0029506: DRAW command "incmesh" hangs on the attached planar face with specified deflection.

Added test case

src/BRepMesh/BRepMesh_Context.cxx

@@ -20,7 +20,9 @@
 #include <BRepMesh_FaceDiscret.hxx>
 #include <BRepMesh_ModelPreProcessor.hxx>
 #include <BRepMesh_ModelPostProcessor.hxx>
+
 #include <BRepMesh_MeshAlgoFactory.hxx>
+#include <BRepMesh_DelabellaMeshAlgoFactory.hxx>
 
 //=======================================================================
 // Function: Constructor
@@ -28,11 +30,33 @@
 //=======================================================================
 BRepMesh_Context::BRepMesh_Context ()
 {
+  enum MeshAlgo
+  {
+    MeshAlgo_Default   = 0x0,
+    MeshAlgo_Delabella = 0x1
+  };
+
+  char* anAlgoVar;
+  anAlgoVar = getenv ("CSF_MeshAlgo");
+  const Standard_Integer anAlgoId = (anAlgoVar ? atoi (anAlgoVar) : MeshAlgo_Default);
+
+  Handle (IMeshTools_MeshAlgoFactory) aAlgoFactory;
+  switch (anAlgoId)
+  {
+  case MeshAlgo_Delabella:
+    aAlgoFactory = new BRepMesh_DelabellaMeshAlgoFactory;
+    break;
+
+  default:
+    aAlgoFactory = new BRepMesh_MeshAlgoFactory;
+    break;
+  }
+
   SetModelBuilder (new BRepMesh_ModelBuilder);
   SetEdgeDiscret  (new BRepMesh_EdgeDiscret);
   SetModelHealer  (new BRepMesh_ModelHealer);
   SetPreProcessor (new BRepMesh_ModelPreProcessor);
-  SetFaceDiscret  (new BRepMesh_FaceDiscret(new BRepMesh_MeshAlgoFactory));
+  SetFaceDiscret  (new BRepMesh_FaceDiscret (aAlgoFactory));
   SetPostProcessor(new BRepMesh_ModelPostProcessor);
 }
 

src/BRepMesh/BRepMesh_CustomBaseMeshAlgo.hxx

@@ -49,12 +49,35 @@ protected:
   Standard_EXPORT virtual void generateMesh () Standard_OVERRIDE
   {
     const Handle (BRepMesh_DataStructureOfDelaun)& aStructure = this->getStructure ();
+    const Standard_Integer aNodesNb = aStructure->NbNodes ();
+
     buildBaseTriangulation ();
 
     std::pair<Standard_Integer, Standard_Integer> aCellsCount = this->getCellsCount (aStructure->NbNodes ());
     BRepMesh_Delaun aMesher (aStructure, aCellsCount.first, aCellsCount.second, Standard_False);
+
+    const Standard_Integer aNewNodesNb = aStructure->NbNodes ();
+    const Standard_Boolean isRemoveAux = aNewNodesNb > aNodesNb;
+    if (isRemoveAux)
+    {
+      IMeshData::VectorOfInteger aAuxVertices (aNewNodesNb - aNodesNb);
+      for (Standard_Integer aExtNodesIt = aNodesNb + 1; aExtNodesIt <= aNewNodesNb; ++aExtNodesIt)
+      {
+        aAuxVertices.Append (aExtNodesIt);
+      }
+
+      // Set aux vertices if there are some to clean up mesh correctly.
+      aMesher.SetAuxVertices (aAuxVertices);
+    }
+
     aMesher.ProcessConstraints ();
 
+    // Destruction of triangles containing aux vertices added (possibly) during base mesh computation.
+    if (isRemoveAux)
+    {
+      aMesher.RemoveAuxElements ();
+    }
+
     BRepMesh_MeshTool aCleaner (aStructure);
     aCleaner.EraseFreeLinks ();
 

