Cesium 一些方法

import * as Cesium from 'cesium';
class MeasureTool {
  constructor(viewer, options = {}) {
    if (viewer && viewer instanceof Cesium.Viewer) {
      // this._drawLayer = new Cesium.CustomDataSource('measureLayer');
      // viewer && viewer.dataSources.add(this._drawLayer);
 
      this._basePath = options.basePath || '';
 
      this._viewer = viewer;
    }
  }
 
  /***
   * 坐标转换 84转笛卡尔
   *
   * @param {Object} {lng,lat,alt} 地理坐标
   *
   * @return {Object} Cartesian3 三维位置坐标
   */
  transformWGS84ToCartesian(position, alt) {
    if (this._viewer) {
      return position
        ? Cesium.Cartesian3.fromDegrees(
            position.lng || position.lon,
            position.lat,
            (position.alt = alt || position.alt),
            Cesium.Ellipsoid.WGS84,
          )
        : Cesium.Cartesian3.ZERO;
    }
  }
  /***
   * 坐标数组转换 笛卡尔转84
   *
   * @param {Array} WSG84Arr {lng,lat,alt} 地理坐标数组
   * @param {Number} alt 拔高
   * @return {Array} Cartesian3 三维位置坐标数组
   */
  transformWGS84ArrayToCartesianArray(WSG84Arr, alt) {
    if (this._viewer && WSG84Arr) {
      var $this = this;
      return WSG84Arr
        ? WSG84Arr.map(function (item) {
            return $this.transformWGS84ToCartesian(item, alt);
          })
        : [];
    }
  }
 
  /***
   * 坐标转换 笛卡尔转84
   *
   * @param {Object} Cartesian3 三维位置坐标
   *
   * @return {Object} {lng,lat,alt} 地理坐标
   */
  transformCartesianToWGS84(cartesian) {
    if (this._viewer && cartesian) {
      var ellipsoid = Cesium.Ellipsoid.WGS84;
      var cartographic = ellipsoid.cartesianToCartographic(cartesian);
      return {
        lng: Cesium.Math.toDegrees(cartographic.longitude),
        lat: Cesium.Math.toDegrees(cartographic.latitude),
        alt: cartographic.height,
      };
    }
  }
 
  /***
   * 坐标数组转换 笛卡尔转86
   *
   * @param {Array} cartesianArr 三维位置坐标数组
   *
   * @return {Array} {lng,lat,alt} 地理坐标数组
   */
  transformCartesianArrayToWGS84Array(cartesianArr) {
    if (this._viewer) {
      var $this = this;
      return cartesianArr
        ? cartesianArr.map(function (item) {
            return $this.transformCartesianToWGS84(item);
          })
        : [];
    }
  }
 
  /**
   * 84坐标转弧度坐标
   * @param {Object} position wgs84
   * @return {Object} Cartographic 弧度坐标
   *
   */
  transformWGS84ToCartographic(position) {
    return position
      ? Cesium.Cartographic.fromDegrees(position.lng || position.lon, position.lat, position.alt)
      : Cesium.Cartographic.ZERO;
  }
 
  /**
   * 拾取位置点
   *
   * @param {Object} px 屏幕坐标
   *
   * @return {Object} Cartesian3 三维坐标
   */
  getCatesian3FromPX(px) {
    if (this._viewer && px) {
      var picks = this._viewer.scene.drillPick(px);
      var cartesian = null;
      var isOn3dtiles = false,
        isOnTerrain = false;
      // drillPick
      for (let i in picks) {
        let pick = picks[i];
 
