[postgis-devel] update topology locally

Rémi Cura remi.cura at gmail.com
Mon Feb 16 10:04:45 PST 2015

I think the topology edition is qgis part is OK (need some cleaning,etc).

Now i'm doing the "recompute edge-linking and face-linking locally".

i'm trying to write the function so it scales nicely.

As you must be well aware, this function is the last step we need to be
able to batch create topology, which is another long wanted and discussed

(Batch creation from linestring:
node with GEOS,
insert node into topology
cut linestring into pieces with nodes (various option, GEOS would be best)
insert linestring pieces as edge, with only start_node and end_node correct
compute edge_linking and face-linking
I already have everything in yellow.


2015-02-11 11:49 GMT+01:00 Rémi Cura <remi.cura at gmail.com>:

> Great,
> thanks !
> I will finish the trigger stuff (that does not udpate left/right and face
> , but correctly link node and edge)
> , then try to write a function that for a list of node, correct the
> edge-linking of all linked edge.
> Cheers,
> Rémi-C
> 2015-02-11 11:23 GMT+01:00 Sandro Santilli <strk at keybit.net>:
>> On Wed, Feb 11, 2015 at 11:15:26AM +0100, Rémi Cura wrote:
>> > Hey everybody (and most probably Sandro),
>> >
>> > Work on trigger is going on.
>> >
>> > I end up with a corrupted topology (by design):
>> > I have list of nodes that have changed ,
>> > association with edges has been updated and is correct (start_node,
>> > end_node).
>> >
>> > Now I would like a function to correct next_lft, next_right, and face
>> only
>> > for the edge associated with my list of nodes.
>> >
>> > Do you know if I can scavenge it somewhere?
>> I've been actually thinking for some time that we'd need such a function.
>> Right now the code computing that (which I call "edge linking") is buried
>> into the ST_AddEdgeModFace and ST_AddEdgeNewFaces functions.
>> The primitive block of such function could be GetNodeEdges:
>> http://postgis.net/docs/manual-dev/GetNodeEdges.html
>> That function does not make use of "edge linking" fields.
>> --strk;
>>   ()   Free GIS & Flash consultant/developer
>>   /\   http://strk.keybit.net/services.html
>> _______________________________________________
>> postgis-devel mailing list
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