mapbox / mapbox/mapbox-maps-android

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

Open
#2,407 9 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

auto-triaged bug :beetle:
Dominant language
Kotlin
Stars
578
Forks
161
PR merge metrics
No merged PRs in 30d

Description

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

Screenshot_20240620_160845_MapboxSandbox

Quality with internet

Screenshot_20240620_161045_MapboxSandbox

Additional links and references

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

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start with the Mapbox Android offline-mode documentation and reproduce the report on Android 14 with Maps SDK 11.4.1 using the shown TilesetDescriptorOptions values for Style.SATELLITE_STREETS. Inspect how minZoom(), maxZoom(), and offline tile-region loading interact; done means the downloaded map retains comparable quality offline and changing maxZoom affects the result as expected.

Written by the indexing model from the issue text.

Assessment

Tech stack
android, kotlin
Domain
mobile-dev
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
42/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.