[geos-devel] [GEOS] #629: Improve the snap algorithm choosing the closest_point as snapped vertex

GEOS geos-trac at osgeo.org
Tue Apr 30 12:26:05 PDT 2013


#629: Improve the snap algorithm choosing the closest_point as snapped vertex
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 Reporter:  aperi2007    |       Owner:  geos-devel@…              
     Type:  enhancement  |      Status:  new                       
 Priority:  major        |   Milestone:                            
Component:  Default      |     Version:  svn-trunk                 
 Severity:  Unassigned   |    Keywords:                            
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 Actually the snap algorithm choose as snap point the first vertex that
 match the rules (under to snap value) calling it "first snappable point".
 This could cause invalid polygon when there is more than one vertex under
 the limit snap value.
 To avoid this kind of invalidity an improve to the algorithm could be to
 snap the closest_point instead of the first snappable point.

 Find the closest_point if a time consuming analyze because should be
 necessary to analyze all the vertex of the geometry.
 But realistic many cases are resolvable checking a more limited number of
 vertex after the the analyzing vertex as example checking 10 or 20 vertex
 after the first snappable point to see if exists a more closest point.

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Ticket URL: <http://trac.osgeo.org/geos/ticket/629>
GEOS <http://geos.refractions.net/>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).


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