Method _processMergeQueue

modules/services/VectorTileService.js:465–494

* _processMergeQueue * Call this sometimes to merge features across tile edges

(source)

   * Call this sometimes to merge features across tile edges
   */
  _processMergeQueue(source) {
    for (const cache of source.zoomCache.values()) {
      for (const [edgeID, mergemap] of cache.toMerge) {  // for each edge

        // Are both tiles loaded?
        const [lowID, highID] = edgeID.split('-');
        const lowTile = source.loaded.get(lowID);
        const highTile = source.loaded.get(highID);
        if (!lowTile || !highTile) continue;

        cache.didMerge.add(edgeID);

        // All the features that share this prophash along this edge can be merged
        for (const [prophash, featureIDs] of mergemap) {
          // Determine geometry type from the first available feature
          const firstFeature = Array.from(featureIDs)
            .map(id => cache.features.get(id))
            .find(Boolean);

          if (firstFeature?.geojson?.geometry?.type === 'LineString') {
            this._mergeLineStrings(cache, prophash, featureIDs, lowTile, highTile);
          } else {
            this._mergePolygons(cache, prophash, featureIDs, lowTile, highTile);
          }
          mergemap.delete(prophash);  // done this prophash
        }
        cache.toMerge.delete(edgeID);
      }
    }
  }


  /**