[V2.17] Text and Icon rendering corruption

[xortuna]

Some of our users are reporting an intermittent issue where all map text is corrupted or missing. This is affects both rendered labels and lines.

It looks like the Font->glyph map isn't aligning or has a DPI mismatch?
The font in the screenshot was "DIN Pro Medium". Restarting the app fixes the issue. We've observed the issue on both Android and iOS, (Screenshot is IOS):

Steps to reproduce the Rendering bug (happens 100% of the time):

1. Open a mapbox map (even the mapbox studio sample app has the bug)
2. Minimise the application, and launch another app (e.g photos)
3. Use the task switcher to go back to mapbox
4. Pan the camera, notice no new map data downloads, eventually you are left with a dead map

Unfortunately I don't have the steps to reproduce the Glyph corruption bug, it seems intermittent and seems to occur after switching back to the application.

IOS:

Mapbox Studio

[flt-phy]

@xortuna we have similar problem I guess (hard to reproduce), but it seems that version 2.18 fixed it, can you check?

[xortuna]

Unfortunately the issue where the app is minimised and restored remains in v2.18

1. Open a mapbox map (even the mapbox studio sample app has the bug)
2. Minimise the application, and launch another app (e.g photos)
3. Use the task switcher to go back to mapbox
4. Pan the camera, notice no new map data downloads so no additional text labels render

Doesn't matter if its IOS or Android.

For other users affected, the temporary work around we are doing is to change the map source on restore, unfortunately on IOS the bug requires you to set a different style and switch back again, android you can simply reload the same style:

  void didChangeAppLifecycleState(AppLifecycleState state) {
    super.didChangeAppLifecycleState(state);
    LoggingService.addLog("App state changed: $state");
    if (state == AppLifecycleState.resumed) {

      //DYEJ - Mapbox POI fix 
      _mapController?.getCameraState().then((value) {
        if (Platform.isIOS) _mapController?.loadStyleURI(MAP_STYLE_SATELLITE);
        _mapController?.loadStyleURI(MAP_STYLE);
      });
    }