Merge pull request #502 from devemux86/overzoom

Map overzoom implementation

docs/Changelog.md

@@ -2,6 +2,7 @@
 
 ## New since 0.9.2
 
+- Map overzoom [#393](https://github.com/mapsforge/vtm/issues/393)
 - S3DB layer [#475](https://github.com/mapsforge/vtm/pull/475)
 - vtm-mvt module with MVT tile decoder [#481](https://github.com/mapsforge/vtm/pull/481)
 - Nextzen MVT / GeoJSON vector tiles [#498](https://github.com/mapsforge/vtm/issues/498)

resources/rendertheme.xsd

@@ -90,6 +90,7 @@
             <xs:enumeration value="ele" />
             <xs:enumeration value="addr:housenumber" />
             <xs:enumeration value="addr_housenumber" /> <!-- Mapzen -->
+            <xs:enumeration value="housenumber" /> <!-- OpenMapTiles -->
             <xs:enumeration value="name" />
             <xs:enumeration value="ref" />
         </xs:restriction>

vtm-json/src/org/oscim/tiling/source/geojson/GeojsonTileSource.java

@@ -1,6 +1,6 @@
 /*
  * Copyright 2014 Hannes Janetzek
- * Copyright 2017 devemux86
+ * Copyright 2017-2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -20,6 +20,7 @@ package org.oscim.tiling.source.geojson;
 import org.oscim.core.MapElement;
 import org.oscim.core.Tag;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.OverzoomTileDataSource;
 import org.oscim.tiling.source.UrlTileDataSource;
 import org.oscim.tiling.source.UrlTileSource;
 
@@ -41,7 +42,7 @@ public abstract class GeojsonTileSource extends UrlTileSource {
 
     @Override
     public ITileDataSource getDataSource() {
-        return new UrlTileDataSource(this, new TileDecoder(this), getHttpEngine());
+        return new OverzoomTileDataSource(new UrlTileDataSource(this, new TileDecoder(this), getHttpEngine()), mOverZoom);
     }
 
     public Tag getFeatureTag() {

vtm-json/src/org/oscim/tiling/source/geojson/MapzenGeojsonTileSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017 devemux86
+ * Copyright 2017-2018 devemux86
  * Copyright 2017 Gustl22
  *
  * This program is free software: you can redistribute it and/or modify it under the
@@ -17,6 +17,8 @@ package org.oscim.tiling.source.geojson;
 
 import org.oscim.core.MapElement;
 import org.oscim.core.Tag;
+import org.oscim.map.Viewport;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.UrlTileSource;
 import org.oscim.utils.FastMath;
 
@@ -32,8 +34,9 @@ public class MapzenGeojsonTileSource extends GeojsonTileSource {
         private String locale = "";
 
         public Builder() {
-            super(DEFAULT_URL, DEFAULT_PATH, 1, 17);
+            super(DEFAULT_URL, DEFAULT_PATH, Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
             keyName("api_key");
+            overZoom(16);
         }
 
         public T locale(String locale) {

vtm-json/src/org/oscim/tiling/source/geojson/NextzenGeojsonTileSource.java

@@ -16,6 +16,8 @@ package org.oscim.tiling.source.geojson;
 
 import org.oscim.core.MapElement;
 import org.oscim.core.Tag;
+import org.oscim.map.Viewport;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.UrlTileSource;
 import org.oscim.utils.FastMath;
 
@@ -31,8 +33,9 @@ public class NextzenGeojsonTileSource extends GeojsonTileSource {
         private String locale = "";
 
         public Builder() {
-            super(DEFAULT_URL, DEFAULT_PATH, 1, 17);
+            super(DEFAULT_URL, DEFAULT_PATH, Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
             keyName("api_key");
+            overZoom(16);
         }
 
         public T locale(String locale) {

vtm-mvt/src/org/oscim/tiling/source/mvt/MapzenMvtTileSource.java

@@ -1,6 +1,6 @@
 /*
  * Copyright 2013 Hannes Janetzek
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -17,7 +17,10 @@
  */
 package org.oscim.tiling.source.mvt;
 
+import org.oscim.map.Viewport;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.OverzoomTileDataSource;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.UrlTileDataSource;
 import org.oscim.tiling.source.UrlTileSource;
 
