Unlike the existing methods, this new method does not return
a single overall time range, but rather (possibly with gaps)
containing all time ranges were we know data actually exists
in the project.
for "early" raster resampling
Notably, this adds the "Average" resampling as an option for
early resampling methods. (A nice side effect is that we also
get mode, cubic spline, Lanczos, ... for free!)
Fixes#40746
This prevents the Python GIL from being released before calling the method
(which is the default behaviour). For very cheap to call c++ methods the
cost of releasing the GIL can outweigh the cost of the c++ call, which means
it's more efficient to retain the hold on the GIL.
Ideally we'd do this everywhere, and switch to an explicit ReleaseGIL
annotation on functions which are slow or risky (raise exceptions, or
do something which can cause a GIL deadlock). But those are very tricky
to identify, so instead just explicitly hold the gil on cheap methods
which are likely to be called many times and could have an impact on
script performance.
The trust flag at the projetc level is only used to read vector layer extent from xml, not from provider.
This flag was not available at the vector layer and data provider level.
We propose a new QgsMapLayer reading flag to propagate the trust layer metadata prohect's read flag an d a new provider options to trust datasource config.
Trusting the datasource config means that the provider can use estimated metadata, the primary key is unique and the detectable geometry type and srid are the same as the requested.
Also
* in settings UI, add a 'Early resampling' checkbox
* in raster properties UI, add similar checkbox
* serialize/deserialize new settings in QgsRasterLayer XML
Fixes#36820
The way QGIS is currently handling resampling is sub-optimal given GDAL >= 2
capability of having sub-pixel accuracy. So when a QgsRasterResampleFilter
is set, make it try to delegate resampling back to the underlying input interface,
and implement that improved resampling in the GDAL provider.
The GDAL resampling will take into account the settings of the QGIS resample
filter: zoom-in resampling kernel, zoom-out resampling kernel and max resampling
factor. The later is important to avoid performance issues if not enough overview
levels are generated (in the case, we will fallback to the generic method, which
may introduce sub-pixel shifts)
