Optimise storage/calculation of geometry bounding boxes

- removes storage of bounding box from QgsPointV2 (gives significant
decrease in size of object)
- more efficient calculation of bounding box for linestrings

Additionally, this commit moves the bounding box invalidation to a
virtual QgsAbstractGeometryV2::clearCache() method, so that other
non-bounding box caches can also be cleared when the geometry
is modified.

python/core/geometry/qgsabstractgeometryv2.sip

@@ -85,12 +85,7 @@ class QgsAbstractGeometryV2
 
     /** Returns the minimal bounding box for the geometry
      */
-    QgsRectangle boundingBox() const;
-
-    /** Calculates the minimal bounding box for the geometry. Derived classes should override this method
-     * to return the correct bounding box.
-     */
-    virtual QgsRectangle calculateBoundingBox() const;
+    virtual QgsRectangle boundingBox() const = 0;
 
     //mm-sql interface
     /** Returns the inherent dimension of the geometry. For example, this is 0 for a point geometry,
@@ -373,4 +368,13 @@ class QgsAbstractGeometryV2
     /** Updates the geometry type based on whether sub geometries contain z or m values.
      */
     void setZMTypeFromSubGeometry( const QgsAbstractGeometryV2* subggeom, QgsWKBTypes::Type baseGeomType );
+
+    /** Default calculator for the minimal bounding box for the geometry. Derived classes should override this method
+     * if a more efficient bounding box calculation is available.
+     */
+    virtual QgsRectangle calculateBoundingBox() const;
+
+    /** Clears any cached parameters associated with the geometry, eg bounding boxes
+     */
+    virtual void clearCache() const;
 };

python/core/geometry/qgscircularstringv2.sip

@@ -16,8 +16,6 @@ class QgsCircularStringV2: public QgsCurveV2
     virtual QgsCircularStringV2* clone() const;
     virtual void clear();
 
-    virtual QgsRectangle calculateBoundingBox() const;
-
     virtual bool fromWkb( QgsConstWkbPtr wkb );
     virtual bool fromWkt( const QString& wkt );
 
@@ -109,6 +107,10 @@ class QgsCircularStringV2: public QgsCurveV2
     virtual bool dropZValue();
     virtual bool dropMValue();
 
+  protected:
+
+    virtual QgsRectangle calculateBoundingBox() const;
+
   private:
     //helper methods for curveToLine
     void segmentize( const QgsPointV2& p1, const QgsPointV2& p2, const QgsPointV2& p3, QList<QgsPointV2>& points ) const;

python/core/geometry/qgscompoundcurvev2.sip

@@ -18,8 +18,6 @@ class QgsCompoundCurveV2: public QgsCurveV2
     virtual QgsCompoundCurveV2* clone() const;
     virtual void clear();
 
-    virtual QgsRectangle calculateBoundingBox() const;
-
     virtual bool fromWkb( QgsConstWkbPtr wkb );
     virtual bool fromWkt( const QString& wkt );
 
@@ -96,4 +94,8 @@ class QgsCompoundCurveV2: public QgsCurveV2
     virtual bool dropZValue();
     virtual bool dropMValue();
 
+  protected:
+
+    virtual QgsRectangle calculateBoundingBox() const;
+
 };

python/core/geometry/qgscurvepolygonv2.sip

@@ -15,8 +15,6 @@ class QgsCurvePolygonV2: public QgsSurfaceV2
     virtual QgsCurvePolygonV2* clone() const;
     void clear();
 
-
-    virtual QgsRectangle calculateBoundingBox() const;
     virtual bool fromWkb( QgsConstWkbPtr wkb );
     virtual bool fromWkt( const QString& wkt );
 
@@ -88,4 +86,8 @@ class QgsCurvePolygonV2: public QgsSurfaceV2
     virtual bool addMValue( double mValue = 0 );
     virtual bool dropZValue();
     virtual bool dropMValue();
+
+  protected:
+
+    virtual QgsRectangle calculateBoundingBox() const;
 };

python/core/geometry/qgscurvev2.sip

@@ -81,6 +81,8 @@ class QgsCurveV2: public QgsAbstractGeometryV2
     virtual int partCount() const;
     virtual QgsPointV2 vertexAt( QgsVertexId id ) const;
 
