[OpenLayers-Dev] Drawing on curves

Klokan Petr Přidal klokan at klokan.cz
Tue Oct 21 08:16:27 EDT 2008


> CURVEPOLYGON doesn't exist in the WKT Spec (afaik). Is there a tool to
> convert from curves to regular polygons? I've seen that path followed in
> the past.

I have seen this in Inkscape: "Flatten bezier" extension, done in python:
https://inkscape.svn.sourceforge.net/svnroot/inkscape/inkscape/trunk/share/extensions/flatten.py

libplot contains also flattening of Beziers into polylines.

We use similar algorithm in Java on the server side for displaying
vector based accuracy analyze of old maps based on GCP sets.
Analyze comes from the online version of MapAnalyst software in
GeoJSON form, it is part of the work for the grant OldMapsOnline.org.
Example of output of raster overlay analyze:
http://oldmapsonline.googlecode.com/svn/trunk/mapanalyst/rasterdemo/index.html
Simple example of output in vectors with fattened Beziers:
http://oldmapsonline.googlecode.com/svn/trunk/mapanalyst/vectordemo/index.html

Klokan Petr Pridal

On Fri, Sep 26, 2008 at 1:21 PM, Christopher Schmidt
<crschmidt at metacarta.com> wrote:
> On Fri, Sep 26, 2008 at 10:20:36AM +0200, Gianni Barrotta wrote:
>> Hi list,
>> I implemented a function that extracts all the features inside a buffer
>> calulated with oracle spatial around a feature.
>> The buffer is represented in WKT (CURVEPOLYGON).
>> It seems that the WKT adapter in OL isn't able to draw curves, so how can I
>> manage this issue?
>> I've found this thicket:
>>
>> http://trac.openlayers.org/ticket/1715
>>
>> is it what I need to draw a CURVEPOLYGON?
>
> CURVEPOLYGON doesn't exist in the WKT Spec (afaik). Is there a tool to
> convert from curves to regular polygons? I've seen that path followed in
> the past.
>
> Regards,
> --
> Christopher Schmidt
> MetaCarta
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