[GeoJSON] erratum 5069

[Jukka Rahkonen]

Hi,

This topic was discussed in this gdal-dev thread 
http://osgeo-org.1560.x6.nabble.com/gdal-dev-Time-for-a-new-GeoJSON-driver-td5278061.html.

Conclusion: the mathematical right hand rule is what the GeoJSON 
specification implements (winding as fingers of the right hand wind, so 
counterclockwise). Unfortunately another well known specification, the 
ESRI shapefile one, calls the opposite winding order with clockwise 
outer ring also as a right hand rule even a better name could have been 
"right arm rule" - when you walk along the rings your right arm points 
to the interior.

The erratum is incorrect.

-Jukka Rahkonen-

Martin Raifer kirjoitti 2018-06-19 18:01:
> I'm wondering about the following reported erratum on rfc7946
> https://www.rfc-editor.org/errata/eid5069 about section 3.1.6.:
> 
>> It seems like the clockwise/counterclockwise descriptions are the 
>> opposite of the right-hand rule. Walking an exterior ring in a 
>> counterclockwise direction would have the exterior of the ring to the 
>> right of the observer.
> 
> I believe that this erratum is incorrect and that the given
> interpretation of the "right hand rule" in rfc7946 – exterior ring
> have counterclockwise winding order – is actually the intended one. Is
> that correct?
> 
> I'm not very familiar with RFC errata (and their statuses [1]), but it
> looks to me like it was reported, but not yet verified or rejected. It
> would certainly be nice to have the status of this erratum clarified
> (for example so that the rfc7946 page no longer IMHO falsely states
> that "Errata Exist"). Or is the verification process already in
> progress?
> 
> Best,
> Martin Raifer
> 
> [1] https://www.rfc-editor.org/errata-definitions/
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