The geometry cache was only used for few geometry editing operations anyway. In earlier versions
of QGIS the geometry cache was also used by old snapping classes which have been replaced
by QgsPointLocator that also keeps a spatial index of geometries and it is not rebuilt on every re-render.
Reasons for removal:
- geometry cache was repopulated on every redraw of layers in editing mode, slowing down rendering
- data structure for the cache was a simple map with features accessed by their ID (no spatial index)
- the cache was only getting refreshed for the current view of the main map canvas (not a generic cache)
- not used for snapping anymore where caching was important to avoid roundtrips to data provider
All pointer based methods have been removed.
Now we have only:
void setGeometry( const QgsGeometry& geom )
and
QgsGeometry geometry() const
Benefits include avoiding a whole lot of tricky pointer lifetime
issues, potential memory leaks, and finally closing #777, which
has survived for over 9 years!...
Impacts on PyQGIS code:
- no more need for the messy
g = QgsGeometry( feature.geometry() )
workaround, just use g = feature.geometry() instead
- IMPORTANT: you can no longer test whether a feature has geometry
using `if f.geometry():`, since QgsFeature::geometry() will
*always* return an object. Instead, use
`if not f.geometry().isEmpty():`, or preferably the new method
`if not f.hasGeometry():`
Fix#777
implicitly shared copy of an internal cache instead of recreating the
coordinate sequence again and again.
Improves performance of the nodetool on large features a lot (refs #13963)
Also introduce Qgs(Coordinate|Ring|Point)SequenceV2 typedefs.
