Base class for Shapes?

[Daniel Calvelo Aros]

Mmmh... Ok, right, different problem, different lobbying needs :)

Anyway, it's easier to build shapes from topology than the other way around.

If you need a strong argument for in-memory shapestores, you might consider
them as a cache for physical database access. We do need this kind of cache.
We would need it for WFS support as well. If you ever tried to build a
classification for a 2000-polygon simple feature stored in a remote PostGIS,
you know what I'm talking about.

WRT GEOS, what would you think of "spatially enabling" SQLite? I'm thinking
out loud here, but since you already can have GEOS in PostGIS, most GEOS
functions can be accessed through PostGIS, bar the latency, connection time
etc. If we are trying to have fast access to feature data, implementing RTree
indexing and geometry functions for SQLite and interfacing that with GEOS
would give you high-level topological operators plus SQL access, all
in-memory... That's yet another project, I'm afraid.

-- Daniel Calvelo Aros

---------- Original Message -----------
From: Jan-Oliver Wagner <jan at intevation.de>
To: thuban-devel at intevation.de
Sent: Thu, 25 Nov 2004 09:14:08 +0100
Subject: Re: [Thuban-devel] Re: Base class for Shapes?

> On Wed, Nov 24, 2004 at 08:29:26PM -0500, Daniel Calvelo Aros wrote:
> > What I would find excellent to have in memory is a topological
> > version of the shapestore. I have been trying to implement cartogram
> > drawing, which involves polygon transformations that must keep e.g. adjacency.
> > So far I have been quite frustrated by the need to build
> > the topology anyway. If shape editing is implemented in any timeframe,
> > topology will be necessary.
> > 
> > Maybe some GRASS "inspiration" might be useful.
> 
> having a topological version of the Layer in memory should
> actually be indpendent of whether the shapestore is in memory
> as well.
> 
> I wonder whether there is a library/tool out there that Thuban
> could use for toplogy support (GEOS?).
> 
> Best
> 
> 	Jan
> -- 
> Jan-Oliver Wagner               http://intevation.de/~jan/
> 
> Intevation GmbH                      http://intevation.de/
> FreeGIS                                http://freegis.org/
> 
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------- End of Original Message -------