Method addPathFeature

src/openlayers/mapping/WebMap.js:3982–4000

* @private * @function WebMap.prototype.addPathFeature * @description 添加数据流图层中轨迹线的feature * @param {Object} source - 轨迹线图层的source * @param {Object} feature - 轨迹线feature * @param {string} identifyField - 标识feature的字段 * @param {Object} featureCache - 存储feature * @param {number} ma

(source, feature, identifyField, featureCache, maxPointCount)

   * @param {number} maxPointCount - 轨迹线最多点个数数量
   */
  addPathFeature(source, feature, identifyField, featureCache, maxPointCount) {
    let coordinates = [];
    var geoID = feature.get(identifyField);
    if (featureCache[geoID]) {
      //加过feautre
      coordinates = featureCache[geoID].getGeometry().getCoordinates();
      coordinates.push(feature.getGeometry().getCoordinates());
      if (maxPointCount && coordinates.length > maxPointCount) {
        coordinates.splice(0, coordinates.length - maxPointCount);
      }
      featureCache[geoID].getGeometry().setCoordinates(coordinates);
    } else {
      coordinates.push(feature.getGeometry().getCoordinates());
      featureCache[geoID] = new Feature({
        geometry: new olGeometry.LineString(coordinates)
      });
      source.addFeature(featureCache[geoID]);
    }
  }

  /**
   * @private