摇一摇js代码

init();
var SHAKE_THRESHOLD = 3000;
var last_update = 0;
var x = y = z = last_x = last_y = last_z = 0;
function init() {
if (window.DeviceMotionEvent) {
window.addEventListener('devicemotion', deviceMotionHandler, false);
} else {
alert('not support mobile event');
}
}
function deviceMotionHandler(eventData) {
var acceleration = eventData.accelerationIncludingGravity;
var curTime = new Date().getTime();
if ((curTime - last_update) > 100) {
var diffTime = curTime - last_update;
last_update = curTime;
x = acceleration.x;
y = acceleration.y;
z = acceleration.z;
var speed = Math.abs(x + y + z - last_x - last_y - last_z) / diffTime * 10000;

if (speed > SHAKE_THRESHOLD) {
alert("摇动了");
media.setAttribute("src", "http://211.148.5.228:8002/Pages/test/Kalimba.mp3");
media.load();
media.play(); 
}
last_x = x;
last_y = y;
last_z = z;
}
}