LCOV - code coverage report
Current view: top level - alg/internal_libqhull - merge_r.c (source / functions) Hit Total Coverage
Test: gdal_filtered.info Lines: 642 2450 26.2 %
Date: 2024-05-02 00:41:30 Functions: 34 83 41.0 %

          Line data    Source code
       1             : /*<html><pre>  -<a                             href="qh-merge_r.htm#TOC"
       2             :   >-------------------------------</a><a name="TOP">-</a>
       3             : 
       4             :    merge_r.c
       5             :    merges non-convex facets
       6             : 
       7             :    see qh-merge_r.htm and merge_r.h
       8             : 
       9             :    other modules call qh_premerge() and qh_postmerge()
      10             : 
      11             :    the user may call qh_postmerge() to perform additional merges.
      12             : 
      13             :    To remove deleted facets and vertices (qhull() in libqhull_r.c):
      14             :      qh_partitionvisible(qh, !qh_ALL, &numoutside);  // visible_list, newfacet_list
      15             :      qh_deletevisible();         // qh.visible_list
      16             :      qh_resetlists(qh, False, qh_RESETvisible);       // qh.visible_list newvertex_list newfacet_list
      17             : 
      18             :    assumes qh.CENTERtype= centrum
      19             : 
      20             :    merges occur in qh_mergefacet and in qh_mergecycle
      21             :    vertex->neighbors not set until the first merge occurs
      22             : 
      23             :    Copyright (c) 1993-2020 C.B. Barber.
      24             :    $Id: //main/2019/qhull/src/libqhull_r/merge_r.c#14 $$Change: 2953 $
      25             :    $DateTime: 2020/05/21 22:05:32 $$Author: bbarber $
      26             : */
      27             : 
      28             : #include "qhull_ra.h"
      29             : 
      30             : #ifndef qh_NOmerge
      31             : 
      32             : /* MRGnone, etc. */
      33             : const char *mergetypes[]= {
      34             :   "none",
      35             :   "coplanar",
      36             :   "anglecoplanar",
      37             :   "concave",
      38             :   "concavecoplanar",
      39             :   "twisted",
      40             :   "flip",
      41             :   "dupridge",
      42             :   "subridge",
      43             :   "vertices",
      44             :   "degen",
      45             :   "redundant",
      46             :   "mirror",
      47             :   "coplanarhorizon",
      48             : };
      49             : 
      50             : /*===== functions(alphabetical after premerge and postmerge) ======*/
      51             : 
      52             : /*-<a                             href="qh-merge_r.htm#TOC"
      53             :   >-------------------------------</a><a name="premerge">-</a>
      54             : 
      55             :   qh_premerge(qh, apexpointid, maxcentrum )
      56             :     pre-merge nonconvex facets in qh.newfacet_list for apexpointid
      57             :     maxcentrum defines coplanar and concave (qh_test_appendmerge)
      58             : 
      59             :   returns:
      60             :     deleted facets added to qh.visible_list with facet->visible set
      61             : 
      62             :   notes:
      63             :     only called by qh_addpoint
      64             :     uses globals, qh.MERGEexact, qh.PREmerge
      65             : 
      66             :   design:
      67             :     mark dupridges in qh.newfacet_list
      68             :     merge facet cycles in qh.newfacet_list
      69             :     merge dupridges and concave facets in qh.newfacet_list
      70             :     check merged facet cycles for degenerate and redundant facets
      71             :     merge degenerate and redundant facets
      72             :     collect coplanar and concave facets
      73             :     merge concave, coplanar, degenerate, and redundant facets
      74             : */
      75       14660 : void qh_premerge(qhT *qh, int apexpointid, realT maxcentrum, realT maxangle /* qh.newfacet_list */) {
      76       14660 :   boolT othermerge= False;
      77             : 
      78       14660 :   if (qh->ZEROcentrum && qh_checkzero(qh, !qh_ALL))
      79        2463 :     return;
      80       12197 :   trace2((qh, qh->ferr, 2008, "qh_premerge: premerge centrum %2.2g angle %4.4g for apex p%d newfacet_list f%d\n",
      81             :             maxcentrum, maxangle, apexpointid, getid_(qh->newfacet_list)));
      82       12197 :   if (qh->IStracing >= 4 && qh->num_facets < 100)
      83           0 :     qh_printlists(qh);
      84       12197 :   qh->centrum_radius= maxcentrum;
      85       12197 :   qh->cos_max= maxangle;
      86       12197 :   if (qh->hull_dim >=3) {
      87       12197 :     qh_mark_dupridges(qh, qh->newfacet_list, qh_ALL); /* facet_mergeset */
      88       12197 :     qh_mergecycle_all(qh, qh->newfacet_list, &othermerge);
      89       12197 :     qh_forcedmerges(qh, &othermerge /* qh.facet_mergeset */);
      90             :   }else /* qh.hull_dim == 2 */
      91           0 :     qh_mergecycle_all(qh, qh->newfacet_list, &othermerge);
