Hi Piotr, Yes, it is slow. As I noted in the README file, performance will not approach that of tangoGPS, or any other native OSM system. The root of the problem is that projection mapping that must occur between the Mercator projection of OSM tiles and the 'un-projected' Xastir view. Each pixel requires a multiple trig operations. Another factor, though far less, is scaling between the 18 zoom layers of the OSM tiles and the 32-bit zoom of Xastir. That zoom transformation also requires a pixel-by-pixel transformation, but the math is linear and therefore far faster than the projection mapping. Of course it is likely that someone can improve on my code, but I can't imagine that it will ever approach the speed of programs that do not have to do projection mapping.
73, ...jerry KA6HLD On Fri, Aug 13, 2010 at 11:53 AM, Piotr Gluszenia Slawinski <[email protected]> wrote: > i've installed new xastir with tiling support on several machines, > and on all of them 'reading tiles' takes lot of time... > compared to how quickly tangogps can render tiles, it's like > (on p233 tablet with 64M ram) : ~2s (tango) vs. ~20s (xastir) > > what takes so much time? is it possible to fix it somehow? > > -- > _______________________________________________ > Xastir mailing list > [email protected] > http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir > _______________________________________________ Xastir mailing list [email protected] http://lists.xastir.org/cgi-bin/mailman/listinfo/xastir