@@ -30,8 +33,9 @@ public class MapzenMvtTileSource extends UrlTileSource {
         private String locale = "";
 
         public Builder() {
-            super(DEFAULT_URL, DEFAULT_PATH, 1, 17);
+            super(DEFAULT_URL, DEFAULT_PATH, Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
             keyName("api_key");
+            overZoom(16);
         }
 
         public T locale(String locale) {
@@ -66,6 +70,6 @@ public class MapzenMvtTileSource extends UrlTileSource {
 
     @Override
     public ITileDataSource getDataSource() {
-        return new UrlTileDataSource(this, new MvtTileDecoder(locale), getHttpEngine());
+        return new OverzoomTileDataSource(new UrlTileDataSource(this, new MvtTileDecoder(locale), getHttpEngine()), mOverZoom);
     }
 }

vtm-mvt/src/org/oscim/tiling/source/mvt/NextzenMvtTileSource.java

@@ -14,7 +14,10 @@
  */
 package org.oscim.tiling.source.mvt;
 
+import org.oscim.map.Viewport;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.OverzoomTileDataSource;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.UrlTileDataSource;
 import org.oscim.tiling.source.UrlTileSource;
 
@@ -27,8 +30,9 @@ public class NextzenMvtTileSource extends UrlTileSource {
         private String locale = "";
 
         public Builder() {
-            super(DEFAULT_URL, DEFAULT_PATH, 1, 17);
+            super(DEFAULT_URL, DEFAULT_PATH, Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
             keyName("api_key");
+            overZoom(16);
         }
 
         public T locale(String locale) {
@@ -63,6 +67,6 @@ public class NextzenMvtTileSource extends UrlTileSource {
 
     @Override
     public ITileDataSource getDataSource() {
-        return new UrlTileDataSource(this, new MvtTileDecoder(locale), getHttpEngine());
+        return new OverzoomTileDataSource(new UrlTileDataSource(this, new MvtTileDecoder(locale), getHttpEngine()), mOverZoom);
     }
 }

vtm-mvt/src/org/oscim/tiling/source/mvt/OpenMapTilesMvtTileSource.java

@@ -1,6 +1,6 @@
 /*
  * Copyright 2013 Hannes Janetzek
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  * Copyright 2018 boldtrn
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
@@ -18,7 +18,10 @@
  */
 package org.oscim.tiling.source.mvt;
 
+import org.oscim.map.Viewport;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.OverzoomTileDataSource;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.UrlTileDataSource;
 import org.oscim.tiling.source.UrlTileSource;
 
@@ -31,7 +34,8 @@ public class OpenMapTilesMvtTileSource extends UrlTileSource {
         private String locale = "";
 
         public Builder() {
-            super(DEFAULT_URL, DEFAULT_PATH, 1, 14);
+            super(DEFAULT_URL, DEFAULT_PATH, Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
+            overZoom(14);
         }
 
         public T locale(String locale) {
@@ -66,6 +70,6 @@ public class OpenMapTilesMvtTileSource extends UrlTileSource {
 
     @Override
     public ITileDataSource getDataSource() {
-        return new UrlTileDataSource(this, new MvtTileDecoder(locale), getHttpEngine());
+        return new OverzoomTileDataSource(new UrlTileDataSource(this, new MvtTileDecoder(locale), getHttpEngine()), mOverZoom);
     }
 }

vtm-themes/resources/assets/vtm/openmaptiles.xml

@@ -376,22 +376,39 @@
     </m>
 
     <!-- building -->
-    <m k="layer" v="building">
+    <m k="layer" v="building|building:part">
-        <m zoom-min="14">
+        <m v="building">
-            <m closed="yes">
+            <m zoom-min="14">
-                <area fade="14" use="building" />
+                <m closed="yes">
+                    <area fade="14" use="building" />
+                </m>
+                <m closed="no">
+                    <line fade="14" use="building" />
+                </m>
             </m>
         </m>
+        <m v="building:part">
+            <m zoom-min="16">
+                <m closed="yes">
+                    <area fade="16" use="building" />
+                </m>
+                <m closed="no">
+                    <line fade="16" use="building" />
+                </m>
+            </m>
+        </m>
+        <m zoom-min="17">
+            <extrusion line-color="#ffd9d8d6" side-color="#eaecebe9" top-color="#eaf9f8f6" />
+        </m>
     </m>
     <!-- housenumber -->
-    <!-- TODO it's weird that not all housenumbers are shown... also needed to put zoom-min to 14 -->
+    <m k="layer" v="housenumber" zoom-min="17">
-    <!--<m k="layer" v="housenumber" zoom-min="14">
+        <caption style="bold" fill="#606060" font-family="condensed" k="housenumber" priority="10"
-        <caption style="bold" fill="#606060" k="housenumber" size="12" stroke="#ffffff"
+            size="12" stroke="#ffffff" stroke-width="2.0" />
-            stroke-width="2.0" />
+    </m>
-    </m>-->
-    <m k="layer" v="poi" zoom-min="14">
-        <m k="subclass">
 