+    virtual QgsRectangle boundingBox() const;
+
     /** Drops any Z dimensions which exist in the geometry.
      * @returns true if Z values were present and have been removed
      * @see dropMValue()
@@ -94,4 +96,9 @@ class QgsCurveV2: public QgsAbstractGeometryV2
      * @note added in QGIS 2.14
      */
     virtual bool dropMValue() = 0;
+
+  protected:
+
+    virtual void clearCache() const;
+
 };

python/core/geometry/qgsgeometrycollectionv2.sip

@@ -66,7 +66,7 @@ class QgsGeometryCollectionV2: public QgsAbstractGeometryV2
     QDomElement asGML3( QDomDocument& doc, int precision = 17, const QString& ns = "gml" ) const;
     QString asJSON( int precision = 17 ) const;
 
-    virtual QgsRectangle calculateBoundingBox() const;
+    virtual QgsRectangle boundingBox() const;
 
     virtual void coordinateSequence( QList< QList< QList< QgsPointV2 > > >& coord /Out/ ) const;
     virtual double closestSegment( const QgsPointV2& pt, QgsPointV2& segmentPt,  QgsVertexId& vertexAfter, bool* leftOf, double epsilon ) const;
@@ -113,4 +113,7 @@ class QgsGeometryCollectionV2: public QgsAbstractGeometryV2
      */
     bool fromCollectionWkt( const QString &wkt, const QList<QgsAbstractGeometryV2*>& subtypes, const QString& defaultChildWkbType = QString() );
 
+    virtual QgsRectangle calculateBoundingBox() const;
+    virtual void clearCache() const;
+
 };

python/core/geometry/qgslinestringv2.sip

@@ -162,4 +162,8 @@ class QgsLineStringV2: public QgsCurveV2
 
     virtual bool convertTo( QgsWKBTypes::Type type );
 
+  protected:
+
+    virtual QgsRectangle calculateBoundingBox() const;
+
 };

python/core/geometry/qgspointv2.sip

@@ -139,6 +139,7 @@ class QgsPointV2: public QgsAbstractGeometryV2
     QPointF toQPointF() const;
 
     //implementation of inherited methods
+    virtual QgsRectangle boundingBox() const;
     virtual QString geometryType() const;
     virtual int dimension() const;
     virtual QgsPointV2* clone() const /Factory/;
@@ -151,7 +152,6 @@ class QgsPointV2: public QgsAbstractGeometryV2
     QDomElement asGML2( QDomDocument& doc, int precision = 17, const QString& ns = "gml" ) const;
     QDomElement asGML3( QDomDocument& doc, int precision = 17, const QString& ns = "gml" ) const;
     QString asJSON( int precision = 17 ) const;
-    virtual QgsRectangle calculateBoundingBox() const;
     void draw( QPainter& p ) const;
     void transform( const QgsCoordinateTransform& ct, QgsCoordinateTransform::TransformDirection d = QgsCoordinateTransform::ForwardTransform );
     void transform( const QTransform& t );

python/core/geometry/qgssurfacev2.sip

@@ -7,4 +7,11 @@ class QgsSurfaceV2: public QgsAbstractGeometryV2
   public:
 
     virtual QgsPolygonV2* surfaceToPolygon() const = 0;
+
+    virtual QgsRectangle boundingBox() const;
+
+  protected:
+
+    virtual void clearCache() const;
+
 };

src/core/geometry/qgsabstractgeometryv2.cpp

@@ -45,15 +45,6 @@ QgsAbstractGeometryV2& QgsAbstractGeometryV2::operator=( const QgsAbstractGeomet
   return *this;
 }
 
-QgsRectangle QgsAbstractGeometryV2::boundingBox() const
-{
-  if ( mBoundingBox.isNull() )
-  {
-    mBoundingBox = calculateBoundingBox();
-  }
-  return mBoundingBox;
-}
-
 bool QgsAbstractGeometryV2::is3D() const
 {
   return QgsWKBTypes::hasZ( mWkbType );

src/core/geometry/qgsabstractgeometryv2.h

@@ -56,12 +56,7 @@ class CORE_EXPORT QgsAbstractGeometryV2
 
     /** Returns the minimal bounding box for the geometry
      */
-    QgsRectangle boundingBox() const;
-
-    /** Calculates the minimal bounding box for the geometry. Derived classes should override this method
-     * to return the correct bounding box.
-     */
-    virtual QgsRectangle calculateBoundingBox() const;
+    virtual QgsRectangle boundingBox() const = 0;
 
     //mm-sql interface
     /** Returns the inherent dimension of the geometry. For example, this is 0 for a point geometry,
@@ -353,11 +348,20 @@ class CORE_EXPORT QgsAbstractGeometryV2
 
   protected:
     QgsWKBTypes::Type mWkbType;
-    mutable QgsRectangle mBoundingBox;
 
