348 mapbox raster tiles

[mradamcox]

Closes #348

Instead of using the Mapbox Static Tile API to pull in a basemap style that combines satellite imagery and road labels, now there is a composite of the Mapbox Raster Tile API satellite with OpenFreeMap labels on top of it created directly in the fronted. This is a big improvement because the Raster Tile API has a much higher free tier limit than the Static Tile API.

There is one funny quirk, even though I force the labels to all be colored white with a grey halo (for the best visibility against the imagery background), one layer, highway-name-major seems to always be painted with black text.

No idea what's going on here, but it's kind of funny.

[mradamcox]

Checking around, and this particular extraction of the top Liberty layers really loses a lot when zoomed out. Going to hold on this for now and look for a better vector style to put on top of the aerial.

Before:

After:

Before:

After:

[mradamcox]

It's possible to apply mapbox styles to pmtiles sources, this may be a good approach: https://github.com/openlayers/ol-mapbox-style/blob/main/examples/pmtiles.js

[mradamcox]

Ended up writing a bug report about the label color display shown in the top post, as I had isolated it to being caused by ol-mapbox-style. The underlying issue is now fixed, so I'll just wait to push this through until the bugfix is released. This will allow me to include the full style with highway shields and labels, because to this point I had just removed the shields layer, not knowing how/if that label color bug would be addressed.

[mradamcox]

At this point it is pretty low priority to get this change into the code base, as visitorship is lower than when the mapbox limits were originally being exceeded. Also, as mentioned in #380 , the vector tile style does not show as many street names as we would like, so it's actually been good to keep the hybrid satellite/streets style in the main app, because sometimes it renders streetnames that the other new vector style doesn't.

I think I'll just merge this in soon to cleanup the PR list, but leave the basemap configuration as is, perhaps relegating the determination of which imagery basemap to use to a setting.