Geometry Boost List: [ggl] Within polygon detection including the polygon borders

Subject: [ggl] Within polygon detection including the polygon borders
From: Barend Gehrels (Barend.Gehrels)
Date: 2009-09-18 16:30:52

Hi Ivan,

Sorry for my very late reaction. I was on holiday from Sep 3 on.

>
> I successfully compiled the examples 
Does this mean I can ignore your other question of Sep 3?

> and now I'm trying to use the ggl. I need to check if a point is 
> inside a polygon, and I want to consider de borders as part of the 
> polygon. Is this possible in ggl? All the tests that I've made showed 
> me that this is not possible. 
That is right, currently it is not possible. We will have another 
function which can be used for this question. It will either be an 
option of "within", or it you could use the "distance" function on 
point-polygon, which is zero or if the polygon is on the border or 
inside. Actually the last one can also be discussed, if the point is 
inside the polygon, it could be less than zero or also as an option.

But both are currently not implemented.

Best regards,
Barend Gehrels
Geodan, Amsterdam