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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

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