Drawing performance improvement

src/axisitem.cpp

@@ -34,6 +34,8 @@ AxisItem::AxisItem(Type type, QGraphicsItem *parent) : QGraphicsItem(parent)
 {
 	_type = type;
 	_size = 0;
+
+	setCacheMode(QGraphicsItem::DeviceCoordinateCache);
 }
 
 void AxisItem::setRange(const RangeF &range)

src/routeitem.cpp

@@ -53,6 +53,7 @@ RouteItem::RouteItem(const Route &route, QGraphicsItem *parent)
 	setToolTip(toolTip());
 	setCursor(Qt::ArrowCursor);
 	setAcceptHoverEvents(true);
+	setCacheMode(QGraphicsItem::DeviceCoordinateCache);
 
 	updateShape();
 

src/scaleitem.cpp

@@ -17,6 +17,8 @@ ScaleItem::ScaleItem(QGraphicsItem *parent) : QGraphicsItem(parent)
 	_units = Metric;
 	_zoom = ZOOM_MIN;
 	_lat = 0;
+
+	setCacheMode(QGraphicsItem::DeviceCoordinateCache);
 }
 
 void ScaleItem::updateBoundingRect()
@@ -112,9 +114,10 @@ void ScaleItem::computeScale()
 	}
 }
 
-void ScaleItem::setLatitude(qreal lat)
+void ScaleItem::setZoom(int z, qreal lat)
 {
 	prepareGeometryChange();
+	_zoom = z;
 	_lat = lat;
 	computeScale();
 	updateBoundingRect();

src/scaleitem.h

@@ -13,8 +13,8 @@ public:
 	void paint(QPainter *painter, const QStyleOptionGraphicsItem *option,
 	  QWidget *widget);
 
-	void setLatitude(qreal lat);
 	void setZoom(int z);
+	void setZoom(int z, qreal lat);
 	void setUnits(enum Units units);
 
 private:

src/trackitem.cpp

@@ -53,6 +53,7 @@ TrackItem::TrackItem(const Track &track, QGraphicsItem *parent)
 	setToolTip(toolTip());
 	setCursor(Qt::ArrowCursor);
 	setAcceptHoverEvents(true);
+	setCacheMode(QGraphicsItem::DeviceCoordinateCache);
 
 	updateShape();
 

src/trackview.cpp

@@ -136,8 +136,7 @@ void TrackView::loadGPX(const GPX &gpx)
 	_scene->setSceneRect(ba);
 	centerOn(ba.center());
 
-	_mapScale->setLatitude(-(br.center().ry() * _scale));
+	_mapScale->setZoom(_zoom, -(br.center().ry() * _scale));
-	_mapScale->setZoom(_zoom);
 	if (_mapScale->scene() != _scene)
 		_scene->addItem(_mapScale);
 }