Feature Request: Importing map overlay

[Blaa00]

It can be difficult to see which train lines are in play based on the questions.

If you could upload a geojson file (containing georeferenced train lines) to the site it could be easily implemented with leaflet using GeoJSON objects.

You could technically use a premade map with all of the trainlines you could filter out. This could also help in the making of the measuring questions related to railwars. But it feels like its less customizable.

I think I could take the implementation upon myself

[taibeled]

This is definitely a good idea!

As a bonus, the Overpass API can automatically fetch all train routes. In src/maps/api.ts there is a findPlacesInZone question. For obtaining the train lines, it can be called with findPlacesInZone("[railway=rail]", "way", "geom"). You can find the output on Overpass turbo: https://overpass-turbo.eu/s/1Y7c. A slight issue with this is that it takes a long time to fetch the data as Overpass has to accumulate all the data. In Japan (like the query I put above), there are somehow 125,406 ways taking up a 100 MB JSON file. Unless if there is a way of simplifying this, displaying the train stations would have a serious delay.

Currently in src/components/Map.tsx I have an interval which will automatically reset if there are multiple geoJSONs on the map. This is necessary for the occasional glitch. You should be able to simply add a property, say doesShowElimination, to the geoJSONs that show elimination and modify the interval (and the other similar instance) to check for that property.

[taibeled]

I added this in 5cba7e7. Let me know if you think that it should be implemented differently. Note that it must be enabled from the options.