support vector tiles produced using the UN Vector Tile Toolkit

[hfu]

Hi. As discussed between @moovida and @hfu over the lunch in the FOSS4G Asia 2018, I would like to collaborate with you on how geopaparazzi can support vector tiles produced using the UN Vector Tile Toolkit.

To be more specific, the vector tiles produced using spinel-produce and spinel. These were prepared for the OSGeo.JP Workshop for the UN Vector Tile Toolkit.

Information provided to @moovida over the lunch

(1) A test site based on Mapbox GL JS

http://vectortiles.xyz:8765/hands-on

(2) the style file (for Mapbox GL *)

http://vectortiles.xyz:8765/hands-on/style.json

(3) mbtiles files (modules in z=6 tile extents)

@hfu can provide. (Or anyone can make them using spinel-produce)

(4) how to make mbtiles

This is explained in the workshop material.

TODO for @hfu

• @hfu shall provide the vector tiles via HTTP/2 or SPDY because HTTPS is required if you share vector tiles in a cross-domain manner (when we use web browsers). Otherwise, CORS error may happen. This is not difficult because the SPDY support was intentionally dropped for the simplicity of the workshop. @hfu will get back when the SPDY-based provision is ready.
• @hfu shall provide access to mbtiles directly. Because geopaparazzi may support storing (vector tile) mbtiles in the application. Meanwhile, as far as I understand from my friend, Mapbox GL Native manages the offline vector tile cache by some Cache Manager.

TODO

• This may involve establishing a translation from Mapbox Style to SLD.

I will be back.

Cheers!

[hfu]

I would like to update this issue by from our recent updates.

A 'community edition' vector tiles that can be accessible from the Internet

I have a demo site at https://hfu.github.io/macrostyle/#14.45/46.49688/11.35445.

The 'community edition' vector tile location

https://vectortiles.xyz/zxy/tapioca/{z}/{x}/{y}.pbf such as https://vectortiles.xyz/zxy/tapioca/10/531/499.pbf.

This uses OpenStreetMap data only. The schema is not the same as OpenMapTiles or other OSM vector tile schema. This covers the whole African continent and several areas in Europe, Asia, and Americas.

Style description used in the demo above

The style description for this demo site is written in Mapbox Style, with Expression enabled. https://github.com/hfu/macrostyle/blob/master/style.json

Vector tile schema used in the demo above

The vector tile schema can be modified by this JavaScript file when producing vector tiles from planet.osm.pbf. It takes about 80 hours with a Macbook Pro, to produce global vector tiles from OSM planet. https://github.com/un-vector-tile-toolkit/produce-320/blob/master/modify.js