+    <m k="layer" v="poi">
+        <m k="subclass">
 
             <!-- Shop -->
             <m select="first" zoom-min="15">
@@ -401,7 +418,7 @@
                 <!--<m v="florist">
                     <symbol src="assets:symbols/shopping/florist.svg" />
                 </m>-->
-                <!--<m v="hairdresser" zoom-min="16">
+                <!--<m v="hairdresser">
                     <symbol src="assets:symbols/shopping/hairdresser.svg" />
                 </m>-->
                 <m v="supermarket|organic">
@@ -418,7 +435,7 @@
             </m>
 
             <!-- Tourism -->
-            <m select="first" zoom-min="14">
+            <m select="first" zoom-min="15">
                 <m v="alpine_hut">
                     <symbol src="assets:symbols/accommodation/alpinehut.svg" />
                 </m>
@@ -437,15 +454,17 @@
                 </m>
             </m>
 
-            <m v="viewpoint">
+            <m select="first" zoom-min="15">
-                <symbol src="assets:symbols/custom/tourist/view_point.svg" />
+                <m v="viewpoint">
-            </m>
+                    <symbol src="assets:symbols/custom/tourist/view_point.svg" />
-            <m v="museum">
+                </m>
-                <symbol src="assets:symbols/custom/tourist/museum.svg" />
+                <m v="museum">
-            </m>
+                    <symbol src="assets:symbols/custom/tourist/museum.svg" />
+                </m>
 
-            <m zoom-min="14">
+                <m select="when-matched">
-                <text use="caption-small-blue" />
+                    <text use="caption-small-blue" />
+                </m>
             </m>
         </m>
     </m>

vtm-web/src/org/oscim/gdx/emu/org/oscim/tiling/source/bitmap/BitmapTileSource.java

@@ -1,3 +1,20 @@
+/*
+ * Copyright 2013 Hannes Janetzek
+ * Copyright 2018 devemux86
+ *
+ * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
+ *
+ * This program is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
 package org.oscim.tiling.source.bitmap;
 
 import com.google.gwt.event.dom.client.ErrorEvent;
@@ -13,9 +30,11 @@ import org.oscim.gdx.client.GwtBitmap;
 import org.oscim.layers.tile.LoadDelayTask;
 import org.oscim.layers.tile.MapTile;
 import org.oscim.layers.tile.TileLoader;
+import org.oscim.map.Viewport;
 import org.oscim.tiling.ITileDataSink;
 import org.oscim.tiling.ITileDataSource;
 import org.oscim.tiling.QueryResult;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.LwHttp;
 import org.oscim.tiling.source.UrlTileSource;
 import org.slf4j.Logger;
@@ -27,7 +46,7 @@ public class BitmapTileSource extends UrlTileSource {
     public static class Builder<T extends Builder<T>> extends UrlTileSource.Builder<T> {
 
         public Builder() {
-            super(null, "/{Z}/{X}/{Y}.png", 0, 17);
+            super(null, "/{Z}/{X}/{Y}.png", Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
         }
 
         public BitmapTileSource build() {

vtm/src/org/oscim/layers/tile/TileManager.java

@@ -1,5 +1,6 @@
 /*
  * Copyright 2013 Hannes Janetzek
+ * Copyright 2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -14,7 +15,6 @@
  * You should have received a copy of the GNU Lesser General Public License along with
  * this program. If not, see <http://www.gnu.org/licenses/>.
  */
-
 package org.oscim.layers.tile;
 
 import org.oscim.core.MapPosition;
@@ -153,12 +153,10 @@ public class TileManager {
         void onTileManagerEvent(Event event, MapTile tile);
     }
 
