cesiumDemo/src/core/measure.js

import {
  Entity,
  Ellipsoid,
  Cartesian3,
  PolylineOutlineMaterialProperty,
  Color,
  ScreenSpaceEventType,
  HeightReference,
  Cartesian2,
  LabelStyle,
  VerticalOrigin,
  ScreenSpaceEventHandler,
  handler,
  defined,
  CallbackProperty,
  Cartographic,
  EllipsoidGeodesic
} from 'cesium/Cesium'

/******************************************* */
//测量空间直线距离 
/******************************************* */

var measureLineSpace = function (cb) {
  var handler = new ScreenSpaceEventHandler(viewer.scene._imageryLayerCollection);
  var positions = [];
  var poly = null;
  var tooltip = document.getElementById("toolTip");
  var distance = 0;
  var cartesian = null;
  var floatingPoint;

  handler.setInputAction(function (movement) {
    tooltip.style.left = movement.endPosition.x + 3 + "px";
    tooltip.style.top = movement.endPosition.y - 25 + "px";
    tooltip.innerHTML = '<p>单击开始，双击结束</p>';

    ///////=================================

    cartesian = viewer.scene.pickPosition(movement.endPosition);

    /////==================================
    //cartesian = viewer.scene.camera.pickEllipsoid(movement.endPosition, viewer.scene.globe.ellipsoid);
    if (positions.length >= 2) {
      if (!defined(poly)) {
        poly = new PolyLinePrimitive(positions);
      } else {
        positions.pop();
        // cartesian.y += (1 + Math.random());
        positions.push(cartesian);
      }
      distance = getSpaceDistance(positions);
      // console.log("distance: " + distance);
      // tooltip.innerHTML='<p>'+distance+'米</p>';
    }
  }, ScreenSpaceEventType.MOUSE_MOVE);

  handler.setInputAction(function (movement) {
    // cartesian = viewer.scene.camera.pickEllipsoid(movement.position, viewer.scene.globe.ellipsoid);
    cartesian = viewer.scene.pickPosition(movement.position);
    if (positions.length == 0) {
      positions.push(cartesian.clone());
    }
    positions.push(cartesian);
    //在三维场景中添加Label
    // var cartographic = Cartographic.fromCartesian(cartesian);
    var textDisance = distance + "米";
    // console.log(textDisance + ",lng:" + cartographic.longitude/Math.PI*180.0);
    floatingPoint = viewer.entities.add({
      name: '空间直线距离',
      // position: Cartesian3.fromDegrees(cartographic.longitude / Math.PI * 180, cartographic.latitude / Math.PI * 180,cartographic.height),
      position: positions[positions.length - 1],
      point: {
        pixelSize: 5,
        color: Color.RED,
        outlineColor: Color.WHITE,
        outlineWidth: 2,
        heightReference: HeightReference.NONE
      },
      label: {
        text: textDisance,
        font: '18px sans-serif',
        fillColor: Color.GOLD,
        style: LabelStyle.FILL_AND_OUTLINE,
        outlineWidth: 2,
        verticalOrigin: VerticalOrigin.BOTTOM,
        pixelOffset: new Cartesian2(20, -20),
        heightReference: HeightReference.NONE
      }
    });
  }, ScreenSpaceEventType.LEFT_CLICK);

  handler.setInputAction(function (movement) {
    handler.destroy();//关闭事件句柄
    positions.pop();//最后一个点无效
    viewer.entities.remove(floatingPoint);
    cb()
  }, ScreenSpaceEventType.LEFT_DOUBLE_CLICK);

  var PolyLinePrimitive = (function () {
    function _(positions) {
      this.options = {
        name: '直线',
        polyline: {
          show: true,
          positions: [],
          material: Color.CHARTREUSE,
          width: 2


        }
      };
      this.positions = positions;
      this._init();
    }

    _.prototype._init = function () {
      var _self = this;
      var _update = function () {
        return _self.positions;
      };
      //实时更新polyline.positions
      this.options.polyline.positions = new CallbackProperty(_update, false);
      viewer.entities.add(this.options);
    };

    return _;
  })();

};

//空间两点距离计算函数
function getSpaceDistance(positions) {
  var distance = 0;
  for (var i = 0; i < positions.length - 1; i++) {

    var point1cartographic = Cartographic.fromCartesian(positions[i]);
    var point2cartographic = Cartographic.fromCartesian(positions[i + 1]);
    /**根据经纬度计算出距离**/
    var geodesic = new EllipsoidGeodesic();
    geodesic.setEndPoints(point1cartographic, point2cartographic);
    var s = geodesic.surfaceDistance;
    //console.log(Math.sqrt(Math.pow(distance, 2) + Math.pow(endheight, 2)));
    //返回两点之间的距离
    s = Math.sqrt(Math.pow(s, 2) + Math.pow(point2cartographic.height - point1cartographic.height, 2));
    distance = distance + s;
  }
  return distance.toFixed(2);
}
export default measureLineSpace