     /** Updates the geometry type based on whether sub geometries contain z or m values.
      */
     void setZMTypeFromSubGeometry( const QgsAbstractGeometryV2* subggeom, QgsWKBTypes::Type baseGeomType );
+
+    /** Default calculator for the minimal bounding box for the geometry. Derived classes should override this method
+     * if a more efficient bounding box calculation is available.
+     */
+    virtual QgsRectangle calculateBoundingBox() const;
+
+    /** Clears any cached parameters associated with the geometry, eg bounding boxes
+     */
+    virtual void clearCache() const {}
+
 };
 
 

src/core/geometry/qgscircularstringv2.cpp

@@ -723,7 +723,7 @@ bool QgsCircularStringV2::insertVertex( QgsVertexId position, const QgsPointV2&
   {
     insertVertexBetween( position.vertex, position.vertex + 1, position.vertex - 1 );
   }
-  mBoundingBox = QgsRectangle(); //set bounding box invalid
+  clearCache(); //set bounding box invalid
   return true;
 }
 
@@ -744,7 +744,7 @@ bool QgsCircularStringV2::moveVertex( QgsVertexId position, const QgsPointV2& ne
   {
     mM[position.vertex] = newPos.m();
   }
-  mBoundingBox = QgsRectangle(); //set bounding box invalid
+  clearCache(); //set bounding box invalid
   return true;
 }
 
@@ -772,7 +772,7 @@ bool QgsCircularStringV2::deleteVertex( QgsVertexId position )
     deleteVertex( position.vertex - 1 );
   }
 
-  mBoundingBox = QgsRectangle(); //set bounding box invalid
+  clearCache(); //set bounding box invalid
   return true;
 }
 

src/core/geometry/qgscircularstringv2.h

@@ -41,8 +41,6 @@ class CORE_EXPORT QgsCircularStringV2: public QgsCurveV2
     virtual QgsCircularStringV2* clone() const override;
     virtual void clear() override;
 
-    virtual QgsRectangle calculateBoundingBox() const override;
-
     virtual bool fromWkb( QgsConstWkbPtr wkb ) override;
     virtual bool fromWkt( const QString& wkt ) override;
 
@@ -134,6 +132,10 @@ class CORE_EXPORT QgsCircularStringV2: public QgsCurveV2
     virtual bool dropZValue() override;
     virtual bool dropMValue() override;
 
+  protected:
+
+    virtual QgsRectangle calculateBoundingBox() const override;
+
   private:
     QVector<double> mX;
     QVector<double> mY;
@@ -152,6 +154,7 @@ class CORE_EXPORT QgsCircularStringV2: public QgsCurveV2
                                      const QgsPointV2& pt, QgsPointV2& segmentPt,  QgsVertexId& vertexAfter, bool* leftOf, double epsilon );
     void insertVertexBetween( int after, int before, int pointOnCircle );
     void deleteVertex( int i );
+
 };
 
 #endif // QGSCIRCULARSTRING_H

src/core/geometry/qgscompoundcurvev2.cpp

@@ -89,10 +89,10 @@ QgsRectangle QgsCompoundCurveV2::calculateBoundingBox() const
     return QgsRectangle();
   }
 
-  QgsRectangle bbox = mCurves.at( 0 )->calculateBoundingBox();
+  QgsRectangle bbox = mCurves.at( 0 )->boundingBox();
   for ( int i = 1; i < mCurves.size(); ++i )
   {
-    QgsRectangle curveBox = mCurves.at( i )->calculateBoundingBox();
+    QgsRectangle curveBox = mCurves.at( i )->boundingBox();
     bbox.combineExtentWith( &curveBox );
   }
   return bbox;
@@ -497,7 +497,7 @@ bool QgsCompoundCurveV2::insertVertex( QgsVertexId position, const QgsPointV2& v
   bool success = mCurves.at( curveId )->insertVertex( curveIds.at( 0 ).second, vertex );
   if ( success )
   {
-    mBoundingBox = QgsRectangle(); //bbox changed
+    clearCache(); //bbox changed
   }
   return success;
 }
@@ -514,7 +514,7 @@ bool QgsCompoundCurveV2::moveVertex( QgsVertexId position, const QgsPointV2& new
   bool success = !curveIds.isEmpty();
   if ( success )
   {
-    mBoundingBox = QgsRectangle(); //bbox changed
+    clearCache(); //bbox changed
   }
   return success;
 }
@@ -531,7 +531,7 @@ bool QgsCompoundCurveV2::deleteVertex( QgsVertexId position )
   bool success = !curveIds.isEmpty();
   if ( success )
   {
-    mBoundingBox = QgsRectangle(); //bbox changed
+    clearCache(); //bbox changed
   }
   return success;
 }

src/core/geometry/qgscompoundcurvev2.h

@@ -42,8 +42,6 @@ class CORE_EXPORT QgsCompoundCurveV2: public QgsCurveV2
     virtual QgsCompoundCurveV2* clone() const override;
     virtual void clear() override;
 
