osmdroid and mapsforge

[Azimuth]

hi,

i use the osmdroid MapViewer, Overlays, etc in my application. The tileprovider is the offline mapnik tileprovider
is there a way to integrate mapsforge as a source-provider in osmdroid? Has anybody already experience with that? I found a wrapper in the osmdroid-library, but how should i use that ?

thanks in advance!

[Neil]

Firstly, mapsforge are discontinuing to support the offline tiles, so osmdroid is actually an alternative to mapsforge in that area. To see how to use the mapsforge wrapper, have a look at the Google wrapper example.

 

Neil

[Jez]

Hi Neil,

I've been meaning to email about mapsforge/osmdroid integration for a while.  I use osmdroid in the CycleStreets Android app, and recently integrated it with the Mapsforge renderer.  I started out your mapsforge wrapper code, but had an existing stack of overlays and user interaction that I wanted to lay on top of it.  Also switching between mapsforge rendering and osmdroid tile rendering was awkward.  I pushed the mapsforge stuff down into a tile overlay, and then had a bit of a revelation and wrapping Mapsforge as an OSMDroid TileSource and TileProvider.  This turns out to be a fantastic way to hook the two together - the coupling is very low, you don't need to change anything you've already built on top of OSMDroid. I use it to provide offline vector maps, not tiles, for the CycleStreets app. 

The source for the TileSource and TileProvider is at
   https://github.com/jezhiggins/android/tree/master/src/org/mapsforge/android/maps

This MapView
   https://github.com/jezhiggins/android/blob/master/src/net/cyclestreets/views/CycleMapView.java
can switch between normal OSDDroid online tile provider and an offline MapsForge tile provider.

It's possible that my code relies on some small patches to MapsForge - I haven't fully unpicked that yet as I made several changes while I thrashed around before hitting on the tilesource thing. The binary jar and the source are up there on GitHub too, though.  OSMDroid does not need patching for this to work. 

I'm happy to look at pulling this out of the CycleStreets source and packaging separately, providing it for the osmdroid-third-party jar or whatever.

Jez

[Neil]

Nice idea!

As I mentioned, mapsforge is deprecating tile download functionality - see this link: https://groups.google.com/d/topic/mapsforge-dev/0xn8vqilcpI/discussion - so it probably doesn't make sense to incorporate it.  Since your code is also open source, it probably makes more sense to leave it at that, and not integrate into osmdroid.

Neil

[Azimuth]

thanks for the replies!

@jeff
The idea is that mapsforge will be used for tile-rendering for osmdroid, right?
that means, that your tileprovider creates PNG / Bitmap tiles and give it to the osmdroid-MapView?
that is a very good solution for offline use, because the mapsforge maps-packages are very small ...

azimuth

On Thursday, June 21, 2012 10:36:57 AM UTC+2, Jez Higgins wrote:

[manimaul]

Jez,

Thank you very much for the example.  Having mapsforge as an osmdroid TileProvider is exactly what I'm looking for... this should be part of Osmdroid IMO.

Will

[Petar Petrov]

Hi Jez,
are you creating rasters on the fly (on the mobile), to feed as tile provider?

I was considering working with vector SVG for map overlays!
since, I realized that I need different raster size for each
particular zoom level my app supports.
the alternative is to stock all the png version of a merker overlay
with your app, making it harder to support and of-curse bigger.

--
All the best,
Petar Petrov
http://ppetrov.net

[Jez Higgins]

On Wednesday, 24 October 2012 11:08:46 UTC+1, ppetrovdotnet wrote:

are you creating rasters on the fly (on the mobile), to feed as tile provider?   

Yes, I'm using MapsForge as a tile provider for OsmDroid, generating tiles images from the vector data on demand.  Because (I assume) they are both working off the same dataset, MapsForge and OsmDroid both use the same projections, zoom levels, and so on.  When OsmDroid requests a particular tile at a particular zoom level, I just hand it off to the MapsForge renderer and then pass the image back out to OsmDroid.

Coming back to my earlier email, the CycleStreets code I pointed to works with OsmDroid and Mapsforge as is, so it's a pretty easy way to hook the two together.

Jez

[Martin]

Hi there Jez.

I've more or less got your code to work and now have a mapforge vector tile layer in OSMDroid - thanks a lot.