        if (
          (pick && pick.primitive instanceof Cesium.Cesium3DTileFeature) ||
          (pick && pick.primitive instanceof Cesium.Cesium3DTileset) ||
          (pick && pick.primitive instanceof Cesium.Model)
        ) {
          //模型上拾取
          isOn3dtiles = true;
        }
        // 3dtilset
        if (isOn3dtiles) {
          this._viewer.scene.pick(px); // pick
          cartesian = this._viewer.scene.pickPosition(px);
          if (cartesian) {
            let cartographic = Cesium.Cartographic.fromCartesian(cartesian);
            if (cartographic.height < 0) cartographic.height = 0;
            let lon = Cesium.Math.toDegrees(cartographic.longitude),
              lat = Cesium.Math.toDegrees(cartographic.latitude),
              height = cartographic.height;
            cartesian = this.transformWGS84ToCartesian({
              lng: lon,
              lat: lat,
              alt: height,
            });
          }
        }
      }
      // 地形
      let boolTerrain = this._viewer.terrainProvider instanceof Cesium.EllipsoidTerrainProvider;
      // Terrain
      if (!isOn3dtiles && !boolTerrain) {
        var ray = this._viewer.scene.camera.getPickRay(px);
        if (!ray) return null;
        cartesian = this._viewer.scene.globe.pick(ray, this._viewer.scene);
        isOnTerrain = true;
      }
      // 地球
      if (!isOn3dtiles && !isOnTerrain && boolTerrain) {
        cartesian = this._viewer.scene.camera.pickEllipsoid(px, this._viewer.scene.globe.ellipsoid);
      }
      if (cartesian) {
        let position = this.transformCartesianToWGS84(cartesian);
        if (position.alt < 0) {
          cartesian = this.transformWGS84ToCartesian(position, 0.1);
        }
        return cartesian;
      }
      return false;
    }
  }
 
  /**
   * 获取84坐标的距离
   * @param {*} positions
   */
  getPositionDistance(positions) {
    let distance = 0;
    for (let i = 0; i < positions.length - 1; i++) {
      let point1cartographic = this.transformWGS84ToCartographic(positions[i]);
      let point2cartographic = this.transformWGS84ToCartographic(positions[i + 1]);
      let geodesic = new Cesium.EllipsoidGeodesic();
      geodesic.setEndPoints(point1cartographic, point2cartographic);
      let s = geodesic.surfaceDistance;
      s = Math.sqrt(
        Math.pow(s, 2) + Math.pow(point2cartographic.height - point1cartographic.height, 2),
      );
      distance = distance + s;
    }
    return distance.toFixed(3);
  }
  /**
   * 计算一组坐标组成多边形的面积
   * @param {*} positions
   */
  getPositionsArea(positions) {
    let result = 0;
    if (positions) {
      let h = 0;
      let ellipsoid = Cesium.Ellipsoid.WGS84;
      positions.push(positions[0]);
      for (let i = 1; i < positions.length; i++) {
        let oel = ellipsoid.cartographicToCartesian(
          this.transformWGS84ToCartographic(positions[i - 1]),
        );
        let el = ellipsoid.cartographicToCartesian(this.transformWGS84ToCartographic(positions[i]));
        h += oel.x * el.y - el.x * oel.y;
      }
      result = Math.abs(h).toFixed(2);
    }
    return result;
  }
  /**
   * 测距
   * @param {*} options
   */
  drawLineMeasureGraphics(options = {}) {
    if (this._viewer && options) {
      var positions = [],
        _lineEntity = new Cesium.Entity(),
        $this = this,
        lineObj,
        _handlers = new Cesium.ScreenSpaceEventHandler(this._viewer.scene.canvas);
      // left
      _handlers.setInputAction(function (movement) {
        var cartesian = $this.getCatesian3FromPX(movement.position);
        if (cartesian && cartesian.x) {
          if (positions.length == 0) {
            positions.push(cartesian.clone());
          }
          // 添加量测信息点
          _addInfoPoint(cartesian);
          positions.push(cartesian);
        }
      }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
 
      _handlers.setInputAction(function (movement) {
        var cartesian = $this.getCatesian3FromPX(movement.endPosition);
        if (positions.length >= 2) {
          if (cartesian && cartesian.x) {
            positions.pop();
            positions.push(cartesian);
          }
        }
      }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
      // right
      _handlers.setInputAction(function (movement) {
        _handlers.destroy();
        _handlers = null;
 
        let cartesian = $this.getCatesian3FromPX(movement.position);
        _addInfoPoint(cartesian);
 
        if (typeof options.callback === 'function') {
          options.callback($this.transformCartesianArrayToWGS84Array(positions), lineObj);
        }
      }, Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
 
