Hi,
today I came across the following problem that I tried to solve with
GEOS.
I had 3.000 linestrings which together formed one large ring. However,
this ring was not simple; it was 8-shaped. I wanted to find out where
the intersection point - or perhaps the intersection line! - was.
The best I could come up with was:
for (i=0; i<count; i++)
{
for (j=i+1; j<count; j++)
{
Geometry *p = linestring[i]->intersection(linestring[j])
if (p)
{
// found something
}
}
}
This is of course rather inefficient! I'd better build a LinearRing from
the lot of them and then query for self-intersection. I did find some
code that does this when looking at how isSimple() is implemented;
however, that code would only find self intersection points, not lines.
I wonder if there is some generic way to determine a geometry's "self
intersection"?
Bye
Frederik
_______________________________________________
geos-devel mailing list
geos-devel@lists.osgeo.org
http://lists.osgeo.org/mailman/listinfo/geos-devel