      92       12197 :   qh_flippedmerges(qh, qh->newfacet_list, &othermerge);
      93       12197 :   if (!qh->MERGEexact || zzval_(Ztotmerge)) {
      94       12197 :     zinc_(Zpremergetot);
      95       12197 :     qh->POSTmerging= False;
      96       12197 :     qh_getmergeset_initial(qh, qh->newfacet_list);
      97       12197 :     qh_all_merges(qh, othermerge, False);
      98             :   }
      99             : } /* premerge */
     100             : 
     101             : /*-<a                             href="qh-merge_r.htm#TOC"
     102             :   >-------------------------------</a><a name="postmerge">-</a>
     103             : 
     104             :   qh_postmerge(qh, reason, maxcentrum, maxangle, vneighbors )
     105             :     post-merge nonconvex facets as defined by maxcentrum and maxangle
     106             :     'reason' is for reporting progress
     107             :     if vneighbors ('Qv'),
     108             :       calls qh_test_vneighbors at end of qh_all_merge from qh_postmerge
     109             : 
     110             :   returns:
     111             :     if first call (qh.visible_list != qh.facet_list),
     112             :       builds qh.facet_newlist, qh.newvertex_list
     113             :     deleted facets added to qh.visible_list with facet->visible
     114             :     qh.visible_list == qh.facet_list
     115             : 
     116             :   notes:
     117             :     called by qh_qhull after qh_buildhull
     118             :     called if a merge may be needed due to
     119             :       qh.MERGEexact ('Qx'), qh_DIMreduceBuild, POSTmerge (e.g., 'Cn'), or TESTvneighbors ('Qv')
     120             :     if firstmerge,
     121             :       calls qh_reducevertices before qh_getmergeset
     122             : 
     123             :   design:
     124             :     if first call
     125             :       set qh.visible_list and qh.newfacet_list to qh.facet_list
     126             :       add all facets to qh.newfacet_list
     127             :       mark non-simplicial facets, facet->newmerge
     128             :       set qh.newvertext_list to qh.vertex_list
     129             :       add all vertices to qh.newvertex_list
     130             :       if a pre-merge occurred
     131             :         set vertex->delridge {will retest the ridge}
     132             :         if qh.MERGEexact
     133             :           call qh_reducevertices()
     134             :       if no pre-merging
     135             :         merge flipped facets
     136             :     determine non-convex facets
     137             :     merge all non-convex facets
     138             : */
     139           0 : void qh_postmerge(qhT *qh, const char *reason, realT maxcentrum, realT maxangle,
     140             :                       boolT vneighbors) {
     141             :   facetT *newfacet;
     142           0 :   boolT othermerges= False;
     143             :   vertexT *vertex;
     144             : 
     145           0 :   if (qh->REPORTfreq || qh->IStracing) {
     146           0 :     qh_buildtracing(qh, NULL, NULL);
     147           0 :     qh_printsummary(qh, qh->ferr);
     148           0 :     if (qh->PRINTstatistics)
     149           0 :       qh_printallstatistics(qh, qh->ferr, "reason");
     150           0 :     qh_fprintf(qh, qh->ferr, 8062, "\n%s with 'C%.2g' and 'A%.2g'\n",
     151             :         reason, maxcentrum, maxangle);
     152             :   }
     153           0 :   trace2((qh, qh->ferr, 2009, "qh_postmerge: postmerge.  test vneighbors? %d\n",
     154             :             vneighbors));
     155           0 :   qh->centrum_radius= maxcentrum;
     156           0 :   qh->cos_max= maxangle;
     157           0 :   qh->POSTmerging= True;
     158           0 :   if (qh->visible_list != qh->facet_list) {  /* first call due to qh_buildhull, multiple calls if qh.POSTmerge */
     159           0 :     qh->NEWfacets= True;
     160           0 :     qh->visible_list= qh->newfacet_list= qh->facet_list;
     161           0 :     FORALLnew_facets {              /* all facets are new facets for qh_postmerge */
     162           0 :       newfacet->newfacet= True;
     163           0 :        if (!newfacet->simplicial)
     164           0 :         newfacet->newmerge= True;   /* test f.vertices for 'delridge'.  'newmerge' was cleared at end of qh_all_merges */
     165           0 :      zinc_(Zpostfacets);
     166             :     }
     167           0 :     qh->newvertex_list= qh->vertex_list;
     168           0 :     FORALLvertices
     169           0 :       vertex->newfacet= True;
     170           0 :     if (qh->VERTEXneighbors) {  /* a merge has occurred */
     171           0 :       if (qh->MERGEexact && qh->hull_dim <= qh_DIMreduceBuild)
     172           0 :         qh_reducevertices(qh);  /* qh_all_merges did not call qh_reducevertices for v.delridge */
     173             :     }
     174           0 :     if (!qh->PREmerge && !qh->MERGEexact)
     175           0 :       qh_flippedmerges(qh, qh->newfacet_list, &othermerges);
     176             :   }
     177           0 :   qh_getmergeset_initial(qh, qh->newfacet_list);
     178           0 :   qh_all_merges(qh, False, vneighbors); /* calls qh_reducevertices before exiting */