-    virtual QgsRectangle calculateBoundingBox() const override;
-
     virtual bool fromWkb( QgsConstWkbPtr wkb ) override;
     virtual bool fromWkt( const QString& wkt ) override;
 
@@ -120,11 +118,16 @@ class CORE_EXPORT QgsCompoundCurveV2: public QgsCurveV2
     virtual bool dropZValue() override;
     virtual bool dropMValue() override;
 
+  protected:
+
+    virtual QgsRectangle calculateBoundingBox() const override;
+
   private:
     QList< QgsCurveV2* > mCurves;
     /** Turns a vertex id for the compound curve into one or more ids for the subcurves
         @return the index of the subcurve or -1 in case of error*/
     QList< QPair<int, QgsVertexId> > curveVertexId( QgsVertexId id ) const;
+
 };
 
 #endif // QGSCOMPOUNDCURVEV2_H

src/core/geometry/qgscurvepolygonv2.cpp

@@ -209,7 +209,7 @@ QgsRectangle QgsCurvePolygonV2::calculateBoundingBox() const
 {
   if ( mExteriorRing )
   {
-    return mExteriorRing->calculateBoundingBox();
+    return mExteriorRing->boundingBox();
   }
   return QgsRectangle();
 }
@@ -666,7 +666,7 @@ bool QgsCurvePolygonV2::insertVertex( QgsVertexId vId, const QgsPointV2& vertex
   else if ( vId.vertex == n )
     ring->moveVertex( QgsVertexId( 0, 0, 0 ), vertex );
 
-  mBoundingBox = QgsRectangle();
+  clearCache();
   return true;
 }
 
@@ -687,7 +687,7 @@ bool QgsCurvePolygonV2::moveVertex( QgsVertexId vId, const QgsPointV2& newPos )
       ring->moveVertex( QgsVertexId( vId.part, vId.ring, n - 1 ), newPos );
     else if ( vId.vertex == n - 1 )
       ring->moveVertex( QgsVertexId( vId.part, vId.ring, 0 ), newPos );
-    mBoundingBox = QgsRectangle();
+    clearCache();
   }
   return success;
 }
@@ -717,7 +717,7 @@ bool QgsCurvePolygonV2::deleteVertex( QgsVertexId vId )
     {
       removeInteriorRing( vId.ring - 1 );
     }
-    mBoundingBox = QgsRectangle();
+    clearCache();
     return true;
   }
 
@@ -729,7 +729,7 @@ bool QgsCurvePolygonV2::deleteVertex( QgsVertexId vId )
       ring->moveVertex( QgsVertexId( 0, 0, n - 2 ), ring->vertexAt( QgsVertexId( 0, 0, 0 ) ) );
     else if ( vId.vertex == n - 1 )
       ring->moveVertex( QgsVertexId( 0, 0, 0 ), ring->vertexAt( QgsVertexId( 0, 0, n - 2 ) ) );
-    mBoundingBox = QgsRectangle();
+    clearCache();
   }
   return success;
 }

src/core/geometry/qgscurvepolygonv2.h

@@ -41,8 +41,6 @@ class CORE_EXPORT QgsCurvePolygonV2: public QgsSurfaceV2
     virtual QgsCurvePolygonV2* clone() const override;
     void clear() override;
 
-
-    virtual QgsRectangle calculateBoundingBox() const override;
     virtual bool fromWkb( QgsConstWkbPtr wkb ) override;
     virtual bool fromWkt( const QString& wkt ) override;
 
@@ -120,6 +118,7 @@ class CORE_EXPORT QgsCurvePolygonV2: public QgsSurfaceV2
     QgsCurveV2* mExteriorRing;
     QList<QgsCurveV2*> mInteriorRings;
 
+    virtual QgsRectangle calculateBoundingBox() const override;
 };
 
 #endif // QGSCURVEPOLYGONV2_H