And make sipify handle this nicely. This means that all our non-flag
style enums correctly map across to IntFlag python enums on Qt 6,
fixing issues with negative enum values for these and providing
a better match for the original c++ enum.
While QVariant::Type can be directly static_cast to QMetaType::Type,
the reverse is not true and many QMetaType::Type values don't
have exact counterparts in QVariant::Type.
So we use the logic:
- If no conversion is possible, QVariant::UserType will be returned.
Note that we don't use QVariant::Invalid, as the value DOES have
a type, it's just one which needs special handling (just like user
types do)
- Some conversions are lossy, in that the QVariant::Type cannot
represent the full range of values possible in QMetaType::Type.
In these cases the returned type will be an "expanded" type
capable of storing the full range of values possible in the
original type. Eg we map QMetaType::Type::Float to QVariant::Type::Double
QgsVariantUtils::variantTypeToMetaType is included for clarity/
completeness/future proof-ness, even though it currently can
be handled with just a simple static cast.
The comparisons among QGIS were conducted on coordinates using a fixed epsilon:
specifically, 1e-8 for QgsPoint and the default value for qgsDoubleNear: 4 *
DBL_EPSILON.
Initially, I've standardized its use to 1e-8 universally; it's already
significantly adequate for our Cartesian cases (1e-3 should suffice for many),
potentially fitting just right for geographical contexts.
Furthermore, in response to precision concerns, we're using the fuzzyEqual
and fuzzyDistanceEqual methods. These methods enable users/developers to
compare geometries more easily and with a given precision.
The API remains intact as operator==/equals() have been shifted into fuzzyEqual
(with an epsilon of 1e-8).
To consolidate the code between fuzzyEqual and fuzzyDistanceEqual, helper
functions, fuzzyHelpers, have been introduced following the logic of the
respective segments to be executed.
As for the sqrDistance and Distance 2D functions, this adds functions for 3D.
To maintain the lowest level, the specific case where a Z could be NaN
is not handled.
It is left to the responsibility of other methods using these functions.
The backward compatibility code is very expensive, as it triggers
a huge number of QSetting object creation and destruction.
We only need to perform this for settings which have changed,
so add API to flag changed settings and only perform backward
migration of changed settings.
This dramatically improves QgsApplication shutdown time (cuts
1.5 seconds off shutdown on a release build!!)
Populating the style library from the database can be a time
consuming process, especially if a user has many symbols
present in their library.
But for many standalone scripts, and for qgis_process, the
style database may not be required.
Let's defer initialization of it until it's actually required,
saving the startup cost in qgis_process and 3rd party scripts.
On my system with a style database containing ~700 items this
cuts down qgis_process startup times by around 25%
