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677 lines
27 KiB
HTML
677 lines
27 KiB
HTML
2 weeks ago
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<!DOCTYPE html>
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<html lang="en-US">
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<head>
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<meta charset="UTF-8">
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<meta http-equiv="X-UA-Compatible" content="IE=Edge">
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<meta name="viewport" content="initial-scale=1.0, user-scalable=no, width=device-width">
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<script>
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var gaProperty = 'UA-2577926-1';
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// Disable tracking if the opt-out cookie exists.
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var disableStr = 'ga-disable-' + gaProperty;
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if (document.cookie.indexOf(disableStr + '=true') > -1) {
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window[disableStr] = true;
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}
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function gaOptout() {
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document.cookie = disableStr + '=true; expires=Thu, 31 Dec 2099 23:59:59 UTC; path=/';
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window[disableStr] = true;
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}
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function gaOptoutRevoke() {
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document.cookie = disableStr + '=false; expires=Thu, 31 Dec 2099 23:59:59 UTC; path=/';
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window[disableStr] = false;
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}
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</script>
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<!-- Global site tag (gtag.js) - Google Analytics -->
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<script async src="https://www.googletagmanager.com/gtag/js?id=UA-2577926-1"></script>
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<script>
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window.dataLayer = window.dataLayer || [];
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function gtag(){dataLayer.push(arguments);}
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gtag('js', new Date());
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gtag('config', 'UA-2577926-1', { 'anonymize_ip': true });
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</script>
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<link rel="stylesheet" type="text/css" href="//cdnjs.cloudflare.com/ajax/libs/cookieconsent2/3.1.0/cookieconsent.min.css" />
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<script src="//cdnjs.cloudflare.com/ajax/libs/cookieconsent2/3.1.0/cookieconsent.min.js"></script>
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<script src="https://unpkg.com/lz-string@1.4.4/libs/lz-string.min.js"></script>
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<script>
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window.addEventListener("load", function() {
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window.cookieconsent.initialise({
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'palette': {
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'popup': {
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'background': '#eaf7f7',
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'text': '#5c7291'
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},
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'button': {
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'background': '#56cbdb',
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'text': '#ffffff'
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}
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},
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'theme': 'edgeless',
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'type': 'opt-out',
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'onInitialise': function (status) {
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if (!this.hasConsented()) {
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gaOptout()
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}
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},
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'onStatusChange': function(status, chosenBefore) {
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if (!this.hasConsented()) {
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gaOptout()
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}
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},
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'onRevokeChoice': function() {
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gaOptoutRevoke()
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}
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})
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});
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</script>
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<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" type="text/css">
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<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.0/css/bootstrap.min.css" type="text/css">
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<link rel="stylesheet" href="./resources/prism/prism-1.20.0.css" type="text/css">
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<link rel="stylesheet" href="./css/ol.css" type="text/css">