Do these vector tiles get cached?
I see no cache folder in the default 'osmdroid' folder and nothing cached in the default mapsforge '/Android/data/
org.mapsforge.android.maps/cache/' folder either.

Martin.

[Jez Higgins]

I've more or less got your code to work and now have a mapforge vector tile layer in OSMDroid - thanks a lot.
 

Cool.
 

Do these vector tiles get cached?
I see no cache folder in the default 'osmdroid' folder and nothing cached in the default mapsforge '/Android/data/
org.mapsforge.android.maps/cache/' folder either.

They're cached in memory, but not written out to disk.  It should be difficult to add if you wanted to, but I didn't bother as the rendering is generally so fast that there's no observable benefit in writing the images out to storage.

Jez
 

[Martin]

Could you give me some hints as to how i'd enable a tile cache on external memory?
If it's straightforward to implement i'd like to do so.

Thanks.

Martin.

[Jez Higgins]

On Sunday, 28 October 2012 07:22:21 UTC, Martin wrote:

Could you give me some hints as to how i'd enable a tile cache on external memory?
If it's straightforward to implement i'd like to do so.

In MapsforgeOSMDroidTileProvider.TileLoader.loadTile we have

    @Override

    public Drawable loadTile(final MapTileRequestState aState) throws CantContinueException

    {

      Drawable tile = drawMapsforgeTile(aState);

      if(tile == null)

        tile = downloadTile(aState);

      return tile;

    }

So, had off to Mapsforge to render the tile.  If Mapsforge failed - no data, out of bounds, etc - we go to the fallback tilesource and download a tile. 

You could extend this to something like

    @Override

    public Drawable loadTile(final MapTileRequestState aState) throws CantContinueException

    {
      Drawable tile = checkCache(aState);
      if(tile != null)
        return tile;

      tile = drawMapsforgeTile(aState);

      if(tile == null)

        tile = downloadTile(aState);

      if(tile != null)
         cacheTile(aState, tile);

      return tile;

    }

The OSMDroid FileWriter class can handle most of the mechanics of managing the cache, so you just need a bit of glue between the two.

Jez

[manimaul]

I've been playing around with this for a bit.  Here is a very simple example utilizing Jez' code to overlay a mapsforge map on top of osmdoid.  I thought I'd share if anyone else is interested in this.

Will

---

import org.mapsforge.android.maps.MapsforgeOSMDroidTileProvider;
import org.mapsforge.android.maps.MapsforgeOSMTileSource;
import org.osmdroid.tileprovider.MapTileProviderArray;
import org.osmdroid.tileprovider.modules.MapTileModuleProviderBase;
import org.osmdroid.tileprovider.modules.NetworkAvailabliltyCheck;
import org.osmdroid.tileprovider.tilesource.TileSourceFactory;
import org.osmdroid.util.GeoPoint;
import org.osmdroid.views.MapController;
import org.osmdroid.views.MapView;
import org.osmdroid.views.overlay.TilesOverlay;

import android.app.Activity;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.view.Menu;

public class MapActivity extends Activity {
    private final static String MAPSFORGE = "Mapsforge";
    private MapView mapView;
   
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_map);
       
        mapView = (MapView) this.findViewById(R.id.mapview);
       
        //
        //mapsforge tile provider setup
        //
       
        final MapsforgeOSMTileSource mapsforgeTileSource = new MapsforgeOSMTileSource(MAPSFORGE);
        mapsforgeTileSource.setMapFile(Environment.getExternalStorageDirectory()+"/washington.map");
       
        final  NetworkAvailabliltyCheck networkCheck = new  NetworkAvailabliltyCheck(this);
       
        final MapsforgeOSMDroidTileProvider mapsforgeProvider =
                new MapsforgeOSMDroidTileProvider(TileSourceFactory.DEFAULT_TILE_SOURCE, networkCheck);
       
        mapsforgeProvider.setTileSource(mapsforgeTileSource);
       
        final MapTileModuleProviderBase[] myProviders = new MapTileModuleProviderBase[1];
        myProviders[0] = mapsforgeProvider;
        final MapTileProviderArray myMapTileProviderArray = new MapTileProviderArray(mapsforgeTileSource, null, myProviders);
        final TilesOverlay myOverlay = new TilesOverlay(myMapTileProviderArray, this);
        mapView.getOverlays().add(myOverlay);
       
        final MyHandler mHandler = new MyHandler(this);
       
        myMapTileProviderArray.setTileRequestCompleteHandler(mHandler);
       
