Cesium 加载 Geoserver 图层,除了会遇到属性条件查询需求,还经常遇到空间查询,这里介绍一下范围查询。
其实就是利用 Geoserver 的 CQL_FILTER 实现功能,即增加 BOX(EXTENT )条件。
本文包括范围过滤核心代码、完整代码以及在线示例。
Geoserver 范围过滤核心代码:
const parameters = {
transparent: true,
format: "image/png",
srs: "EPSG:4326",
// 非必填
styles: style || "",
}
// geoserver 传入范围
bbox && (parameters.cql_filter = ' bbox(the_geom,' + bbox + ')');
// 添加geoserver发布的wms数据
layer = viewer.imageryLayers.addImageryProvider(new Cesium.WebMapServiceImageryProvider({
url: "http://openlayers.vip/geoserver/cite/wms",
// 必填
layers: "cite:2000",
parameters: parameters
}));
<!DOCTYPE html>
<html lang="en">
<head>
<!-- Use correct character set. -->
<meta charset="utf-8"/>
<!-- Tell IE to use the latest, best version. -->
<meta http-equiv="X-UA-Compatible" content="IE=edge"/>
<!-- Make the application on mobile take up the full browser screen and disable user scaling. -->
<meta
name="viewport"
content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no"
/>
<title>Cesium WMS EXTENT</title>
<script src="./Cesium.js"></script>
<script src="http://www.openlayers.vip/examples/resources/jquery-3.5.1.min.js"></script>
<style>
@import url(./Widgets/widgets.css);
html,
body,
#cesiumContainer {
width: 100%;
height: 100%;
margin: 0;
padding: 0;
overflow: hidden;
}
</style>
<script>
var _hmt = _hmt || [];
(function () {
var hm = document.createElement("script");
hm.src = "https://hm.baidu.com/hm.js?f80a36f14f8a73bb0f82e0fdbcee3058";
var s = document.getElementsByTagName("script")[0];
s.parentNode.insertBefore(hm, s);
})();
</script>
</head>
<body>
<br/>
<button id="geoserverFunc" onClick="geoserverFunc()">geoserver</button>
<button id="clearFunc" onClick="clearFunc(),viewer.entities.removeAll();">清空</button>
<div id="cesiumContainer"></div>
<script>
// 这个 tk 只能在本域名下使用
var token = '2b7cbf61123cbe4e9ec6267a87e7442f';
// 服务域名
var tdtUrl = 'https://t{s}.tianditu.gov.cn/';
// 服务负载子域
var subdomains = ['0', '1', '2', '3', '4', '5', '6', '7'];
var viewer = new Cesium.Viewer('cesiumContainer', {
shouldAnimate: true,
selectionIndicator: true,
animation: false, //动画
homeButton: false, //home键
geocoder: false, //地址编码
baseLayerPicker: false, //图层选择控件
timeline: false, //时间轴
fullscreenButton: false, //全屏显示
infoBox: false, //点击要素之后浮窗
sceneModePicker: false, //投影方式 三维/二维
navigationInstructionsInitiallyVisible: false, //导航指令
navigationHelpButton: false, //帮助信息
selectionIndicator: false, // 选择
imageryProvider: new window.Cesium.WebMapTileServiceImageryProvider({
//影像底图
url: "http://t{s}.tianditu.com/img_w/wmts?service=wmts&request=GetTile&version=1.0.0&LAYER=img&tileMatrixSet=w&TileMatrix={TileMatrix}&TileRow={TileRow}&TileCol={TileCol}&style=default&format=tiles&tk=" + token,
subdomains: subdomains,
layer: "tdtImgLayer",
style: "default",
format: "image/jpeg",
tileMatrixSetID: "GoogleMapsCompatible",//使用谷歌的瓦片切片方式
show: true
})
});
viewer.imageryLayers.addImageryProvider(new window.Cesium.WebMapTileServiceImageryProvider({
//影像注记
url: "http://t{s}.tianditu.com/cia_w/wmts?service=wmts&request=GetTile&version=1.0.0&LAYER=cia&tileMatrixSet=w&TileMatrix={TileMatrix}&TileRow={TileRow}&TileCol={TileCol}&style=default.jpg&tk=" + token,
subdomains: subdomains,
layer: "tdtCiaLayer",
style: "default",
format: "image/jpeg",
tileMatrixSetID: "GoogleMapsCompatible",
show: true
}));
// // 叠加国界服务
var iboMap = new window.Cesium.UrlTemplateImageryProvider({
url: tdtUrl + 'DataServer?T=ibo_w&x={x}&y={y}&l={z}&tk=' + token,
subdomains: subdomains,
tilingScheme: new window.Cesium.WebMercatorTilingScheme(),
maximumLevel: 10
});
viewer.imageryLayers.addImageryProvider(iboMap);
// 加载 geoserver 图层
let layer;
// 添加图层
function geoserverFunc(bbox, style) {
clearFunc();
const parameters = {
transparent: true,
format: "image/png",
srs: "EPSG:4326",
// 非必填
styles: style || "",
}
// geoserver 传入范围
bbox && (parameters.cql_filter = ' bbox(the_geom,' + bbox + ')');
// 添加geoserver发布的wms数据
layer = viewer.imageryLayers.addImageryProvider(new Cesium.WebMapServiceImageryProvider({
url: "http://openlayers.vip/geoserver/cite/wms",
// 必填
layers: "cite:2000",
parameters: parameters
}));
flyToRectangle();
}
// 清空
function clearFunc() {
