> > I am wondering, though, if there is a way to download a > large area of > > tiles explicitly for offline use? > > I just thought of a sneaky way: Write a Perl or Python > script which uses xastir_udp_client to send packets into > Xastir. Set up Xastir to track the object. Have the object > run along the map in a zig-zag pattern across the area of > interest. Repeat at each zoom level you're interested in. > That will force caching of the tiles of interest. Yea, you > can tell I lost too much sleep last night playing with code... > > Of course it would be easier/more efficient to write a block > of code for Xastir to just snag the tiles over a region and > between two zoom levels. Or a separate outside program to do > the same and then force Xastir to think it cached them. >
I run a GPS simulator for times when panning around does not really serve me well. The simulator sends a GPS sentence (RMC) from one serial port into another every 1-5 seconds to simulate motion. I use the simulator for APRSIS32 and ExpertGPS. APRSIS32 uses the OSM tiles and ExpertGPS uses the Terra Server tiles. For long trips, such as a recent one from NH to AR, I use Google maps to route the trip. I can modify the route by dragging the blue line, such as to avoid New York City for NH to AR, then I submit it to GMaptoGPX [FULL is selected]. The resulting text is saved in a GPX file and sent by the simulator to the appropriate software. If you are unfamiliar with GMaptoGPX, you can check it out here: http://www.elsewhere.org/journal/gmaptogpx/ I create files for gridsquares on occasion. I mainly do this to grab the area around where I live and play. I create this file with Excel and my increment is 1 minute (distance). Since the tiles servers are not instantaneous, I slow down the timer to run the simulator at a slow speed. Moving once per second or every few seconds spreads out the retrieval over a much longer period of time. If tiles are not queued, then movement will need to be slower or the path will need to run more than once. I limit the amount of area retrieved at one time. For instance, I typically only retrieve one quadrant of a gridsquare at a time, such as FN42-SW or FN42-NE. I am not sure this is really needed but it can't hurt. Besides there is a lot of time my system is not dealing with me, like when I sleep. APRSIS32 grabs a couple levels of zoom at a time. I set it to zoom level 14 because it will also grab level 15. ExpertGPS only grabs the zoom level currently displayed. But it does use the same level for a few displays. I don't know if what I am doing falls within the retrieval guidelines or not. I know of no way to know. If I exceed the limits and get shut off, I would not be liking it. Best regards, Fred _______________________________________________ Xastir mailing list [email protected] http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir
