text: /*=========================================================================
   *
   *  Copyright NumFOCUS
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *         http://www.apache.org/licenses/LICENSE-2.0.txt
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   *
   *=========================================================================*/
  #ifndef itkQuadEdgeMeshEulerOperatorSplitVertexFunction_hxx
  #define itkQuadEdgeMeshEulerOperatorSplitVertexFunction_hxx
  
  #include "itkQuadEdgeMeshEulerOperatorSplitVertexFunction.h"
  
  namespace itk
  {
  template <typename TMesh, typename TQEType>
  typename QuadEdgeMeshEulerOperatorSplitVertexFunction<TMesh, TQEType>::OutputType
  QuadEdgeMeshEulerOperatorSplitVertexFunction<TMesh, TQEType>::Evaluate(QEType * h, QEType * g)
  {
    if (!this->m_Mesh)
    {
      itkDebugMacro("No mesh present.");
      return ((QEType *)nullptr);
    }
  
    if ((h == (QEType *)nullptr) || (g == (QEType *)nullptr))
    {
      itkDebugMacro("One or more argument(s) is(are) null.");
      return ((QEType *)nullptr);
    }
  
    if (h == g)
    {
      itkDebugMacro("The two half-edges are the same. No antenna allowed.");
      return ((QEType *)nullptr);
    }
  
    if (h->GetDestination() != g->GetDestination())
    {
      itkDebugMacro("The two half-edges must be incident to the same vertex.");
      return ((QEType *)nullptr);
    }
  
    // delete the faces
    this->m_Mesh->DeleteFace(h->GetRight());
    this->m_Mesh->DeleteFace(g->GetRight());
  
    // splice to create a new point and disconnect the rings
    this->m_NewPoint = this->m_Mesh->Splice(h->GetSym(), g->GetSym());
  
    // then add a new edge
    QEType * ReturnedEdge = this->m_Mesh->AddEdge(g->GetDestination(), h->GetDestination());
  
    // Build two new faces
    this->m_Mesh->AddFace(h->GetSym());
    this->m_Mesh->AddFace(g->GetSym());
    this->m_Mesh->Modified();
  
    return (ReturnedEdge);
  }
  } // end namespace itk
  
  #endif
  