[geos-devel] [GEOS] #876: rgeos::writeWKT() pass polygon direction as parameter

GEOS geos-trac at osgeo.org
Thu May 31 23:43:41 PDT 2018

#876: rgeos::writeWKT() pass polygon direction as parameter
 Reporter:  dennisguse       |       Owner:  geos-devel@…
     Type:  enhancement      |      Status:  new
 Priority:  minor            |   Milestone:  3.6.3
Component:  Default          |     Version:  3.6.2
 Severity:  Feature Request  |  Resolution:
 Keywords:  WKT              |

Comment (by dennisguse):

 Until now I was thinking the same, but the spec says something different:

 Page 26 of current spec:
 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.

Ticket URL: <https://trac.osgeo.org/geos/ticket/876#comment:2>
GEOS <http://trac.osgeo.org/geos>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).

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