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<link rel="stylesheet" href="./resources/layout.css" type="text/css">
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<script src="https://unpkg.com/elm-pep"></script>
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<script src="https://cdn.polyfill.io/v3/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,TextDecoder"></script>
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<script src="https://cdnjs.cloudflare.com/ajax/libs/core-js/3.18.3/minified.js"></script>
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<link rel="stylesheet" href="offscreen-canvas.css">
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<title>Vector tiles rendered in an offscreen canvas</title>
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</head>
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<body>
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<header class="navbar navbar-expand-sm navbar-dark mb-3 py-0" role="navigation">
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<a class="navbar-brand" href="https://openlayers.org/"><img src="./resources/logo-70x70.png" alt=""> OpenLayers</a>
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<button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#olmenu" aria-controls="olmenu" aria-expanded="false" aria-label="Toggle navigation">
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<span class="navbar-toggler-icon"></span>
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</button>
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<!-- menu items that get hidden below 768px width -->
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<nav class="collapse navbar-collapse" id="olmenu">
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<ul class="nav navbar-nav ml-auto">
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<li class="nav-item dropdown">
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<a class="nav-link dropdown-toggle" href="#" id="docdropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Docs</a>
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<div class="dropdown-menu dropdown-menu-right mb-3" aria-labelledby="docdropdown">
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<a class="dropdown-item" href="../doc/">Docs</a>
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<div class="dropdown-divider"></div>
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<a class="dropdown-item" href="../doc/quickstart.html"><i class="fa fa-check fa-fw mr-2 fa-lg"></i>Quick Start</a>
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<a class="dropdown-item" href="../doc/faq.html"><i class="fa fa-question fa-fw mr-2 fa-lg"></i>FAQ</a>
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<a class="dropdown-item" href="../doc/tutorials/"><i class="fa fa-book fa-fw mr-2 fa-lg"></i>Tutorials</a>
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<a class="dropdown-item" href="/workshop/"><i class="fa fa-graduation-cap fa-fw mr-2 fa-lg"></i>Workshop</a>
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<div class="dropdown-divider"></div>
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<a class="dropdown-item" href="https://stackoverflow.com/questions/tagged/openlayers"><i class="fa fa-stack-overflow fa-fw mr-2"></i>Ask a Question</a>
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</div>
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</li>
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<li class="nav-item active"><a class="nav-link" href="../examples/">Examples</a></li>
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<li class="nav-item"><a class="nav-link" href="../apidoc/"><i class="fa fa-sitemap mr-1"></i>API</a></li>
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<li class="nav-item dropdown">
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<a class="nav-link dropdown-toggle" href="#" id="codedropdown" role="button" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">Code</a>
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<div class="dropdown-menu dropdown-menu-right mb-3" aria-labelledby="codedropdown">
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<a class="dropdown-item" href="https://github.com/openlayers/openlayers"><i class="fa fa-github fa-fw mr-2 fa-lg"></i>Repository</a>
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<a class="dropdown-item" href="/download/"><i class="fa fa-download fa-fw mr-2 fa-lg"></i>Download</a>
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</div>
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</li>
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</ul>
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</nav>
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</header>
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<div class="container-fluid line-numbers">
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<div id="latest-check" class="alert alert-warning alert-dismissible" role="alert" style="display:none">
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<button id="latest-dismiss" type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">×</span></button>
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This example uses OpenLayers v<span>6.12.0</span>. The <a id="latest-link" href="#" class="alert-link">latest</a> is v<span id="latest-version"></span>.
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</div>
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<div id="experimental-notice" class="alert alert-warning alert-dismissible" role="alert">
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<button id="experimental-dismiss" type="button" class="close" data-dismiss="alert" aria-label="Close"><span aria-hidden="true">×</span></button>
