Function createGetEntity

packages/engine/Source/DataSources/EntityCluster.js:634–688

(
  collectionProperty,
  CollectionConstructor,
  unusedIndicesProperty,
  entityIndexProperty,
)

});

function createGetEntity(
  collectionProperty,
  CollectionConstructor,
  unusedIndicesProperty,
  entityIndexProperty,
) {
  return function (entity) {
    let collection = this[collectionProperty];

    if (!defined(this._collectionIndicesByEntity)) {
      this._collectionIndicesByEntity = {};
    }

    let entityIndices = this._collectionIndicesByEntity[entity.id];

    if (!defined(entityIndices)) {
      entityIndices = this._collectionIndicesByEntity[entity.id] = {
        billboardIndex: undefined,
        labelIndex: undefined,
        pointIndex: undefined,
      };
    }

    if (defined(collection) && defined(entityIndices[entityIndexProperty])) {
      return collection.get(entityIndices[entityIndexProperty]);
    }

    if (!defined(collection)) {
      collection = this[collectionProperty] = new CollectionConstructor({
        scene: this._scene,
      });
    }

    let index;
    let entityItem;

    const unusedIndices = this[unusedIndicesProperty];
    if (unusedIndices.length > 0) {
      index = unusedIndices.shift();
      entityItem = collection.get(index);
    } else {
      entityItem = collection.add();
      index = collection.length - 1;
    }

    entityIndices[entityIndexProperty] = index;

    const that = this;
    Promise.resolve().then(function () {
      that._clusterDirty = true;
    });

    return entityItem;
  };
}

function removeEntityIndicesIfUnused(entityCluster, entityId) {
  const indices = entityCluster._collectionIndicesByEntity[entityId];