[postgis-devel] Specifying end cap and join styles Buffer op

strk strk at keybit.net
Fri Jun 19 15:00:32 PDT 2009


On Fri, Jun 19, 2009 at 02:46:35PM -0700, Paul Ramsey wrote:
> Hm, loverly. Look how Oracle does it:
> 
> http://download.oracle.com/docs/cd/B28359_01/appdev.111/b28400/sdo_objgeom.htm#i856140
> 
> A "param string". I wonder how they decide what values deserve their
> own slot and who has to live in the string.

There's an example, and it's all-inclusive:

	'arc_tolerance=0.05 unit=km'

No end cap or join style. Not sure if arc_tolerance may be
similar to GEOS's mitre limit. Martin ?

We could accept these in a single string:

'endcap_style=round|flat|square join_style=round|mitre|bevel mitre_limit=5.0'

Note though that this wouldn't really make us Oracle-compatible
as we use third numeric argument  for  quadrant segments whereas oracle uses
that for precision (tolerance).

> Overload ST_Buffer().

Ok.

--strk;

 Free GIS & Flash consultant/developer      ()  ASCII Ribbon Campaign
 http://foo.keybit.net/~strk/services.html  /\  Keep it simple! 



More information about the postgis-devel mailing list