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This example uses features that are not part of the stable API and subject to change between releases. Consult the <a href="https://openlayers.org/en/latest/apidoc/">API documentation</a>
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to see what is supported in the latest release.
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</div>
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<div class="row-fluid">
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<a href="#" id="codepen-button" class="btn btn-link float-right">
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<i class="fa fa-codepen fa-lg"></i> Edit
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</a>
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<div class="span12">
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<h4 id="title">Vector tiles rendered in an offscreen canvas</h4>
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<p class="tags">
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<span class="badge-group">
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<a
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href="./index.html?q=worker" class="badge badge-info">worker</a
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><a
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class="badge badge-info tag-modal-toggle text-white"
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data-toggle="modal"
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data-target="#tag-example-list"
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data-title="worker"
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data-content="
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<a class="list-group-item list-group-item-action active" href="./offscreen-canvas.html">Vector tiles rendered in an offscreen canvas</a>
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<a class="list-group-item list-group-item-action" href="./worker.html">Worker</a>"
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tabindex="0"
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>2</a>
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</span>
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<span class="badge-group">
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<a
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href="./index.html?q=offscreencanvas" class="badge badge-info">offscreencanvas</a
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><a
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class="badge badge-info tag-modal-toggle text-white"
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data-toggle="modal"
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data-target="#tag-example-list"
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data-title="offscreencanvas"
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data-content="
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<a class="list-group-item list-group-item-action active" href="./offscreen-canvas.html">Vector tiles rendered in an offscreen canvas</a>"
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tabindex="0"
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>1</a>
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</span>
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<span class="badge-group">
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<a
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href="./index.html?q=vector-tiles" class="badge badge-info">vector-tiles</a
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><a
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class="badge badge-info tag-modal-toggle text-white"
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data-toggle="modal"
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data-target="#tag-example-list"
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data-title="vector-tiles"
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data-content="
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<a class="list-group-item list-group-item-action active" href="./offscreen-canvas.html">Vector tiles rendered in an offscreen canvas</a>"
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tabindex="0"
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>1</a>
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</span>
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</p>
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<div class="modal modal-tag-example" id="tag-example-list" tabindex="-1" role="dialog" aria-labelledby="tag-example-title" aria-hidden="true">
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<div class="modal-dialog modal-dialog-scrollable" role="document">
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<div class="modal-content">
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<div class="modal-header">
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<h5 class="modal-title" id="tag-example-title"></h5>
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<button type="button" class="close" data-dismiss="modal" aria-label="Close">
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<span aria-hidden="true">×</span>
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</button>
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</div>
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<div class="modal-body">
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<div class="list-group"></div>
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</div>
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</div>
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</div>