     179           0 :   FORALLnew_facets
     180           0 :     newfacet->newmerge= False;   /* Was True if no vertex in f.vertices was 'delridge' */
     181           0 : } /* post_merge */
     182             : 
     183             : /*-<a                             href="qh-merge_r.htm#TOC"
     184             :   >-------------------------------</a><a name="all_merges">-</a>
     185             : 
     186             :   qh_all_merges(qh, othermerge, vneighbors )
     187             :     merge all non-convex facets
     188             : 
     189             :     set othermerge if already merged facets (calls qh_reducevertices)
     190             :     if vneighbors ('Qv' at qh.POSTmerge)
     191             :       tests vertex neighbors for convexity at end (qh_test_vneighbors)
     192             :     qh.facet_mergeset lists the non-convex ridges in qh_newfacet_list
     193             :     qh.degen_mergeset is defined
     194             :     if qh.MERGEexact && !qh.POSTmerging,
     195             :       does not merge coplanar facets
     196             : 
     197             :   returns:
     198             :     deleted facets added to qh.visible_list with facet->visible
     199             :     deleted vertices added qh.delvertex_list with vertex->delvertex
     200             : 
     201             :   notes:
     202             :     unless !qh.MERGEindependent,
     203             :       merges facets in independent sets
     204             :     uses qh.newfacet_list as implicit argument since merges call qh_removefacet()
     205             :     [apr'19] restored qh_setdellast in place of qh_next_facetmerge.  Much faster for post-merge
     206             : 
     207             :   design:
     208             :     while merges occur
     209             :       for each merge in qh.facet_mergeset
     210             :         unless one of the facets was already merged in this pass
     211             :           merge the facets
     212             :         test merged facets for additional merges
     213             :         add merges to qh.facet_mergeset
     214             :         if qh.POSTmerging
     215             :           periodically call qh_reducevertices to reduce extra vertices and redundant vertices
     216             :       after each pass, if qh.VERTEXneighbors
     217             :         if qh.POSTmerging or was a merge with qh.hull_dim<=5
     218             :           call qh_reducevertices
     219             :           update qh.facet_mergeset if degenredundant merges
     220             :       if 'Qv' and qh.POSTmerging
     221             :         test vertex neighbors for convexity
     222             : */
     223       12197 : void qh_all_merges(qhT *qh, boolT othermerge, boolT vneighbors) {
     224             :   facetT *facet1, *facet2, *newfacet;
     225             :   mergeT *merge;
     226       12197 :   boolT wasmerge= False, isreduce;
     227             :   void **freelistp;  /* used if !qh_NOmem by qh_memfree_() */
     228             :   vertexT *vertex;
     229             :   realT angle, distance;
     230             :   mergeType mergetype;
     231       12197 :   int numcoplanar=0, numconcave=0, numconcavecoplanar= 0, numdegenredun= 0, numnewmerges= 0, numtwisted= 0;
     232             : 
     233       12197 :   trace2((qh, qh->ferr, 2010, "qh_all_merges: starting to merge %d facet and %d degenerate merges for new facets f%d, othermerge? %d\n",
     234             :             qh_setsize(qh, qh->facet_mergeset), qh_setsize(qh, qh->degen_mergeset), getid_(qh->newfacet_list), othermerge));
     235             : 
     236             :   while (True) {
     237       12197 :     wasmerge= False;
     238       12198 :     while (qh_setsize(qh, qh->facet_mergeset) > 0 || qh_setsize(qh, qh->degen_mergeset) > 0) {
     239           1 :       if (qh_setsize(qh, qh->degen_mergeset) > 0) {
     240           0 :         numdegenredun += qh_merge_degenredundant(qh);
     241           0 :         wasmerge= True;
     242             :       }
     243           2 :       while ((merge= (mergeT *)qh_setdellast(qh->facet_mergeset))) {
     244           1 :         facet1= merge->facet1;
     245           1 :         facet2= merge->facet2;
     246           1 :         vertex= merge->vertex1;  /* not used for qh.facet_mergeset*/
     247           1 :         mergetype= merge->mergetype;
     248           1 :         angle= merge->angle;
     249           1 :         distance= merge->distance;
     250           1 :         qh_memfree_(qh, merge, (int)sizeof(mergeT), freelistp);   /* 'merge' is invalid */
     251           1 :         if (facet1->visible || facet2->visible) {
     252           0 :           trace3((qh, qh->ferr, 3045, "qh_all_merges: drop merge of f%d (del? %d) into f%d (del? %d) mergetype %d, dist %4.4g, angle %4.4g.  One or both facets is deleted\n",
     253             :             facet1->id, facet1->visible, facet2->id, facet2->visible, mergetype, distance, angle));
     254           0 :           continue;
     255           1 :         }else if (mergetype == MRGcoplanar || mergetype == MRGanglecoplanar) {
     256           1 :           if (qh->MERGEindependent) {
