Easing Equations in JavaScript

easing_equations_as_functions.js

// quadratic -----------------------------------------------------------------------------------------

easeInQuad(t, b, c, d) {
	t /= d;
	return c * t * t + b;
}

easeOutQuad(t, b, c, d) {
	t /= d;
	return -c * t*(t-2) + b;
};

easeInOutQuad(t, b, c, d) {
	t /= d/2;
	if (t < 1) return c/2*t*t + b;
	t--;
	return -c/2 * (t*(t-2) - 1) + b;
};

// cubic -----------------------------------------------------------------------------------------

easeInCubic(t, b, c, d) {
	t /= d;
	return c * t * t * t + b;
}

easeOutCubic(t, b, c, d) {
	t /= d;
	t--;
	return c*(t*t*t + 1) + b;
};

easeInOutCubic(t, b, c, d) {
	t /= d/2;
	if (t < 1) return c/2*t*t*t + b;
	t -= 2;
	return c/2*(t*t*t + 2) + b;
};

// quartic -----------------------------------------------------------------------------------------

easeInQuart(t, b, c, d) {
	t /= d;
	return c * t * t * t * t + b;
}

easeOutQuart(t, b, c, d) {
	t /= d;
	t--;
	return -c * (t*t*t*t - 1) + b;
};

easeInOutQuart(t, b, c, d) {
	t /= d/2;
	if (t < 1) return c/2*t*t*t*t + b;
	t -= 2;
	return -c/2 * (t*t*t*t - 2) + b;
};

// quinitc -----------------------------------------------------------------------------------------

easeInQuint(t, b, c, d) {
	t /= d;
	return c * t * t * t * t * t + b;
}

easeOutQuint(t, b, c, d) {
	t /= d;
	t--;
	return c*(t*t*t*t*t + 1) + b;
};

easeInOutQuint(t, b, c, d) {
	t /= d/2;
	if (t < 1) return c/2*t*t*t*t*t + b;
	t -= 2;
	return c/2*(t*t*t*t*t + 2) + b;
};

// sinusoidal -----------------------------------------------------------------------------------------

easeInSine(t, b, c, d) {
	return -c * Math.cos(t / d * (Math.PI / 2)) + c + b;
}

easeOutSine(t, b, c, d) {
	return c * Math.sin(t/d * (Math.PI/2)) + b;
};

easeInOutSine(t, b, c, d) {
	return -c/2 * (Math.cos(Math.PI*t/d) - 1) + b;
};

// exponential -----------------------------------------------------------------------------------------

easeInExpo(t, b, c, d) {
	return c * Math.pow(2, 10 * (t / d - 1)) + b;
}

easeOutExpo(t, b, c, d) {
	return c * ( -Math.pow( 2, -10 * t/d ) + 1 ) + b;
};

easeInOutExpo(t, b, c, d) {
	t /= d/2;
	if (t < 1) return c/2 * Math.pow( 2, 10 * (t - 1) ) + b;
	t--;
	return c/2 * ( -Math.pow( 2, -10 * t) + 2 ) + b;
};

// circular -----------------------------------------------------------------------------------------

easeInOutCirc(t, b, c, d) {
	t /= d/2;
	if (t < 1) return -c/2 * (Math.sqrt(1 - t*t) - 1) + b;
	t -= 2;
	return c/2 * (Math.sqrt(1 - t*t) + 1) + b;
};

easeInCirc(t, b, c, d) {
	t /= d;
	return -c * (Math.sqrt(1 - t * t) - 1) + b;
}

easeOutCirc(t, b, c, d) {
	t /= d;
	t--;
	return c * Math.sqrt(1 - t*t) + b;
};