src/BRepMesh/BRepMesh_DelabellaBaseMeshAlgo.cxx

@@ -0,0 +1,155 @@
+// Created on: 2019-07-05
+// Copyright (c) 2019 OPEN CASCADE SAS
+// Created by: Oleg AGASHIN
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#include <BRepMesh_DelabellaBaseMeshAlgo.hxx>
+#include <BRepMesh_MeshTool.hxx>
+#include <BRepMesh_Delaun.hxx>
+
+#include "delabella.h"
+
+//=======================================================================
+// Function: Constructor
+// Purpose : 
+//=======================================================================
+BRepMesh_DelabellaBaseMeshAlgo::BRepMesh_DelabellaBaseMeshAlgo ()
+{
+}
+
+//=======================================================================
+// Function: Destructor
+// Purpose : 
+//=======================================================================
+BRepMesh_DelabellaBaseMeshAlgo::~BRepMesh_DelabellaBaseMeshAlgo ()
+{
+}
+
+//=======================================================================
+//function : buildBaseTriangulation
+//purpose  :
+//=======================================================================
+void BRepMesh_DelabellaBaseMeshAlgo::buildBaseTriangulation()
+{
+  const Handle(BRepMesh_DataStructureOfDelaun)& aStructure = this->getStructure();
+
+  Bnd_B2d aBox;
+  const Standard_Integer aNodesNb = aStructure->NbNodes ();
+  std::vector<Standard_Real> aPoints (2 * (aNodesNb + 4));
+  for (Standard_Integer aNodeIt = 0; aNodeIt < aNodesNb; ++aNodeIt)
+  {
+    const BRepMesh_Vertex& aVertex = aStructure->GetNode (aNodeIt + 1);
+
+    const size_t aBaseIdx = 2 * static_cast<size_t> (aNodeIt);
+    aPoints[aBaseIdx + 0] = aVertex.Coord ().X ();
+    aPoints[aBaseIdx + 1] = aVertex.Coord ().Y ();
+
+    aBox.Add (gp_Pnt2d(aVertex.Coord ()));
+  }
+
+  aBox.Enlarge (0.1 * (aBox.CornerMax () - aBox.CornerMin ()).Modulus ());
+  const gp_XY aMin = aBox.CornerMin ();
+  const gp_XY aMax = aBox.CornerMax ();
+
+  aPoints[2 * aNodesNb + 0] = aMin.X ();
+  aPoints[2 * aNodesNb + 1] = aMin.Y ();
+  aStructure->AddNode (BRepMesh_Vertex (
+    aPoints[2 * aNodesNb + 0],
+    aPoints[2 * aNodesNb + 1], BRepMesh_Free));
+
+  aPoints[2 * aNodesNb + 2] = aMax.X ();
+  aPoints[2 * aNodesNb + 3] = aMin.Y ();
+  aStructure->AddNode (BRepMesh_Vertex (
+    aPoints[2 * aNodesNb + 2],
+    aPoints[2 * aNodesNb + 3], BRepMesh_Free));
+
+  aPoints[2 * aNodesNb + 4] = aMax.X ();
+  aPoints[2 * aNodesNb + 5] = aMax.Y ();
+  aStructure->AddNode (BRepMesh_Vertex (
+    aPoints[2 * aNodesNb + 4],
+    aPoints[2 * aNodesNb + 5], BRepMesh_Free));
+
+  aPoints[2 * aNodesNb + 6] = aMin.X ();
+  aPoints[2 * aNodesNb + 7] = aMax.Y ();
+  aStructure->AddNode (BRepMesh_Vertex (
+    aPoints[2 * aNodesNb + 6],
+    aPoints[2 * aNodesNb + 7], BRepMesh_Free));
+
+  const Standard_Real aDiffX = (aMax.X () - aMin.X ());
+  const Standard_Real aDiffY = (aMax.Y () - aMin.Y ());
+  for (size_t i = 0; i < aPoints.size(); i += 2)
+  {
+    aPoints[i + 0] = (aPoints[i + 0] - aMin.X ()) / aDiffX - 0.5;
+    aPoints[i + 1] = (aPoints[i + 1] - aMin.Y ()) / aDiffY - 0.5;
+  }
+
+  IDelaBella* aTriangulator = IDelaBella::Create();
+  try
+  {
+    if (aTriangulator != NULL)
+    {
+      const int aVerticesNb = aTriangulator->Triangulate (
+        static_cast<int>(aPoints.size () / 2),
+        &aPoints[0], &aPoints[1], 2 * sizeof (Standard_Real));
+
+      if (aVerticesNb > 0)
+      {
+        const DelaBella_Triangle* aTrianglePtr = aTriangulator->GetFirstDelaunayTriangle();
+        while (aTrianglePtr != NULL)
+        {
+          Standard_Integer aNodes[3] = {
+            aTrianglePtr->v[0]->i + 1,
+            aTrianglePtr->v[2]->i + 1,
+            aTrianglePtr->v[1]->i + 1
+          };
+
+          Standard_Integer aEdges       [3];
+          Standard_Boolean aOrientations[3];
+          for (Standard_Integer k = 0; k < 3; ++k)
+          {
+            const BRepMesh_Edge aLink (aNodes[k], aNodes[(k + 1) % 3], BRepMesh_Free);
+
+            const Standard_Integer aLinkInfo = aStructure->AddLink (aLink);
+            aEdges       [k] = Abs (aLinkInfo);
+            aOrientations[k] = aLinkInfo > 0;
+          }
+
+          const BRepMesh_Triangle aTriangle (aEdges, aOrientations, BRepMesh_Free);
+          aStructure->AddElement (aTriangle);
+
+          aTrianglePtr = aTrianglePtr->next;
+        }
+      }
+
+      aTriangulator->Destroy ();
+    }
+  }
+  catch (Standard_Failure const& theException)
+  {
+    if (aTriangulator != NULL)
+    {
+      aTriangulator->Destroy ();
+    }
+
+    throw Standard_Failure (theException);
+  }
+  catch (...)
+  {
+    if (aTriangulator != NULL)
+    {
+      aTriangulator->Destroy ();
+    }
+
+    throw Standard_Failure ("BRepMesh_DelabellaBaseMeshAlgo::buildBaseTriangulation: exception in triangulation algorithm");
+  }
+}