-    ;
-
     public TileManager(Map map, int cacheLimit) {
         mMap = map;
-        mMaxZoom = 20;
+        mMaxZoom = map.viewport().getMaxZoomLevel();
-        mMinZoom = 0;
+        mMinZoom = map.viewport().getMinZoomLevel();
         mCacheLimit = cacheLimit;
         mCacheReduce = 0;
 

vtm/src/org/oscim/layers/tile/vector/OsmTileLayer.java

@@ -1,6 +1,6 @@
 /*
  * Copyright 2013 Hannes Janetzek
- * Copyright 2016 devemux86
+ * Copyright 2016-2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -21,16 +21,15 @@ import org.oscim.core.Tag;
 import org.oscim.core.TagSet;
 import org.oscim.layers.tile.TileLoader;
 import org.oscim.map.Map;
+import org.oscim.tiling.TileSource;
 import org.oscim.utils.Utils;
 
 public class OsmTileLayer extends VectorTileLayer {
 
-    private static final int MAX_ZOOMLEVEL = 17;
-    private static final int MIN_ZOOMLEVEL = 2;
     private static final int CACHE_LIMIT = 150;
 
     public OsmTileLayer(Map map) {
-        this(map, MIN_ZOOMLEVEL, MAX_ZOOMLEVEL);
+        this(map, map.viewport().getMinZoomLevel(), TileSource.MAX_ZOOM);
     }
 
     public OsmTileLayer(Map map, int zoomMin, int zoomMax) {

vtm/src/org/oscim/layers/tile/vector/VectorTileLoader.java

@@ -55,7 +55,6 @@ public class VectorTileLoader extends TileLoader implements RenderStyle.Callback
     protected static final byte LAYERS = 11;
 
     public static final byte STROKE_MIN_ZOOM = 12;
-    public static final byte STROKE_MAX_ZOOM = 17;
 
     protected IRenderTheme renderTheme;
 

vtm/src/org/oscim/map/Viewport.java

@@ -39,13 +39,13 @@ import org.oscim.utils.FastMath;
  */
 public class Viewport {
 
-    public final static int MAX_ZOOMLEVEL = 20;
+    public final static int MAX_ZOOM_LEVEL = 20;
-    public final static int MIN_ZOOMLEVEL = 2;
+    public final static int MIN_ZOOM_LEVEL = 2;
     public final static float MIN_TILT = 0;
     public final static float MAX_TILT = 65;
 
-    protected double mMaxScale = (1 << MAX_ZOOMLEVEL);
+    protected double mMaxScale = (1 << MAX_ZOOM_LEVEL);
-    protected double mMinScale = (1 << MIN_ZOOMLEVEL);
+    protected double mMinScale = (1 << MIN_ZOOM_LEVEL);
 
     protected float mMinTilt = MIN_TILT;
     protected float mMaxTilt = MAX_TILT;
@@ -92,7 +92,7 @@ public class Viewport {
         mPos.scale = mMinScale;
         mPos.x = 0.5;
         mPos.y = 0.5;
-        mPos.zoomLevel = MIN_ZOOMLEVEL;
+        mPos.zoomLevel = MIN_ZOOM_LEVEL;
         mPos.bearing = 0;
         mPos.tilt = 0;
         mPos.roll = 0;

vtm/src/org/oscim/tiling/OverzoomDataSink.java

@@ -0,0 +1,60 @@
+/*
+ * Copyright 2018 devemux86
+ *
+ * This program is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.oscim.tiling;
+
+import org.oscim.backend.CanvasAdapter;
+import org.oscim.backend.canvas.Bitmap;
+import org.oscim.core.MapElement;
+import org.oscim.core.Tile;
+import org.oscim.utils.geom.TileClipper;
+
+class OverzoomDataSink implements ITileDataSink {
+
+    private final ITileDataSink sink;
+
+    private final TileClipper clipper;
+    private final float dx, dy, scale;
+
+    OverzoomDataSink(ITileDataSink sink, Tile overzoomTile, Tile tile) {
+        this.sink = sink;
+
+        int diff = tile.zoomLevel - overzoomTile.zoomLevel;
+        dx = (tile.tileX - (overzoomTile.tileX << diff)) * Tile.SIZE;
+        dy = (tile.tileY - (overzoomTile.tileY << diff)) * Tile.SIZE;
+        scale = 1 << diff;
+        float buffer = 32 * CanvasAdapter.getScale();
+        clipper = new TileClipper((dx - buffer) / scale, (dy - buffer) / scale,
+                (dx + Tile.SIZE + buffer) / scale, (dy + Tile.SIZE + buffer) / scale);
+    }
+
+    @Override
+    public void process(MapElement element) {
+        if (!clipper.clip(element))
+            return;
+        element.scale(scale, scale);
+        element.translate(-dx, -dy);
+        sink.process(element);
+    }
+
+    @Override
+    public void setTileImage(Bitmap bitmap) {
+        sink.setTileImage(bitmap);
+    }
+
+    @Override
+    public void completed(QueryResult result) {
+        sink.completed(result);
+    }
+}

