显示源代码
billboard聚合
 开发文档
            <!DOCTYPE html>
<html>
    <head>
        <meta charset="UTF-8" />
        <meta
            name="viewport"
            content="initial-scale=1,maximum-scale=1,user-scalable=no"
        />
        <link
            href="http://ua.bigemap.com:30081/bmsdk/bigemap-gl.js/v1.1.0/Widgets/widgets.css"
            rel="stylesheet"
        />
        <script src="http://ua.bigemap.com:30081/bmsdk/bigemap-gl.js/v1.1.0/bigemap-gl.js"></script>
        <style>
            body {
                margin: 0;
                padding: 0;
            }
            #container {
                position: absolute;
                top: 0;
                bottom: 0;
                width: 100%;
            }
            .bmgl-widget-credits {
                display: none;
            }
        </style>
        <title>Google Map Streets</title>
    </head>
    <body>
        <div id="container"></div>

        <script>
            bmgl.Config.HTTP_URL = 'http://ua.bigemap.com:30081/bmsdk/';
            var viewer = new bmgl.Viewer("container", {
                mapId: "bigemap.dc-tian-w-satellite",
            });
        
            const  initClusterCollection = (viewer) => {
                // console.log(bmgl,'bbbb');
                new bmgl.GeoJsonDataSource()
                    .load("/bmgl/cluster/poi.json")
                    .then((dataSource) => {
                        viewer.dataSources.add(dataSource);
                        // 设置聚合参数
                        dataSource.clustering.enabled = true;
                        dataSource.clustering.pixelRange = 60;
                        dataSource.clustering.minimumClusterSize = 4;
                        // foreach用于调用数组的每个元素,并将元素传递给回调函数。
                        dataSource.entities.values.forEach((entity) => {
                            // console.log(entity);
                            // 将点拉伸一定高度,防止被地形压盖
                            entity.position._value.z += 50.0;
                            // 使用大小为64*64的icon,缩小展示poi
                            entity.billboard = {
                                image: "/bmgl/cluster/point.png",
                                width: 32,
                                height: 32,
                            };
                            entity.label = {
                                // text: "POI",
                                text:entity._name,
                                font: "bold 15px Microsoft YaHei",
                                // 竖直对齐方式
                                verticalOrigin: bmgl.VerticalOrigin.CENTER,
                                // 水平对齐方式
                                horizontalOrigin: bmgl.HorizontalOrigin.LEFT,
                                // 偏移量
                                pixelOffset: new bmgl.Cartesian2(-14.0,-28.0),
                            };
                        });
                        // 添加监听函数
                        dataSource.clustering.clusterEvent.addEventListener(
                            function (clusteredEntities, cluster) {
                                // 关闭自带的显示聚合数量的标签
                                cluster.label.show = false;
                                cluster.billboard.show = true;
                                cluster.billboard.verticalOrigin =
                                    bmgl.VerticalOrigin.BOTTOM;

                                // 根据聚合数量的多少设置不同层级的图片以及大小
                                if (clusteredEntities.length >= 20) {
                                    cluster.billboard.image =
                                        combineIconAndLabel(
                                            "/bmgl/cluster/jhGray.png",
                                            clusteredEntities.length,
                                            64
                                        );
                                    cluster.billboard.width = 72;
                                    cluster.billboard.height = 72;
                                    // cluster.billboard.scale = 0.6;
                                } else if (clusteredEntities.length >= 12) {
                                    cluster.billboard.image =
                                        combineIconAndLabel(
                                            "/bmgl/cluster/jhBlue.png",
                                            clusteredEntities.length,
                                            64
                                        );
                                    cluster.billboard.width = 64;
                                    cluster.billboard.height = 64;
                                    // cluster.billboard.scale = 0.6;
                                } else if (clusteredEntities.length >= 8) {
                                    cluster.billboard.image =
                                        combineIconAndLabel(
                                            "/bmgl/cluster/jhGreen.png",
                                            clusteredEntities.length,
                                            64
                                        );
                                    cluster.billboard.width = 56;
                                    cluster.billboard.height = 56;
                                    // cluster.billboard.scale = 0.6;
                                } else {
                                    cluster.billboard.image =
                                        combineIconAndLabel(
                                            "/bmgl/cluster/jhRed.png",
                                            clusteredEntities.length,
                                            64
                                        );
                                    cluster.billboard.width = 40;
                                    cluster.billboard.height = 40;
                                    // cluster.billboard.scale = 0.6;
                                }
                            }
                        );
                    });
            };

            // 将使用的图片和文字联合转换为canvas
            const combineIconAndLabel = (url, label, size) => {
                // 创建画布对象
                let canvas = document.createElement("canvas");
                canvas.width = size;
                canvas.height = size;
                let ctx = canvas.getContext("2d");
                let promise = new bmgl.Resource.fetchImage(url).then(
                    (image) => {
                        try {
                            ctx.drawImage(image, 0, 0);
                        } catch (e) {
                            console.log(e);
                        }
                        ctx.fillStyle = bmgl.Color.WHITE.toCssColorString();
                        ctx.font = "bold 12px Microsoft YaHei";
                        ctx.textAlign = "center";
                        ctx.textBaseline = "middle";
                        ctx.fillText(label, size / 4, size / 4);
                        // console.log(`ctx`,ctx);  
                        return canvas;
                    }
                );
                return promise;
            };
            
            // 初始化点位聚合
            initClusterCollection(viewer)
        </script>
    </body>
</html>