OpenMapTiles styling

[Zoran Smilevski]

Hello!

I'm using OpenMapTiles maps with VTM and would like to render it with a similar theme like OSM Bright. First I tried to write a xml theme, but then saw that would be easier to write custom ThemeBuilder. So I started writing JsonThemeBuilder which parses Maputnik JSON output and now I have a problem with some filter implementations.

Example for layer "place-country-other" in OSM Bright style:

"filter": [
  "all",
  [
    "==",
    "class",
    "country"
  ],
  [
    ">=",
    "rank",
    3
  ],
  [
    "!has",
    "iso_a2"
  ]
]

For first filter is easy, I just need to create a parent rule with k="class" and v="country". Also last is possible with parent rule where k="iso_a2" and v="~". But how to implement second rule? Is that even possible? Do I need to write a custom Rule class and implement matchesTags function? Or I'm doing completely wrong that?

Thanks for any advice!

[Emux]

Why not just use regular xml themes which are supported by the library and used by all?

There is a openmaptiles.xml theme example used in OpenMapTilesMvtActivity sample.

--
Emux

[Zoran Smilevski]

Yes, I tried, it works fine, but OSM Bright theme is much more beautiful in my opinion. So I wanted to replicate it. And is easy to make custom styles with Maputnik. So why not support it? Can make a pull request if someone else is interested in this, I guess I'm not the only one who's interested in this. VTM looks much nicer project than Mapbox.

[Emux]

Theme format alone cannot determine map appearance.
It's actually map / theme engine which defines rendering.

If anyone wants to try different theme format for VTM, I'd be happy to review it.

Note: if need extra dependencies, then should exist in separate module.

--
Emux