[Marble-devel] Marble slow in trunk due to latest GeoData changes

[Torsten Rahn]

Hi,

As you might have noticed Marble is a lot slower in trunk (especially with maps 
that display placemarks, like Atlas, Plain Map, Satellite View) than in the 
0.10.0 release.

From my initial investigations this is due to the recent changes in GeoData:
We currently iterate through the whole geodata tree to check which item is 
visible. Since the default placemarks amount to >10000 items this is a slow 
procedure. (Unfortunately I only now realized why having the GeoDataRender as a 
plugin wasn't that bad as an idea ....).

We have plans that would get us back to the old performance again (or even 
better performance). For this some further changes regarding GeoData are 
required:

We need some instance that periodically parses the whole GeoData tree (as long 
as there are changes to the tree or as long as the observer moves) and 
connects/adds each item of the GeoDataDocument to a proxy-GeoDataDocument that 
only holds all the  truely visible stuff. The View would only operate on the 
proxy-GeoDataDocument and not on the real one.
This would reduce the amount of data drastically and would improve speed again.

Stay tuned until we get it fixed :-) (idis: Maybe we can come up with a quick and 
dirty workaround?)

Torsten