Greetings OSM developers,
Has anyone considered, designed, and/or implemented an extension to
mod_tile to support serving raw metatile files to clients?
I've got my own tile server running using mod_tile and renderd and my
own application that consumes OSM-compatible tiles. I really don't like
seeing the individual tiles arrive on my Android devices and would like
to extend the knowledge of the metatile format into my client
application. That way, a single round-trip to the server brings back
multiple tiles rather than one per round-trip. The client caches tiles
in an MBtiles database, so it can easily extract the individual tiles
from the metatile and locally access them as needed.
I've looked at mod_tile and it appears to be an easy thing to add. I'm
considering extending the /status and /dirty approach to include a /meta
option. I'm not completely sold on this because I'm actually planning
to return the entire meta tile for the specified /z/x/y.png that was
requested along with http response headers describing the metatile
parameters. The latter part allows the client to not have to assume
that the server is doing 8x8 metatiles but will be told on each response
how many are in the file.
By returning a full metatile when a single tile is requested (with the
/meta trailer), the client doesn't need to be aware of the metatile path
naming, but only the format of extracting specific tiles from the
metatile file.
I'm open to prior art in this area and/or comments on the thinking
described above. If I do this, is it something that anyone would be
interested in having commited back to the repository? In any case, it
will be 100% backward compatible and possibly even a compile or runtime
option for mod_tile to include this feature.
Lynn (D) - KJ4ERJ - Author of APRSISMO, an Amateur Radio APRS Client for
Android under MOAI
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