        //
        //end mapsforge tile provider setup
        //
       
        mapView.setMultiTouchControls(true);
       
        final MapController mapController = mapView.getController();
        mapController.setZoom(10);
       
        final GeoPoint startPoint = new GeoPoint(47329981,-122456359);
        mapController.setCenter(startPoint);
       
    }
   
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_map, menu);
        return true;
    }
   
    private static class MyHandler extends Handler {
        private MapActivity mapActivity;
       
        public MyHandler(final MapActivity mapActivity) {
            this.mapActivity = mapActivity;
        }
       
        public void handleMessage(Message msg) {
            mapActivity.mapView.invalidate();
        }
    }
   
}

[Ifor]

I have managed to get Jez's code modified to go though the tile cache system which I think is nessasary on an older phone.  I really think the code should get into the main development stream it's a very nice addition being able to have a local .map file for a big area localy as an alternative to haveing tile based files localy.

 

Basicaly I have had to modify the FileWriter class to make things protected so I can extend it to add in a new save() method taking the bitmap that MapsForge has generated and writing it to the cache.  There are modifications to Jez's tile source so it will work with the cache and then a variation on the Basic tile provider to use the new tile writer and add the new mapsforge provider into the chain.

[Martin]

That sounds very interesting - do you plan to share your code?

Thanks.

Martin.

[Ifor]

I would like to share my code by getting it into the project properly but don’t know how to go about this.  The fact I have had to change the TileWriter so I can extend it means you need more than just my new files...

 

I have the code checked out as a read only setup from 5 or 6 weeks back and at the moment am not at all keen on updating it as issues 388 will affect me.

 

Ifor

From: Martin

Sent: Saturday, January 05, 2013 9:37 AM

To: osmd...@googlegroups.com

Subject: Re: osmdroid and mapsforge

 

[Martin]

OK.

I'll continue to watch this thread and hopefully you'll post if and when your code is available?

Thanks.

Martin.

[Sergey Yakovlev]

One more interested man here. Don`t abandon it please :)

суббота, 5 января 2013 г., 14:15:58 UTC+4 пользователь Ifor написал:

[emux]

Mapsforge 0.4.0 (rewrite branch):
With the new layer architecture (currently under development in the Git rewrite branch) tile downloading is added again.
https://groups.google.com/forum/?fromgroups=#!topic/mapsforge-dev/cXQDkTQL00Y

[MKergall]

+10 !

In my opinion, having mapsforge vector maps fully integrated as one of the standard tile providers is the main improvement to bring to osmdroid.

And on mapsforge side, having an automatic downloading of mapsforge maps (tiles) is a must have. Reasonably small areas, and a caching mechanism just like osmdroid one.

Ultimately, why not thinking about merging both projects, instead of having each one reinventing the wheel (GeoPoint, overlays, sample apps,...)?

[emux]

Hi,

I've been experimenting lately with using Mapsforge as tile provider to Osmdroid
and indeed the result is interesting.

Though the rendering speed is quite slow..
I wonder what are your experiences about this?

I suspect the "synchronized" production of each tile bitmap is the cause,
but again without it the MapDatabase read gets corrupted.
Any ideas?

Best regards, Emux
https://play.google.com/store/apps/details?id=gr.talent.cruiser

[Martin]

Yes Jez's code give us only a single rendering thread.

I recently ported Jez's code to work with the GoogleMaps TileProvider class and had hoped to modify it so that it could render tiles on multiple threads.
But it was above my skill levels so i gave up!

If anyone is interested in seeing the TileProvider implementation then let me know.

Martin.

[Tony Montana]

welcome all!
Please share the results of your labors, really need to solution of this problem.
Thanks.

[emux]

I have not invested more time at this idea.
But for completeness it's worth mentioning (if not already)
that another example of this approach exists here.

--
Emux
Cruiser - Atlas

[MKergall]

I just integrated the solution from Salida Software in OSMBonusPack.
It works.

Unfortunately, this method doesn't allow to simply change the tile provider on an existing map.
I added some code in a GenericMapView, to keep as much MapView attributes as possible. But it's not ideal.

I will have a look on Jez method.