[Gdal-dev] Radical OGR Update

[Frank Warmerdam]

Folks,

I am suffering from a growing compulsion to make a substantial update to OGR
before a GDAL 1.2.0 release.  In particular I would like to make some movement
to unifying GDAL and OGR in the following ways:

  o Merge the driver architectures of GDAL and OGR, so there is one driver
    registry, and a call to GDALOpen() can be used to open raster and vector
    datasets.
  o OGRDataSource and OGRLayer would be derived from GDALMajorObject which
    provides metadata services.
  o The TestCapability() mechanism in OGR would be reimplemented in some manner
    on the basis of metadata as capabilities are handled in GDAL.
  o Some degree of merger between GDALDataset and OGRDataSource would be
    achieved so it would become possible to have a single dataset with both
    raster bands and vector layers.  For instance, for formats like PCIDSK,
    OGDI datasources, and DODS datasources.  The raster and vector SDTS drivers
    would be merged.

The intent is that the changes would not result in any disruption for
GDAL raster applications; however, some minor changes might be required for
OGR applications.  All OGR drivers would require some modification and GDAL
drivers *might* require very minor changes.

It seems that if I am going to make a change of this magnitude, it would be
best to do so before the 1.2.0 release cycle.

One other change I am kicking around is to allow passing options into the
Open() call.  This would allow special processing such as is already done for
S-57 files with various CPLSetConfigOption() calls.  However
CPLSetConfigOption() is a pretty clumsy instrument in a potentially
multi-threaded application since it is global rather than affecting just a
single open call.

I am interested in any other opinions on the wisdom of my suggested changes,
approaches people would like to suggest or other work items that should be
done in the same overhaul pass.

Best regards,

-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | Geospatial Programmer for Rent