Should we continue faking zoom levels for non-Mapbox GL maps?

[ebrelsford]

As mentioned in #129 here.

Both Google and Leaflet maps use zoom levels that are off by 1 from Mapbox GL/Maplibre maps. In our current implementation we bump the zoom levels to prioritize maps aligning in the interface rather than the zoom levels being 100% accurate. For example:

For Google Maps we do this in a few places:

https://github.com/stamen/maperture/blob/ed54ba1d634f66a4f722527d1caa33af7037bffa/src/components/GoogleMap.svelte#L68-L76

https://github.com/stamen/maperture/blob/ed54ba1d634f66a4f722527d1caa33af7037bffa/src/components/GoogleMap.svelte#L35-L45

And we do something similar for Leaflet maps.

The argument for keeping this as it is is that we will generally only be using Google/Leaflet maps as reference maps and it is less important that the zoom levels are accurate. Looking at multiple map panes with the Google/Leaflet maps at different scales could be confusing.

[bdon]

Couldn't we drop leaflet completely in favor of display via maplibre raster sources? example

https://github.com/bdon/maperture/blob/main/public/config/osm-carto.json

passing tileSize=256 should make the viewports match 1:1 for reference.

[ebrelsford]

We certainly could use mapbox/maplibre for raster sources or at least have that as an option! We would want to hold on to Leaflet support for Tangram for now though I believe.