      _lineEntity.polyline = {
        width: options.width || 5,
        material: options.material || Cesium.Color.BLUE.withAlpha(0.8),
        clampToGround: false,
      };
      _lineEntity.polyline.positions = new Cesium.CallbackProperty(function () {
        return positions;
      }, false);
 
      lineObj = this._viewer.entities.add(_lineEntity);
 
      //添加坐标点
      function _addInfoPoint(position) {
        var _labelEntity = new Cesium.Entity();
        _labelEntity.position = position;
        _labelEntity.point = {
          pixelSize: 10,
          outlineColor: Cesium.Color.BLUE,
          outlineWidth: 5,
        };
        _labelEntity.label = {
          text:
            (
              $this.getPositionDistance($this.transformCartesianArrayToWGS84Array(positions)) / 1000
            ).toFixed(4) + '公里',
          show: true,
          showBackground: true,
          font: '14px monospace',
          horizontalOrigin: Cesium.HorizontalOrigin.LEFT,
          verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
          pixelOffset: new Cesium.Cartesian2(-10, -10), //left top
        };
        $this._viewer.entities.add(_labelEntity);
      }
    }
  }
 
  /**
   * 测面积
   * @param {*} options
   */
  drawAreaMeasureGraphics(options = {}) {
    if (this._viewer && options) {
      var positions = [],
        $this = this,
        mouse = null,
        primitiveline = null,
        primitive = null,
        pointPrimitives = null,
        _handler = new Cesium.ScreenSpaceEventHandler(this._viewer.scene.canvas);
      // left
      _handler.setInputAction(function (movement) {
        var cartesian = $this._viewer.scene.pickPosition(movement.position);
        let carto_pt = Cesium.Cartographic.fromCartesian(cartesian);
        if (cartesian) {
          positions.push(
            Cesium.Cartesian3.fromDegrees(
              Cesium.Math.toDegrees(carto_pt.longitude),
              Cesium.Math.toDegrees(carto_pt.latitude),
              Cesium.Math.toDegrees(500),
            ),
          );
          if (mouse) {
            _polinePositions.push(
              Cesium.Cartesian3.fromDegrees(
                Cesium.Math.toDegrees(mouse.longitude),
                Cesium.Math.toDegrees(mouse.latitude),
                Cesium.Math.toDegrees(500),
              ),
            );
            updatePrimitivePosition(primitive, primitiveline, pointPrimitives, positions);
          } else {
            create(positions);
          }
        } else {
          updatePrimitivePosition(primitive, primitiveline, pointPrimitives, positions);
        }
      }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
      // mouse
      _handler.setInputAction(function (movement) {
        var cartesian = $this._viewer.scene.pickPosition(movement.position);
        let carto_pt = Cesium.Cartographic.fromCartesian(cartesian);
        mouse = carto_pt;
      }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
 
      // right
      _handler.setInputAction(function (movement) {
        let cartesian = $this.getCatesian3FromPX(movement.endPosition);
 
        _handler.destroy();
 
        positions.push(positions[0]);
        updatePrimitivePosition(primitive, primitiveline, pointPrimitives, positions);
        // 添加信息点
        _addInfoPoint(positions[0]);
      }, Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
 
      function create(positions) {
        pointPrimitives = new Cesium.PointPrimitiveCollection();
        positions.forEach((res) => {
          var pointPrimitive = new Cesium.PointPrimitive({
            position: res,
            color: Cesium.Color.BLUE,
            pixelSize: 10,
          });
 
