lib/cpm/Algorithms/QuadEdge/MeshZipFunction.hxx

   1 #ifndef __CPM__ALGORITHMS__QUADEDGE__MESHZIPFUNCTION__HXX__
   2 #define __CPM__ALGORITHMS__QUADEDGE__MESHZIPFUNCTION__HXX__
   3
   4 // -------------------------------------------------------------------------
   5 template< class M >
   6 typename cpm::Algorithms::QuadEdge::MeshZipFunction< M >::
   7 TOutput cpm::Algorithms::QuadEdge::MeshZipFunction< M >::
   8 Evaluate( const TInput& e )
   9 {
  10   if( !this->m_Mesh )
  11   {
  12     itkDebugMacro( "No mesh present" );
  13     return( TEdge::NoGeometry );
  14
  15   } // fi
  16
  17   if( e->IsLeftSet( ) )
  18   {
  19     itkDebugMacro( "Incoming edge must be adjacent to NOFACE" );
  20     return( TEdge::NoGeometry );
  21
  22   } // fi
  23
  24   //     Initial state                          Final state        //
  25   //                                                               //
  26   //   |               |                         \       /         //
  27   //   |               |                          \     /          //
  28   //   |               |                           \   /           //
  29   //   |               |                            \ /            //
  30   //   VTrashed      Vkept                           V             //
  31   //    \             /                              |             //
  32   //     \           /                               |             //
  33   //      \         ^                                |             //
  34   //       \       /                                 |             //
  35   //        \     e                                  |             //
  36   //         \   /                                   |             //
  37   //          \ /                                    |             //
  38   //  ------- Org --------                --------- Org ---------  //
  39   //         / | \                                 / | \           //
  40   //        /  |  \                               /  |  \          //
  41   //       /   |   \                             /   |   \         //
  42   //
  43   // This is the original situation:
  44   //
  45   //         \                        /                            //
  46   //          \                      ^                             //
  47   //           \                    a                              //
  48   //            \                  /                               //
  49   //    ------ VRite            VLeft --------                     //
  50   //            / \             / \                                //
  51   //           /   \           /   \                               //
  52   //          /     b         ^     \                              //
  53   //         /       \       /       \                             //
  54   //        /         v     e   Rite  \                            //
  55   //       /           \   /    Face   \                           //
  56   //      /             \ /             \                          //
  57   //     V ------------ Org ------------ VOpposite                 //
  58   //                   / | \                                       //
  59   //                  /  |  \                                      //
  60   //
  61   // Store for latter usage (since e and e->GetRight( ) will be deleted):
  62   TEdge* a = e->GetLnext( );
  63   TEdge* b = e->GetOnext( )->GetSym( );
  64   TOutput VLeft = e->GetDestination( );
  65   TOutput VRight = b->GetOrigin( );
  66   bool wasFacePresent = e->IsRightSet( );
  67   TOutput resultingPointId = TEdge::NoGeometry;
  68
  69   // We should be cautious and consider the case when the very
  70   // initial situation was the following:
  71   //                                                       //
  72   //                   *                                   //
  73   //        *                     *                        //
  74   //                                                       //
  75   //             VRight = VLeft                             //
  76   //                  / \                                  //
  77   //                 /   \                                 //
  78   //                /     \                                //
  79   //       *        |  *  |        *                       //
  80   //                \     /                                //
  81   //                 \   /                                 //
  82   //                  \ /                                  //
  83   //        --------- Org ---------                        //
  84   //                 / | \                                 //
  85   //                /  |  \                                //
  86   //               /   |   \                               //
  87   if( VRight == VLeft )
  88   {
  89     if( e->IsWire( ) && b->IsWire( ) )
  90     {
  91       /* TODO
  92          this->m_Mesh->LightWeightDeleteEdge(e);
  93          this->m_Mesh->LightWeightDeleteEdge(b);
  94       */
  95       return( resultingPointId );
  96
  97     } // fi
  98
  99   } // fi
 100
 101   // Delete the Edge e and it's right face:
 102   /* TODO:
 103      if( wasFacePresent )
 104      this->m_Mesh->DeleteFace( e->GetRight( ) );
 105      this->m_Mesh->LightWeightDeleteEdge(e);
 106   */
 107
 108   // We should be cautious and consider the case when the very