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</div>
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<div id="map" class="map">
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<pre id="info" class="info"/>
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</div>
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</div>
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<form method="POST" id="codepen-form" target="_blank" action="https://codesandbox.io/api/v1/sandboxes/define">
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<input id="codesandbox-params" type="hidden" name="parameters">
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</form>
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</div>
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<div class="row-fluid">
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<div class="span12">
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<p id="shortdesc">Example of a map that delegates rendering to a worker.</p>
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<div id="docs"><p>The map in this example is rendered in a web worker, using <code>OffscreenCanvas</code>. <strong>Note:</strong> This is currently only supported in Chrome and Edge.</p>
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</div>
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</div>
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</div>
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<div class="row-fluid">
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<h5 class="source-heading">main.js</h5>
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<pre><code id="example-js-source" class="language-js">import 'ol/ol.css';
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import Layer from 'ol/layer/Layer';
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import Map from 'ol/Map';
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import Source from 'ol/source/Source';
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import View from 'ol/View';
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import stringify from 'json-stringify-safe';
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import {FullScreen} from 'ol/control';
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import {compose, create} from 'ol/transform';
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import {createXYZ} from 'ol/tilegrid';
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import {toString as toTransformString} from 'ol/transform';
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const worker = new Worker('./worker.js', {type: 'module'});
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let container,
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transformContainer,
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canvas,
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rendering,
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workerFrameState,
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mainThreadFrameState;
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// Transform the container to account for the differnece between the (newer)
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// main thread frameState and the (older) worker frameState
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function updateContainerTransform() {
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if (workerFrameState) {
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const viewState = mainThreadFrameState.viewState;
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const renderedViewState = workerFrameState.viewState;
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const center = viewState.center;
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const resolution = viewState.resolution;
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const rotation = viewState.rotation;
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const renderedCenter = renderedViewState.center;
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const renderedResolution = renderedViewState.resolution;
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const renderedRotation = renderedViewState.rotation;
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const transform = create();
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// Skip the extra transform for rotated views, because it will not work
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// correctly in that case
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if (!rotation) {
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compose(
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transform,
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(renderedCenter[0] - center[0]) / resolution,
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(center[1] - renderedCenter[1]) / resolution,
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renderedResolution / resolution,
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renderedResolution / resolution,
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rotation - renderedRotation,
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0,
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0
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);
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}
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transformContainer.style.transform = toTransformString(transform);
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}
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}
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const map = new Map({
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layers: [
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new Layer({
