Hey- Rupesh M G wrote: > > Hi, > > Could you please tell me how to buffer a lineString, and get the > vertices of a polygon from it? >
Currently, there is not a way to buffer geometries on the client side with OpenLayers. You can send your geometry to a buffering service somewhere (search for "webprocessingservice" or something similar). I have put together a rough buffer operation that works with OpenLayers geometries: http://dev.openlayers.org/sandbox/tschaub/geom/examples/geometry-buffer.html There are plenty of issues with this (no simplification to remove self-intersections). I'll be improving this and putting together an external lib to do this over the next week or so. Tim > Thanks & Regards, > Rupesh > > > > [EMAIL PROTECTED] > Sent by: [EMAIL PROTECTED] > > 02/12/2008 09:34 PM > Please respond to > [email protected] > > > > To > [email protected] > cc > > Subject > Users Digest, Vol 17, Issue 13 > > > > > > > > > > > ------------------------------ > > Message: 8 > Date: Tue, 12 Feb 2008 10:52:21 -0500 > From: Tim Schaub <[EMAIL PROTECTED]> > Subject: Re: [OpenLayers-Users] boundaries of lineString > Cc: [email protected] > Message-ID: <[EMAIL PROTECTED]> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > Hey- > > Rupesh M G wrote: > > > > Thank you for the reply. But I think it is not correct. > > > > For example, if I draw the linestring with 4 points, I'm able to see a > > polygon with 8 vertices. > > A linestring geometry with 4 points has 4 points. When you see it > rendered, it looks like a polygon to you, but the geometry is just a > linestring. > > It sounds like you're talking about buffering a geometry. When you > buffer a linestring geometry, you get a polygon geometry. > > Tim > > > > > But if I print the components.length of the linestring, it just says 4. > > > > I tried it with the example in the url > > http://openlayers.org/dev/examples/vector-features.html > > > > > > Regards, > > Rupesh > > > > > > > > *"Pierre GIRAUD" <[EMAIL PROTECTED]>* > > > > 02/11/2008 03:58 PM > > > > > > To > > "Rupesh M G" <[EMAIL PROTECTED]> > > cc > > [email protected] > > Subject > > Re: [OpenLayers-Users] boundaries of lineString > > > > > > > > > > > > > > > > > > It should be quite easy because geometry like lineString and Polygon > > are composite geometries. > > For example, a OpenLayers.LineString has a 'components' property which > > is an array of OpenLayers.Points. > > That way, you can get all the vertices using a loop like following : > > > > for(var i=0; i <= thelinestring.components.length; i++) { > > // do something with thelinestring.components[i] which is an OL point > > } > > > > Regards, > > Pierre > > > > On Feb 11, 2008 9:02 AM, Rupesh M G <[EMAIL PROTECTED]> wrote: > > > > > > Hi, > > > > > > I'm working on an application about roads. There I need to > mark a > > > part of the road, and execute some query. > > > > > > My user will click a set of points to form a sequence of lines passing > > > through the center of the road, because there can be bends in the > road. > > > > > > I plan to draw a lineString going through these points. Using a bigger > > > strokeWidth, I can show it like a road (or like a filled polygon). > > > > > > Is there any way to get the vertices of that polygon? > > > > > > > > > Thanks & Regards, > > > Rupesh > > > > > > > > ------------------------------ > > _______________________________________________ > Users mailing list > [email protected] > http://openlayers.org/mailman/listinfo/users > > > End of Users Digest, Vol 17, Issue 13 > ************************************* > > > > > _ > > DISCLAIMER:__ _ > > "The information in this e-mail and any attachment is intended only for > the person to whom it is addressed and may contain confidential and/or > privileged material. 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