avoid exits from MMG5_coltet()

src/mmg3d/boulep_3d.c

@@ -748,41 +748,47 @@
 
 /**
  * \param mesh pointer to the mesh structure.
- * \param start index of the starting tetra.
- * \param ip index in \a start of the looked point.
+ * \param start index of the starting tetrahedron.
+ * \param ip index in \a start of the desired vertex.
  * \param iface index in \a start of the starting face.
  * \param listv pointer to the computed volumic ball.
  * \param ilistv pointer to the computed volumic ball size.
  * \param lists pointer to the computed surfacic ball.
  * \param ilists pointer to the computed surfacic ball size.
  * \param refmin return the reference of one of the two subdomains in presence
  * \param refplus return the reference of the other subdomain in presence
- * \param isnm is the looked point \a ip non-manifold?
- * \return -1 if fail, 1 otherwise.
+ * \param isnm is the vertex non-manifold?
+ * \return 1 if succesful, a negative value if the ball cannot be computed:
+ * -1 if a surface ball had too many elements,
+ * -2 if there are more than two references around,
+ * -3 if an edge cannot be found, and
+ * -4 if a volume ball had too many elements.
+ * Among these, -1, -3 and -4 can be taken as a sign that further remeshing
+ * is not possible, while -2 just mean the job could not be done.
  *
  * Compute the volumic ball of a SURFACE point \a p, as well as its surfacic
- * ball, starting from tetra \a start, with point \a ip, and face \a if in tetra
+ * ball, starting from tetra \a start, with point \a ip, and face \a if in the
  * volumic ball.
  * \a listv[k] = 4*number of tet + index of point surfacic ball.
  * \a lists[k] = 4*number of tet + index of face.
  *
- * \warning Don't work for a non-manifold point if \a start has an adjacent
- * through \a iface (for example : a non-manifold subdomain). Thus, if \a ip is
+ * \warning Doesn't work for a non-manifold point if \a start has an adjacent
+ * through \a iface (for example: a non-manifold subdomain). Thus, if \a ip is
  * non-manifold, must be called only if \a start has no adjacent through iface.
  *
  */
-int MMG5_boulesurfvolpNom(MMG5_pMesh mesh,MMG5_int start,int ip,int iface,
-                          int64_t *listv,int *ilistv,MMG5_int *lists,int *ilists,
-                          MMG5_int *refmin,MMG5_int *refplus,int isnm)
+int MMG5_boulesurfvolpNom(MMG5_pMesh mesh, MMG5_int start, int ip, int iface,
+                          int64_t *listv, int *ilistv, MMG5_int *lists, int *ilists,
+                          MMG5_int *refmin, MMG5_int *refplus, int isnm)
 {
-  MMG5_pTetra   pt,pt1;
+  MMG5_pTetra   pt, pt1;
   MMG5_pxTetra  pxt;
-  MMG5_int      k,k1,nump,*adja,piv,na,nb,adj,cur,nvstart,fstart,aux,base;
-  int8_t        iopp,ipiv,i,j,l,isface;
+  MMG5_int      k, k1, nump, *adja, piv, na, nb, adj, cur, nvstart, fstart, aux, base;
+  int8_t        iopp, ipiv, i, j, l, isface;
   static int8_t mmgErr0=0, mmgErr1=0, mmgErr2=0;
-  
+
   if ( isnm ) assert(!mesh->adja[4*(start-1)+iface+1]);
-  
+
   base = ++mesh->base;
   *ilists  = 0;
   *ilistv  = 0;
@@ -814,16 +820,15 @@
                 MMG3D_indPt(mesh,nump));
         mmgErr0 = 1;
       }
-
       return -1;
     }
-    
+
     aux = nb;
     nb = piv;
     piv = aux;
     nvstart = k;
     adj = k;
-    
+
     /* Now unfold shell of edge (na,nb) starting from k (included)*/
     do {
       k = adj;
@@ -835,22 +840,22 @@
         assert(i<4);
         listv[(*ilistv)] = 4*k+i;
         (*ilistv)++;
-        
+
         /* Identify references of both subdomains in presence */
         if ( *refmin == -1 )
           *refmin = pt->ref;
         else {
           if ( *refplus == -1 ) {
             if ( pt->ref != *refmin  ) *refplus = pt->ref;
           }
-          else if ( pt->ref != *refmin && pt->ref != *refplus ) return -1;
+          else if ( pt->ref != *refmin && pt->ref != *refplus ) return -2;
         }
         pt->flag = base;
       }
-      
+
       /* identification of edge number in tetra k */
-      if ( !MMG3D_findEdge(mesh,pt,k,na,nb,0,&mmgErr2,&i) ) return -1;
-      
+      if ( !MMG3D_findEdge(mesh,pt,k,na,nb,0,&mmgErr2,&i) ) return -3;
+
       /* set sense of travel */
       if ( pt->v[ MMG5_ifar[i][0] ] == piv ) {
         iopp = MMG5_ifar[i][0];
@@ -878,14 +883,14 @@
     while ( adj && (adj != nvstart) && !isface );
   }
   while ( 4*k+iopp != fstart );
-  
+
   /* Now, surfacic ball is complete ; finish travel of volumic ball */
   cur = 0;  // Check numerotation
   while ( cur < (*ilistv) ) {
     k = listv[cur]/4;
     i = listv[cur]%4; // index of point p in tetra k
     adja = &mesh->adja[4*(k-1)+1];
-    
+
     for (l=0; l<3; l++) {
       i  = MMG5_inxt3[i];
       k1 = adja[i];
@@ -894,11 +899,11 @@
       pt1 = &mesh->tetra[k1];
       if ( pt1->flag == base )  continue;
       pt1->flag = base;
-      
+
       for (j=0; j<4; j++)
         if ( pt1->v[j] == nump )  break;
       assert(j<4);
-      
+
       /* overflow */
       if ( *ilistv > MMG3D_LMAX-3 ) {
         if ( !mmgErr1 ) {
@@ -909,24 +914,24 @@
                   " or/and the maximum mesh.\n");
           mmgErr1 = 1;
         }
-        return -1;
+        return -4;
       }
       listv[(*ilistv)] = 4*k1+j;
       (*ilistv)++;
-      
+
       /* Identify references of both subdomains in presence */
       if ( *refmin == -1 )
         *refmin = pt1->ref;
       else {
         if ( *refplus == -1 ) {
           if ( pt1->ref != *refmin  ) *refplus = pt1->ref;
         }
-        else if ( pt1->ref != *refmin && pt1->ref != *refplus ) return -1;
+        else if ( pt1->ref != *refmin && pt1->ref != *refplus ) return -2;
       }
     }
     cur++;
   }
-  
+
   return 1;
 }
 

