获取鼠标移动速度

Question

我没有从 Whosebug 得到确切的 solution/calculation 所以我创建了一个问题

var timestamp = null;
var mY = 0;
$(document).mousemove(function(e) {
    var now = Date.now();
    currentmY = e.pageY;



    mY = e.pageY;
    timestamp = now;
});

我需要获取鼠标移动垂直角度时的速度值。

https://jsfiddle.net/58tjr9o1/

Answer 1

以下代码会在id="update-speed"的span内不断更新鼠标的垂直移动速度。代码不言自明且易于理解，它只是保存了当前位置、先前位置、当前时间和先前时间，然后使用此公式计算速度 (speed = (pos2 - pos1) / (time2 - time1).

HTML

<span id="update-speed">Update speed</span>

JS

var prev_time = new Date();
var prev_pos_y = 0;

$(document).mousemove(function(e) {

var now = new Date();
current_pos_y = e.pageY;

time_interval = now.getTime() - prev_time.getTime();

if(time_interval != 0)
    {
        speed = ( Math.abs(current_pos_y - prev_pos_y) / time_interval );
}
else
    speed = 0;

console.log(speed);

$('#update-speed').text(speed);


prev_time = now;
prev_pos_y = current_pos_y;


});

Answer 2

速度就是距离除以所用时间：

speed = distance / time

距离currentmY - mY，时间now - timestamp。所以最后，你得到：

var timestamp = 0;
var mY = 0;
$(document).mousemove(function(e) {
    var now = Date.now();
    currentmY = e.screenY;

    var dt = now - timestamp;
    var distance = Math.abs(currentmY - mY);
    var speed = Math.round(distance / dt * 1000);
    console.log(dt, distance, speed);
    document.getElementById("speed").innerHTML = speed;

    mY = currentmY;
    timestamp = now;
});

注意 * 1000，因为时间戳以毫秒为单位。速度在这里pixels/second.

参见 this updated fiddle。

获取鼠标移动速度

Get mouse moving speed

javascript

jquery

html

performance

mousemove