问减慢谷歌panTo函数的速度

EN

var EasingAnimator = function(opt){
        opt = opt || {};
        this.easingInterval = opt.easingInterval;
        this.duration = opt.duration || 1000;
        this.step = opt.step || 50;
        this.easingFn = opt.easingFn  || function easeInOutElastic(t, b, c, d) {
            if ((t/=d/2) < 1) return c/2*t*t*t*t + b;
            return -c/2 * ((t-=2)*t*t*t - 2) + b;
        };
        this.callBack = opt.callBack || function(){};
    };
EasingAnimator.makeFromCallback = function(callBack){
    return new EasingAnimator({
        callBack: callBack
    });
};
EasingAnimator.prototype.easeProp = function(obj, propDict){
    propDict = propDict || {};

    var self = this,
        t = 0,
        out_vals = JSON.parse(JSON.stringify(obj));

    clearInterval(self.easingInterval);
    self.easingInterval = setInterval(function(){
        t+= self.step;
        if (t >= self.duration) {
            clearInterval(self.easingInterval);
            self.callBack(propDict);
            return;
        }
        var percent = self.easingFn(t, 0, 1, self.duration);
        Object.keys(propDict).forEach(function(key, i) {
            var old_val = obj[key];

            out_vals[key] = old_val - percent*(old_val - propDict[key]);
        });
        self.callBack(out_vals);
    }, self.step);
};

dom_elem.addEventListener('click', function(event){
    var point = map.getCenter();

    easingAnimator.easeProp({
        lat: point.lat(),
        lng: point.lng()
    }, points[i]);
});