vtm/src/org/oscim/tiling/OverzoomTileDataSource.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2018 devemux86
+ *
+ * This program is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+package org.oscim.tiling;
+
+import org.oscim.layers.tile.MapTile;
+
+public class OverzoomTileDataSource implements ITileDataSource {
+
+    private final ITileDataSource tileDataSource;
+    private final int overZoom;
+
+    public OverzoomTileDataSource(ITileDataSource tileDataSource, int overZoom) {
+        this.tileDataSource = tileDataSource;
+        this.overZoom = overZoom;
+    }
+
+    @Override
+    public void query(MapTile tile, ITileDataSink sink) {
+        MapTile mapTile = tile;
+        ITileDataSink dataSink = sink;
+        int diff = tile.zoomLevel - overZoom;
+        if (diff > 0) {
+            mapTile = new MapTile(tile.node, tile.tileX >> diff, tile.tileY >> diff, overZoom);
+            dataSink = new OverzoomDataSink(sink, mapTile, tile);
+        }
+        tileDataSource.query(mapTile, dataSink);
+    }
+
+    @Override
+    public void dispose() {
+        tileDataSource.dispose();
+    }
+
+    @Override
+    public void cancel() {
+        tileDataSource.cancel();
+    }
+}

vtm/src/org/oscim/tiling/TileDataSink.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 devemux86
+ * Copyright 2016-2018 devemux86
  *
  * This program is free software: you can redistribute it and/or modify it under the
  * terms of the GNU Lesser General Public License as published by the Free Software
@@ -12,34 +12,32 @@
  * You should have received a copy of the GNU Lesser General Public License along with
  * this program. If not, see <http://www.gnu.org/licenses/>.
  */
-package org.oscim.tiling.source.mapfile;
+package org.oscim.tiling;
 
 import org.oscim.backend.canvas.Bitmap;
 import org.oscim.core.MapElement;
-import org.oscim.tiling.ITileDataSink;
-import org.oscim.tiling.QueryResult;
 
-class MultiMapDataSink implements ITileDataSink {
+public class TileDataSink implements ITileDataSink {
 
     private QueryResult result;
-    private final ITileDataSink tileDataSink;
+    private final ITileDataSink sink;
 
-    MultiMapDataSink(ITileDataSink tileDataSink) {
+    public TileDataSink(ITileDataSink sink) {
-        this.tileDataSink = tileDataSink;
+        this.sink = sink;
     }
 
-    QueryResult getResult() {
+    public QueryResult getResult() {
         return result;
     }
 
     @Override
     public void process(MapElement element) {
-        tileDataSink.process(element);
+        sink.process(element);
     }
 
     @Override
     public void setTileImage(Bitmap bitmap) {
-        tileDataSink.setTileImage(bitmap);
+        sink.setTileImage(bitmap);
     }
 
     @Override

vtm/src/org/oscim/tiling/TileSource.java

@@ -19,6 +19,7 @@
 package org.oscim.tiling;
 
 import org.oscim.layers.tile.bitmap.BitmapTileLayer.FadeStep;
+import org.oscim.map.Viewport;
 
 import java.util.HashMap;
 
@@ -26,7 +27,9 @@ public abstract class TileSource {
 
     public abstract static class Builder<T extends Builder<T>> {
         protected float alpha = 1;
-        protected int zoomMin, zoomMax;
+        protected int zoomMin = Viewport.MIN_ZOOM_LEVEL;
+        protected int zoomMax = TileSource.MAX_ZOOM;
+        protected int overZoom = TileSource.MAX_ZOOM;
         protected FadeStep[] fadeSteps;
         protected String name;
         protected int tileSize = 256;
@@ -46,6 +49,11 @@ public abstract class TileSource {
             return self();
         }
 
+        public T overZoom(int zoom) {
+            overZoom = zoom;
+            return self();
+        }
+
         public T fadeSteps(FadeStep[] fadeSteps) {
             this.fadeSteps = fadeSteps;
             return self();
@@ -69,24 +77,38 @@ public abstract class TileSource {
         public abstract TileSource build();
     }
 
