Optimise QgsCurve::asQPolygonF for linestring geometries

python/core/auto_generated/geometry/qgscurve.sip.in

@@ -177,7 +177,7 @@ Returns the y-coordinate of the specified node in the line string.
 :return: y-coordinate of node, or 0.0 if index is out of bounds
 %End
 
-    QPolygonF asQPolygonF() const;
+    virtual QPolygonF asQPolygonF() const;
 %Docstring
 Returns a QPolygonF representing the points.
 %End

python/core/auto_generated/geometry/qgslinestring.sip.in

@@ -216,6 +216,7 @@ segment in the line.
 
     virtual bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false );
 
+    virtual QPolygonF asQPolygonF() const;
 
     virtual bool fromWkb( QgsConstWkbPtr &wkb );
 

src/core/geometry/qgscurve.h

@@ -164,7 +164,7 @@ class CORE_EXPORT QgsCurve: public QgsAbstractGeometry
     /**
      * Returns a QPolygonF representing the points.
      */
-    QPolygonF asQPolygonF() const;
+    virtual QPolygonF asQPolygonF() const;
 
     /**
      * Returns the straight distance of the curve, i.e. the direct/euclidean distance

src/core/geometry/qgslinestring.cpp

@@ -274,6 +274,21 @@ bool QgsLineString::removeDuplicateNodes( double epsilon, bool useZValues )
   return result;
 }
 
+QPolygonF QgsLineString::asQPolygonF() const
+{
+  const int nb = mX.size();
+  QPolygonF points( nb );
+
+  const double *x = mX.constData();
+  const double *y = mY.constData();
+  QPointF *dest = points.data();
+  for ( int i = 0; i < nb; ++i )
+  {
+    *dest++ = QPointF( *x++, *y++ );
+  }
+  return points;
+}
+
 bool QgsLineString::fromWkb( QgsConstWkbPtr &wkbPtr )
 {
   if ( !wkbPtr )

src/core/geometry/qgslinestring.h

@@ -210,6 +210,7 @@ class CORE_EXPORT QgsLineString: public QgsCurve
     bool isEmpty() const override;
     QgsLineString *snappedToGrid( double hSpacing, double vSpacing, double dSpacing = 0, double mSpacing = 0 ) const override SIP_FACTORY;
     bool removeDuplicateNodes( double epsilon = 4 * DBL_EPSILON, bool useZValues = false ) override;
+    virtual QPolygonF asQPolygonF() const override;
 
     bool fromWkb( QgsConstWkbPtr &wkb ) override;
     bool fromWkt( const QString &wkt ) override;