Don't rescale the view on map change

src/atlas.cpp

@@ -227,6 +227,26 @@ qreal Atlas::zoomFit(const QSize &size, const QRectF &br)
 	return _zoom;
 }
 
+qreal Atlas::zoomFit(qreal resolution, const Coordinates &c)
+{
+	_zoom = 0;
+
+	for (int z = 0; z < _zooms.count(); z++) {
+		for (int i = _zooms.at(z).first; i <= _zooms.at(z).second; i++) {
+			if (!_bounds.at(i).first.contains(_maps.at(i)->ll2pp(c)))
+				continue;
+
+			if (_maps.at(i)->resolution(_maps.at(i)->ll2xy(c)) < resolution)
+				return _zoom;
+
+			_zoom = z;
+			break;
+		}
+	}
+
+	return _zoom;
+}
+
 qreal Atlas::zoomIn()
 {
 	_zoom = qMin(_zoom + 1, _zooms.size() - 1);

src/atlas.h

@@ -21,6 +21,7 @@ public:
 
 	qreal zoom() const;
 	qreal zoomFit(const QSize &size, const QRectF &br);
+	qreal zoomFit(qreal resolution, const Coordinates &c);
 	qreal zoomIn();
 	qreal zoomOut();
 

src/emptymap.cpp

@@ -41,6 +41,17 @@ qreal EmptyMap::zoomFit(const QSize &size, const QRectF &br)
 	return _scale;
 }
 
+qreal EmptyMap::zoomFit(qreal resolution, const Coordinates &c)
+{
+	_scale = (360.0 * resolution) / (WGS84_RADIUS * 2 * M_PI
+	  * cos(deg2rad(c.lat())));
+
+	_scale = qMax(_scale, SCALE_MAX);
+	_scale = qMin(_scale, SCALE_MIN);
+
+	return _scale;
+}
+
 qreal EmptyMap::resolution(const QPointF &p) const
 {
 	return (WGS84_RADIUS * 2 * M_PI * _scale / 360.0

src/emptymap.h

@@ -17,6 +17,7 @@ public:
 
 	qreal zoom() const {return _scale;}
 	qreal zoomFit(const QSize &size, const QRectF &br);
+	qreal zoomFit(qreal resolution, const Coordinates &c);
 	qreal zoomIn();
 	qreal zoomOut();
 

src/map.h

@@ -22,6 +22,7 @@ public:
 
 	virtual qreal zoom() const = 0;
 	virtual qreal zoomFit(const QSize &size, const QRectF &br) = 0;
+	virtual qreal zoomFit(qreal resolution, const Coordinates &c) = 0;
 	virtual qreal zoomIn() = 0;
 	virtual qreal zoomOut() = 0;
 

src/offlinemap.h

@@ -28,6 +28,7 @@ public:
 
 	qreal zoom() const {return 0;}
 	qreal zoomFit(const QSize &, const QRectF &) {return 0;}
+	qreal zoomFit(qreal, const Coordinates &) {return 0;}
 	qreal zoomIn() {return 0;}
 	qreal zoomOut() {return 0;}
 

src/onlinemap.cpp

@@ -27,19 +27,12 @@ static QPoint mercator2tile(const QPointF &m, int z)
 
 static qreal zoom2scale(int zoom)
 {
-	return ((360.0/(qreal)(1<<zoom))/(qreal)TILE_SIZE);
+	return (360.0/(qreal)((1<<zoom) * TILE_SIZE));
 }
 
 static int scale2zoom(qreal scale)
 {
-	int zoom = (int)log2(360.0/(scale * (qreal)TILE_SIZE));
+	return (int)log2(360.0/(scale * (qreal)TILE_SIZE));
-
-	if (zoom < ZOOM_MIN)
-		return ZOOM_MIN;
-	if (zoom > ZOOM_MAX)
-		return ZOOM_MAX;
-
-	return zoom;
 }
 