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render: function (frameState) {
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if (!container) {
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container = document.createElement('div');
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container.style.position = 'absolute';
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container.style.width = '100%';
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container.style.height = '100%';
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transformContainer = document.createElement('div');
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transformContainer.style.position = 'absolute';
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transformContainer.style.width = '100%';
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transformContainer.style.height = '100%';
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container.appendChild(transformContainer);
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canvas = document.createElement('canvas');
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canvas.style.position = 'absolute';
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canvas.style.left = '0';
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canvas.style.transformOrigin = 'top left';
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transformContainer.appendChild(canvas);
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}
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mainThreadFrameState = frameState;
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updateContainerTransform();
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if (!rendering) {
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rendering = true;
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worker.postMessage({
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action: 'render',
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frameState: JSON.parse(stringify(frameState)),
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});
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} else {
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frameState.animate = true;
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}
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return container;
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},
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source: new Source({
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attributions: [
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'<a href="https://www.maptiler.com/copyright/" target="_blank">© MapTiler</a>',
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'<a href="https://www.openstreetmap.org/copyright" target="_blank">© OpenStreetMap contributors</a>',
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],
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}),
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}),
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],
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target: 'map',
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view: new View({
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resolutions: createXYZ({tileSize: 512}).getResolutions(),
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center: [0, 0],
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zoom: 2,
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}),
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});
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map.addControl(new FullScreen());
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map.on('pointermove', function (evt) {
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if (evt.dragging) {
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return;
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}
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const pixel = map.getEventPixel(evt.originalEvent);
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worker.postMessage({
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action: 'requestFeatures',
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pixel: pixel,
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});
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});
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// Worker messaging and actions
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worker.addEventListener('message', (message) => {
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|
|
if (message.data.action === 'loadImage') {
|
||
|
|
// Image loader for ol-mapbox-style
|
||
|
|
const image = new Image();
|
||
|
|
image.crossOrigin = 'anonymous';
|
||
|
|
image.addEventListener('load', function () {
|
||
|
|
createImageBitmap(image, 0, 0, image.width, image.height).then(
|
||
|
|
(imageBitmap) => {
|
||
|
|
worker.postMessage(
|
||
|
|
{
|
||
|
|
action: 'imageLoaded',
|
||
|
|
image: imageBitmap,
|
||
|
|
src: message.data.src,
|
||
|
|
},
|
||
|
|
[imageBitmap]
|
||
|
|
);
|
||
|
|
}
|
||
|
|
);
|
||
|
|
});
|
||
|
|
image.src = message.data.src;
|
||
|
|
} else if (message.data.action === 'getFeatures') {
|
||
|
|
showInfo(message.data.features);
|
||
|
|
} else if (message.data.action === 'requestRender') {
|
||
|
|
// Worker requested a new render frame
|
||
|
|
map.render();
|
||
|
|
} else if (canvas && message.data.action === 'rendered') {
|
||
|
|
// Worker provies a new render frame
|
||
|
|
requestAnimationFrame(function () {
|
||
|
|
const imageData = message.data.imageData;
|
||
|
|
canvas.width = imageData.width;
|
||
|
|
canvas.height = imageData.height;
|
||
|
|
canvas.getContext('2d').drawImage(imageData, 0, 0);
|
||
|
