原文链接及内容
此示例说明如何跟踪设备方向的更改。使用gyronorm.js库可以访问并标准化来自浏览器的事件。
main.js代码如下：
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| import Map from 'ol/Map.js';
import OSM from 'ol/source/OSM.js';
import TileLayer from 'ol/layer/Tile.js';
import View from 'ol/View.js';
import {toRadians} from 'ol/math.js';
const view = new View({
center: [0, 0],
zoom: 2,
});
const map = new Map({
layers: [
new TileLayer({
source: new OSM(),
}),
],
target: 'map',
view: view,
});
function el(id) {
return document.getElementById(id);
}
const gn = new GyroNorm();
gn.init().then(function () {
gn.start(function (event) {
const center = view.getCenter();
const resolution = view.getResolution();
const alpha = toRadians(event.do.alpha);
const beta = toRadians(event.do.beta);
const gamma = toRadians(event.do.gamma);
el('alpha').innerText = alpha + ' [rad]';
el('beta').innerText = beta + ' [rad]';
el('gamma').innerText = gamma + ' [rad]';
center[0] -= resolution * gamma * 25;
center[1] += resolution * beta * 25;
view.setCenter(center);
});
});
|
界面布局文件index.html代码如下：
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| <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Device Orientation</title>
<link rel="stylesheet" href="node_modules/ol/ol.css">
<style>
.map {
width: 100%;
height: 400px;
}
</style>
</head>
<body>
<div id="map" class="map"></div>
<p>
<div>α : <code id="alpha"></code></div>
<div>β : <code id="beta"></code></div>
<div>γ : <code id="gamma"></code></div>
</p>
<script src="https://cdn.jsdelivr.net/npm/elm-pep@1.0.6/dist/elm-pep.js"></script>
<script src="https://cdn.jsdelivr.net/npm/gyronorm@2.0.6/dist/gyronorm.complete.min.js"></script>
<script type="module" src="main.js"></script>
</body>
</html>
|
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