     257           1 :             if ((!facet1->tested && facet1->newfacet)
     258           1 :             || (!facet2->tested && facet2->newfacet)) {
     259           0 :               trace3((qh, qh->ferr, 3064, "qh_all_merges: drop merge of f%d (tested? %d) into f%d (tested? %d) mergetype %d, dist %2.2g, angle %4.4g.  Merge independent sets of coplanar merges\n",
     260             :                 facet1->id, facet1->visible, facet2->id, facet2->visible, mergetype, distance, angle));
     261           0 :               continue;
     262             :             }
     263             :           }
     264             :         }
     265           1 :         trace3((qh, qh->ferr, 3047, "qh_all_merges: merge f%d and f%d type %d dist %2.2g angle %4.4g\n",
     266             :           facet1->id, facet2->id, mergetype, distance, angle));
     267           1 :         if (mergetype == MRGtwisted)
     268           0 :           qh_merge_twisted(qh, facet1, facet2);
     269             :         else
     270           1 :           qh_merge_nonconvex(qh, facet1, facet2, mergetype);
     271           1 :         numnewmerges++;
     272           1 :         numdegenredun += qh_merge_degenredundant(qh);
     273           1 :         wasmerge= True;
     274           1 :         if (mergetype == MRGconcave)
     275           0 :           numconcave++;
     276           1 :         else if (mergetype == MRGconcavecoplanar)
     277           0 :           numconcavecoplanar++;
     278           1 :         else if (mergetype == MRGtwisted)
     279           0 :           numtwisted++;
     280           1 :         else if (mergetype == MRGcoplanar || mergetype == MRGanglecoplanar)
     281           1 :           numcoplanar++;
     282             :         else {
     283           0 :           qh_fprintf(qh, qh->ferr, 6394, "qhull internal error (qh_all_merges): expecting concave, coplanar, or twisted merge.  Got merge f%d f%d v%d mergetype %d\n",
     284           0 :             getid_(facet1), getid_(facet2), getid_(vertex), mergetype);
     285           0 :           qh_errexit2(qh, qh_ERRqhull, facet1, facet2);
     286             :         }
     287             :       } /* while qh_setdellast */
     288           1 :       if (qh->POSTmerging && qh->hull_dim <= qh_DIMreduceBuild
     289           0 :       && numnewmerges > qh_MAXnewmerges) {
     290           0 :         numnewmerges= 0;
     291           0 :         wasmerge= othermerge= False;
     292           0 :         qh_reducevertices(qh);  /* otherwise large post merges too slow */
     293             :       }
     294           1 :       qh_getmergeset(qh, qh->newfacet_list); /* qh.facet_mergeset */
     295             :     } /* while facet_mergeset or degen_mergeset */
     296       12197 :     if (qh->VERTEXneighbors) {  /* at least one merge */
     297       12197 :       isreduce= False;
     298       12197 :       if (qh->POSTmerging && qh->hull_dim >= 4) {
     299           0 :         isreduce= True;
     300       12197 :       }else if (qh->POSTmerging || !qh->MERGEexact) {
     301       12197 :         if ((wasmerge || othermerge) && qh->hull_dim > 2 && qh->hull_dim <= qh_DIMreduceBuild)
     302        9686 :           isreduce= True;
     303             :       }
     304       12197 :       if (isreduce) {
     305        9686 :         wasmerge= othermerge= False;
     306        9686 :         if (qh_reducevertices(qh)) {
     307           0 :           qh_getmergeset(qh, qh->newfacet_list); /* facet_mergeset */
     308           0 :           continue;
     309             :         }
     310             :       }
     311             :     }
     312       12197 :     if (vneighbors && qh_test_vneighbors(qh /* qh.newfacet_list */))
     313           0 :       continue;
     314       12197 :     break;
     315             :   } /* while (True) */
     316       12197 :   if (wasmerge || othermerge) {
     317           0 :     trace3((qh, qh->ferr, 3033, "qh_all_merges: skip qh_reducevertices due to post-merging, no qh.VERTEXneighbors (%d), or hull_dim %d ==2 or >%d\n", qh->VERTEXneighbors, qh->hull_dim, qh_DIMreduceBuild))
     318           0 :     FORALLnew_facets {
     319           0 :       newfacet->newmerge= False;
     320             :     }
     321             :   }
     322       12197 :   if (qh->CHECKfrequently && !qh->MERGEexact) {
     323           0 :     qh->old_randomdist= qh->RANDOMdist;
     324           0 :     qh->RANDOMdist= False;
     325           0 :     qh_checkconvex(qh, qh->newfacet_list, qh_ALGORITHMfault);
     326             :     /* qh_checkconnect(qh); [this is slow and it changes the facet order] */
     327           0 :     qh->RANDOMdist= qh->old_randomdist;
     328             :   }
     329       12197 :   trace1((qh, qh->ferr, 1009, "qh_all_merges: merged %d coplanar %d concave %d concavecoplanar %d twisted facets and %d degen or redundant facets.\n",
     330             :     numcoplanar, numconcave, numconcavecoplanar, numtwisted, numdegenredun));
     331       12197 :   if (qh->IStracing >= 4 && qh->num_facets < 500)
     332           0 :     qh_printlists(qh);
     333       12197 : } /* all_merges */
     334             : 
     335             : /*-<a                             href="qh-merge_r.htm#TOC"
