Geometry Boost List: [ggl] "touches" in boost.geometry?

Subject: [ggl] "touches" in boost.geometry?
From: Barend Gehrels (barend)
Date: 2011-10-10 00:01:14

Hi Adam,

On 9-10-2011 22:30, Adam Wulkiewicz wrote:
> Barend Gehrels wrote:
>> Hi Aleksandar,
>>
>> The touches algorithm is planned but not included, also not in the
>> extensions. I once started it and today looked at it, but it is not
>> suitable for inclusion yet. However it is on the list.
>>
>> As far as I know it cannot be done by using existing algorithms.
>
>
> Hi Barand,
>
> Please add to the todo list an algorithm checking if geometries 
> intersects but not taking boundries into account (intersects() && 
> !touches()). It would be used e.g. in rtree traversing in tests for 
> nodes'/boxes containing geometries which may be within some area. 
> Still there is no need to hurry since there is no big difference 
> between this and plain intersects() which is used now.
>
Is that not the "within" algorithm? Because "within" means is completely 
within, so should not touch any boundary... But it should then probably 
be implemented for e.g. polygon/box polygon/polygon, for your purposes.

By the way, touches() in OGC perspective means never an intersection, so 
only two borders touching, or a point lying on a border.

Regards, Barend