Overview support missing in some formats

[rprinceley]

Some dataset implementation do not include code to initialize the overview manager ( oOvManager.Initialize ). This makes it difficult to handle overviews in a generic manner.

Adding

  poDS->oOvManager.Initialize( poDS, poOpenInfo->pszFilename );

after

  poDS->TryLoadXML();

fixes this issue in XPM, GFF, etc.

[warmerdam]

I have added overview support to the XPM (r18239, r18241) and terragen (r18240) to match the changes made by rprinceley in the 1.6-esri branch (r17312,r17313). The other portions of r17312 appear to already be in trunk and were possibly back ported.

While GFF was mentioned in this ticket, and is lacking overview support, I have no test data for this format and I'm hesitant to modify the driver without the ability to test it.

[Even Rouault]

Frank,

I see I had found a sample available online. See http://trac.osgeo.org/gdal/browser/trunk/autotest/gdrivers/gff.py.

The public page is ​http://www.sandia.gov/radar/sar-data.html

[warmerdam]

overview, pam and virtualio support added in the gff driver (r18243).

[warmerdam]

Sorry, actually done in (r18244).