src/mmg3d/mmg3d1.c

@@ -880,12 +880,12 @@
  * \param mesh pointer to the mesh structure.
  * \param met pointer to the metric structure.
  * \param typchk type of checking permformed for edge length (hmin or LSHORT criterion).
- * \return -1 if failed, number of collapsed points otherwise.
+ * \return a negative value in case of failure, number of collapsed points otherwise.
  *
- * Attempt to collapse small edges.
+ * Attempt to collapse short edges.
  *
  */
-static int MMG5_coltet(MMG5_pMesh mesh,MMG5_pSol met,int8_t typchk) {
+static MMG5_int MMG5_coltet(MMG5_pMesh mesh,MMG5_pSol met,int8_t typchk) {
   MMG5_pTetra     pt,ptloc;
   MMG5_pxTetra    pxt;
   MMG5_pPoint     p0,p1;
@@ -897,7 +897,7 @@
   int             l,kk,isloc,ifac1;
   int16_t         tag,isnm,isnmint;
   int8_t          i,j,ip,iq;
-  int             ier;
+  int             ier, bsret;   // function return values/error codes
 
   nc = nnm = 0;
 
@@ -963,15 +963,21 @@
               }
               else {
                 if ( mesh->adja[4*(k-1)+1+i] )  continue;
-                if (MMG5_boulesurfvolpNom(mesh,k,ip,i,
-                                          list,&ilist,lists,&ilists,&refmin,&refplus,p0->tag & MG_NOM) < 0 )
-                  return -1;
+
+                bsret = MMG5_boulesurfvolpNom(mesh,k,ip,i,
+                                              list,&ilist,lists,&ilists,&refmin,&refplus,p0->tag & MG_NOM);
+                if(bsret==-1 || bsret==-3 || bsret==-4){
+                  return -3;   // fatal
+                }else if(bsret==-2){
+                  continue;    // ball computation failed: cannot handle this vertex
+                }
+                assert(bsret==1 && "unexpected return value from MMG5_boulesurfvolpNom");
               }
             }
             else {
               if (MMG5_boulesurfvolp(mesh,k,ip,i,
                                      list,&ilist,lists,&ilists,p0->tag & MG_NOM) < 0 )
-                return -1;
+                return -2;
             }
           }
           else {
@@ -1094,15 +1100,20 @@
               }
               else {
                 if ( mesh->adja[4*(k-1)+1+i] )  continue;
-                if (MMG5_boulesurfvolpNom(mesh,k,ip,i,
-                                          list,&ilist,lists,&ilists,&refmin,&refplus,p0->tag & MG_NOM) < 0 )
-                  return -1;
+                bsret = MMG5_boulesurfvolpNom(mesh,k,ip,i,
+                                              list,&ilist,lists,&ilists,&refmin,&refplus,p0->tag & MG_NOM);
+                if(bsret==-1 || bsret==-3 || bsret==-4){
+                  return -3;   // fatal
+                }else if(bsret==-2){
+                  continue;    // ball computation failed: cannot handle this vertex
+                }
+                assert(bsret==1 && "unexpected return value from MMG5_boulesurfvolpNom");
               }
             }
             else {
               if (MMG5_boulesurfvolp(mesh,k,ip,i,
                                      list,&ilist,lists,&ilists,p0->tag & MG_NOM) < 0 )
-                return -1;
+                return -4;
             }
           }
           else {
@@ -1134,13 +1145,13 @@
 
         if ( ilist > 0 ) {
           ier = MMG5_colver(mesh,met,list,ilist,iq,typchk);
-          if ( ier < 0 ) return -1;
+          if ( ier < 0 ) return -5;
           else if ( ier ) {
             MMG3D_delPt(mesh,ier);
             break;
           }
         }
-        else if (ilist < 0 ) return -1;
+        else if (ilist < 0 ) return -6;
       }
       if ( ier ) {
         p1->flag = base;