Describes tile store usage modes.
Tile store enabled for accessing loaded tile packs. The implementation first checks tile store when requesting a tile. If a tile pack is already loaded, the tile will be extracted and returned. Otherwise, the implementation falls back to requesting the individual tile and storing it in the disk cache.
Tile store enabled for accessing local tile packs and for loading new tile packs from server. All tile requests are converted to tile pack requests, i.e. the tile pack that includes the request tile will be loaded, and the tile extracted from it. In this mode, no individual tile requests will be made. This mode can be useful if the map trajectory is predefined and the user cannot pan freely (e.g. navigation use cases), so that there is a good chance tile packs are already loaded in the vicinity of the user. If users can pan freely, this mode is not recommended. Otherwise, panning will download tile packs instead of using individual tiles. Note that this means that we could first download an individual tile, and then a tile pack that also includes this tile. The individual tile in the disk cache won’t be used as long as the up-to-date tile pack exists in the cache.