          pointPrimitives.add(pointPrimitive);
        });
        viewer.scene.primitives.add(pointPrimitives);
        // 创建线段的颜色
        var colorline = Cesium.Color.BLUE.withAlpha(0.8);
        // 创建线段
        var geometryline = new Cesium.GeometryInstance({
          geometry: new Cesium.PolylineGeometry({
            positions: positions,
            width: 5,
            vertexFormat: Cesium.PolylineColorAppearance.VERTEX_FORMAT,
          }),
          attributes: {
            color: Cesium.ColorGeometryInstanceAttribute.fromColor(colorline),
          },
        });
        primitiveline = new Cesium.Primitive({
          geometryInstances: [geometryline],
          appearance: new Cesium.PolylineColorAppearance(),
        });
        viewer.scene.primitives.add(primitiveline);
        // 创建面的颜色
        var color = Cesium.Color.WHITE.withAlpha(0.51);
        var polygonGeometry = new Cesium.PolygonGeometry({
          polygonHierarchy: new Cesium.PolygonHierarchy(positions),
          vertexFormat: Cesium.PerInstanceColorAppearance.VERTEX_FORMAT,
        });
        var geometryInstance = new Cesium.GeometryInstance({
          geometry: polygonGeometry,
          attributes: {
            color: Cesium.ColorGeometryInstanceAttribute.fromColor(color),
          },
        });
        primitive = new Cesium.GroundPrimitive({
          geometryInstances: geometryInstance,
          appearance: new Cesium.PerInstanceColorAppearance({
            translucent: false,
            closed: true,
          }),
        });
        // 将线段添加到场景中
        viewer.scene.primitives.add(primitive);
      }
      function updatePrimitivePosition(primitive, primitiveline, pointPrimitives, newPositions) {
        viewer.scene.primitives.remove(primitive);
        viewer.scene.primitives.remove(primitiveline);
        viewer.scene.primitives.remove(pointPrimitives);
        create(newPositions);
      }
      function _addInfoPoint(position) {
        var _labelEntity = new Cesium.Entity();
        _labelEntity.position = position;
        _labelEntity.point = {
          pixelSize: 10,
        };
        _labelEntity.label = {
          text:
            (
              $this.getPositionsArea($this.transformCartesianArrayToWGS84Array(positions)) /
              1000000.0
            ).toFixed(4) + '平方公里',
          show: true,
          showBackground: true,
          font: '14px monospace',
          horizontalOrigin: Cesium.HorizontalOrigin.LEFT,
          verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
          pixelOffset: new Cesium.Cartesian2(-20, -20), //left top
        };
        $this._viewer.entities.add(_labelEntity);
      }
    }
  }
 
  /**
   * 画三角量测
   * @param {*} options
   */
  drawTrianglesMeasureGraphics(options = {}) {
    options.style = options.style || {
      width: 3,
      material: Cesium.Color.BLUE.withAlpha(0.5),
    };
    if (this._viewer && options) {
      var _trianglesEntity = new Cesium.Entity(),
        _tempLineEntity = new Cesium.Entity(),
        _tempLineEntity2 = new Cesium.Entity(),
        _positions = [],
        _tempPoints = [],
        _tempPoints2 = [],
        $this = this,
        _handler = new Cesium.ScreenSpaceEventHandler(this._viewer.scene.canvas);
      // 高度
      function _getHeading(startPosition, endPosition) {
        if (!startPosition && !endPosition) return 0;
        if (Cesium.Cartesian3.equals(startPosition, endPosition)) return 0;
        let cartographic = Cesium.Cartographic.fromCartesian(startPosition);
        let cartographic2 = Cesium.Cartographic.fromCartesian(endPosition);
        return (cartographic2.height - cartographic.height).toFixed(2);
      }
      // 偏移点
      function _computesHorizontalLine(positions) {
        let cartographic = Cesium.Cartographic.fromCartesian(positions[0]);
        let cartographic2 = Cesium.Cartographic.fromCartesian(positions[1]);
        return Cesium.Cartesian3.fromDegrees(
          Cesium.Math.toDegrees(cartographic.longitude),
          Cesium.Math.toDegrees(cartographic.latitude),
          cartographic2.height,
        );
      }
      // left
      _handler.setInputAction(function (movement) {
        var position = $this.getCatesian3FromPX(movement.position);
        if (!position && !position.z) return false;
        if (_positions.length == 0) {
          _positions.push(position.clone());
          _positions.push(position.clone());
          _tempPoints.push(position.clone());
          _tempPoints.push(position.clone());
        } else {
          _handler.destroy();
          if (typeof options.callback === 'function') {
            options.callback({
              e: _trianglesEntity,
              e2: _tempLineEntity,
              e3: _tempLineEntity2,
            });
          }
        }
      }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
      // mouse
      _handler.setInputAction(function (movement) {
        var position = $this.getCatesian3FromPX(movement.endPosition);
        if (position && _positions.length > 0) {
          //直线
          _positions.pop();
          _positions.push(position.clone());
          let horizontalPosition = _computesHorizontalLine(_positions);
          //高度
          _tempPoints.pop();
          _tempPoints.push(horizontalPosition.clone());
          //水平线
          _tempPoints2.pop(), _tempPoints2.pop();
          _tempPoints2.push(position.clone());
          _tempPoints2.push(horizontalPosition.clone());
        }
      }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
 