src/BRepMesh/BRepMesh_DelabellaBaseMeshAlgo.hxx

@@ -0,0 +1,46 @@
+// Created on: 2019-07-05
+// Copyright (c) 2019 OPEN CASCADE SAS
+// Created by: Oleg AGASHIN
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _BRepMesh_DelabellaBaseMeshAlgo_HeaderFile
+#define _BRepMesh_DelabellaBaseMeshAlgo_HeaderFile
+
+#include <BRepMesh_CustomBaseMeshAlgo.hxx>
+#include <NCollection_Shared.hxx>
+#include <IMeshTools_Parameters.hxx>
+
+class BRepMesh_DataStructureOfDelaun;
+class BRepMesh_Delaun;
+
+//! Class provides base fuctionality to build face triangulation using Delabella project.
+//! Performs generation of mesh using raw data from model.
+class BRepMesh_DelabellaBaseMeshAlgo : public BRepMesh_CustomBaseMeshAlgo
+{
+public:
+
+  //! Constructor.
+  Standard_EXPORT BRepMesh_DelabellaBaseMeshAlgo ();
+
+  //! Destructor.
+  Standard_EXPORT virtual ~BRepMesh_DelabellaBaseMeshAlgo ();
+
+  DEFINE_STANDARD_RTTI_INLINE(BRepMesh_DelabellaBaseMeshAlgo, BRepMesh_CustomBaseMeshAlgo)
+
+protected:
+
+  //! Builds base triangulation using Delabella project.
+  Standard_EXPORT virtual void buildBaseTriangulation() Standard_OVERRIDE;
+};
+
+#endif

