support pmtiles

[RobJN]

See: https://protomaps.com/docs/pmtiles

Adding support would be useful for those who'd like to adopt the new format for the reasons explained on their site.

Thanks for considering this request. Rob

[iandees]

That's a good idea. I wonder if @bdon would have any interest in writing it?

[bdon]

It has some overlap with https://github.com/onthegomap/planetiler/issues/98 which may eventually get extracted into a standalone Java package. Some parts of JOSM package that may be relevant are:

• if JOSM provides functions for doing compression/decompression (GZIP at minimum)
• functions for HTTP requests or even signed requests with an awsv4 Authorization header
• whether to support read-only pmtiles (not writing) and whether it needs only a set tiles for display or more advanced tasks like listing all tiles

[tsmock]

As a heads up, I'm writing a plugin for PMTiles support right now. I'm just about done too. It will live in the JOSM SVN repository.

[bdon]

@tsmock cool! most of the Java related code for pmtiles right now lives here: https://github.com/onthegomap/planetiler/blob/main/planetiler-core/src/main/java/com/onthegomap/planetiler/pmtiles/

[tsmock]

I already wrote the reading implementation. And debugged it.

Have a screenshot (you probably recognize it -- I was testing against the test files in the specification directory):