Prefer render quality rather than render speed

src/map/IMG/dem.h

@@ -41,4 +41,4 @@ private:
 
 }
 
-#endif // IMG_ELEVATIONTREE_H
+#endif // IMG_DEM_H

src/map/IMG/rastertile.cpp

@@ -30,7 +30,6 @@ using namespace IMG;
 #define WATER 1
 
 #define BLUR_RADIUS 3
-#define DELTA 0.05 /* DEM3 resolution in degrees */
 
 static const QColor textColor(Qt::black);
 static const QColor haloColor(Qt::white);
@@ -477,9 +476,11 @@ MatrixD RasterTile::elevation(int extend) const
 
 		for (int i = 0; i < ll.size(); i++)
 			rect = rect.united(ll.at(i));
-		// Extra margin for edge()
-		rect = rect.united(Coordinates(rect.right() + DELTA,
-		  rect.bottom() - DELTA));
+		// Extra margin for always including the next DEM tile on the map tile
+		// edges (the DEM tile resolution is usally < 5% of the map tile)
+		double delta = rect.width() / 16;
+		rect = rect.united(Coordinates(rect.right() + delta,
+		  rect.bottom() - delta));
 
 		_data->elevations(rect, _zoom, &tiles);
 

src/map/IMG/vectortile.cpp

@@ -276,7 +276,10 @@ void VectorTile::elevations(const RectC &rect, const Zoom &zoom,
 		}
 	}
 
-	int level = _dem->level(zoom);
+	// Shift the DEM level to get better data then what the map defines for
+	// the given zoom (we prefer rendering quality rather than speed). For
+	// maps with a single level this has no effect.
+	int level = _dem->level(zoom) / 2;
 	QList<const DEMTile*> tiles(_dem->tiles(rect, level));
 	for (int i = 0; i < tiles.size(); i++) {
 		const DEMTile *tile = tiles.at(i);

src/map/hillshading.h

@@ -8,7 +8,7 @@ class HillShading
 {
 public:
 	static QImage render(const MatrixD &m, int extend, quint8 alpha = 96,
-	  double z = 0.3, double azimuth = 315, double elevation = 25);
+	  double z = 0.6, double azimuth = 315, double elevation = 45);
 };
 
 #endif // HILLSHADING_H