fix doc and more cleaning

src/analysis/interpolation/NormVecDecorator.h

@@ -39,6 +39,7 @@ class ANALYSIS_EXPORT NormVecDecorator: public TriDecorator
     //! Enumeration for the state of a point. Normal means, that the point is not on a BreakLine, BreakLine means that the point is on a breakline (but not an end point of it) and EndPoint means, that it is an endpoint of a breakline.
     enum PointState {Normal, BreakLine, EndPoint};
     NormVecDecorator();
+    //! Constructor for TriDecorator with an existing triangulation
     NormVecDecorator( QgsTriangulation *tin );
     ~NormVecDecorator() override;
     int addPoint( const QgsPoint &p ) override;

src/analysis/interpolation/TriDecorator.h

@@ -33,6 +33,7 @@ class ANALYSIS_EXPORT TriDecorator : public QgsTriangulation
   public:
     //! Constructor for TriDecorator
     TriDecorator() = default;
+    //! Constructor for TriDecorator with an existing triangulation
     explicit TriDecorator( QgsTriangulation *t );
     void addLine( const QVector< QgsPoint> &points, QgsInterpolator::SourceType lineType ) override;
     int addPoint( const QgsPoint &p ) override;

src/analysis/interpolation/qgsdualedgetriangulation.cpp

@@ -74,7 +74,7 @@ void QgsDualEdgeTriangulation::addLine( const QVector<QgsPoint> &points, QgsInte
   int i = 0;
   for ( const QgsPoint &point : points )
   {
-    actpoint = mDecorator->addPoint( point );
+    actpoint = addPoint( point );
     i++;
     if ( actpoint != -100 )
     {
@@ -89,7 +89,7 @@ void QgsDualEdgeTriangulation::addLine( const QVector<QgsPoint> &points, QgsInte
 
   for ( ; i < points.size(); ++i )
   {
-    currentpoint = mDecorator->addPoint( points.at( i ) );
+    currentpoint = addPoint( points.at( i ) );
     if ( currentpoint != -100 && actpoint != -100 && currentpoint != actpoint )//-100 is the return value if the point could not be not inserted
     {
       insertForcedSegment( actpoint, currentpoint, lineType );
@@ -2102,8 +2102,8 @@ void QgsDualEdgeTriangulation::ruppertRefinement()
     /*******otherwise, try to add the circumcenter to the triangulation************************************************************************************************/
 
     QgsPoint p( 0, 0, 0 );
-    mDecorator->calcPoint( circumcenter.x(), circumcenter.y(), p );
-    int pointno = mDecorator->addPoint( p );
+    calcPoint( circumcenter.x(), circumcenter.y(), p );
+    int pointno = addPoint( p );
 
     if ( pointno == -100 || pointno == mTwiceInsPoint )
     {
@@ -3022,7 +3022,6 @@ QgsMesh QgsDualEdgeTriangulation::triangulationToMesh() const
 {
   QVector<bool> alreadyVisitedEdges( mHalfEdge.count(), false );
 
-  //QSet<HalfEdge *> edgeToTreat = QSet<HalfEdge *>::fromList( mHalfEdge.toList() );
   QVector< bool> edgeToTreat( mHalfEdge.count(), true );
   QHash<HalfEdge *, int > edgesHash;
   for ( int i = 0; i < mHalfEdge.count(); ++i )
@@ -3114,7 +3113,7 @@ int QgsDualEdgeTriangulation::splitHalfEdge( int edge, float position )
 
   //calculate the z-value of the point to insert
   QgsPoint zvaluepoint( 0, 0, 0 );
-  mDecorator->calcPoint( p->x(), p->y(), zvaluepoint );
+  calcPoint( p->x(), p->y(), zvaluepoint );
   p->setZ( zvaluepoint.z() );
 
   //insert p into mPointVector
@@ -3151,7 +3150,7 @@ int QgsDualEdgeTriangulation::splitHalfEdge( int edge, float position )
   checkSwap( mHalfEdge[dualedge]->getNext(), 0 );
   checkSwap( mHalfEdge[edge3]->getNext(), 0 );
 
