设备方向传感器到CSS转换

时间:2019-06-18 12:19:17

标签: javascript css 3d transform orientation

我创建了the following widget (see demo here)来模仿chrome开发人员标签上的传感器标签:


enter image description here


我的代码侦听设备的定向事件,并尝试将值转换为适合css转换比例的方式,

let phone = document.querySelector(".phone");
    window.addEventListener('deviceorientation', (event) => {
      phone.style.transform =
        "rotateY(" + ( event.alpha) + "deg) "
        +
        "rotateX(" + (90 - event.beta) + "deg) "
        +
        "rotateZ(" + (event.gamma ) + "deg)";
    })

但是,如果我对这些值玩得足够多,则我的小部件和chrome小部件将不同步。显然,我的计算是错误的,我想念什么?

要测试我的代码,只需转到demo,打开“开发工具”的“传感器”标签并使用小部件。

任何帮助将不胜感激。

更新: 要进入“传感器”选项卡:打开dev工具,按Esc,在第二个面板上,单击左侧的3点并选择传感器。

更新: 有问题的值的示例是:
alpha:-77.6163
beta:-173.4458
伽玛:-40.4889

1 个答案:

答案 0 :(得分:2)

在铬和铬中就是这样:

codepen

最重要的部分是,当我们应用gamma角度变换时,该轴已经通过先前的beta角度变换旋转了。因此,我们需要将伽马旋转角不应用于(0, 0, 1)轴,而是应用于考虑β角的变换轴。

来源:

function degreesToRadians (deg) {
    return deg * Math.PI / 180;
}

class EulerAngles {
  constructor(alpha, beta, gamma) {
    this.alpha = alpha;
    this.beta = beta;
    this.gamma = gamma;
  }
  
  toRotate3DString() {
    const gammaAxisY = -Math.sin(degreesToRadians(this.beta));
    const gammaAxisZ = Math.cos(degreesToRadians(this.beta));
    const axis = {
      alpha: [0, 1, 0],
      beta: [-1, 0, 0],
      gamma: [0, gammaAxisY, gammaAxisZ]
    };
    return (
      "rotate3d(" +
      axis.alpha.join(",") +
      "," +
      this.alpha +
      "deg) " +
      "rotate3d(" +
      axis.beta.join(",") +
      "," +
      this.beta +
      "deg) " +
      "rotate3d(" +
      axis.gamma.join(",") +
      "," +
      this.gamma +
      "deg)"
    );
  }
}

function ready(fn) {
  if (
    document.attachEvent
      ? document.readyState === "complete"
      : document.readyState !== "loading"
  ) {
    fn();
  } else {
    document.addEventListener("DOMContentLoaded", fn);
  }
}

ready(() => {
  let phone = document.querySelector(".phone");
  window.addEventListener("deviceorientation", event => {
    console.log(event);
    const eulerAngles = new EulerAngles(event.alpha, -90 + event.beta, event.gamma)
    phone.style.transform = eulerAngles.toRotate3DString();
  });
});