Re: [Jts-topo-suite-user] Polygon offset

[Martin D. <mtn...@gm...>]

(Brian, pls cc the list so everyone can participate).

That's the way buffer is designed to work. If you have a different
requirement, you'll need to provide a picture showing the input and the
desired output.  (The image you sent before didn't really show the problem,
I don't think?)


On Thu, Nov 28, 2013 at 10:03 AM, Brian Sanjeewa Rupasinghe <
ji...@gm...> wrote:

> These are the parameters i use to buffer polygons
>
> BufferParameters BufP = new BufferParameters();
> BufP.setEndCapStyle(3);
> BufP.setJoinStyle(2);
> BufP.setQuadrantSegments(1);
>
> Problem is, buffer fills concave rectangular hollows on the boundary of
> polygon when
> the buffer distance is greater than the hollow width.
>
> Brian.
>
>
>
>
> On Thu, Nov 28, 2013 at 5:43 PM, Martin Davis <mtn...@gm...> wrote:
>
>> Have you tried using the JOIN_MITRE corner style?
>>
>>
>> http://tsusiatsoftware.net/jts/javadoc/com/vividsolutions/jts/operation/buffer/BufferParameters.html#JOIN_MITRE
>>
>>
>> On Thu, Nov 28, 2013 at 9:38 AM, Brian Sanjeewa Rupasinghe <
>> ji...@gm...> wrote:
>>
>>> Hi,
>>>
>>> To clarify more,  just inflating a polygon with an offset distance
>>> preserving concave corners. My requirement is to enlarge a polygon with a
>>> scale factor equally from all edges. When i use Affine transformation with
>>> the base point as centroid, it works for
>>> rectangular polygons. But when the polygon's centroid lies outside for
>>> irregular
>>> polygons,  enlargement is not symmetrical from all edges. See the
>>> following figure for
>>> what i want after offset.
>>>
>>>
>>>
>>>
>>> [image: alt text]
>>>
>>> Cheers, Brian.
>>>
>>
>>
>