Ensure all FGPositioned related functions return SGSharedPtr
instead of raw pointers to allow automatic conversion to
nasal ghosts without custom helper functions.
In preparation for adding POI data, extend the FGPositioned type enum, and the cache code to handle arbitrary POI types. (Adding more in the future is straightforward now)
Also support removing user waypoints, which was requested by the Garmin G196 developers.
Use a RAII object to manage cache transactions, and reset queries immediately after they are done, to avoid auto-commit transactions lasting long periods of time. Re-write the commit and step logic to handle SQLITE_BUSY, with progressively increasing waits when there is DB contention (multiple processes accessing the DB).
ThorstenB identified some cases where mod-times changing could lead to corrupted ground-cache data in the DB - handle both of these. What's still unclear is why the mod-times changes; hopefully the additional debug info will reveal this.
Tolerate Octree leaf children which have been moved outside their leaf's BBox. This is necessary since lazy-loading of ILS and threshold files can cause re-locations even during child traversal, where updating the hierarchy is very complex. Instead, simply tolerate this case, and rely on the real position data (which is correct).
Make landings and takeoffs look more correct; tweak climb-out and touchdown phases in particular, so the turn to destination heading occurs earlier on climb out, and touchdown occurs close the GS transmitter / some distance down the runway from the beginning.
Avoid the application becoming unresponsive during nav-cache rebuilds. We still have to wait for the rebuild, but perform it on a helper thread so the main GUI thread stays responsive and hence doesn't trigger a beach-ball / 'not responding' alert. Also ensures there's some feedback (the spinner) during the rebuild operation, so users don't think we've hung.
Cache the parsed navigation and airport data in a binary file to reduce
startup times and memory consumption (since only referenced FGPositioned
elements are held in memory).
Data will be reimported when the mod-time of any input file is changed.
If a global file is changed (nav.dat, awy.dat, apt.dat, etc), the cache
will be completely rebuilt, which takes approximately 30 seconds on
moderate hardware. (Future work may reduce this).