src/BRepMesh/BRepMesh_DelabellaMeshAlgoFactory.cxx

@@ -0,0 +1,143 @@
+// Created on: 2019-07-05
+// Copyright (c) 2019 OPEN CASCADE SAS
+// Created by: Oleg AGASHIN
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#include <BRepMesh_DelabellaMeshAlgoFactory.hxx>
+#include <BRepMesh_DefaultRangeSplitter.hxx>
+#include <BRepMesh_NURBSRangeSplitter.hxx>
+#include <BRepMesh_SphereRangeSplitter.hxx>
+#include <BRepMesh_CylinderRangeSplitter.hxx>
+#include <BRepMesh_ConeRangeSplitter.hxx>
+#include <BRepMesh_TorusRangeSplitter.hxx>
+#include <BRepMesh_DelaunayBaseMeshAlgo.hxx>
+#include <BRepMesh_DelabellaBaseMeshAlgo.hxx>
+#include <BRepMesh_CustomDelaunayBaseMeshAlgo.hxx>
+#include <BRepMesh_DelaunayNodeInsertionMeshAlgo.hxx>
+#include <BRepMesh_DelaunayDeflectionControlMeshAlgo.hxx>
+#include <BRepMesh_BoundaryParamsRangeSplitter.hxx>
+
+namespace
+{
+  struct DefaultBaseMeshAlgo
+  {
+    typedef BRepMesh_DelaunayBaseMeshAlgo Type;
+  };
+
+  template<class RangeSplitter>
+  struct DefaultNodeInsertionMeshAlgo
+  {
+    typedef BRepMesh_DelaunayNodeInsertionMeshAlgo<RangeSplitter, BRepMesh_DelaunayBaseMeshAlgo> Type;
+  };
+
+  struct BaseMeshAlgo
+  {
+    typedef BRepMesh_DelabellaBaseMeshAlgo Type;
+  };
+
+  template<class RangeSplitter>
+  struct NodeInsertionMeshAlgo
+  {
+    typedef BRepMesh_DelaunayNodeInsertionMeshAlgo<RangeSplitter, BRepMesh_CustomDelaunayBaseMeshAlgo<BRepMesh_DelabellaBaseMeshAlgo> > Type;
+  };
+
+  template<class RangeSplitter>
+  struct DeflectionControlMeshAlgo
+  {
+    typedef BRepMesh_DelaunayDeflectionControlMeshAlgo<RangeSplitter, BRepMesh_CustomDelaunayBaseMeshAlgo<BRepMesh_DelabellaBaseMeshAlgo> > Type;
+  };
+}
+
+//=======================================================================
+// Function: Constructor
+// Purpose : 
+//=======================================================================
+BRepMesh_DelabellaMeshAlgoFactory::BRepMesh_DelabellaMeshAlgoFactory ()
+{
+}
+
+//=======================================================================
+// Function: Destructor
+// Purpose : 
+//=======================================================================
+BRepMesh_DelabellaMeshAlgoFactory::~BRepMesh_DelabellaMeshAlgoFactory ()
+{
+}
+
+//=======================================================================
+// Function: GetAlgo
+// Purpose : 
+//=======================================================================
+Handle(IMeshTools_MeshAlgo) BRepMesh_DelabellaMeshAlgoFactory::GetAlgo(
+  const GeomAbs_SurfaceType    theSurfaceType,
+  const IMeshTools_Parameters& theParameters) const
+{
+  switch (theSurfaceType)
+  {
+  case GeomAbs_Plane:
+    return theParameters.InternalVerticesMode ?
+      new NodeInsertionMeshAlgo<BRepMesh_DefaultRangeSplitter>::Type :
+      new BaseMeshAlgo::Type;
+    break;
+
+  case GeomAbs_Sphere:
+    {
+      NodeInsertionMeshAlgo<BRepMesh_SphereRangeSplitter>::Type* aMeshAlgo =
+        new NodeInsertionMeshAlgo<BRepMesh_SphereRangeSplitter>::Type;
+      aMeshAlgo->SetPreProcessSurfaceNodes (Standard_True);
+      return aMeshAlgo;
+    }
+    break;
+
+  case GeomAbs_Cylinder:
+    return theParameters.InternalVerticesMode ?
+      new DefaultNodeInsertionMeshAlgo<BRepMesh_CylinderRangeSplitter>::Type :
+      new DefaultBaseMeshAlgo::Type;
+    break;
+
+  case GeomAbs_Cone:
+    {
+      NodeInsertionMeshAlgo<BRepMesh_ConeRangeSplitter>::Type* aMeshAlgo =
+        new NodeInsertionMeshAlgo<BRepMesh_ConeRangeSplitter>::Type;
+      aMeshAlgo->SetPreProcessSurfaceNodes (Standard_True);
+      return aMeshAlgo;
+    }
+    break;
+
+  case GeomAbs_Torus:
+    {
+      NodeInsertionMeshAlgo<BRepMesh_TorusRangeSplitter>::Type* aMeshAlgo =
+        new NodeInsertionMeshAlgo<BRepMesh_TorusRangeSplitter>::Type;
+      aMeshAlgo->SetPreProcessSurfaceNodes (Standard_True);
+      return aMeshAlgo;
+    }
+    break;
+
+  case GeomAbs_SurfaceOfRevolution:
+    {
+      DeflectionControlMeshAlgo<BRepMesh_BoundaryParamsRangeSplitter>::Type* aMeshAlgo =
+        new DeflectionControlMeshAlgo<BRepMesh_BoundaryParamsRangeSplitter>::Type;
+      aMeshAlgo->SetPreProcessSurfaceNodes (Standard_True);
+      return aMeshAlgo;
+    }
+    break;
+
+  default:
+    {
+      DeflectionControlMeshAlgo<BRepMesh_NURBSRangeSplitter>::Type* aMeshAlgo =
+        new DeflectionControlMeshAlgo<BRepMesh_NURBSRangeSplitter>::Type;
+      aMeshAlgo->SetPreProcessSurfaceNodes (Standard_True);
+      return aMeshAlgo;
+    }
+  }
+}

