[QGIS-Developer] Length measurement weirdness (again)

[Paolo Cavallini]

Il 04/05/2018 01:18, Nyall Dawson ha scritto:

> It's not a bug as much as very confusing 2.x behavior. The obscure
> link between a "rendering" setting (OTF projection) and ellipsoidal
> calculations (area/distance) is extremely confusing for users. We
> couldn't change this in 2.x because of the API freeze and how embedded
> this logic was in many areas of QGIS code and API.

I understand, thanks for the explanation. Then why not disabling
measurements when OTF is off? giving a totally false measurement does
not seem a good idea.
I believe 2.18 will be around for a good while, and I hate sending
around wrong results of which the user has no clue whatsoever.
Still unclear to me why the lack of ellipsoid would lead to 40% error,
but that's my ignorance.
All the best.
-- 
Paolo Cavallini - www.faunalia.eu
QGIS & PostGIS courses: http://www.faunalia.eu/training.html
https://www.google.com/trends/explore?date=all&geo=IT&q=qgis,arcgis