|
canvas.style.transform = message.data.transform;
|
||
|
|
workerFrameState = message.data.frameState;
|
||
|
|
updateContainerTransform();
|
||
|
|
});
|
||
|
|
rendering = false;
|
||
|
|
}
|
||
|
|
});
|
||
|
|
|
||
|
|
const info = document.getElementById('info');
|
||
|
|
function showInfo(propertiesFromFeatures) {
|
||
|
|
if (propertiesFromFeatures.length == 0) {
|
||
|
|
info.innerText = '';
|
||
|
|
info.style.opacity = 0;
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
const properties = propertiesFromFeatures.map((e) =>
|
||
|
|
Object.keys(e)
|
||
|
|
.filter((key) => !key.includes(':'))
|
||
|
|
.reduce((newObj, currKey) => ((newObj[currKey] = e[currKey]), newObj), {})
|
||
|
|
);
|
||
|
|
info.innerText = JSON.stringify(properties, null, 2);
|
||
|
|
info.style.opacity = 1;
|
||
|
|
}
|
||
|
|
</code></pre>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<div class="row-fluid">
|
||
|
|
<h5 class="source-heading">index.html</h5>
|
||
|
|
<pre><code id="example-html-source" class="language-markup"><!DOCTYPE html>
|
||
|
|
<html lang="en">
|
||
|
|
<head>
|
||
|
|
<meta charset="UTF-8">
|
||
|
|
<title>Vector tiles rendered in an offscreen canvas</title>
|
||
|
|
<!-- Pointer events polyfill for old browsers, see https://caniuse.com/#feat=pointer -->
|
||
|
|
<script src="https://unpkg.com/elm-pep"></script>
|
||
|
|
<!-- The lines below are only needed for old environments like Internet Explorer and Android 4.x -->
|
||
|
|
<script src="https://cdn.polyfill.io/v3/polyfill.min.js?features=fetch,requestAnimationFrame,Element.prototype.classList,TextDecoder"></script>
|
||
|
|
<script src="https://cdnjs.cloudflare.com/ajax/libs/core-js/3.18.3/minified.js"></script>
|
||
|
|
<style>
|
||
|
|
.map {
|
||
|
|
width: 100%;
|
||
|
|
height:400px;
|
||
|
|
}
|
||
|
|
.map {
|
||
|
|
background: rgba(232, 230, 223, 1);
|
||
|
|
position: relative;
|
||
|
|
}
|
||
|
|
.map .ol-rotate {
|
||
|
|
left: .5em;
|
||
|
|
bottom: .5em;
|
||
|
|
top: auto;
|
||
|
|
right: auto;
|
||
|
|
}
|
||
|
|
|
||
|
|
.info {
|
||
|
|
z-index: 1;
|
||
|
|
opacity: 0;
|
||
|
|
position: absolute;
|
||
|
|
bottom: 0;
|
||
|
|
left: 0;
|
||
|
|
margin: 0;
|
||
|
|
background: rgba(0,60,136,0.7);
|
||
|
|
color: white;
|
||
|
|
border: 0;
|
||
|
|
transition: opacity 100ms ease-in;
|
||
|
|
}
|
||
|
|
</style>
|
||
|
|
</head>
|
||
|
|
<body>
|
||
|
|
<div id="map" class="map">
|
||
|
|
<pre id="info" class="info"/>
|
||
|
|
</div> <script src="main.js"></script>
|
||
|
|
</body>
|
||
|
|
</html></code></pre>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<div class="row-fluid extra-source">
|
||
|
|
<h5 class="source-heading">worker.js</h5>
|
||
|
|
<pre><code class="language-js">import MVT from 'ol/format/MVT';
|
||
|
|
import TileQueue from 'ol/TileQueue';
|
||
|
|
import VectorTileLayer from 'ol/layer/VectorTile';
|
||
|
|
import VectorTileSource from 'ol/source/VectorTile';
|
||
|
|
import stringify from 'json-stringify-safe';
|
||
|
|
import styleFunction from 'ol-mapbox-style/dist/stylefunction';
|
||
|
|
import {get} from 'ol/proj';
|
||
|
|
import {inView} from 'ol/layer/Layer';
|
||
|
|
import {getTilePriority as tilePriorityFunction} from 'ol/TileQueue';
|
||
|
|
|
||
|
|
/** @type {any} */
|
||
|
|
const worker = self;
|
||
|
|
|
||
|
|
let frameState, pixelRatio, rendererTransform;
|
||
|
|
const canvas = new OffscreenCanvas(1, 1);
|
||
|
|
// OffscreenCanvas does not have a style, so we mock it
|
||
|
|
canvas.style = {};
|
||
|
|
const context = canvas.getContext('2d');
|
||
|
|
|
||
|
|
const sources = {
|
||
|
|
landcover: new VectorTileSource({
|
||
|
|
maxZoom: 9,
|
||
|
|
format: new MVT(),
|
||
|
|
url: 'https://api.maptiler.com/tiles/landcover/{z}/{x}/{y}.pbf?key=Get your own API key at https://www.maptiler.com/cloud/',
|
||
|
|
}),
|
||
|
|
contours: new VectorTileSource({
|
||
|
|
minZoom: 9,
|
||
|
|
maxZoom: 14,
|
||
|
|
format: new MVT(),
|
||
|
|
url: 'https://api.maptiler.com/tiles/contours/{z}/{x}/{y}.pbf?key=Get your own API key at https://www.maptiler.com/cloud/',
|
||
|
|
}),
|
||
|
|
openmaptiles: new VectorTileSource({
|
||
|
|
format: new MVT(),
|
||
|
|
maxZoom: 14,
|
||
|
|
url: 'https://api.maptiler.com/tiles/v3/{z}/{x}/{y}.pbf?key=Get your own API key at https://www.maptiler.com/cloud/',
|
||
|
|
}),
|
||
|
|
};
|
||
|
|
const layers = [];
|
||
|
|
|
||
|
|
// Font replacement so we do not need to load web fonts in the worker
|
||
|
|
function getFont(font) {
|
||
|
|
return font[0].replace('Noto Sans', 'serif').replace('Roboto', 'sans-serif');
|
||
|
|
}
|
||
|
|
|
||
|
|
function loadStyles() {
|
||
|
|
const styleUrl =
|
||
|
|
'https://api.maptiler.com/maps/topo/style.json?key=Get your own API key at https://www.maptiler.com/cloud/';
|
||
|
|
|
||
|
|
fetch(styleUrl)
|
||
|
|
.then((data) => data.json())
|
||
|
|
.then((styleJson) => {
|
||
|
|
const buckets = [];
|
||
|
|
let currentSource;
|
||
|
|
styleJson.layers.forEach((layer) => {
|
||
|
|
if (!layer.source) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
if (currentSource !== layer.source) {
|
||
|
|
currentSource = layer.source;
|
||
|
|
buckets.push({
|
||
|
|
source: layer.source,
|
||
|
|
layers: [],
|
||
|
|
});
|
||
|
|
}
|
||
|
|
buckets[buckets.length - 1].layers.push(layer.id);
|
||
|
|
});
|
||
|
|
|
||
|
|
const spriteUrl =
|
||
|
|
styleJson.sprite + (pixelRatio > 1 ? '@2x' : '') + '.json';
|
||
|
|
const spriteImageUrl =
|
||
|
|
styleJson.sprite + (pixelRatio > 1 ? '@2x' : '') + '.png';
|
||
|
|
fetch(spriteUrl)
|
||
|
|
.then((data) => data.json())
|
||
|
|
.then((spriteJson) => {
|
||
|
|
buckets.forEach((bucket) => {
|
||
|
|
const source = sources[bucket.source];
|
||
|
|
if (!source) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
const layer = new VectorTileLayer({
|
||
|
|
declutter: true,
|
||
|
|
source,
|
||
|
|