src/BRepMesh/BRepMesh_DelabellaMeshAlgoFactory.hxx

@@ -0,0 +1,44 @@
+// Created on: 2019-07-05
+// Copyright (c) 2019 OPEN CASCADE SAS
+// Created by: Oleg AGASHIN
+//
+// This file is part of Open CASCADE Technology software library.
+//
+// This library is free software; you can redistribute it and/or modify it under
+// the terms of the GNU Lesser General Public License version 2.1 as published
+// by the Free Software Foundation, with special exception defined in the file
+// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
+// distribution for complete text of the license and disclaimer of any warranty.
+//
+// Alternatively, this file may be used under the terms of Open CASCADE
+// commercial license or contractual agreement.
+
+#ifndef _BRepMesh_DelabellaMeshAlgoFactory_HeaderFile
+#define _BRepMesh_DelabellaMeshAlgoFactory_HeaderFile
+
+#include <Standard_Transient.hxx>
+#include <Standard_Type.hxx>
+#include <GeomAbs_SurfaceType.hxx>
+#include <IMeshTools_MeshAlgoFactory.hxx>
+
+//! Implementation of IMeshTools_MeshAlgoFactory providing Delabella-based
+//! algorithms of different compexity depending on type of target surface.
+class BRepMesh_DelabellaMeshAlgoFactory : public IMeshTools_MeshAlgoFactory
+{
+public:
+
+  //! Constructor.
+  Standard_EXPORT BRepMesh_DelabellaMeshAlgoFactory ();
+
+  //! Destructor.
+  Standard_EXPORT virtual ~BRepMesh_DelabellaMeshAlgoFactory ();
+
+  //! Creates instance of meshing algorithm for the given type of surface.
+  Standard_EXPORT virtual Handle(IMeshTools_MeshAlgo) GetAlgo(
+    const GeomAbs_SurfaceType    theSurfaceType,
+    const IMeshTools_Parameters& theParameters) const Standard_OVERRIDE;
+
+  DEFINE_STANDARD_RTTI_INLINE(BRepMesh_DelabellaMeshAlgoFactory, IMeshTools_MeshAlgoFactory)
+};
+
+#endif

src/BRepMesh/BRepMesh_Delaun.cxx

@@ -89,7 +89,8 @@ BRepMesh_Delaun::BRepMesh_Delaun (
   const Standard_Boolean                        isFillCircles)
 : myMeshData ( theOldMesh ),
   myCircles (new NCollection_IncAllocator(
-             IMeshData::MEMORY_BLOCK_SIZE_HUGE))
+             IMeshData::MEMORY_BLOCK_SIZE_HUGE)),
+  mySupVert (3)
 {
   if (isFillCircles)
   {
@@ -103,7 +104,8 @@ BRepMesh_Delaun::BRepMesh_Delaun (
 //=======================================================================
 BRepMesh_Delaun::BRepMesh_Delaun(IMeshData::Array1OfVertexOfDelaun& theVertices)
 : myCircles (theVertices.Length(), new NCollection_IncAllocator(
-             IMeshData::MEMORY_BLOCK_SIZE_HUGE))
+             IMeshData::MEMORY_BLOCK_SIZE_HUGE)),
+  mySupVert (3)
 {
   if ( theVertices.Length() > 2 )
   {
@@ -123,7 +125,8 @@ BRepMesh_Delaun::BRepMesh_Delaun(
   IMeshData::Array1OfVertexOfDelaun&            theVertices)
 : myMeshData( theOldMesh ),
   myCircles ( theVertices.Length(), new NCollection_IncAllocator(
-             IMeshData::MEMORY_BLOCK_SIZE_HUGE))
+             IMeshData::MEMORY_BLOCK_SIZE_HUGE)),
+  mySupVert (3)
 {
   if ( theVertices.Length() > 2 )
   {
@@ -140,7 +143,8 @@ BRepMesh_Delaun::BRepMesh_Delaun(
   IMeshData::VectorOfInteger&                   theVertexIndices)
 : myMeshData( theOldMesh ),
   myCircles ( theVertexIndices.Length(), new NCollection_IncAllocator(
-             IMeshData::MEMORY_BLOCK_SIZE_HUGE))
+             IMeshData::MEMORY_BLOCK_SIZE_HUGE)),
+  mySupVert (3)
 {
   perform(theVertexIndices);
 }
@@ -155,7 +159,8 @@ BRepMesh_Delaun::BRepMesh_Delaun (const Handle (BRepMesh_DataStructureOfDelaun)&
                                   const Standard_Integer                         theCellsCountV)
 : myMeshData (theOldMesh),
   myCircles (theVertexIndices.Length (), new NCollection_IncAllocator(
-             IMeshData::MEMORY_BLOCK_SIZE_HUGE))
+             IMeshData::MEMORY_BLOCK_SIZE_HUGE)),
+  mySupVert (3)
 {
   perform (theVertexIndices, theCellsCountU, theCellsCountV);
 }
@@ -284,14 +289,14 @@ void BRepMesh_Delaun::superMesh(const Bnd_Box2d& theBox)
   Standard_Real aDeltaMax = Max( aDeltaX, aDeltaY );
   Standard_Real aDelta    = aDeltaX + aDeltaY;
 