+    // FIXME Same as BuildingLayer.MAX_ZOOM
+    public static final int MAX_ZOOM = 17;
+
     protected float mAlpha = 1;
-    protected int mZoomMin = 0;
+    protected int mZoomMin = Viewport.MIN_ZOOM_LEVEL;
-    protected int mZoomMax = 20;
+    protected int mZoomMax = TileSource.MAX_ZOOM;
+    protected int mOverZoom = TileSource.MAX_ZOOM;
+    protected FadeStep[] mFadeSteps;
     protected String mName;
     protected int mTileSize = 256;
 
+    protected final Options options = new Options();
+    public ITileCache tileCache;
+
     protected TileSource() {
     }
 
     protected TileSource(int zoomMin, int zoomMax) {
+        this(zoomMin, zoomMax, zoomMax);
+    }
+
+    protected TileSource(int zoomMin, int zoomMax, int overZoom) {
         mZoomMin = zoomMin;
         mZoomMax = zoomMax;
+        mOverZoom = overZoom;
     }
 
     public TileSource(Builder<?> builder) {
         mAlpha = builder.alpha;
         mZoomMin = builder.zoomMin;
         mZoomMax = builder.zoomMax;
+        mOverZoom = builder.overZoom;
         mFadeSteps = builder.fadeSteps;
         mName = builder.name;
         mTileSize = builder.tileSize;
@@ -98,12 +120,6 @@ public abstract class TileSource {
 
     public abstract void close();
 
-    protected final Options options = new Options();
-
-    public ITileCache tileCache;
-
-    private FadeStep[] mFadeSteps;
-
     public float getAlpha() {
         return mAlpha;
     }
@@ -123,6 +139,10 @@ public abstract class TileSource {
         return mZoomMin;
     }
 
+    public int getOverZoom() {
+        return mOverZoom;
+    }
+
     public void setFadeSteps(FadeStep[] fadeSteps) {
         mFadeSteps = fadeSteps;
     }

vtm/src/org/oscim/tiling/source/UrlTileSource.java

@@ -1,6 +1,6 @@
 /*
  * Copyright 2013 Hannes Janetzek
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  * Copyright 2016 Izumi Kawashima
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
@@ -19,6 +19,7 @@
 package org.oscim.tiling.source;
 
 import org.oscim.core.Tile;
+import org.oscim.map.Viewport;
 import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.LwHttp.LwHttpFactory;
 
@@ -39,9 +40,13 @@ public abstract class UrlTileSource extends TileSource {
         protected Builder() {
         }
 
-        protected Builder(String url, String tilePath, int zoomMin, int zoomMax) {
+        protected Builder(String url, String tilePath) {
             this.url = url;
             this.tilePath = tilePath;
+        }
+
+        protected Builder(String url, String tilePath, int zoomMin, int zoomMax) {
+            this(url, tilePath);
             this.zoomMin = zoomMin;
             this.zoomMax = zoomMax;
         }
@@ -97,7 +102,7 @@ public abstract class UrlTileSource extends TileSource {
     }
 
     protected UrlTileSource(String urlString, String tilePath) {
-        this(urlString, tilePath, 0, 17);
+        this(urlString, tilePath, Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
     }
 
     protected UrlTileSource(String urlString, String tilePath, int zoomMin, int zoomMax) {

vtm/src/org/oscim/tiling/source/bitmap/BitmapTileSource.java

@@ -1,10 +1,29 @@
+/*
+ * Copyright 2013 Hannes Janetzek
+ * Copyright 2018 devemux86
+ *
+ * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
+ *
+ * This program is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
 package org.oscim.tiling.source.bitmap;
 
 import org.oscim.backend.CanvasAdapter;
 import org.oscim.backend.canvas.Bitmap;
 import org.oscim.core.Tile;
+import org.oscim.map.Viewport;
 import org.oscim.tiling.ITileDataSink;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.ITileDecoder;
 import org.oscim.tiling.source.LwHttp;
 import org.oscim.tiling.source.UrlTileDataSource;
@@ -21,7 +40,7 @@ public class BitmapTileSource extends UrlTileSource {
     public static class Builder<T extends Builder<T>> extends UrlTileSource.Builder<T> {
 
         public Builder() {
-            super(null, "/{Z}/{X}/{Y}.png", 0, 17);
+            super(null, "/{Z}/{X}/{Y}.png", Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
         }
 