     336             :   >-------------------------------</a><a name="all_vertexmerges">-</a>
     337             : 
     338             :   qh_all_vertexmerges(qh, apexpointid, facet, &retryfacet )
     339             :     merge vertices in qh.vertex_mergeset and subsequent merges
     340             : 
     341             :   returns:
     342             :     returns retryfacet for facet (if defined)
     343             :     updates qh.facet_list, qh.num_facets, qh.vertex_list, qh.num_vertices
     344             :     mergesets are empty
     345             :     if merges, resets facet lists
     346             : 
     347             :   notes:
     348             :     called from qh_qhull, qh_addpoint, and qh_buildcone_mergepinched
     349             :     vertex merges occur after facet merges and qh_resetlists
     350             : 
     351             :   design:
     352             :     while merges in vertex_mergeset (MRGvertices)
     353             :       merge a pair of pinched vertices
     354             :       update vertex neighbors
     355             :       merge non-convex and degenerate facets and check for ridges with duplicate vertices
     356             :       partition outside points of deleted, "visible" facets
     357             : */
     358       14663 : void qh_all_vertexmerges(qhT *qh, int apexpointid, facetT *facet, facetT **retryfacet) {
     359             :   int numpoints; /* ignore count of partitioned points.  Used by qh_addpoint for Zpbalance */
     360             : 
     361       14663 :   if (retryfacet)
     362           0 :     *retryfacet= facet;
     363       14663 :   while (qh_setsize(qh, qh->vertex_mergeset) > 0) {
     364           0 :     trace1((qh, qh->ferr, 1057, "qh_all_vertexmerges: starting to merge %d vertex merges for apex p%d facet f%d\n",
     365             :             qh_setsize(qh, qh->vertex_mergeset), apexpointid, getid_(facet)));
     366           0 :     if (qh->IStracing >= 4  && qh->num_facets < 1000)
     367           0 :       qh_printlists(qh);
     368           0 :     qh_merge_pinchedvertices(qh, apexpointid /* qh.vertex_mergeset, visible_list, newvertex_list, newfacet_list */);
     369           0 :     qh_update_vertexneighbors(qh); /* update neighbors of qh.newvertex_list from qh_newvertices for deleted facets on qh.visible_list */
     370             :                            /* test ridges and merge non-convex facets */
     371           0 :     qh_getmergeset(qh, qh->newfacet_list);
     372           0 :     qh_all_merges(qh, True, False); /* calls qh_reducevertices */
     373           0 :     if (qh->CHECKfrequently)
     374           0 :       qh_checkpolygon(qh, qh->facet_list);
     375           0 :     qh_partitionvisible(qh, !qh_ALL, &numpoints /* qh.visible_list qh.del_vertices*/);
     376           0 :     if (retryfacet)
     377           0 :       *retryfacet= qh_getreplacement(qh, *retryfacet);
     378           0 :     qh_deletevisible(qh /* qh.visible_list  qh.del_vertices*/);
     379           0 :     qh_resetlists(qh, False, qh_RESETvisible /* qh.visible_list newvertex_list qh.newfacet_list */);
     380           0 :     if (qh->IStracing >= 4  && qh->num_facets < 1000) {
     381           0 :       qh_printlists(qh);
     382           0 :       qh_checkpolygon(qh, qh->facet_list);
     383             :     }
     384             :   }
     385       14663 : } /* all_vertexmerges */
     386             : 
     387             : /*-<a                             href="qh-merge_r.htm#TOC"
     388             :   >-------------------------------</a><a name="appendmergeset">-</a>
     389             : 
     390             :   qh_appendmergeset(qh, facet, vertex, neighbor, mergetype, dist, angle )
     391             :     appends an entry to qh.facet_mergeset or qh.degen_mergeset
     392             :     if 'dist' is unknown, set it to 0.0
     393             :         if 'angle' is unknown, set it to 1.0 (coplanar)
     394             : 
     395             :   returns:
     396             :     merge appended to facet_mergeset or degen_mergeset
     397             :       sets ->degenerate or ->redundant if degen_mergeset
     398             : 
     399             :   notes:
     400             :     caller collects statistics and/or caller of qh_mergefacet
     401             :     see: qh_test_appendmerge()
     402             : 
     403             :   design:
     404             :     allocate merge entry
     405             :     if regular merge
     406             :       append to qh.facet_mergeset
     407             :     else if degenerate merge and qh.facet_mergeset is all degenerate
     408             :       append to qh.degen_mergeset
     409             :     else if degenerate merge
     410             :       prepend to qh.degen_mergeset (merged last)
     411             :     else if redundant merge
     412             :       append to qh.degen_mergeset
     413             : */
     414           1 : void qh_appendmergeset(qhT *qh, facetT *facet, facetT *neighbor, mergeType mergetype, coordT dist, realT angle) {
     415             :   mergeT *merge, *lastmerge;
     416             :   void **freelistp; /* used if !qh_NOmem by qh_memalloc_() */
