text: import * as Cesium from "cesium/Cesium";
  
  /**
     *圆形扩大扫描圈
     * */
  function AddCircleScanPostStage(viewer, cartographicCenter, maxRadius, scanColor, duration) {
      var ScanSegmentShader =
          "uniform sampler2D colorTexture;\n" +
          "uniform sampler2D depthTexture;\n" +
          "varying vec2 v_textureCoordinates;\n" +
          "uniform vec4 u_scanCenterEC;\n" +
          "uniform vec3 u_scanPlaneNormalEC;\n" +
          "uniform float u_radius;\n" +
          "uniform vec4 u_scanColor;\n" +
          "vec4 toEye(in vec2 uv, in float depth)\n" +
          " {\n" +
          " vec2 xy = vec2((uv.x * 2.0 - 1.0),(uv.y * 2.0 - 1.0));\n" +
          " vec4 posInCamera =czm_inverseProjection * vec4(xy, depth, 1.0);\n" +
          " posInCamera =posInCamera / posInCamera.w;\n" +
          " return posInCamera;\n" +
          " }\n" +
          "vec3 pointProjectOnPlane(in vec3 planeNormal, in vec3 planeOrigin, in vec3 point)\n" +
          "{\n" +
          "vec3 v01 = point -planeOrigin;\n" +
          "float d = dot(planeNormal, v01) ;\n" +
          "return (point - planeNormal * d);\n" +
          "}\n" +
          "float getDepth(in vec4 depth)\n" +
          "{\n" +
          "float z_window = czm_unpackDepth(depth);\n" +
          "z_window = czm_reverseLogDepth(z_window);\n" +
          "float n_range = czm_depthRange.near;\n" +
          "float f_range = czm_depthRange.far;\n" +
          "return (2.0 * z_window - n_range - f_range) / (f_range - n_range);\n" +
          "}\n" +
          "void main()\n" +
          "{\n" +
          "gl_FragColor = texture2D(colorTexture, v_textureCoordinates);\n" +
          "float depth = getDepth( texture2D(depthTexture, v_textureCoordinates));\n" +
          "vec4 viewPos = toEye(v_textureCoordinates, depth);\n" +
          "vec3 prjOnPlane = pointProjectOnPlane(u_scanPlaneNormalEC.xyz, u_scanCenterEC.xyz, viewPos.xyz);\n" +
          "float dis = length(prjOnPlane.xyz - u_scanCenterEC.xyz);\n" +
          "float cricle_radius = 10.0;\n" +
          "if(dis < cricle_radius)\n" +
          "{\n" +
          "vec3 light_color = vec3(0.9, 0.65, 0.5);\n" +
          "vec2 uv = v_textureCoordinates.xy*3.0;\n" +
          "float light = 0.1 / distance(normalize(uv), uv);\n" +
          "gl_FragColor = vec4(vec3(light),1.0);\n" +
          "}\n" +
          "}\n";
  
      var _Cartesian3Center = Cesium.Cartographic.toCartesian(cartographicCenter);
      var _Cartesian4Center = new Cesium.Cartesian4(_Cartesian3Center.x, _Cartesian3Center.y, _Cartesian3Center.z, 1);
      var _CartographicCenter1 = new Cesium.Cartographic(cartographicCenter.longitude, cartographicCenter.latitude, cartographicCenter.height + 500);
      var _Cartesian3Center1 = Cesium.Cartographic.toCartesian(_CartographicCenter1);
      var _Cartesian4Center1 = new Cesium.Cartesian4(_Cartesian3Center1.x, _Cartesian3Center1.y, _Cartesian3Center1.z, 1);
      var _time = (new Date()).getTime();
      var _scratchCartesian4Center = new Cesium.Cartesian4();
      var _scratchCartesian4Center1 = new Cesium.Cartesian4();
      var _scratchCartesian3Normal = new Cesium.Cartesian3();
      var ScanPostStage = new Cesium.PostProcessStage({
          fragmentShader: ScanSegmentShader,
          uniforms: {
              u_scanCenterEC: function () {
                  return Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center, _scratchCartesian4Center);
              },
              u_scanPlaneNormalEC: function () {
                  var temp = Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center, _scratchCartesian4Center);
                  var temp1 = Cesium.Matrix4.multiplyByVector(viewer.camera._viewMatrix, _Cartesian4Center1, _scratchCartesian4Center1);
                  _scratchCartesian3Normal.x = temp1.x - temp.x;
                  _scratchCartesian3Normal.y = temp1.y - temp.y;
                  _scratchCartesian3Normal.z = temp1.z - temp.z;
                  Cesium.Cartesian3.normalize(_scratchCartesian3Normal, _scratchCartesian3Normal);
                  return _scratchCartesian3Normal;
  
              },
              u_radius: function () {
                  return maxRadius * (((new Date()).getTime() - _time) % duration) / duration;
              },
              u_scanColor: scanColor
          }
      });
      viewer.scene.postProcessStages.add(ScanPostStage);
      return (ScanPostStage);
  
  }
  function addCircleLight(viewer, data) {
      //防止移动、放大缩小会视觉偏移depthTestAgainstTerrain
      //设置该属性为true之后，标绘将位于地形的顶部；如果设为false（默认值），那么标绘将位于平面上。
      //缺陷：开启该属性有可能在切换图层时会引发标绘消失的bug。
      viewer.scene.globe.depthTestAgainstTerrain = true;
      var CartographicCenter = new Cesium.Cartographic(Cesium.Math.toRadians(data.lon), Cesium.Math.toRadians(data.lat), 0); //中心位子
      return AddCircleScanPostStage(viewer, CartographicCenter, data.r, data.scanColor, data.interval);
  }
  
  /**
     *测试用例
     * */
  // const circleScan = ysc.addCircleScan(viewer, {
  //     lon: 117.217124,//经度
  //     lat: 31.809777, //纬度
  //     scanColor: new Cesium.Color(0.5, 0.5, 0.5, 1),
  //     r: 1500,//扫描半径
  //     interval: 4000//时间间隔
  // });
  export { addCircleLight }
  