[postgis-devel] [PostGIS] #845: ST_Intersects() precision error - returns false instead of true

[PostGIS]

#845: ST_Intersects() precision error - returns false instead of true
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 Reporter:  cdestigter  |       Owner:  pramsey      
     Type:  defect      |      Status:  new          
 Priority:  medium      |   Milestone:  PostGIS 2.0.0
Component:  postgis     |     Version:  1.5.X        
 Keywords:              |  
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Comment(by nicklas):

 No, It's not.

 In distance functions the pt_in_ring function is used for point in polygon
 tests. I guess that is why ST_Distance returns 0.0. pt_in_ring is a stab-
 line algorithm implementation that is old. So we also have a winding
 number algorithm implementation.

 Is there a reason to have two different? I have read somewhere that the
 winding number algorithm is more stable (when bugs are fixed) and the same
 performance.

 In 3D I have rewritten pt_in_ring to project the polygon to 2D and then
 use stabline algorithm. Maybe it is time top clean up and get winding
 algorithm working and move to that also in distance?

 What is the name on that function?

 /Nicklas

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/845#comment:5>
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