Map fractional zoom, fix #487

docs/Changelog.md

@@ -6,6 +6,7 @@
 - vtm-mvt module with MVT tile decoder [#481](https://github.com/mapsforge/vtm/pull/481)
 - OpenMapTiles MVT vector tiles [#482](https://github.com/mapsforge/vtm/issues/482)
 - Improved theme styles [#479](https://github.com/mapsforge/vtm/pull/479)
+- Map fractional zoom [#487](https://github.com/mapsforge/vtm/issues/487)
 - Render theme fallback internal resources [#477](https://github.com/mapsforge/vtm/issues/477)
 - Fix libGDX flickering [#148](https://github.com/mapsforge/vtm/issues/148) [#149](https://github.com/mapsforge/vtm/issues/149)
 - JTS (LocationTech) [#484](https://github.com/mapsforge/vtm/issues/484)

vtm/src/org/oscim/core/MapPosition.java

@@ -1,6 +1,6 @@
 /*
  * Copyright 2012 Hannes Janetzek
- * Copyright 2016 devemux86
+ * Copyright 2016-2018 devemux86
  *
  * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
  *
@@ -107,6 +107,26 @@ public class MapPosition {
         return scale;
     }
 
+    public MapPosition setScale(double scale) {
+        this.zoomLevel = FastMath.log2((int) scale);
+        this.scale = scale;
+        return this;
+    }
+
+    /**
+     * @return the fractional zoom.
+     */
+    public double getZoom() {
+        return Math.log(scale) / Math.log(2);
+    }
+
+    /**
+     * Sets the fractional zoom.
+     */
+    public void setZoom(double zoom) {
+        setScale(Math.pow(2, zoom));
+    }
+
     public int getZoomLevel() {
         return zoomLevel;
     }
@@ -117,12 +137,6 @@ public class MapPosition {
         return this;
     }
 
-    public MapPosition setScale(double scale) {
-        this.zoomLevel = FastMath.log2((int) scale);
-        this.scale = scale;
-        return this;
-    }
-
     public void setPosition(GeoPoint geoPoint) {
         setPosition(geoPoint.getLatitude(), geoPoint.getLongitude());
     }