run forwards for half of the duration, then backwards for the rest of the duration.