Raphaël Easing Equations
var ef = R.easing_formulas = {
linear: function (n) {
return n;
},
"<": function (n) {
return pow(n, 1.7);
},
">": function (n) {
return pow(n, .48);
},
"<>": function (n) {
var q = .48 - n / 1.04,
Q = math.sqrt(.1734 + q * q),
x = Q - q,
X = pow(abs(x), 1 / 3) * (x < 0 ? -1 : 1),
y = -Q - q,
Y = pow(abs(y), 1 / 3) * (y < 0 ? -1 : 1),
t = X + Y + .5;
return (1 - t) * 3 * t * t + t * t * t;
},
backIn: function (n) {
var s = 1.70158;
return n * n * ((s + 1) * n - s);
},
backOut: function (n) {
n = n - 1;
var s = 1.70158;
return n * n * ((s + 1) * n + s) + 1;
},
elastic: function (n) {
if (n == !!n) {
return n;
}
return pow(2, -10 * n) * math.sin((n - .075) * (2 * PI) / .3) + 1;
},
bounce: function (n) {
var s = 7.5625,
p = 2.75,
l;
if (n < (1 / p)) {
l = s * n * n;
} else {
if (n < (2 / p)) {
n -= (1.5 / p);
l = s * n * n + .75;
} else {
if (n < (2.5 / p)) {
n -= (2.25 / p);
l = s * n * n + .9375;
} else {
n -= (2.625 / p);
l = s * n * n + .984375;
}
}
}
return l;
}
};
ef.easeIn = ef["ease-in"] = ef["<"];
ef.easeOut = ef["ease-out"] = ef[">"];
ef.easeInOut = ef["ease-in-out"] = ef["<>"];
ef["back-in"] = ef.backIn;
ef["back-out"] = ef.backOut;
Another fun chunk of code directly from the Raphaël source. Makes me think of the Penner easing equations.