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farmOS / farmOS-map

farmOS-map is an OpenLayers wrapper library designed for agricultural mapping needs. It can be used in any project that has similar requirements.
https://farmOS.github.io/farmOS-map
MIT License
40 stars 22 forks source link

Provide method for transforming extent #171

Open paul121 opened 2 years ago

paul121 commented 2 years ago

I would like to get the lat/lon for the four corners of the current view's extent. This s.o. explains how it can be done: https://stackoverflow.com/questions/28166471/openlayer3-how-to-get-coordinates-of-viewport

Unfortunately var extent = map.getView().calculateExtent(map.getSize()); returns an extent in EPSG:3857 not EPSG:4326. OL has a method for transforming extents: extent = ol.proj.transformExtent(extent, 'EPSG:3857', 'EPSG:4326'); but because farmOS-map does not export this function it is not accessible without bundling parts of OL myself.

Could we either export this function and make it available at window.farmOS.map or make it available on the farmOS-map instance itself?

paul121 commented 2 years ago

I'm hoping to find an alternative solution to the use-case I described above but it seems that this would be a useful function to have available

paul121 commented 1 year ago

It would also be convenient to have the basic transform function so you can convert an OL coordinate to lat/lon. Common uses may be the center of the view or the event.coordinate when clicking on the map.

https://openlayers.org/en/latest/apidoc/module-ol_proj.html#.transform