 109   // initial situation was the following:
 110   //               \       /                               //
 111   //                \     /                                //
 112   //                 \   /                                 //
 113   //                  \ /                                  //
 114   //            VRight = VLeft ------- VOpposite           //
 115   //                  / \            _/                    //
 116   //                 /   \         _/                      //
 117   //                /     \   *  _/                        //
 118   //                |     |    _/                          //
 119   //                \     /  _/                            //
 120   //                 \   / _/                              //
 121   //                  \ /_/                                //
 122   //        --------- Org ---------                        //
 123   //                 / | \                                 //
 124   //                /  |  \                                //
 125   //               /   |   \                               //
 126   //
 127   // in which case the current situation is the following:
 128   //
 129   //               \       /                               //
 130   //                \     /                                //
 131   //                 \   /                                 //
 132   //                  \ /                                  //
 133   //            VRight = VLeft ------- VOpposite           //
 134   //                  /              _/                    //
 135   //                 /             _/                      //
 136   //                /            _/                        //
 137   //                |          _/                          //
 138   //                \        _/                            //
 139   //                 \     _/                              //
 140   //                  \  _/                                //
 141   //        --------- Org ---------                        //
 142   //                 / | \                                 //
 143   //                /  |  \                                //
 144   //               /   |   \                               //
 145   //
 146   // and hence the connectivity part of "Zip" job is already done.
 147   // Check for that case:
 148   //
 149   if( VLeft != VRight )
 150   {
 151     // We are now left with the following situation
 152     //
 153     //         \                        /                  //
 154     //          \                      ^                   //
 155     //           \                    a                    //
 156     //            \                  /                     //
 157     //   ----- VRight              VLeft --------          //
 158     //            / \               \                      //
 159     //           /   \               \                     //
 160     //          /     b               \                    //
 161     //         /       \               \                   //
 162     //        /         v               \                  //
 163     //       /           \               \                 //
 164     //      /             \               \                //
 165     //     V ------------ Org ------------ VOpposite       //
 166     //                   / | \                             //
 167     //                  /  |  \                            //
 168     //
 169     // where we just miss a simple Mesh::Splice( ) to obtain::
 170     //
 171     //          \     /                                    //
 172     //           \   /                                     //
 173     //            \ /                                      //
 174     // ---- VRight = VLeft ------ VOpposite                //
 175     //            / \             /                        //
 176     //           /   \           /                         //
 177     //          /     b         /                          //
 178     //         /       \       /                           //
 179     //        /         v     /                            //
 180     //       /           \   /                             //
 181     //      /             \ /                              //
 182     //     V ------------ Org ------------                 //
 183     //                   / | \                             //
 184     //                  /  |  \                            //
 185     //
 186     // TODO: resultingPointId = this->m_Mesh->Splice(a, b);
 187
 188   } // fi
 189
 190   // We restore the deleted face (when it was present):
 191   /* TODO:
 192      if( wasFacePresent )
 193      this->m_Mesh->AddFace(b);
 194   */
 195   this->m_Mesh->Modified( );
 196   return( resultingPointId );
 197 }
 198
 199 // -------------------------------------------------------------------------
 200 template< class M >
 201 cpm::Algorithms::QuadEdge::MeshZipFunction< M >::
 202 MeshZipFunction( )
 203   : Superclass( )
 204 {
 205 }
 206
 207 // -------------------------------------------------------------------------
 208 template< class M >
 209 cpm::Algorithms::QuadEdge::MeshZipFunction< M >::
 210 ~MeshZipFunction( )
 211 {
 212 }
 213
 214 #endif // __CPM__ALGORITHMS__QUADEDGE__MESHZIPFUNCTION__HXX__
 215
 216 // eof - $RCSfile$