     417             :   const char *mergename;
     418             : 
     419           1 :   if ((facet->redundant && mergetype != MRGmirror) || neighbor->redundant) {
     420           0 :     trace3((qh, qh->ferr, 3051, "qh_appendmergeset: f%d is already redundant (%d) or f%d is already redundant (%d).  Ignore merge f%d and f%d type %d\n",
     421             :       facet->id, facet->redundant, neighbor->id, neighbor->redundant, facet->id, neighbor->id, mergetype));
     422           0 :     return;
     423             :   }
     424           1 :   if (facet->degenerate && mergetype == MRGdegen) {
     425           0 :     trace3((qh, qh->ferr, 3077, "qh_appendmergeset: f%d is already degenerate.  Ignore merge f%d type %d (MRGdegen)\n",
     426             :       facet->id, facet->id, mergetype));
     427           0 :     return;
     428             :   }
     429           1 :   if (!qh->facet_mergeset || !qh->degen_mergeset) {
     430           0 :     qh_fprintf(qh, qh->ferr, 6403, "qhull internal error (qh_appendmergeset): expecting temp set defined for qh.facet_mergeset (0x%x) and qh.degen_mergeset (0x%x).  Got NULL\n",
     431             :       qh->facet_mergeset, qh->degen_mergeset);
     432             :     /* otherwise qh_setappend creates a new set that is not freed by qh_freebuild() */
     433           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
     434             :   }
     435           1 :   if (neighbor->flipped && !facet->flipped) {
     436           0 :     if (mergetype != MRGdupridge) {
     437           0 :       qh_fprintf(qh, qh->ferr, 6355, "qhull internal error (qh_appendmergeset): except for MRGdupridge, cannot merge a non-flipped facet f%d into flipped f%d, mergetype %d, dist %4.4g\n",
     438             :         facet->id, neighbor->id, mergetype, dist);
     439           0 :       qh_errexit(qh, qh_ERRqhull, NULL, NULL);
     440             :     }else {
     441           0 :       trace2((qh, qh->ferr, 2106, "qh_appendmergeset: dupridge will merge a non-flipped facet f%d into flipped f%d, dist %4.4g\n",
     442             :         facet->id, neighbor->id, dist));
     443             :     }
     444             :   }
     445           1 :   qh_memalloc_(qh, (int)sizeof(mergeT), freelistp, merge, mergeT);
     446           1 :   merge->angle= angle;
     447           1 :   merge->distance= dist;
     448           1 :   merge->facet1= facet;
     449           1 :   merge->facet2= neighbor;
     450           1 :   merge->vertex1= NULL;
     451           1 :   merge->vertex2= NULL;
     452           1 :   merge->ridge1= NULL;
     453           1 :   merge->ridge2= NULL;
     454           1 :   merge->mergetype= mergetype;
     455           1 :   if(mergetype > 0 && mergetype < sizeof(mergetypes)/sizeof(char *))
     456           1 :     mergename= mergetypes[mergetype];
     457             :   else
     458           0 :     mergename= mergetypes[MRGnone];
     459           1 :   if (mergetype < MRGdegen)
     460           1 :     qh_setappend(qh, &(qh->facet_mergeset), merge);
     461           0 :   else if (mergetype == MRGdegen) {
     462           0 :     facet->degenerate= True;
     463           0 :     if (!(lastmerge= (mergeT *)qh_setlast(qh->degen_mergeset))
     464           0 :     || lastmerge->mergetype == MRGdegen)
     465           0 :       qh_setappend(qh, &(qh->degen_mergeset), merge);
     466             :     else
     467           0 :       qh_setaddnth(qh, &(qh->degen_mergeset), 0, merge);    /* merged last */
     468           0 :   }else if (mergetype == MRGredundant) {
     469           0 :     facet->redundant= True;
     470           0 :     qh_setappend(qh, &(qh->degen_mergeset), merge);
     471             :   }else /* mergetype == MRGmirror */ {
     472           0 :     if (facet->redundant || neighbor->redundant) {
     473           0 :       qh_fprintf(qh, qh->ferr, 6092, "qhull internal error (qh_appendmergeset): facet f%d or f%d is already a mirrored facet (i.e., 'redundant')\n",
     474             :            facet->id, neighbor->id);
     475           0 :       qh_errexit2(qh, qh_ERRqhull, facet, neighbor);
     476             :     }
     477           0 :     if (!qh_setequal(facet->vertices, neighbor->vertices)) {
     478           0 :       qh_fprintf(qh, qh->ferr, 6093, "qhull internal error (qh_appendmergeset): mirrored facets f%d and f%d do not have the same vertices\n",
     479             :            facet->id, neighbor->id);
     480           0 :       qh_errexit2(qh, qh_ERRqhull, facet, neighbor);
     481             :     }
     482           0 :     facet->redundant= True;
     483           0 :     neighbor->redundant= True;
     484           0 :     qh_setappend(qh, &(qh->degen_mergeset), merge);
     485             :   }
     486           1 :   if (merge->mergetype >= MRGdegen) {
     487           0 :     trace3((qh, qh->ferr, 3044, "qh_appendmergeset: append merge f%d and f%d type %d (%s) to qh.degen_mergeset (size %d)\n",
     488             :       merge->facet1->id, merge->facet2->id, merge->mergetype, mergename, qh_setsize(qh, qh->degen_mergeset)));
     489             :   }else {
     490           1 :     trace3((qh, qh->ferr, 3027, "qh_appendmergeset: append merge f%d and f%d type %d (%s) dist %2.2g angle %4.4g to qh.facet_mergeset (size %d)\n",
