README

composer require smnandre/easing-functions

EasingFunctions is a PHP library that provides a collection of easing functions commonly used in animations, transitions, and smooth interpolations.

It includes standard easing equations: quadratic, cubic, quartic, quintic, sine, exponential, circular, elastic, and bounce functions.

Each of them is available in three variations:

In: The motion starts slowly and accelerates.
Out: The motion starts quickly and decelerates.
InOut: A combination of both, accelerating at the start and decelerating at the end.

Easing Functions

x	In	Out	InOut
Cubic	`easeInCubic`	`easeOutCubic`	`easeInOutCubic`
Quart	`easeInQuart`	`easeOutQuart`	`easeInOutQuart`
Quad	`easeInQuad`	`easeOutQuad`	`easeInOutQuad`
Quint	`easeInQuint`	`easeOutQuint`	`easeInOutQuint`
Sine	`easeInSine`	`easeOutSine`	`easeInOutSine`
Expo	`easeInExpo`	`easeOutExpo`	`easeInOutExpo`
Circ	`easeInCirc`	`easeOutCirc`	`easeInOutCirc`
Back	`easeInBack`	`easeOutBack`	`easeInOutBack`
Bounce	`easeInBounce`	`easeOutBounce`	`easeInOutBounce`
Elastic	`easeInElastic`	`easeOutElastic`	`easeInOutElastic`

Installation

composer require smnandre/easing-functions

Usage

Easing\Functions::easeOutCubic(0);
// 0
Easing\Functions::easeOutCubic(0.5);
// 0.875

$values = array_map(Easing\Functions::easeOutCubic(...), range(0, 1, 0.1));
echo implode(" ", $values);
// 0 0.271 0.488 0.657 0.784 0.875 0.936 0.973 0.992 0.999 1

Functions

Easing Functions

Name	Formulae	Preview
`easeOutCubic`	$1 - pow(1 - x, 3)$
`easeInOutCubic`	$x < 0.5 ? 4 * pow(x, 3) : 1 - pow(-2 * x + 2, 3) / 2$
`easeInQuart`	$pow(x, 4)$
`easeOutQuart`	$1 - pow(1 - x, 4)$
`easeInOutQuart`	$x < 0.5 ? 8 * pow(x, 4) : 1 - pow(-2 * x + 2, 4) / 2$
`easeInCubic`	$pow(x, 3)$
`easeInQuad`	$x * x$
`easeOutQuad`	$1 - (1 - x) * (1 - x)$
`easeInOutQuad`	$x < 0.5 ? 2 * x * x : 1 - pow(-2 * x + 2, 2) / 2$
`easeInQuint`	$pow(x, 5)$
`easeOutQuint`	$1 - pow(1 - x, 5)$
`easeInOutQuint`	$x < 0.5 ? 16 * pow(x, 5) : 1 - pow(-2 * x + 2, 5) / 2$
`easeInSine`	$1 - cos((x * pi()) / 2)$
`easeOutSine`	$sin((x * pi()) / 2)$
`easeInOutSine`	$-(cos(pi() * x) - 1) / 2$
`easeInExpo`	$x == 0 ? 0 : pow(2, 10 * x - 10)$
`easeOutExpo`	$x == 1 ? 1 : 1 - pow(2, -10 * x)$
`easeInOutExpo`	$x == 0 ? 0 : x == 1 ? 1 : x < 0.5 ? pow(2, 20 * x - 10) / 2 : (2 - pow(2, -20 * x + 10)) / 2$
`easeInCirc`	$1 - sqrt(1 - pow(x, 2))$
`easeOutCirc`	$sqrt(1 - pow(x - 1, 2))$
`easeInOutCirc`	$x < 0.5 ? (1 - sqrt(1 - pow(2 * x, 2))) / 2 : (sqrt(1 - pow(-2 * x + 2, 2)) + 1) / 2$
`easeInBack`	$2.70158 * pow(x, 3) - 1.70158 * pow(x, 2)$
`easeOutBack`	$1 + 2.70158 * pow(x - 1, 3) + 1.70158 * pow(x - 1, 2)$
`easeInOutBack`	$x < 0.5 ? (pow(2 * x, 2) * ((3.59258 * 2 * x) - 2.59258)) / 2 : (pow(2 * x - 2, 2) * ((3.59258 * (x * 2 - 2)) + 2.59258) + 2) / 2$
`easeInBounce`	$1 - easeOutBounce(1 - x)$
`easeOutBounce`	See `bounceOut` function
`easeInOutBounce`	$x < 0.5 ? (1 - easeOutBounce(1 - 2 * x)) / 2 : (1 + easeOutBounce(2 * x - 1)) / 2$
`easeInElastic`	$x == 0 ? 0 : x == 1 ? 1 : -pow(2, 10 * x - 10) * sin((x * 10 - 10.75) * ((2 * pi()) / 3))$
`easeOutElastic`	$x == 0 ? 0 : x == 1 ? 1 : pow(2, -10 * x) * sin((x * 10 - 0.75) * ((2 * pi()) / 3)) + 1$
`easeInOutElastic`	$x == 0 ? 0 : x == 1 ? 1 : x < 0.5 ? -(pow(2, 20 * x - 10) * sin((20 * x - 11.125) * ((2 * pi()) / 4.5))) / 2 : (pow(2, -20 * x + 10) * sin((20 * x - 11.125) * ((2 * pi()) / 4.5))) / 2 + 1$