enable non-existent zoom levels with tile overscaling

[mathewlippincott]

I'm trying to work with pole photos and they are about 1cm square on my screen at the lowest zoom level possible. Is there any way to work smaller? I don't need better resolution. my experience is suggesting that auto-placement will make pole mapping easier but I can't prove it because of #153

[jywarren]

This works in native Leaflet layers: Leaflet/Leaflet#1798 and Leaflet/Leaflet#1802

However, it doesn't in the Google map tile plugin. It seems that we should be able to get L.Google to inherit from L.TileLayer (as in this abandoned pull request) to allow it to inherit this ability, but that doesn't seem to be working in my tests.

I think L.Google overrides some other L.TileLayer methods, which we have to port back in; key sections here: Leaflet/Leaflet@b03f322#diff-41e07cc2f66148151bde6b9e17c7f183R461

[jywarren]

How urgent is this? Should I work on #153 instead?

[jywarren]

It looks like the Google tile plugin was refactored for v1.0 of Leaflet: shramov/leaflet-plugins#112

That means this may be easier to implement now, as the above error may not break it. We'd need to update the dependency in bower.json (https://github.com/publiclab/mapknitter/blob/master/bower.json#L17) to:

    "leaflet-plugins": "~1.5.3",

and run bower install, then manually test.

I think we may need to change line 13 of this file, but it's already set to 24, which I believe is high enough, so it might be a simple upgrade and it'll start working.

https://github.com/publiclab/mapknitter/tree/master/app/assets/javascripts/mapknitter/Map.js#L13

[markfox1]

This is great news as it would make MapKnitter much more useful for high-resolution low-altitude maps. On the off chance that it was already working, I had a look at some previous maps I made. Zooming is limited to 30 m (based on the scale on the bottom-left). Unfortunately, MapKnitter gets stuck at that zoom level and doesn't allow panning after zooming in (or out).

After looking at this again, it looks like new maps work fine.

[jywarren]

This was solved with our upgrade to Leaflet 1.x!