dist/wheel.js
function Wheel(parent, options) {
        _classCallCheck(this, Wheel);

        var _this = _possibleConstructorReturn(this, (Wheel.__proto__ || Object.getPrototypeOf(Wheel)).call(this, parent));

        options = options || {};
        _this.percent = options.percent || 0.1;
        _this.center = options.center;
        _this.reverse = options.reverse;
        _this.smooth = options.smooth;
        _this.interrupt = typeof options.interrupt === 'undefined' ? true : options.interrupt;
        return _this;
    }
function Wheel(parent, options) {
        _classCallCheck(this, Wheel);

        var _this = _possibleConstructorReturn(this, (Wheel.__proto__ || Object.getPrototypeOf(Wheel)).call(this, parent));

        options = options || {};
        _this.percent = options.percent || 0.1;
        _this.center = options.center;
        _this.reverse = options.reverse;
        _this.smooth = options.smooth;
        _this.interrupt = typeof options.interrupt === 'undefined' ? true : options.interrupt;
        return _this;
    }
@private
@param {Viewport} parent
@param {object} [options]
@param {number} [options.percent=0.1] percent to scroll with each spin
@param {number} [options.smooth] smooth the zooming by providing the number of frames to zoom between wheel spins
@param {boolean} [options.interrupt=true] stop smoothing with any user input on the viewport
@param {boolean} [options.reverse] reverse the direction of the scroll
@param {PIXI.Point} [options.center] place this point at center during zoom instead of current mouse position

@event wheel({wheel: {dx, dy, dz}, event, viewport})