Javascript "bump"识别(移动设备)

Question

我需要一个简单的解决方案来识别移动网络应用程序中的“凸起”。目前是这样的:

waitForBump = function () {
    if (window.DeviceMotionEvent != undefined) {
        window.addEventListener("devicemotion", accelerometerUpdate, true);
    }
}

accelerometerUpdate = function(e) {
    var aX = e.accelerationIncludingGravity.x * 1;
    var aY = e.accelerationIncludingGravity.y * 1;
    var aZ = e.accelerationIncludingGravity.z * 1;

    if ((aX * aY * aZ) >= 1000) { // here is the point!
        bump();
    }
}

bump = function() {
    window.removeEventListener("devicemotion", accelerometerUpdate, true);

    // do something...
}

感谢任何有关搜索正确算法的帮助或提示!

Answer 1

通过使用引用值比较加速度得到了更好的东西:

waitForBump = function () {
    if (window.DeviceMotionEvent != undefined) {
        window.addEventListener("devicemotion", accelerometerUpdate, true);
    }
}

var kFilteringFactor = 0.1;

var accX = null;
var accY = null;
var accZ = null;

accelerometerUpdate = function(e) {
    var prevAccX = accX;
    var prevAccY = accY;
    var prevAccZ = accZ;

    var aX = e.accelerationIncludingGravity.x * 1;
    var aY = e.accelerationIncludingGravity.y * 1;
    var aZ = e.accelerationIncludingGravity.z * 1;

    accX = aX - ((aX * kFilteringFactor) + (accX * (1.0 - kFilteringFactor)));
    accY = aY - ((aY * kFilteringFactor) + (accY * (1.0 - kFilteringFactor)));
    accZ = aZ - ((aZ * kFilteringFactor) + (accZ * (1.0 - kFilteringFactor)));

    if (prevAccX == null || prevAccY == null || prevAccZ == null) return;

    var deltaX = Math.abs((accX - prevAccX)) * kFilteringFactor;
    var deltaY = Math.abs((accY - prevAccY)) * kFilteringFactor;
    var deltaZ = Math.abs((accZ - prevAccZ)) * kFilteringFactor;

    if (deltaX > 2 || deltaY > 2 || deltaZ > 2) bump();
}

bump = function() {
    window.removeEventListener("devicemotion", accelerometerUpdate, true);

    accX = null;
    accY = null;
    accZ = null;

    // do something
}

对于我来说，比较大于 2 的增量就足够了。将此值设置为适当的阈值，您就可以开始了!