[geos-devel] Re: [GEOS] #501: Snap operation: wrong snapping

[GEOS]

#501: Snap operation: wrong snapping
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 Reporter:  aperi2007   |       Owner:  geos-devel@…              
     Type:  defect      |      Status:  new                       
 Priority:  major       |   Milestone:  GEOS Future               
Component:  Default     |     Version:  svn-trunk                 
 Severity:  Unassigned  |    Keywords:  jtsfail                   
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Comment(by strk):

 First vertices are snapped:
 {{{
 Checking for a snap for source coordinate 0 0
  misuring distance between snap point 0.1 0 and source point 0 0
  points are within distance (0.1) returning iterator to snap point
  Found snap point 0.1 0
  Source point became 0.1 0

 Checking for a snap for source coordinate 10 0
  misuring distance between snap point 0.1 0 and source point 10 0
  misuring distance between snap point 9.1 0 and source point 10 0
  points are within distance (0.9) returning iterator to snap point
  Found snap point 9.1 0
  Source point became 9.1 0
 }}}

 Then segments are snapped:

 {{{
 Snapping segment from: (0.1 0, 9.1 0)
  Checking for a segment to snap to snapPt 0.1 0
   Checking segment LINESEGMENT(0.1 0,9.1 0) for snapping against point 0.1
 0
    One of segment endpoints equal snap point, returning too_far
    No segment to snap
  Checking for a segment to snap to snapPt 9.1 0
   Checking segment LINESEGMENT(0.1 0,9.1 0) for snapping against point 9.1
 0
    One of segment endpoints equal snap point, returning too_far
    No segment to snap
  Checking for a segment to snap to snapPt 10.01 0
   Checking segment LINESEGMENT(0.1 0,9.1 0) for snapping against point
 10.01 0
    dist=0.91 minDist=3 snapTolerance=2
    Segment/snapPt distance within tolerance and closer then previous match
 (0.91)
    Segment to be snapped found, inserting point
  Checking for a segment to snap to snapPt 10.9 0
   Checking segment LINESEGMENT(0.1 0,10.01 0) for snapping against point
 10.9 0
    dist=0.89 minDist=3 snapTolerance=2
    Segment/snapPt distance within tolerance and closer then previous match
 (0.89)
   Checking segment LINESEGMENT(10.01 0,9.1 0) for snapping against point
 10.9 0
    dist=0.89 minDist=0.89 snapTolerance=2
    Segment to be snapped found, inserting point
 After segment snapping, srcCoors are: (0.1 0, 10.9 0, 10.01 0, 9.1 0)
 }}}

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Ticket URL: <http://trac.osgeo.org/geos/ticket/501#comment:6>
GEOS <http://geos.refractions.net/>
GEOS (Geometry Engine - Open Source) is a C++ port of the Java Topology Suite (JTS).