WFS Filter : enhance support for spatial operations

[assefa]

Initially reported by Bart,

we can't get a WFS Intersects filter to work against ArcSDE. It seems Mapserver retrieves all the rows and tries and let GEOS do the intersection. Is my impression correct?

Ideally it would use FILTER to set a spatial WHERE clause, something like:

SHAPE intersects POLYGON ((131970.3045120624 453455.16526662686, 131969.21075920813 453349.07123976306, 132075.30478607194 453347.9774869088, 132076.3985389262 453454.0715137726, 131970.3045120624 453455.16526662686))

[bartvde]

It is not possible using ArcSDE to set a spatial filter using SQL, you can only use SQL of the underlying database. So using FILTER is not really an option.

It does work to set the map extent to the MBR of the search shape in the case of an INTERSECTS. I'll attach a slightly modified patch from Assefa which does this.

[bartvde]

Patch against 5.0.2:

--- mapogcfilter.c.orig 2008-03-05 09:21:04.000000000 +0100
+++ mapogcfilter.c      2008-03-05 10:08:53.000000000 +0100
@@ -141,6 +141,7 @@
     int bUseGeos = 0;
     int geos_operator = -1;
     shapeObj *psTmpShape = NULL;
+    rectObj sCurrentExtent;

     if (!psNode || !map || iLayerIndex < 0 ||
         iLayerIndex > map->numlayers-1)
@@ -381,7 +382,27 @@
 #endif
             }
             else
+            {
+              if ( geos_operator == MS_GEOS_INTERSECTS)
+              {
+                sCurrentExtent.minx = map->extent.minx;
+                sCurrentExtent.miny = map->extent.miny;
+                sCurrentExtent.maxx = map->extent.maxx;
+                sCurrentExtent.maxy = map->extent.maxy;
+                map->extent.minx = psQueryShape->bounds.minx;
+                map->extent.miny = psQueryShape->bounds.miny;
+                map->extent.maxx = psQueryShape->bounds.maxx;
+                map->extent.maxy = psQueryShape->bounds.maxy;
+              }
               msQueryByOperator(map, lp->index,  psQueryShape, geos_operator);
+              if ( geos_operator == MS_GEOS_INTERSECTS)
+              {
+                   map->extent.minx = sCurrentExtent.minx;
+                   map->extent.miny = sCurrentExtent.miny;
+                   map->extent.maxx = sCurrentExtent.maxx;
+                   map->extent.maxy = sCurrentExtent.maxy;
+              }
+            }
         }
         else
         {

[dionw]

Above attachment is an update of bartvde's patch against 5.2.0-beta4.

[assefa]

This has to wait until 5.2 is released. I am setting it to 5.4 but we can possibly add it for 5.2.1

[bartvde]

Assefa, do you have any idea whether or not this is still an issue in trunk?

[bartvde]

A Within filter with a polygon on an Oracle layer does a full table scan in MS 5.6, so this is still a problem.

[assefa]

All drivers need to address this. RFC http://mapserver.org/development/rfc/ms-rfc-64.html has laid the ground for drivers to implement a full spatial queries nativley. But until it is done, It is not there, Setting to FUTURE.