[Gdal-dev] OGR Polygon question

William Lyons wlyons at prologic-inc.com
Wed Feb 16 17:42:07 EST 2005


Frank and List,

Is there a C API equivalent to the following: ?

OGRPolygon.getExteriorRing()
OGRPolygon.getInteriorRing()

Thanks for the help,

William Lyons

-----Original Message-----
From: Frank Warmerdam [mailto:fwarmerdam at gmail.com] 
Sent: Wednesday, February 16, 2005 4:57 PM
To: William Lyons
Cc: gdal-dev at xserve.flids.com
Subject: Re: [Gdal-dev] OGR Polygon question

On Wed, 16 Feb 2005 16:12:09 -0500, William Lyons
<wlyons at prologic-inc.com> wrote:
>
> Howdy List, 
> 
> Just a quick question about the capabilities of the OGR C API. 
> 
> Is it possible to differentiate between the exterior and interior
rings of
> an OGRPolygon via the C API? 

William, 

Properly speaking the OGRPolygon is only supposed to have one
exterior ring, and it should be the outside.  There are likely some OGR
drivers that still return multipolygons as polygons in which case there
is
no real way to determine what are exterior rings.  But the correct
solution
is for the underlying driver to be fixed. 

Best regards,
-- 
---------------------------------------+--------------------------------
------
I set the clouds in motion - turn up   | Frank Warmerdam,
warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent




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