[geos-devel] [GEOS] #1071: Setting lower precision of polygon always collapses polygon

[GEOS]

#1071: Setting lower precision of polygon always collapses polygon
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 Reporter:  Brendan Ward  |       Owner:  geos-devel@…
     Type:  defect        |      Status:  new
 Priority:  major         |   Milestone:
Component:  Default       |     Version:  3.5.1
 Severity:  Unassigned    |  Resolution:
 Keywords:                |
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Comment (by mdavis):

 The goal of GEOS operations is to always produce valid output.  A polygon
 with zero extent is invalid, so the closest valid result is `POLYGON
 EMPTY`.  Another way to put this is that if a polygon collapses completely
 due to rounding, it disappears rather than becoming a point.

 The collapsed LinearRing result is in fact also invalid.  So probably the
 current result  is out of spec, and should be changed to become
 `LINEARRING EMPTY`.  (In fact this should be the behaviour of the latest
 GEOS version incorporating OverlayNG).

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Ticket URL: <https://trac.osgeo.org/geos/ticket/1071#comment:1>
GEOS <http://trac.osgeo.org/geos>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).