- Added fixes for the OGC API Tiles driver

[doublebyte1]

The OGC API Tiles dataset was not working as expected.

A complete document was being passed to TileMatrixSet::parse, which was causing a series of issues:

• the comparisons with the well-known uris were never verified
• all the other ways of retrieving a TMS were failing and it was falling back to reading TMS from a file (which had the entire document in the filename causing buffer overflow)

The well-known URI was being compared to a word/name, rather than an uri. I added support to two of the most popular ones, but we could add more.

Submitted changes:

• Passed uri to TileMatrixSet::parse
• updated uris of well-known tile matrix sets

With these changes, I can read raster and vector tiles from these urls:

gdalinfo -oo API=TILES --config CPL_DEBUG ON "OGCAPI:https://maps.gnosis.earth/ogcapi/collections/blueMarble"
ogrinfo -oo API=TILES --config CPL_DEBUG ON "OGCAPI:https://maps.gnosis.earth/ogcapi/collections/Daraa"

[rouault]

More fixes are needed to support OGC 2D Tile Matrix Set v2: cf #6882
And we must still support v1 because of other uses in GDAL

[doublebyte1]

"InspireCRS84Quad")

Yes. I would like to address #6882 on a different PR.

[rouault]

I would like to address #6882 on a different PR.

sounds good. Make sure to have commit hooks installed to have correct code formatting: cf https://gdal.org/development/dev_practices.html#commit-hooks

[doublebyte1]

@rouault Thank you for the feedback! 🙏🏽

With 13360c5, I was able to run successfully all the tests in the test suite:

100% tests passed, 0 tests failed out of 28

Label Time Summary:
quicktest    = 156.70 sec*proc (19 tests)

Total Test time (real) = 156.91 sec
Process finished with exit code 0

[jerstlouis]

@doublebyte1
Not sure what the logic is, but it is totally OK for a 2D TMS to not have a URI, so this should probably not fail here?
Only registered 2DTMS have a uri.

Also, I would also expect the URI-matching-based identification (for registered 2DTMSs) to have happened before using the tileMatrixSetURI property of the tileset instead. If the tileMatrixSetURI was a match for a registered 2DTMS, the client would not need to download the 2DTMS definition at all (the DownloadJSon() call above I think).

[doublebyte1]

@jerstlouis you are right. There are other ways of parsing the TMS information.

I will need to refactor the code, to send the entire document (as before) and to parse the uri at the beginning of the parse function.

[jerstlouis]

@doublebyte1 Yes essentially it could use the URI already checked at:

https://github.com/OSGeo/gdal/blob/master/frmts/ogcapi/gdalogcapidataset.cpp#L1489

const auto oTileMatrixSetURI = oTileset.GetString("tileMatrixSetURI");

and if this URI is predefined (e.g., WebMercatorQuad or WorldCRS84Quad), then it does not need to call DownloadJSon(osTilingSchemeURL.c_str(), ....

This InitWithTilesAPI() method is very long though, so it would benefit from being split into different methods each performing one specific high level task.

[doublebyte1]

@jerstlouis for the time being, I am just checking if it can get an uri, and if not it defaults to what was there before (e.g.: sending the entire document). At least this is now working for well-known uris.

[jerstlouis]

@doublebyte1 Yes it seems that this method accepts either an identifier or a full document, which is quite confusing.
Ideally, there would be a diferent method gdal::TileMatrixSet::fromIdentifier() and parse() would always expect a TileMatrixSet definition.

Then, parse() itself could be the one first looking for the uri inside of the definition and then calling gdal::TileMatrixSet::fromIdentifier() when it is found.

But what I was saying earlier, is that when parsing the tileset, it is oTileMatrixSetURI (in the tileset metadata, not the tile matrix set definition) that should be used with gdal::TileMatrixSet::fromIdentifier() (or parse()) before downloading the TileMatrixSet definition.

[doublebyte1]

@jerstlouis I got that, but I don't want to address this refactoring in this PR.