Opened 6 years ago
Closed 4 years ago
#876 closed enhancement (wontfix)
rgeos::writeWKT() pass polygon direction as parameter
Reported by: | dennisguse | Owned by: | |
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Priority: | minor | Milestone: | 3.9.0 |
Component: | Default | Version: | 3.6.2 |
Severity: | Feature Request | Keywords: | WKT |
Cc: |
Description
I am using rgeos::writeWKT() to export geo data for import into Microsoft SQLServer. Sadly, the server is picky about the polygon orientation (ie., clockwise, counter-clockwise).
However, rgeos::writeWKT() does not support to to define the orientation. It would be awesome to add this option.
Workaround for me: So far, I convert the (wrongly inverted) polygons in SQLServer by checking the actual size and if too large invert them.
Change History (6)
comment:1 by , 6 years ago
comment:2 by , 6 years ago
Until now I was thinking the same, but the spec says something different:
Page 26 of current spec: http://portal.opengeospatial.org/files/?artifact_id=25355 Highlighting mine.
<<The exterior boundary LinearRing defines the “top” of the surface which is the side of the surface from which the exterior boundary appears to traverse the boundary in a counter clockwise direction. The interior LinearRings will have the opposite orientation, and appear as clockwise when viewed from the “top”,>>
In addition, I tested the interpretation of Openlayers (v4.6.5) for WKT: they seem to ignore the direction of the polygon and always use the smaller area as inner part.
comment:3 by , 6 years ago
Milestone: | 3.6.3 → 3.8.0 |
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comment:4 by , 5 years ago
Milestone: | 3.8.0 → 3.9.0 |
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Forcing rgeos::writeWKT() to output CCW exterior rings, etc, means it becomes impossible to output CW rings in other applications, which will be Bad for them. Only reasonable way forward I see it to pull the isCCW() method up to Geometry and then leave it to the user to GEOSReverse() the ones they want to reverse.
comment:5 by , 4 years ago
I'm going to close this out, since GEOSNormalize() already exists, and forces CCW orientation onto rings.
comment:6 by , 4 years ago
Resolution: | → wontfix |
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Status: | new → closed |
WKT is a standard, which I don't think prescribes a specific orientation