      // create entity
 
      //直线
      _trianglesEntity.polyline = {
        positions: new Cesium.CallbackProperty(function () {
          return _positions;
        }, false),
        ...options.style,
      };
      _trianglesEntity.position = new Cesium.CallbackProperty(function () {
        return _positions[0];
      }, false);
      _trianglesEntity.point = {
        pixelSize: 5,
        outlineColor: Cesium.Color.BLUE,
        outlineWidth: 5,
      };
      // _trianglesEntity.label = {
      //   text: new Cesium.CallbackProperty(function () {
      //     return (
      //       '直线:' +
      //       $this.getPositionDistance($this.transformCartesianArrayToWGS84Array(_positions)) +
      //       '米'
      //     );
      //   }, false),
      //   show: true,
      //   showBackground: true,
      //   font: '14px monospace',
      //   horizontalOrigin: Cesium.HorizontalOrigin.LEFT,
      //   verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
      //   pixelOffset: new Cesium.Cartesian2(50, -100), //left top
      // };
      //高度
      _tempLineEntity.polyline = {
        positions: new Cesium.CallbackProperty(function () {
          return _tempPoints;
        }, false),
        ...options.style,
      };
      _tempLineEntity.position = new Cesium.CallbackProperty(function () {
        return _tempPoints2[1];
      }, false);
      _tempLineEntity.point = {
        pixelSize: 5,
        outlineColor: Cesium.Color.BLUE,
        outlineWidth: 5,
      };
      _tempLineEntity.label = {
        text: new Cesium.CallbackProperty(function () {
          return '高度:' + _getHeading(_tempPoints[0], _tempPoints[1]) + '米';
        }, false),
        show: true,
        showBackground: true,
        font: '14px monospace',
        horizontalOrigin: Cesium.HorizontalOrigin.LEFT,
        verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
        pixelOffset: new Cesium.Cartesian2(50, -100), //left top
      };
      //水平
      _tempLineEntity2.polyline = {
        positions: new Cesium.CallbackProperty(function () {
          return _tempPoints2;
        }, false),
        ...options.style,
      };
      _tempLineEntity2.position = new Cesium.CallbackProperty(function () {
        return _positions[1];
      }, false);
      _tempLineEntity2.point = {
        pixelSize: 5,
        outlineColor: Cesium.Color.BLUE,
        outlineWidth: 5,
      };
      // _tempLineEntity2.label = {
      //   text: new Cesium.CallbackProperty(function () {
      //     return (
      //       '水平距离:' +
      //       $this.getPositionDistance($this.transformCartesianArrayToWGS84Array(_tempPoints2)) +
      //       '米'
      //     );
      //   }, false),
      //   show: true,
      //   showBackground: true,
      //   font: '14px monospace',
      //   horizontalOrigin: Cesium.HorizontalOrigin.LEFT,
      //   verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
      //   pixelOffset: new Cesium.Cartesian2(-150, -20), //left top
      // };
      this._viewer.entities.add(_tempLineEntity2);
      this._viewer.entities.add(_tempLineEntity);
      this._viewer.entities.add(_trianglesEntity);
    }
  }
  /**
   * 角度测量
   */
  drawAngleMeasyre(options = {}) {
    if (this._viewer && options) {
      var positions = [],
        _lineEntity = new Cesium.Entity(),
        $this = this,
        lineObj,
        _handlers = new Cesium.ScreenSpaceEventHandler(this._viewer.scene.canvas);
      // left
      _handlers.setInputAction(function (movement) {
        var cartesian = $this.getCatesian3FromPX(movement.position);
        if (cartesian && cartesian.x) {
          if (positions.length == 0) {
            positions.push(cartesian.clone());
            // 添加量测信息点
            _addInfoPoint(cartesian);
            positions.push(cartesian);
          }
        }
      }, Cesium.ScreenSpaceEventType.LEFT_CLICK);
 