-  mDecorator->addPoint( QgsPoint( p->x(), p->y(), 0 ) );//dirty hack to enforce update of decorators
+  addPoint( QgsPoint( p->x(), p->y(), 0 ) );//dirty hack to enforce update of decorators
 
   return mPointVector.count() - 1;
 }

src/analysis/interpolation/qgsdualedgetriangulation.h

@@ -43,14 +43,16 @@
  * \ingroup analysis
  * DualEdgeTriangulation is an implementation of a triangulation class based on the dual edge data structure.
  * \note Not available in Python bindings.
+ *
+ * \since QGIS 3.16
 */
 class ANALYSIS_EXPORT QgsDualEdgeTriangulation: public QgsTriangulation
 {
   public:
     QgsDualEdgeTriangulation();
-    QgsDualEdgeTriangulation( int nop, QgsTriangulation *decorator );
+    //! Constructor with a number of points to reserve
+    QgsDualEdgeTriangulation( int nop );
     ~QgsDualEdgeTriangulation() override;
-    void setDecorator( QgsTriangulation *d ) {mDecorator = d;}
     void addLine( const QVector< QgsPoint > &points, QgsInterpolator::SourceType lineType ) override;
     int addPoint( const QgsPoint &p ) override;
     //! Performs a consistency check, remove this later
@@ -116,8 +118,6 @@ class ANALYSIS_EXPORT QgsDualEdgeTriangulation: public QgsTriangulation
     TriangleInterpolator *mTriangleInterpolator = nullptr;
     //! Member to store the behavior in case of crossing forced segments
     QgsTriangulation::ForcedCrossBehavior mForcedCrossBehavior = QgsTriangulation::DeleteFirst;
-    //! Pointer to the decorator using this triangulation. It it is used directly, mDecorator equals this
-    QgsTriangulation *mDecorator = nullptr;
     //! Inserts an edge and makes sure, everything is OK with the storage of the edge. The number of the HalfEdge is returned
     unsigned int insertEdge( int dual, int next, int point, bool mbreak, bool forced );
     //! Inserts a forced segment between the points with the numbers p1 and p2 into the triangulation and returns the number of a HalfEdge belonging to this forced edge or -100 in case of failure
@@ -167,14 +167,12 @@ class ANALYSIS_EXPORT QgsDualEdgeTriangulation: public QgsTriangulation
 #ifndef SIP_RUN
 
 inline QgsDualEdgeTriangulation::QgsDualEdgeTriangulation()
-  : mDecorator( this )
 {
   mPointVector.reserve( DEFAULT_STORAGE_FOR_POINTS );
   mHalfEdge.reserve( DEFAULT_STORAGE_FOR_HALF_EDGES );
 }
 
-inline QgsDualEdgeTriangulation::QgsDualEdgeTriangulation( int nop, QgsTriangulation *decorator )
-  : mDecorator( decorator ? decorator : this )
+inline QgsDualEdgeTriangulation::QgsDualEdgeTriangulation( int nop )
 {
   mPointVector.reserve( nop );
   mHalfEdge.reserve( nop );

src/analysis/interpolation/qgstininterpolator.cpp

@@ -79,7 +79,7 @@ void QgsTinInterpolator::setTriangulationSink( QgsFeatureSink *sink )
 
 void QgsTinInterpolator::initialize()
 {
-  QgsDualEdgeTriangulation *dualEdgeTriangulation = new QgsDualEdgeTriangulation( 100000, nullptr );
+  QgsDualEdgeTriangulation *dualEdgeTriangulation = new QgsDualEdgeTriangulation( 100000 );
   if ( mInterpolation == CloughTocher )
   {
     NormVecDecorator *dec = new NormVecDecorator();

src/analysis/interpolation/qgstriangulation.h

@@ -35,6 +35,8 @@ class QgsFeedback;
  * \ingroup analysis
  * Interface for Triangulation classes.
  * \note Not available in Python bindings.
+ *
+ * \since QGIS 3.16
 */
 class ANALYSIS_EXPORT QgsTriangulation
 {