MapboxGL请求加载512尺寸瓦片

作者：yx

文章目录

前言
一、关键代码
二、完整代码
三、结果验证

前言

平常我们使用更多的是256* 256尺寸的瓦片出图，但有的客户需要以512* 512尺寸大小的瓦片出图，对于leaflet可以直接修改tilesize参数为512，例如：
在这里插入图片描述
但是对于MapboxGL而言修改tilesize参数为512是不生效的：

是因为mapbox原生的问题，512比256zoom要低一级，需要对请求地址的z值进行处理，接下来一起看看如何处理

一、关键代码

 transformRequest: (url, resourceType) => {
                   if (resourceType === 'Tile') {
                    let zStr = url.substr(url.indexOf("z=") + 2, url.length).split("&")[0]
                    return {
                        url: url.replace(`z=${zStr}`, `z=${(Number(zStr) + 1).toString()}`)
                   }}

利用这个方法，将Z值解析出来，然后对Z值进行加一的操作。

二、完整代码

<!--********************************************************************
* Copyright© 2000 - 2022 SuperMap Software Co.Ltd. All rights reserved.
*********************************************************************-->
<!DOCTYPE html>
<html>
<head>
    <meta charset='utf-8'/>
    <meta name='viewport' content='initial-scale=1,maximum-scale=1,user-scalable=no'/>
    <title data-i18n="resources.title_tiledMapLayer"></title>
    <script type="text/javascript" src="../js/include-web.js"></script>
    <style>
        body {
            margin: 0;
            padding: 0;
        }

        #map {
            position: absolute;
            top: 0;
            bottom: 0;
            width: 100%;
        }
    </style>
</head>
<body>
<div id='map'></div>
<script type="text/javascript" exclude='iclient-mapboxgl' src="../../dist/mapboxgl/include-mapboxgl.js"></script>
<script type="text/javascript">
    var host = window.isLocal ? window.server : "https://iserver.supermap.io";
    var attribution = "<a href='https://www.mapbox.com/about/maps/' target='_blank'>© Mapbox </a>" +
        " with <span>© <a href='https://iclient.supermap.io' target='_blank'>SuperMap iClient</a> | </span>" +
        " Map Data <span>© <a href='http://support.supermap.com.cn/product/iServer.aspx' target='_blank'>SuperMap iServer</a></span> ";

    var map = new mapboxgl.Map({
        container: 'map', // container id
        style: {
            "version": 8,
            "sources": {
                "raster-tiles": {
                    "attribution": attribution,
                    "type": "raster",
                    "tiles": [host + '/iserver/services/map-china400/rest/maps/China/zxyTileImage.png?width=512&height=512&z={z}&x={x}&y={y}'],
                    "tileSize":512
                }
            },
            "layers": [{
                "id": "simple-tiles",
                "type": "raster",
                "source": "raster-tiles",
                "minzoom": 0,
                "maxzoom": 22
            }]
        },
        center: [120.143, 30.236], // starting position
        zoom: 3 ,// starting zoom
        transformRequest: (url, resourceType) => {
                   if (resourceType === 'Tile') {
                    let zStr = url.substr(url.indexOf("z=") + 2, url.length).split("&")[0]

                    return {
                        url: url.replace(`z=${zStr}`, `z=${(Number(zStr) + 1).toString()}`)
                   };
                   }
                   }
    });
    map.addControl(new mapboxgl.NavigationControl(), 'top-left');

</script>

</body>
</html>