- Introduce clipScreenCoordinates property for GeoPolyline. This allows for restoring the

  previous slow behavior that creates all possible screen coordinates.
- Fix memory leak.

src/lib/marble/declarative/GeoPolyline.cpp

@@ -28,7 +28,8 @@ namespace Marble
         m_observable(false),
         m_lineColor(Qt::black),
         m_lineWidth(1),
-        m_tessellate(true)
+        m_tessellate(true),
+        m_clipScreenCoordinates(true)
     {
         setFlag(ItemHasContents, true);
     }
@@ -59,10 +60,19 @@ namespace Marble
             m_screenPolygons.clear();
             QVector<QPolygonF*> fullScreenPolygons;
             bool success = m_map->screenCoordinatesFromGeoDataLineString(lineString, fullScreenPolygons);
-            for (auto reducedPolygon : qAsConst(fullScreenPolygons)) {
-                m_screenPolygons << reducedPolygon->intersected(displayPolygon);
+            if (m_clipScreenCoordinates) {
+                for (auto reducedPolygon : qAsConst(fullScreenPolygons)) {
+                    m_screenPolygons << reducedPolygon->intersected(displayPolygon);
+                }
+            }
+            else {
+                for (auto eachPolygon : qAsConst(fullScreenPolygons)) {
+                    m_screenPolygons << *eachPolygon;
+                }
             }
 
+            qDeleteAll(fullScreenPolygons);
+
             QVariantList previousScreenCoordinates;
             previousScreenCoordinates = m_screenCoordinates;
             m_screenCoordinates.clear();
@@ -178,6 +188,11 @@ namespace Marble
         return m_tessellate;
     }
 
+    bool GeoPolyline::clipScreenCoordinates() const
+    {
+        return m_clipScreenCoordinates;
+    }
+
     void GeoPolyline::setTessellate(bool tessellate)
     {
         if (m_tessellate == tessellate)
@@ -187,6 +202,15 @@ namespace Marble
         emit tessellateChanged(m_tessellate);
     }
 
+    void GeoPolyline::setClipScreenCoordinates(bool clipped)
+    {
+        if (m_clipScreenCoordinates == clipped)
+            return;
+
+        m_clipScreenCoordinates = clipped;
+        emit clipScreenCoordinatesChanged(m_clipScreenCoordinates);
+    }
+
     qreal GeoPolyline::readonlyX() const
     {
         return x();

src/lib/marble/declarative/GeoPolyline.h

@@ -38,6 +38,10 @@ namespace Marble
         Q_PROPERTY( QColor lineColor READ lineColor WRITE setLineColor NOTIFY lineColorChanged )
         Q_PROPERTY( qreal lineWidth READ lineWidth WRITE setLineWidth NOTIFY lineWidthChanged )
 
+        // When enabled only those screenCoordinates are calculated and rendered that are visible on the screen.
+        // Setting this to false can severely reduce performance. Therefore this defaults to true.
+        Q_PROPERTY( bool clipScreenCoordinates READ clipScreenCoordinates WRITE setClipScreenCoordinates NOTIFY clipScreenCoordinatesChanged )
+
     public:
         /** Constructor */
         explicit GeoPolyline( QQuickItem *parent = nullptr );
@@ -57,10 +61,12 @@ namespace Marble
         QColor lineColor() const;
         qreal lineWidth() const;
         bool tessellate() const;
+        bool clipScreenCoordinates() const;
 
         void setLineColor(const QColor& lineColor);
         void setLineWidth(const qreal lineWidth);
         void setTessellate(bool tessellate);
+        void setClipScreenCoordinates(bool clipped);
 
         qreal readonlyX() const;
 
@@ -79,6 +85,7 @@ namespace Marble
         void lineWidthChanged(qreal lineWidth);
 
         void tessellateChanged(bool tessellate);
+        void clipScreenCoordinatesChanged(bool enabled);
 
         void readonlyXChanged();
         void readonlyYChanged();
@@ -98,6 +105,7 @@ namespace Marble
         QColor m_lineColor;
         qreal m_lineWidth;
         bool m_tessellate;
+        bool m_clipScreenCoordinates;
 
         void updateScreenPositions();
     };