      _handlers.setInputAction(function (movement) {
        var cartesian = $this.getCatesian3FromPX(movement.endPosition);
        if (positions.length > 0) {
          if (cartesian && cartesian.x) {
            positions.pop();
            positions.push(cartesian);
          }
        }
      }, Cesium.ScreenSpaceEventType.MOUSE_MOVE);
      // right
      _handlers.setInputAction(function (movement) {
        _handlers.destroy();
        _handlers = null;
 
        let cartesian = $this.getCatesian3FromPX(movement.position);
        if (cartesian && cartesian.x) {
          positions.pop();
          positions.push(cartesian);
        }
        _addInfoPoint(cartesian);
 
        if (typeof options.callback === 'function') {
          options.callback($this.transformCartesianArrayToWGS84Array(positions), lineObj);
        }
      }, Cesium.ScreenSpaceEventType.LEFT_DOUBLE_CLICK);
 
      _lineEntity.polyline = {
        width: options.width || 5,
        material: options.material || Cesium.Color.BLUE.withAlpha(0.8),
        clampToGround: false,
      };
      _lineEntity.polyline.positions = new Cesium.CallbackProperty(function () {
        return positions;
      }, false);
 
      lineObj = this._viewer.entities.add(_lineEntity);
 
      //添加坐标点
      function _addInfoPoint(position) {
        var _labelEntity = new Cesium.Entity();
        if (positions.length > 1) {
          var vector = Cesium.Cartesian3.subtract(
            positions[0],
            positions[1],
            new Cesium.Cartesian3(),
          );
 
          // 计算角度
          var angle = Cesium.Cartesian3.angleBetween(vector, new Cesium.Cartesian3(1, 0, 0)); // 使用 (1, 0, 0) 向量计算角度
          var angleDegrees = Cesium.Math.toDegrees(angle);
          _labelEntity.position = position;
          _labelEntity.point = {
            pixelSize: 10,
            outlineColor: Cesium.Color.BLUE,
            outlineWidth: 5,
          };
          _labelEntity.label = {
            text: '角度' + angleDegrees.toFixed(4) + '°',
            show: true,
            showBackground: true,
            font: '14px monospace',
            horizontalOrigin: Cesium.HorizontalOrigin.LEFT,
            verticalOrigin: Cesium.VerticalOrigin.BOTTOM,
            pixelOffset: new Cesium.Cartesian2(-10, -10), //left top
          };
          $this._viewer.entities.add(_labelEntity);
        } else {
          var _labelEntity = new Cesium.Entity();
          _labelEntity.position = position;
          _labelEntity.point = {
            pixelSize: 10,
            outlineColor: Cesium.Color.BLUE,
            outlineWidth: 5,
          };
 
          $this._viewer.entities.add(_labelEntity);
        }
      }
    }
  }
}
export default MeasureTool;