         public BitmapTileSource build() {

vtm/src/org/oscim/tiling/source/mapfile/MapDatabase.java

@@ -2,7 +2,7 @@
  * Copyright 2010, 2011, 2012 mapsforge.org
  * Copyright 2013, 2014 Hannes Janetzek
  * Copyright 2014-2015 Ludwig M Brinckmann
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  * Copyright 2016 Andrey Novikov
  * Copyright 2017 Gustl22
  *
@@ -32,6 +32,7 @@ import org.oscim.core.Tile;
 import org.oscim.layers.tile.MapTile;
 import org.oscim.tiling.ITileDataSink;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.mapfile.header.SubFileParameter;
 import org.oscim.utils.Parameters;
 import org.oscim.utils.geom.TileClipper;
@@ -414,7 +415,7 @@ public class MapDatabase implements ITileDataSource {
 
         // At large query zoom levels use enlarged buffer
         int buffer;
-        if (queryParameters.queryZoomLevel > MapFileTileSource.MAX_ZOOM_LEVEL)
+        if (queryParameters.queryZoomLevel > TileSource.MAX_ZOOM)
             buffer = Tile.SIZE / 2;
         else
             buffer = (int) (16 * CanvasAdapter.getScale() + 0.5f);
@@ -956,7 +957,7 @@ public class MapDatabase implements ITileDataSource {
                 // At large query zoom levels clip everything
                 if ((!e.tags.containsKey(Tag.KEY_BUILDING)
                         && !e.tags.containsKey(Tag.KEY_BUILDING_PART))
-                        || queryParameters.queryZoomLevel > MapFileTileSource.MAX_ZOOM_LEVEL) {
+                        || queryParameters.queryZoomLevel > TileSource.MAX_ZOOM) {
                     if (!mTileClipper.clip(e)) {
                         continue;
                     }

vtm/src/org/oscim/tiling/source/mapfile/MapFileTileSource.java

@@ -1,7 +1,7 @@
 /*
  * Copyright 2013 mapsforge.org
  * Copyright 2013 Hannes Janetzek
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -18,7 +18,9 @@
  */
 package org.oscim.tiling.source.mapfile;
 
+import org.oscim.map.Viewport;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.OverzoomTileDataSource;
 import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.mapfile.header.MapFileHeader;
 import org.oscim.tiling.source.mapfile.header.MapFileInfo;
@@ -37,7 +39,6 @@ public class MapFileTileSource extends TileSource implements IMapFileTileSource
      * Amount of cache blocks that the index cache should store.
      */
     private static final int INDEX_CACHE_SIZE = 64;
-    static final int MAX_ZOOM_LEVEL = 17;
     private static final String READ_ONLY_MODE = "r";
 
     MapFileHeader fileHeader;
@@ -54,11 +55,15 @@ public class MapFileTileSource extends TileSource implements IMapFileTileSource
     private Callback callback;
 
     public MapFileTileSource() {
-        this(0, MAX_ZOOM_LEVEL);
+        this(Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
     }
 
     public MapFileTileSource(int zoomMin, int zoomMax) {
-        super(zoomMin, zoomMax);
+        this(zoomMin, zoomMax, zoomMax);
+    }
+
+    public MapFileTileSource(int zoomMin, int zoomMax, int overZoom) {
+        super(zoomMin, zoomMax, overZoom);
     }
 
     /**
@@ -149,7 +154,7 @@ public class MapFileTileSource extends TileSource implements IMapFileTileSource
     @Override
     public ITileDataSource getDataSource() {
         try {
-            return new MapDatabase(this);
+            return new OverzoomTileDataSource(new MapDatabase(this), mOverZoom);
         } catch (IOException e) {
             log.debug(e.getMessage());
         }

vtm/src/org/oscim/tiling/source/mapfile/MultiMapDatabase.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  *
  * This program is free software: you can redistribute it and/or modify it under the
  * terms of the GNU Lesser General Public License as published by the Free Software
@@ -18,6 +18,7 @@ import org.oscim.core.Tile;
 import org.oscim.layers.tile.MapTile;
 import org.oscim.tiling.ITileDataSink;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.TileDataSink;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -25,10 +26,8 @@ import java.util.List;
 public class MultiMapDatabase implements ITileDataSource {
 
     private final List<MapDatabase> mapDatabases = new ArrayList<>();
-    private final MultiMapFileTileSource tileSource;
 
-    public MultiMapDatabase(MultiMapFileTileSource tileSource) {
+    public MultiMapDatabase() {
-        this.tileSource = tileSource;
     }
 
     public boolean add(MapDatabase mapDatabase) {
@@ -39,13 +38,13 @@ public class MultiMapDatabase implements ITileDataSource {
     }
 