     491             :       merge->facet1->id, merge->facet2->id, merge->mergetype, mergename, merge->distance, merge->angle, qh_setsize(qh, qh->facet_mergeset)));
     492             :   }
     493             : } /* appendmergeset */
     494             : 
     495             : 
     496             : /*-<a                             href="qh-merge_r.htm#TOC"
     497             :   >-------------------------------</a><a name="appendvertexmerge">-</a>
     498             : 
     499             :   qh_appendvertexmerge(qh, vertex, vertex2, mergetype, distance, ridge1, ridge2 )
     500             :     appends a vertex merge to qh.vertex_mergeset
     501             :     MRGsubridge includes two ridges (from MRGdupridge)
     502             :     MRGvertices includes two ridges
     503             : 
     504             :   notes:
     505             :     called by qh_getpinchedmerges for MRGsubridge
     506             :     called by qh_maybe_duplicateridge and qh_maybe_duplicateridges for MRGvertices
     507             :     only way to add a vertex merge to qh.vertex_mergeset
     508             :     checked by qh_next_vertexmerge
     509             : */
     510           0 : void qh_appendvertexmerge(qhT *qh, vertexT *vertex, vertexT *destination, mergeType mergetype, realT distance, ridgeT *ridge1, ridgeT *ridge2) {
     511             :   mergeT *merge;
     512             :   void **freelistp; /* used if !qh_NOmem by qh_memalloc_() */
     513             :   const char *mergename;
     514             : 
     515           0 :   if (!qh->vertex_mergeset) {
     516           0 :     qh_fprintf(qh, qh->ferr, 6387, "qhull internal error (qh_appendvertexmerge): expecting temp set defined for qh.vertex_mergeset (0x%x).  Got NULL\n",
     517             :       qh->vertex_mergeset);
     518             :     /* otherwise qh_setappend creates a new set that is not freed by qh_freebuild() */
     519           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
     520             :   }
     521           0 :   qh_memalloc_(qh, (int)sizeof(mergeT), freelistp, merge, mergeT);
     522           0 :   merge->angle= qh_ANGLEnone;
     523           0 :   merge->distance= distance;
     524           0 :   merge->facet1= NULL;
     525           0 :   merge->facet2= NULL;
     526           0 :   merge->vertex1= vertex;
     527           0 :   merge->vertex2= destination;
     528           0 :   merge->ridge1= ridge1;
     529           0 :   merge->ridge2= ridge2;
     530           0 :   merge->mergetype= mergetype;
     531           0 :   if(mergetype > 0 && mergetype < sizeof(mergetypes)/sizeof(char *))
     532           0 :     mergename= mergetypes[mergetype];
     533             :   else
     534           0 :     mergename= mergetypes[MRGnone];
     535           0 :   if (mergetype == MRGvertices) {
     536           0 :     if (!ridge1 || !ridge2 || ridge1 == ridge2) {
     537           0 :       qh_fprintf(qh, qh->ferr, 6106, "qhull internal error (qh_appendvertexmerge): expecting two distinct ridges for MRGvertices.  Got r%d r%d\n",
     538           0 :         getid_(ridge1), getid_(ridge2));
     539           0 :       qh_errexit(qh, qh_ERRqhull, NULL, ridge1);
     540             :     }
     541             :   }
     542           0 :   qh_setappend(qh, &(qh->vertex_mergeset), merge);
     543           0 :   trace3((qh, qh->ferr, 3034, "qh_appendvertexmerge: append merge v%d into v%d r%d r%d dist %2.2g type %d (%s)\n",
     544             :     vertex->id, destination->id, getid_(ridge1), getid_(ridge2), distance, merge->mergetype, mergename));
     545           0 : } /* appendvertexmerge */
     546             : 
     547             : 
     548             : /*-<a                             href="qh-merge_r.htm#TOC"
     549             :   >-------------------------------</a><a name="basevertices">-</a>
     550             : 
     551             :   qh_basevertices(qh, samecycle )
     552             :     return temporary set of base vertices for samecycle
     553             :     samecycle is first facet in the cycle
     554             :     assumes apex is SETfirst_( samecycle->vertices )
     555             : 
     556             :   returns:
     557             :     vertices(settemp)
     558             :     all ->seen are cleared
     559             : 
     560             :   notes:
     561             :     uses qh_vertex_visit;
     562             : 
     563             :   design:
     564             :     for each facet in samecycle
     565             :       for each unseen vertex in facet->vertices
     566             :         append to result
     567             : */
     568           0 : setT *qh_basevertices(qhT *qh, facetT *samecycle) {
     569             :   facetT *same;
     570             :   vertexT *apex, *vertex, **vertexp;
     571           0 :   setT *vertices= qh_settemp(qh, qh->TEMPsize);
     572             : 
     573           0 :   apex= SETfirstt_(samecycle->vertices, vertexT);
     574           0 :   apex->visitid= ++qh->vertex_visit;
     575           0 :   FORALLsame_cycle_(samecycle) {
     576           0 :     if (same->mergeridge)
     577           0 :       continue;