 
@@ -181,12 +174,30 @@ qreal OnlineMap::zoomFit(const QSize &size, const QRectF &br)
 		Coordinates bottomRight(br.bottomRight());
 		QRectF tbr(Mercator().ll2xy(topLeft), Mercator().ll2xy(bottomRight));
 		QPointF sc(tbr.width() / size.width(), tbr.height() / size.height());
+
 		_zoom = scale2zoom(qMax(sc.x(), sc.y()));
+		if (_zoom < ZOOM_MIN)
+			_zoom = ZOOM_MIN;
+		if (_zoom > ZOOM_MAX)
+			_zoom = ZOOM_MAX;
 	}
 
 	return _zoom;
 }
 
+qreal OnlineMap::zoomFit(qreal resolution, const Coordinates &c)
+{
+	_zoom = (int)(log2((WGS84_RADIUS * 2 * M_PI * cos(deg2rad(c.lat())))
+	  / resolution) - log2(TILE_SIZE));
+
+	if (_zoom < ZOOM_MIN)
+		_zoom = ZOOM_MIN;
+	if (_zoom > ZOOM_MAX)
+		_zoom = ZOOM_MAX;
+
+	return _zoom;
+}
+
 qreal OnlineMap::resolution(const QPointF &p) const
 {
 	qreal scale = zoom2scale(_zoom);

src/onlinemap.h

@@ -20,6 +20,7 @@ public:
 
 	qreal zoom() const {return _zoom;}
 	qreal zoomFit(const QSize &size, const QRectF &br);
+	qreal zoomFit(qreal resolution, const Coordinates &c);
 	qreal zoomIn();
 	qreal zoomOut();
 

src/pathview.cpp

@@ -8,7 +8,6 @@
 #include "poi.h"
 #include "data.h"
 #include "map.h"
-#include "emptymap.h"
 #include "trackitem.h"
 #include "routeitem.h"
 #include "waypointitem.h"
@@ -16,10 +15,11 @@
 #include "keys.h"
 #include "pathview.h"
 
-#define MAX_ZOOM      1
+
-#define MIN_ZOOM      -3
+#define MAX_DIGITAL_ZOOM 1
-#define MARGIN        10.0
+#define MIN_DIGITAL_ZOOM -3
-#define SCALE_OFFSET  7
+#define MARGIN           10.0
+#define SCALE_OFFSET     7
 
 static void unite(QRectF &rect, const QPointF &p)
 {
@@ -271,6 +271,10 @@ void PathView::setPalette(const Palette &palette)
 
 void PathView::setMap(Map *map)
 {
+	QPointF pos = mapToScene(QRect(QPoint(), viewport()->size()).center());
+	Coordinates center = _map->xy2ll(pos);
+	qreal resolution = _map->resolution(pos);
+
 	_map->unload();
 	disconnect(_map, SIGNAL(loaded()), this, SLOT(redraw()));
 
@@ -280,7 +284,7 @@ void PathView::setMap(Map *map)
 
 	resetDigitalZoom();
 
-	mapScale();
+	_map->zoomFit(resolution, center);
 	_scene->setSceneRect(_map->bounds());
 
 	for (int i = 0; i < _tracks.size(); i++)
@@ -295,10 +299,9 @@ void PathView::setMap(Map *map)
 		it.value()->setMap(_map);
 	updatePOIVisibility();
 
-	QPointF center = contentCenter();
+	centerOn(_map->ll2xy(center));
-	centerOn(center);
 
-	_res = _map->resolution(center);
+	_res = _map->resolution(_map->ll2xy(center));
 	_mapScale->setResolution(_res);
 
 	resetCachedContent();
@@ -420,8 +423,8 @@ void PathView::zoom(int zoom, const QPoint &pos, const Coordinates &c)
 
 	if (_digitalZoom) {
 		if (((_digitalZoom > 0 && zoom > 0) && (!shift || _digitalZoom
-		  >= MAX_ZOOM)) || ((_digitalZoom < 0 && zoom < 0) && (!shift
+		  >= MAX_DIGITAL_ZOOM)) || ((_digitalZoom < 0 && zoom < 0) && (!shift
-		  || _digitalZoom <= MIN_ZOOM)))
+		  || _digitalZoom <= MIN_DIGITAL_ZOOM)))
 			return;
 
 		digitalZoom(zoom);