     @Override
-    public void query(MapTile tile, ITileDataSink mapDataSink) {
+    public void query(MapTile tile, ITileDataSink sink) {
-        MultiMapDataSink multiMapDataSink = new MultiMapDataSink(mapDataSink);
+        TileDataSink dataSink = new TileDataSink(sink);
         for (MapDatabase mapDatabase : mapDatabases) {
             if (mapDatabase.supportsTile(tile))
-                mapDatabase.query(tile, multiMapDataSink);
+                mapDatabase.query(tile, dataSink);
         }
-        mapDataSink.completed(multiMapDataSink.getResult());
+        sink.completed(dataSink.getResult());
     }
 
     @Override

vtm/src/org/oscim/tiling/source/mapfile/MultiMapFileTileSource.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2017 devemux86
+ * Copyright 2016-2018 devemux86
  *
  * This program is free software: you can redistribute it and/or modify it under the
  * terms of the GNU Lesser General Public License as published by the Free Software
@@ -15,7 +15,9 @@
 package org.oscim.tiling.source.mapfile;
 
 import org.oscim.core.BoundingBox;
+import org.oscim.map.Viewport;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.OverzoomTileDataSource;
 import org.oscim.tiling.TileSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -34,11 +36,15 @@ public class MultiMapFileTileSource extends TileSource implements IMapFileTileSo
     private final Map<MapFileTileSource, int[]> zoomsByTileSource = new HashMap<>();
 
     public MultiMapFileTileSource() {
-        this(0, 17);
+        this(Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
     }
 
     public MultiMapFileTileSource(int zoomMin, int zoomMax) {
-        super(zoomMin, zoomMax);
+        this(zoomMin, zoomMax, zoomMax);
+    }
+
+    public MultiMapFileTileSource(int zoomMin, int zoomMax, int overZoom) {
+        super(zoomMin, zoomMax, overZoom);
     }
 
     public boolean add(MapFileTileSource mapFileTileSource) {
@@ -65,7 +71,7 @@ public class MultiMapFileTileSource extends TileSource implements IMapFileTileSo
 
     @Override
     public ITileDataSource getDataSource() {
-        MultiMapDatabase multiMapDatabase = new MultiMapDatabase(this);
+        MultiMapDatabase multiMapDatabase = new MultiMapDatabase();
         for (MapFileTileSource mapFileTileSource : mapFileTileSources) {
             try {
                 MapDatabase mapDatabase = new MapDatabase(mapFileTileSource);
@@ -77,7 +83,7 @@ public class MultiMapFileTileSource extends TileSource implements IMapFileTileSo
                 log.debug(e.getMessage());
             }
         }
-        return multiMapDatabase;
+        return new OverzoomTileDataSource(multiMapDatabase, mOverZoom);
     }
 
     @Override

vtm/src/org/oscim/tiling/source/oscimap4/OSciMap4TileSource.java

@@ -1,5 +1,6 @@
 /*
  * Copyright 2013 Hannes Janetzek
+ * Copyright 2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -16,7 +17,10 @@
  */
 package org.oscim.tiling.source.oscimap4;
 
+import org.oscim.map.Viewport;
 import org.oscim.tiling.ITileDataSource;
+import org.oscim.tiling.OverzoomTileDataSource;
+import org.oscim.tiling.TileSource;
 import org.oscim.tiling.source.UrlTileDataSource;
 import org.oscim.tiling.source.UrlTileSource;
 
@@ -28,7 +32,8 @@ public class OSciMap4TileSource extends UrlTileSource {
     public static class Builder<T extends Builder<T>> extends UrlTileSource.Builder<T> {
 
         public Builder() {
-            super(DEFAULT_URL, DEFAULT_PATH, 1, 17);
+            super(DEFAULT_URL, DEFAULT_PATH, Viewport.MIN_ZOOM_LEVEL, TileSource.MAX_ZOOM);
+            overZoom(17);
         }
 
         public OSciMap4TileSource build() {
@@ -55,6 +60,6 @@ public class OSciMap4TileSource extends UrlTileSource {
 
     @Override
     public ITileDataSource getDataSource() {
-        return new UrlTileDataSource(this, new TileDecoder(), getHttpEngine());
+        return new OverzoomTileDataSource(new UrlTileDataSource(this, new TileDecoder(), getHttpEngine()), mOverZoom);
     }
 }