var Velocity = require('velocity-vector'); // courtesy of https://github.com/julianshapiro/velocity/issues/283 // We only use easeOutBounce (easeInBounce is just sort of nonsensical) function bounce( p ) { var pow2, bounce = 4; while ( p < ( ( pow2 = Math.pow( 2, --bounce ) ) - 1 ) / 11 ) {} return 1 / Math.pow( 4, 3 - bounce ) - 7.5625 * Math.pow( ( pow2 * 3 - 2 ) / 22 - p, 2 ); } Velocity.Easings.easeOutBounce = function(p) { return 1 - bounce(1 - p); }