-  mySupVert[0] = myMeshData->AddNode(
-    BRepMesh_Vertex( ( aMinX + aMaxX ) / 2, aMaxY + aDeltaMax, BRepMesh_Free ) );
+  mySupVert.Append (myMeshData->AddNode(
+    BRepMesh_Vertex( ( aMinX + aMaxX ) / 2, aMaxY + aDeltaMax, BRepMesh_Free ) ) );
 
-  mySupVert[1] = myMeshData->AddNode(
-    BRepMesh_Vertex( aMinX - aDelta, aMinY - aDeltaMin, BRepMesh_Free ) );
+  mySupVert.Append (myMeshData->AddNode(
+    BRepMesh_Vertex( aMinX - aDelta, aMinY - aDeltaMin, BRepMesh_Free ) ) );
 
-  mySupVert[2] = myMeshData->AddNode(
-    BRepMesh_Vertex( aMaxX + aDelta, aMinY - aDeltaMin, BRepMesh_Free ) );
+  mySupVert.Append (myMeshData->AddNode(
+    BRepMesh_Vertex( aMaxX + aDelta, aMinY - aDeltaMin, BRepMesh_Free ) ) );
 
   Standard_Integer e[3];
   Standard_Boolean o[3];
@@ -300,7 +305,7 @@ void BRepMesh_Delaun::superMesh(const Bnd_Box2d& theBox)
     Standard_Integer aFirstNode = aNodeId;
     Standard_Integer aLastNode  = (aNodeId + 1) % 3;
     Standard_Integer aLinkIndex = myMeshData->AddLink( BRepMesh_Edge(
-      mySupVert[aFirstNode], mySupVert[aLastNode], BRepMesh_Free ) );
+      mySupVert (aFirstNode), mySupVert (aLastNode), BRepMesh_Free ) );
 
     e[aNodeId] = Abs(aLinkIndex);
     o[aNodeId] = (aLinkIndex > 0);
@@ -367,28 +372,41 @@ void BRepMesh_Delaun::compute(IMeshData::VectorOfInteger& theVertexIndexes)
     createTrianglesOnNewVertices( theVertexIndexes );
   }
 
-  // Destruction of triangles containing a top of the super triangle
-  BRepMesh_SelectorOfDataStructureOfDelaun aSelector( myMeshData );
-  for (Standard_Integer aSupVertId = 0; aSupVertId < 3; ++aSupVertId)
-    aSelector.NeighboursOfNode( mySupVert[aSupVertId] );
+  RemoveAuxElements ();
+}
 
-  aLoopEdges.Clear();
-  IMeshData::IteratorOfMapOfInteger aFreeTriangles( aSelector.Elements() );
-  for ( ; aFreeTriangles.More(); aFreeTriangles.Next() )
-    deleteTriangle( aFreeTriangles.Key(), aLoopEdges );
+//=======================================================================
+//function : RemoveAuxElements
+//purpose  : 
+//=======================================================================
+void BRepMesh_Delaun::RemoveAuxElements ()
+{
+  Handle (NCollection_IncAllocator) aAllocator = new NCollection_IncAllocator (
+    IMeshData::MEMORY_BLOCK_SIZE_HUGE);
+
+  IMeshData::MapOfIntegerInteger aLoopEdges (10, aAllocator);
+
+  // Destruction of triangles containing a top of the super triangle
+  BRepMesh_SelectorOfDataStructureOfDelaun aSelector (myMeshData);
+  for (Standard_Integer aSupVertId = 0; aSupVertId < mySupVert.Size(); ++aSupVertId)
+    aSelector.NeighboursOfNode (mySupVert (aSupVertId));
+
+  IMeshData::IteratorOfMapOfInteger aFreeTriangles (aSelector.Elements ());
+  for (; aFreeTriangles.More (); aFreeTriangles.Next ())
+    deleteTriangle (aFreeTriangles.Key (), aLoopEdges);
 
