Offline mode has very low resolution for `Style.SATELLITE_STREETS` tiles. Does `TilesetDescriptorOptions` ignore `.maxZoom()`?

[askat]

Environment

• Android OS version: 14
• Devices affected: Google Pixel 7, Samsung Galaxy Tab 8
• Maps SDK Version: 11.4.1

Observed behavior and steps to reproduce

I'm trying to implement offline mode for my app. User can draw a polygon which will be downloaded and displayed when there is no internet connection. I'm using code from Mapbox's documentation to download Style.SATELLITE_STREETS tiles.

The problem is unless I zoom to max before downloading Style.SATELLITE_STREETS map the quality of downloaded tiles is very low.

 private fun downloadPolygon() {
        val polygon = Polygon.fromLngLats(listOf(points)) // Polygon that user drawn

        val stylePackLoadOptions = StylePackLoadOptions.Builder()
            .glyphsRasterizationMode(GlyphsRasterizationMode.IDEOGRAPHS_RASTERIZED_LOCALLY)
            .build()

        val tilesetDescriptor = offlineManager.createTilesetDescriptor(
            TilesetDescriptorOptions.Builder()
                .styleURI(Style.SATELLITE_STREETS) // <-- Trying to download SATELLITE_STREETS tiles
                .pixelRatio(2f)
                .minZoom(12)
                .maxZoom(16) // <-- This isn't working for SATELLITE_STREETS
                .build()
        )

        val tileRegionLoadOptions = TileRegionLoadOptions.Builder()
            .geometry(polygon)
            .descriptors(listOf(tilesetDescriptor))
            .acceptExpired(true)
            .networkRestriction(NetworkRestriction.NONE)
            .build()

        offlineManager.loadStylePack(
            Style.SATELLITE_STREETS,
            stylePackLoadOptions,
            { progress -> },
            { expected -> }
        )

        tileStore.loadTileRegion(
            UUID.randomUUID().toString(), // Random id for region
            tileRegionLoadOptions,
            { progress -> }
        ) { expected -> }
    }

After download I disconnect phone from internet and try to view map but the quality of map is very bad. If I connect to internet again map quality increases.

I tried to test with different values for maxZoom() but quality is still bad when no internet

Expected behavior

Map's quality in offline mode must be the same as in online mode

Quality without internet

Quality with internet

Additional links and references

I found similar issue for iOS: https://github.com/mapbox/mapbox-maps-ios/issues/1056

[kiryldz]

@askat can you please share the camera state for the blurry screenshot (mapboxMap.cameraState) + enable couple debug options:

val debugOptions: MutableList<MapDebugOptions> = mutableListOf(
    MapDebugOptions.TILE_BORDERS,
    MapDebugOptions.PARSE_STATUS,
  )
mapboxMap.setDebug(debugOptions, true)

[askat]

@kiryldz I hope I got it right. 1) Here is the mapboxMap.cameraState log

[center: Point{type=Point, bbox=null, coordinates=[55.130000000000024, 25.120000000000015]}, padding: [top: 0.0, left: 0.0, bottom: 0.0, right: 0.0], zoom: 12.0, bearing: -0.0, pitch: 0.0]

2) Here is screenshot with debug enabled and internet disabled

[askat]

@kiryldz Here another screenshots:

Without internet

Right after I enabled internet

[kiryldz]

@askat thanks for addition information! I've reached to needed team and turned out we already have an internal ticket tracking this issue. I do not have any timelines sadly but if any new information will pop up - we will add it here, in this GH issue.

[AntoBouteiller]

@askat same issue than this one https://github.com/mapbox/mapbox-maps-android/issues/1460

The issue is not the resolution, the saved map is just not loaded, what you are seeing is the cached maps, this is why the resolution is ok if you zoom before downloading.

You need to add .pixelRatio(2f) to the tilesetDescriptor

@kiryldz I don't know if this will be fixed one day, but in the meantime would it be possible to update the documentation ?

[askat]

@AntoBouteiller Thanks for your response, Antoine. I already added .pixelRatio(2f) to the TilesetDescriptor as you can see in the issue description. Unfortunately it didn't fix this problem. Or maybe I'm trying to download tileset incorrectly. Did you try this solution yourself?

[AntoBouteiller]

@askat Sorry I didn't see that. Yes, it fixed the issue for me.

[paulsUsername]

We are experiencing the exact same issue above. On devices that seem to return less than 2.0 for:

hApplication.resources.displayMetrics.density

i.e. return 1.75 then the issue happens. When a device returns 2.0 or more there is no issue. This is only observation, I have no idea about causation. We are passing 2f for pixel ration. The values passed for max zoom seem to have no affect.

[paulsUsername]

One thing we have found is that, you need to ensure the style pack download has finished before you download the tilesets. Seems to resolve the issue, no idea why.