[gdal-dev] RFC 48: Geographical networks support
bishop.dev at gmail.com
Thu Jul 9 13:04:30 PDT 2015
I have just finished the integration of GSoC2014 work into the
geographical network support in GDAL.
The major changes from original code:
1) The base network class (GNMNetwork) is inherited form GDALDataset. So
any GDAL utility, that works with GDALDataset can work with GNMNetwork.
2) Geographical network is a new type of data, additionally to the
DCAP_RASTER and DCAP_VECTOR, added DCAP_GNM
3) I created the generic implementation of GDAL geographical network
(GNMGenericNetwork). The generic network have some features: support of
connection rules, support virtual vertices and edges, etc. The
GNMNetwork API can be changed in future as common functions to generic
network and some other networks (pgRouting, ArcGIS, OSRM, etc.) should
be moved to the GNMNetwork class.
4) Two network drivers created for generic network: file based
datasource and db based datasource. The file network driver tested on
ESRI shapefile and db - on PostGIS. The another vector datasource which
are not applicable with this drivers should have their own drivers.
5) The main method of created and configured GNMNetwork is GetPath,
which return the temporary OGRLayer (similar to ExecuteSQL).
6) By default the GNM is switched off. The ./configure --with-gnm should
be run to enable GNM. Mayne set it on by default?
7) The python binding is implemented and used in tests.
The RFC 48 in most cases is actual, except C API, which is not
implemented. Do we need it?
- diff with binary test data -
- diff without binary test data -
- binary test data -
Code reviewing and testing are welcome. Also the some decisions in
implementation can be discussed.
The GDAL 2.0 provide ability to create datasets combine vector and
raster data (drivers support both types).
In case of PostGIS we can have the driver combined vector, raster and
networks (pgRouting). Maybe someone give an idea how it can be done.
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