   // All edges that remain free are removed from aLoopEdges;
   // only the boundary edges of the triangulation remain there
-  IMeshData::MapOfIntegerInteger::Iterator aFreeEdges( aLoopEdges );
-  for ( ; aFreeEdges.More(); aFreeEdges.Next() )
+  IMeshData::MapOfIntegerInteger::Iterator aFreeEdges (aLoopEdges);
+  for (; aFreeEdges.More (); aFreeEdges.Next ())
   {
-    if ( myMeshData->ElementsConnectedTo( aFreeEdges.Key() ).IsEmpty() )
-      myMeshData->RemoveLink( aFreeEdges.Key() );
+    if (myMeshData->ElementsConnectedTo (aFreeEdges.Key ()).IsEmpty ())
+      myMeshData->RemoveLink (aFreeEdges.Key ());
   }
 
   // The tops of the super triangle are destroyed
-  for (Standard_Integer aSupVertId = 0; aSupVertId < 3; ++aSupVertId)
-    myMeshData->RemoveNode( mySupVert[aSupVertId] );
+  for (Standard_Integer aSupVertId = 0; aSupVertId < mySupVert.Size (); ++aSupVertId)
+    myMeshData->RemoveNode (mySupVert (aSupVertId));
 }
 
 //=======================================================================
@@ -771,9 +789,7 @@ void BRepMesh_Delaun::cleanupMesh()
               myMeshData->ElementNodes (aCurTriangle, v);
               for (int aNodeIdx = 0; aNodeIdx < 3 && isCanNotBeRemoved; ++aNodeIdx)
               {
-                if (v[aNodeIdx] == mySupVert[0] ||
-                    v[aNodeIdx] == mySupVert[1] ||
-                    v[aNodeIdx] == mySupVert[2])
+                if (isSupVertex (v[aNodeIdx]))
                 {
                   isCanNotBeRemoved = Standard_False;
                 }

src/BRepMesh/BRepMesh_Delaun.hxx

@@ -147,6 +147,17 @@ public:
                                              const Standard_Real    theSqTolerance,
                                              Standard_Integer&      theEdgeOn) const;
 
+  //! Explicitly sets ids of auxiliary vertices used to build mesh and used by 3rd-party algorithms.
+  inline void SetAuxVertices (const IMeshData::VectorOfInteger& theSupVert)
+  {
+    mySupVert = theSupVert;
+  }
+
+  //! Destruction of auxiliary triangles containing the given vertices.
+  //! Removes auxiliary vertices also.
+  //! @param theAuxVertices auxiliary vertices to be cleaned up.
+  Standard_EXPORT void RemoveAuxElements ();
+
 private:
 
   enum ReplaceFlag
@@ -354,11 +365,25 @@ private:
   //! Performs insertion of internal edges into mesh.
   void insertInternalEdges();
 
+  //! Checks whether the given vertex id relates to super contour.
+  inline Standard_Boolean isSupVertex (const Standard_Integer theVertexIdx)
+  {
+    for (IMeshData::VectorOfInteger::Iterator aIt (mySupVert); aIt.More (); aIt.Next ())
+    {
+      if (theVertexIdx == aIt.Value ())
+      {
+        return Standard_True;
+      }
+    }
+
+    return Standard_False;
+  }
+
 private:
 
   Handle(BRepMesh_DataStructureOfDelaun) myMeshData;
   BRepMesh_CircleTool                    myCircles;
-  Standard_Integer                       mySupVert[3];
+  IMeshData::VectorOfInteger             mySupVert;
   BRepMesh_Triangle                      mySupTrian;
 
 };

src/BRepMesh/DELABELLA_LICENSE

@@ -0,0 +1,22 @@
+MIT License
+
+DELABELLA - Delaunay triangulation library
+Copyright (C) 2018 GUMIX - Marcin Sokalski
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

src/BRepMesh/FILES

@@ -86,3 +86,9 @@ BRepMesh_VertexTool.cxx
 BRepMesh_VertexTool.hxx
 BRepMesh_CustomBaseMeshAlgo.hxx
 BRepMesh_CustomDelaunayBaseMeshAlgo.hxx
+delabella.h
+delabella.cpp
+BRepMesh_DelabellaBaseMeshAlgo.hxx
+BRepMesh_DelabellaBaseMeshAlgo.cxx
+BRepMesh_DelabellaMeshAlgoFactory.hxx
+BRepMesh_DelabellaMeshAlgoFactory.cxx

