[josm-dev] Optimizations for larger data sets
Frederik Ramm
frederik at remote.org
Sat Dec 8 19:06:22 GMT 2007
Hi,
>> 5. Rewritten MergeVisitor to avoid O(N^2) algorithm.
>> Otherwise updating a window from the server takes looong
>> time and you'd like to do such an update before you push
>> your few-days-old-snapshot based changes back to the server.
Gabriel, haven't you done something in the MergeVisitor a few days ago?
>> *) Keep precomputed bbox of complete ways:
>> This allows faster painting of ways both in close-zoom (you filter out
>> the complete way quickly if it is off-screen) and wide-view (you filter
>> out/dot-replace small ways) cases.
>
> Frederik has been talking about adding a "presentation layer" for some while
> now. That would presumably include a better representation for drawing.
Yes, sadly I haven't done a thing yet but it has always been my plan to
add an extra layer of objects above the current data objects, and to
keep display caching stuff in these. That would require a good deal more
memory but I would avoid cluttering the OSM data objects with stuff like
indexes and bounding boxes. But I'm open to other suggestions.
Bye
Frederik
More information about the josm-dev
mailing list