nextgis / android_gisapp

:dart: GIS application for Android
http://nextgis.com/nextgis-mobile
GNU General Public License v3.0
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Unavailable raster tiles make usage difficult #572

Open olivierdalang opened 7 years ago

olivierdalang commented 7 years ago

Hi !

There's a small problem that makes raster usage almost impossible here.

Case A. With an online XYZ layer, when zooming in, the previous tiles disappear while loading the z+1 tiles showing the gray NextGIS background. This makes usage very slow as you need to wait for the new background tiles to load before being able to do anything. Navigation is also made difficult since the NextGIS background is fixed (so you don't have visual feedback about panning/zooming). Here, with a bad connexion, online XYZ layers are not really usable.

Case B. A related (probably the same) problem happens with both local tiles (zipped xyz folder) and online tiles when zooming further than max resolution. Again, the NextGIS background is shown, instead of an upscaled max available zoom. This is very problematic for us, as we work with land lots data, where we currently zoom in quite a lot (displaying the max available zoom at x4 or x8 upscale).

In those two cases, expected behaviour would be to display max available zoom by upscaling the available tiles (while loading the next tiles in case A). This is how most of viewers work.

Thanks for the awesome app still ! I tried tons of geo collection apps, and this one ranges amongst the bests !! (Also I hope it's not a duplicate issue as I don't speak russian)