
Geometry : 
Subject: Re: [geometry] Spatial Index for arc
From: Adam Wulkiewicz (adam.wulkiewicz_at_[hidden])
Date: 20130826 17:10:56
Hi,
jeffpoly wrote:
>
> As I understand, the boost geometry does not support arc yet, for
> example,which is defined by three points. I wonder if such arc could be
> used for spatial index queries, the same as linestring or polygon?
>
The rtree internally uses boolean algorithms defined in boost::geometry,
such as intersects() or within(). If the algorithm is implemented for a
Box(or Point) and some Geometry then this Geometry may be used in a query.
I don't know if some kind of Arc concept is planned. Maybe a Bezier
curve which might be used to describe an arc. Unfortunately for now the
arc may be only approximated, e.g. by a LineString.
Alternatively you could try to use nsphere from extensions and after
performing a query for intersection with a circle, filter Values which
are intersecting the interesting part.
Still, probably the most simple solution is quering for Values
intersecting arc's bounding box and then check them manually.
Regards,
Adam
Geometry list run by mateusz at loskot.net