RE: [aprsisce] prefetching tiles
- Phew????That's a fair few tiles.Bet you the local telco's would love that on a mobile data connection.lolRobin ZL3REWSee my response to N7FMH to see why this is not necessarily a good idea. It has to do with what area coverage is desired for the increasing zoom levels, all of the area originally covered or just the center as if you had manually zoomed the whole way in at a constant screen center. The client currently does the former on the prefetch which results in a 4x tile count for each zoom closer. The latter does a constant tile count per level, but doesn't end up fetching detail for ALL of the area originally viewed.
From: firstname.lastname@example.org [mailto:email@example.com] On Behalf Of Lynn W. Deffenbaugh
Sent: Monday, 1 March 2010 1:20 p.m.
Subject: Re: [aprsisce] prefetching tiles
See the table at http://wiki.openstreetmap.org/wiki/Slippy_map_tilenames#Zoom_levels to get an idea of the total tile count for various zooms. For your suggestion of 15, if you did this while zoomed out to the planet view, you'd end up fetching (left column is zoom tile count, right column is cumulative total).
1 1 2 4 5 3 16 21 4 64 85 5 256 341 6 1024 1365 7 4096 5461 8 16384 21845 9 65536 87381 10 262144 349525 11 1048576 1398101 12 4194304 5592405 13 16777216 22369621 14 67108864 89478485 15 268435456 357913941 16 1073741824 1431655765 17 4294967296 5726623061 18 17179869184 22906492245
Oh, and you'd have to multiply all of those numbers by the number of tiles it takes to fill the screen from which you did the Prefetch.
Lynn (D) - KJ4ERJ
when prefetching tiles is there a way to change how many zoom levels is prefetched? i think its 5 but can you cange it to like 15 in the xml file? ------------------------------------ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/aprsisce/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/aprsisce/join (Yahoo! ID required) <*> To change settings via email: firstname.lastname@example.org email@example.com <*> To unsubscribe from this group, send an email to: firstname.lastname@example.org <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/