[mapserver-dev] bug in WFS writer?

Bart van den Eijnden (OSGIS) bartvde at osgis.nl
Wed Mar 19 15:26:21 EDT 2008

Hey Steve,

Do you remember the bug number or changeset for that point-in-polygon 
fix? It sounds like it could be the culprit indeed.

You're right it could be a problem in TatukGIS theoretically, but in 
this case things were checked also in ArcGIS. So it would be strange for 
2 clients to have it wrong, though still possible.

Mapserver version: 4.10.2.

I haven't got the source data as yet (it's in Oracle Spatial), but I'll 
try to get it.


Best regards,

Steve Lime wrote:
> Couple of questions:
>   - how are you defining a "problem", based on TatukGIS's rendering or some other method? I'm not saying there isn't a problem but how do you know it's not a problem with the renderer?
>   - do you have the source data (a shapefile?) available for testing?
>   - what version of MapServer?
> I recall another bug recently similar to this. It had to do with the MapServer point-in-polygon being indeterminate when a point in one part is on a polygon edge. The function is key to determining inner and outer rings. I thought I fixed it though, at least in SVN. Since a legal polygon can only share 1 vertex with an edge I updated the code to check at least 2 and one more to break the tie if one happened to be on an edge. That worked in any testing I had done.
> Steve
>>>> On 3/19/2008 at 1:16 PM, in message <47E15866.2010407 at osgis.nl>, "Bart van den
> Eijnden (OSGIS)" <bartvde at osgis.nl> wrote:
>> Hi list,
>> it seems Mapserver WFS has a problem with geometries having a (common) 
>> point in them which touches the geometry itself. Mapserver WMS seems to 
>> draw these polygons okay.
>> An example (look for instance at the second and third geometry):
>> WMS:
>> http://www.osgis.nl/download/umn/wms.png 
>> WFS in TatukGIS (screendump):
>> http://www.osgis.nl/download/umn/tatuk.png 
>> WFS xml file:
>> http://www.osgis.nl/download/umn/wfs.xml 
>> Any ideas what could be causing this? Does this ring a bell to anyone?
>> Best regards,
>> Bart

Bart van den Eijnden
OSGIS, Open Source GIS
bartvde at osgis.nl

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