minZoom: source.getTileGrid().getMinZoom(),
|
||
|
|
});
|
||
|
|
layer.getRenderer().useContainer = function (target, transform) {
|
||
|
|
this.containerReused = this.getLayer() !== layers[0];
|
||
|
|
this.canvas = canvas;
|
||
|
|
this.context = context;
|
||
|
|
this.container = {
|
||
|
|
firstElementChild: canvas,
|
||
|
|
style: {
|
||
|
|
opacity: layer.getOpacity(),
|
||
|
|
},
|
||
|
|
};
|
||
|
|
rendererTransform = transform;
|
||
|
|
};
|
||
|
|
styleFunction(
|
||
|
|
layer,
|
||
|
|
styleJson,
|
||
|
|
bucket.layers,
|
||
|
|
undefined,
|
||
|
|
spriteJson,
|
||
|
|
spriteImageUrl,
|
||
|
|
getFont
|
||
|
|
);
|
||
|
|
layers.push(layer);
|
||
|
|
});
|
||
|
|
worker.postMessage({action: 'requestRender'});
|
||
|
|
});
|
||
|
|
});
|
||
|
|
}
|
||
|
|
|
||
|
|
// Minimal map-like functionality for rendering
|
||
|
|
const tileQueue = new TileQueue(
|
||
|
|
(tile, tileSourceKey, tileCenter, tileResolution) =>
|
||
|
|
tilePriorityFunction(
|
||
|
|
frameState,
|
||
|
|
tile,
|
||
|
|
tileSourceKey,
|
||
|
|
tileCenter,
|
||
|
|
tileResolution
|
||
|
|
),
|
||
|
|
() => worker.postMessage({action: 'requestRender'})
|
||
|
|
);
|
||
|
|
|
||
|
|
const maxTotalLoading = 8;
|
||
|
|
const maxNewLoads = 2;
|
||
|
|
|
||
|
|
worker.addEventListener('message', (event) => {
|
||
|
|
if (event.data.action === 'requestFeatures') {
|
||
|
|
const layersInView = layers.filter((l) =>
|
||
|
|
inView(l.getLayerState(), frameState.viewState)
|
||
|
|
);
|
||
|
|
const observables = layersInView.map((l) =>
|
||
|
|
l.getFeatures(event.data.pixel)
|
||
|
|
);
|
||
|
|
Promise.all(observables).then((res) => {
|
||
|
|
const features = res.flat();
|
||
|
|
worker.postMessage({
|
||
|
|
action: 'getFeatures',
|
||
|
|
features: JSON.parse(stringify(features.map((e) => e.getProperties()))),
|
||
|
|
});
|
||
|
|
});
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
if (event.data.action !== 'render') {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
frameState = event.data.frameState;
|
||
|
|
if (!pixelRatio) {
|
||
|
|
pixelRatio = frameState.pixelRatio;
|
||
|
|
loadStyles();
|
||
|
|
}
|
||
|
|
frameState.tileQueue = tileQueue;
|
||
|
|
frameState.viewState.projection = get('EPSG:3857');
|
||
|
|
layers.forEach((layer) => {
|
||
|
|
if (inView(layer.getLayerState(), frameState.viewState)) {
|
||
|
|
const renderer = layer.getRenderer();
|
||
|
|
renderer.renderFrame(frameState, canvas);
|
||
|
|
}
|
||
|
|
});
|
||
|
|
layers.forEach(
|
||
|
|
(layer) => layer.getRenderer().context && layer.renderDeclutter(frameState)
|
||
|
|
);
|
||
|
|
if (tileQueue.getTilesLoading() < maxTotalLoading) {
|
||
|
|
tileQueue.reprioritize();
|
||
|
|
tileQueue.loadMoreTiles(maxTotalLoading, maxNewLoads);
|
||
|
|
}
|
||
|
|
const imageData = canvas.transferToImageBitmap();
|
||
|
|
worker.postMessage(
|
||
|
|
{
|
||
|
|
action: 'rendered',
|
||
|
|
imageData: imageData,
|
||
|
|
transform: rendererTransform,
|
||
|
|
frameState: JSON.parse(stringify(frameState)),
|
||
|
|
},
|
||
|
|
[imageData]
|
||
|
|
);
|
||
|
|
});
|
||
|
|
</code></pre>
|
||
|
|
</div>
|
||
|
|
<div class="row-fluid">
|
||
|
|
<h5 class="source-heading">package.json</h5>
|
||
|
|
<pre><code id="example-pkg-source" class="language-json">{
|
||
|
|
"name": "offscreen-canvas",
|
||
|
|
"dependencies": {
|
||
|
|
"ol": "6.12.0",
|
||
|
|
"json-stringify-safe": "^5.0.1"
|
||
|
|
},
|
||
|
|
"devDependencies": {
|
||
|
|
"parcel": "^2.0.0"
|
||
|
|
},
|
||
|
|
"scripts": {
|
||
|
|
"start": "parcel index.html",
|
||
|
|
"build": "parcel build --public-url . index.html"
|
||
|
|
}
|
||
|
|
}</code></pre>
|
||
|
|
</div>
|
||
|
|
</div>
|
||
|
|
|
||
|
|
<script src="https://code.jquery.com/jquery-3.5.1.min.js"></script>
|
||
|
|
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.0/js/bootstrap.bundle.min.js"></script>
|
||
|
|
<script src="./resources/prism/prism-1.20.0.min.js"></script>
|
||
|
|
<script src="./resources/common.js"></script>
|
||
|
|
<script src="common.js"></script>
|
||
|
|
<script src="offscreen-canvas.js"></script>
|
||
|
|
<script>
|
||
|
|
$('#tag-example-list').on('show.bs.modal', function (event) {
|
||
|
|
const button = $(event.relatedTarget); // Button that triggered the modal
|
||
|
|
const title = button.data('title');
|
||
|
|
const content = button.data('content');
|
||
|
|
const modal = $(this)
|
||
|
|
modal.find('.modal-title').text(title);
|
||
|
|
modal.find('.modal-body').html(content);
|
||
|
|
});
|
||
|
|
|
||
|
|
var packageUrl = 'https://raw.githubusercontent.com/openlayers/openlayers.github.io/build/package.json';
|
||
|
|
fetch(packageUrl).then(function(response) {
|
||
|
|
return response.json();
|
||
|
|
}).then(function(json) {
|
||
|
|
var latestVersion = json.version;
|
||
|
|
document.getElementById('latest-version').innerHTML = latestVersion;
|
||
|
|
var url = window.location.href;
|
||
|
|
var branchSearch = url.match(/\/([^\/]*)\/examples\//);
|
||
|
|
var cookieText = 'dismissed=-' + latestVersion + '-';
|
||
|
|
var dismissed = document.cookie.indexOf(cookieText) != -1;
|
||
|
|
if (branchSearch && !dismissed && /^v[0-9\.]*$/.test(branchSearch[1]) && '6.12.0' != latestVersion) {
|
||
|
|
var link = url.replace(branchSearch[0], '/latest/examples/');
|
||
|
|
fetch(link, {method: 'head'}).then(function(response) {
|
||
|
|
var a = document.getElementById('latest-link');
|
||
|
|
a.href = response.status == 200 ? link : '../../latest/examples/';
|
||
|
|
});
|
||
|
|
var latestCheck = document.getElementById('latest-check');
|
||
|
|
latestCheck.style.display = '';
|
||
|
|
document.getElementById('latest-dismiss').onclick = function() {
|
||
|
|
latestCheck.style.display = 'none';
|
||
|
|
document.cookie = cookieText;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
});
|
||
|
|
</script>
|
||
|
|
</body>
|
||
|
|
</html>
|