src/BRepMesh/delabella.h

@@ -0,0 +1,68 @@
+/*
+DELABELLA - Delaunay triangulation library
+Copyright (C) 2018 GUMIX - Marcin Sokalski
+*/
+
+#ifndef DELABELLA_H
+#define DELABELLA_H
+
+// returns: positive value: number of triangle indices, negative: number of line segment indices (degenerated input)
+//          triangle indices in abc array are always returned in clockwise order
+// DEPRECIATED. move to new API either extern "C" or IDelaBella (C++)
+int DelaBella(int points, const double* xy/*[points][2]*/, int* abc/*[2*points-5][3]*/, int (*errlog)(const char* fmt,...) = printf);
+
+struct DelaBella_Vertex
+{
+	int i; // index of original point
+	double x, y; // coordinates (input copy)
+	DelaBella_Vertex* next; // next silhouette vertex
+};
+
+struct DelaBella_Triangle
+{
+	DelaBella_Vertex* v[3]; // 3 vertices spanning this triangle
+	DelaBella_Triangle* f[3]; // 3 adjacent faces, f[i] is at the edge opposite to vertex v[i]
+	DelaBella_Triangle* next; // next triangle (of delaunay set or hull set)
+};
+
+#ifdef __cplusplus
+struct IDelaBella
+{
+	static IDelaBella* Create();
+
+	virtual void Destroy() = 0;
+
+	virtual void SetErrLog(int(*proc)(void* stream, const char* fmt, ...), void* stream) = 0;
+
+	// return 0: no output 
+	// negative: all points are colinear, output hull vertices form colinear segment list, no triangles on output
+	// positive: output hull vertices form counter-clockwise ordered segment contour, delaunay and hull triangles are available
+	// if 'y' pointer is null, y coords are treated to be located immediately after every x
+	// if advance_bytes is less than 2*sizeof coordinate type, it is treated as 2*sizeof coordinate type  
+	virtual int Triangulate(int points, const float* x, const float* y = 0, int advance_bytes = 0) = 0;
+	virtual int Triangulate(int points, const double* x, const double* y = 0, int advance_bytes = 0) = 0;
+
+	// num of points passed to last call to Triangulate()
+	virtual int GetNumInputPoints() const = 0;
+
+	// num of verts returned from last call to Triangulate()
+	virtual int GetNumOutputVerts() const = 0;
+
+	virtual const DelaBella_Triangle* GetFirstDelaunayTriangle() const = 0; // valid only if Triangulate() > 0
+	virtual const DelaBella_Triangle* GetFirstHullTriangle() const = 0; // valid only if Triangulate() > 0
+	virtual const DelaBella_Vertex*   GetFirstHullVertex() const = 0; // if Triangulate() < 0 it is list, otherwise closed contour! 
+};
+#else
+void* DelaBella_Create();
+void  DelaBella_Destroy(void* db);
+void  DelaBella_SetErrLog(void* db, int(*proc)(void* stream, const char* fmt, ...), void* stream);
+int   DelaBella_TriangulateFloat(void* db, int points, float* x, float* y = 0, int advance_bytes = 0);
+int   DelaBella_TriangulateDouble(void* db, int points, double* x, double* y = 0, int advance_bytes = 0);
+int   DelaBella_GetNumInputPoints(void* db);
+int   DelaBella_GetNumOutputVerts(void* db);
+const DelaBella_Triangle* GetFirstDelaunayTriangle(void* db);
+const DelaBella_Triangle* GetFirstHullTriangle(void* db);
+const DelaBella_Vertex*   GetFirstHullVertex(void* db);
+#endif
+
+#endif

tests/bugs/mesh/bug26074

@@ -0,0 +1,19 @@
+puts "========="
+puts "0026074: BRepMesh_IncrementalMesh meshes a specific shape for a long time"
+puts "========="
+puts ""
+
+set ::env(CSF_MeshAlgo) 1
+
+restore [locate_data_file bug26074.brep] result
+tclean result
+
+incmesh result 0.01116 -a 15 -parallel
+checktrinfo result -tri
+
+vinit
+vsetdispmode 1
+vdefaults -autoTriang 0
+vdisplay result
+vfit
+checkview -screenshot -3d -path ${imagedir}/${test_image}.png

tests/bugs/mesh/bug29506

@@ -0,0 +1,19 @@
+puts "========="
+puts "0029506: DRAW command 'incmesh' hangs on the attached planar face with specified deflection."
+puts "========="
+puts ""
+
+set ::env(CSF_MeshAlgo) 1
+
+restore [locate_data_file bug29506.brep] result
+tclean result
+
+incmesh result 1e-6
+checktrinfo result -tri 44437 -nod 44437 -defl 9.9999999999999995e-07
+
+vinit
+vsetdispmode 1
+vdefaults -autoTriang 0
+vdisplay result
+vfit
+checkview -screenshot -3d -path ${imagedir}/${test_image}.png