layer && viewer.imageryLayers.remove(layer) , layer = undefined;
// viewer._container.style.cursor = "default";
}
/**
* @description: 飞行定位到一个矩形
* @return {*}
*/
function flyToRectangle(RectangleCD) {
// 添加定位信息
RectangleCD = RectangleCD || [
Cesium.Cartesian3.fromDegrees(
115.41380999600005,
39.44197808500007,
0
),
Cesium.Cartesian3.fromDegrees(
117.49920000500002,
41.05928408300005,
0
),
];
var rec = Cesium.Rectangle.fromCartesianArray(RectangleCD);
var boundingSphere = Cesium.BoundingSphere.fromRectangle3D(rec);
viewer.camera.flyToBoundingSphere(boundingSphere, {
duration: 2,
complete: function () {
},
offset: {
heading: Cesium.Math.toRadians(0.0),
pitch: Cesium.Math.toRadians(-90),
range: 0.0,
},
});
}
let _positions = [], floatingPoint, _entities_rectangle = [], _rectangle;
// 标绘完加载矩形
function loadRectangle(data) {
var shape = viewer.entities.add({
name: "rectangle",
rectangle: {
coordinates: Cesium.Rectangle.fromCartesianArray(data),
material: Cesium.Color.RED.withAlpha(0.5)
}
});
_entities_rectangle.push(shape);
return shape;
}
// 创建标绘矩形
function createRectangle() {
var shape = viewer.entities.add({
name: "rectangle",
rectangle: {
coordinates: new Cesium.CallbackProperty(function () {
var obj = Cesium.Rectangle.fromCartesianArray(_positions);
return obj;
}, false),
material: Cesium.Color.RED.withAlpha(0.5)
}
});
_entities_rectangle.push(shape);
return shape;
}
// 屏幕坐标转为弧度坐标
function getCatesian3FromPX(px) {
let cartesian;
let ray = viewer.camera.getPickRay(px);
if (!ray) return null;
cartesian = viewer.scene.globe.pick(ray, viewer.scene);
return cartesian;
}
let _entities_point = [];
// 清除锚点
function clearPoint() {
for (let i = 0; i < _entities_point.length; i++) {
viewer.entities.remove(_entities_point[i]);
}
_entities_point = []; //脏数据
}
//创建点
function createPoint(cartesian) {
var point = viewer.entities.add({
position: cartesian,
point: {
pixelSize: 10,
color: Cesium.Color.YELLOW,
}
});
_entities_point.push(point);
return point;
}
// 是否关闭已标绘矩形
let flagDraw = false;
// 开始标绘
function startCreate() {
// 关闭左键双击
viewer.cesiumWidget.screenSpaceEventHandler.removeInputAction(Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
// 鼠标形状
viewer._container.style.cursor = "crosshair";
let handler = new Cesium.ScreenSpaceEventHandler(viewer.scene.canvas);
// 左键单击开始绘制
handler.setInputAction(function (evt) {
if (flagDraw) {
viewer.entities.removeAll();
flagDraw = false;
}
//屏幕坐标转地形上坐标
let cartesian = getCatesian3FromPX(evt.position);
if (_positions.length == 0) {
_positions.push(cartesian.clone());
floatingPoint = createPoint(cartesian);
createPoint(cartesian);// 绘制点
}
_positions.push(cartesian);
}, Cesium.ScreenSpaceEventType.LEFT_CLICK);
// 移动绘制矩形
handler.setInputAction(function (evt) {
if (_positions.length < 3) return;
let cartesian = getCatesian3FromPX(evt.endPosition);
if (!Cesium.defined(_rectangle)) {
_rectangle = createRectangle();
}
floatingPoint.position.setValue(cartesian);
if (_rectangle) {
_positions.pop();
_positions.push(cartesian);
}
}, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
// 右键单击结束绘制
handler.setInputAction(function (evt) {
if (!_rectangle) return;
let cartesian = getCatesian3FromPX(evt.position);
_positions.pop();
_positions.push(cartesian);
createPoint(cartesian);// 绘制点
_rectangleData = _positions.concat();
viewer.entities.remove(_rectangle); //移除
_rectangle = null;
_positions = [];
floatingPoint.position.setValue(cartesian);
let rectangle = loadRectangle(_rectangleData); //加载
let southwest = Cesium.Rectangle.southwest(rectangle.rectangle.coordinates._value);
let northeast = Cesium.Rectangle.northeast(rectangle.rectangle.coordinates._value);
// 转换为 bbox 字符
let tempResult = Cesium.Math.toDegrees(southwest.longitude) + ',';
tempResult += Cesium.Math.toDegrees(southwest.latitude) + ',';
tempResult += Cesium.Math.toDegrees(northeast.longitude) + ',';
tempResult += Cesium.Math.toDegrees(northeast.latitude);
_entities_rectangle.push(rectangle);
// _rectangleLast = rectangle;
geoserverFunc(tempResult);
flagDraw = true;
}, Cesium.ScreenSpaceEventType.RIGHT_CLICK);
alert('一次单击两次,并且拖动画矩形和修改矩形,右击结束并保存 BBOX!');
}
geoserverFunc()
startCreate()
</script>
</body>
</html>
Cesium 在线示例:Cesium 图层以及范围过滤