Cesium学习笔记11——坐标量测

代码：

 1 var annotations;
 2 function axToolCoordinate(layer) {
 3     var handler=new  Cesium.ScreenSpaceEventHandler(viewer.canvas);
 4     annotations=viewer.scene.primitives.add( new Cesium.LabelCollection());
 5     handler.setInputAction(function (evt){
 6         var pickedObject=viewer.scene.pick(evt.position);
 7         if(viewer.scene.pickPositionSupported && Cesium.defined(pickedObject)){
 8             var cartesian=viewr.scene.pickPosition(evt.position);
 9             if(Cesium.defined(cartesian))
10             {
11                 var cartographic=Cesium.Cartographic.fromCartesian(cartesian);
12                 var lng=Cesium.Math.toDegrees(cartographic.longitude);
13                 var lat=Cesium.Math.toDegrees(cartographic.latitude);
14                 var height=cartographic.height;
15                 annotate(cartesian,lng,lat,height);
16             }
17         }
18         else{
19             var ray=viewer.camera.getPickRay(evt.position);
20             var cartesian=viewer.scene.globe.pick(ray,viewer.scene);
21             if(Cesium.defined(cartesian)){
22                 var cartographic=Cesium.Cartographic.fromCartesian(cartesian);
23                 var lng=Cesium.Math.toDegrees(cartographic.longitude);
24                 var lat=Cesium.Math.toDegrees(cartographic.latitude);
25                 var height=cartographic.height;
26                 annotate(cartesian,lng,lat,height);
27             }
28         }
29     },Cesium.ScreenSpaceEventType.LEFT_CLICK);
30 
31     handler.setInputAction(function (){
32         viewer.entities.removeAll();
33         annotations.removeAll();
34     },Cesium.ScreenSpaceEventType.RIGHT_CLICK);
35 }
36 
37 function createPoint(worldPostion){
38     var point = viewer.entities.add({
39         position:worldPostion,
40         point:{
41             color:Cesium.Color.CRIMSON,
42             pixelSize:9,
43             outlineColor:Cesium.Color.ALICEBLUE,
44             outlineWidth:2,
45             disableDepthTestDistance:1000
46         }
47     });
48 }
49 
50 function annotate(cartesian,lng,lat, height){
51     createPoint (cartesian);
52     annotations.add({
53         position:cartesian,
54         text:
55         'Lon:'+lng.toFixed(5)+'\u00B0'+
56         '\nLat:'+lat.toFixed(5)+'\u00B0'+
57         '\nHeight:'+height.toFixed(2)+'m',
58         showBackground:true,
59         font:'22px monospace',
60         horizontalOrigin: Cesium.HorizontalOrigin.LEFT,
61         verticalOrigin: Cesium.VerticalOrigin.Bottom,
62         disableDepthTestDiatane:Number.POSITIVE_INFINITY
63     });
64 }