     578           0 :     FOREACHvertex_(same->vertices) {
     579           0 :       if (vertex->visitid != qh->vertex_visit) {
     580           0 :         qh_setappend(qh, &vertices, vertex);
     581           0 :         vertex->visitid= qh->vertex_visit;
     582           0 :         vertex->seen= False;
     583             :       }
     584             :     }
     585             :   }
     586           0 :   trace4((qh, qh->ferr, 4019, "qh_basevertices: found %d vertices\n",
     587             :          qh_setsize(qh, vertices)));
     588           0 :   return vertices;
     589             : } /* basevertices */
     590             : 
     591             : /*-<a                             href="qh-merge_r.htm#TOC"
     592             :   >-------------------------------</a><a name="check_dupridge">-</a>
     593             : 
     594             :   qh_check_dupridge(qh, facet1, dist1, facet2, dist2 )
     595             :     Check dupridge between facet1 and facet2 for wide merge
     596             :     dist1 is the maximum distance of facet1's vertices to facet2
     597             :     dist2 is the maximum distance of facet2's vertices to facet1
     598             : 
     599             :   returns
     600             :     Level 1 log of the dupridge with the minimum distance between vertices
     601             :     Throws error if the merge will increase the maximum facet width by qh_WIDEduplicate (100x)
     602             : 
     603             :   notes:
     604             :     only called from qh_forcedmerges
     605             : */
     606           0 : void qh_check_dupridge(qhT *qh, facetT *facet1, realT dist1, facetT *facet2, realT dist2) {
     607             :   vertexT *vertex, **vertexp, *vertexA, **vertexAp;
     608             :   realT dist, innerplane, mergedist, outerplane, prevdist, ratio, vertexratio;
     609           0 :   realT minvertex= REALmax;
     610             : 
     611           0 :   mergedist= fmin_(dist1, dist2);
     612           0 :   qh_outerinner(qh, NULL, &outerplane, &innerplane);  /* ratio from qh_printsummary */
     613           0 :   FOREACHvertex_(facet1->vertices) {     /* The dupridge is between facet1 and facet2, so either facet can be tested */
     614           0 :     FOREACHvertexA_(facet1->vertices) {
     615           0 :       if (vertex > vertexA){   /* Test each pair once */
     616           0 :         dist= qh_pointdist(vertex->point, vertexA->point, qh->hull_dim);
     617           0 :         minimize_(minvertex, dist);
     618             :         /* Not quite correct.  A facet may have a dupridge and another pair of nearly adjacent vertices. */
     619             :       }
     620             :     }
     621             :   }
     622           0 :   prevdist= fmax_(outerplane, innerplane);
     623           0 :   maximize_(prevdist, qh->ONEmerge + qh->DISTround);
     624           0 :   maximize_(prevdist, qh->MINoutside + qh->DISTround);
     625           0 :   ratio= mergedist/prevdist;
     626           0 :   vertexratio= minvertex/prevdist;
     627           0 :   trace0((qh, qh->ferr, 16, "qh_check_dupridge: dupridge between f%d and f%d (vertex dist %2.2g), dist %2.2g, reverse dist %2.2g, ratio %2.2g while processing p%d\n",
     628             :         facet1->id, facet2->id, minvertex, dist1, dist2, ratio, qh->furthest_id));
     629           0 :   if (ratio > qh_WIDEduplicate) {
     630           0 :     qh_fprintf(qh, qh->ferr, 6271, "qhull topology error (qh_check_dupridge): wide merge (%.1fx wider) due to dupridge between f%d and f%d (vertex dist %2.2g), merge dist %2.2g, while processing p%d\n- Allow error with option 'Q12'\n",
     631             :       ratio, facet1->id, facet2->id, minvertex, mergedist, qh->furthest_id);
     632           0 :     if (vertexratio < qh_WIDEpinched)
     633           0 :       qh_fprintf(qh, qh->ferr, 8145, "- Experimental option merge-pinched-vertices ('Q14') may avoid this error.  It merges nearly adjacent vertices.\n");
     634           0 :     if (qh->DELAUNAY)
     635           0 :       qh_fprintf(qh, qh->ferr, 8145, "- A bounding box for the input sites may alleviate this error.\n");
     636           0 :     if (!qh->ALLOWwide)
     637           0 :       qh_errexit2(qh, qh_ERRwide, facet1, facet2);
     638             :   }
     639           0 : } /* check_dupridge */
     640             : 
     641             : /*-<a                             href="qh-merge_r.htm#TOC"
     642             :   >-------------------------------</a><a name="checkconnect">-</a>
     643             : 
     644             :   qh_checkconnect(qh)
     645             :     check that new facets are connected
     646             :     new facets are on qh.newfacet_list
     647             : 
     648             :   notes:
     649             :     this is slow and it changes the order of the facets
     650             :     uses qh.visit_id
     651             : 
     652             :   design:
     653             :     move first new facet to end of qh.facet_list
     654             :     for all newly appended facets
     655             :       append unvisited neighbors to end of qh.facet_list
     656             :     for all new facets
     657             :       report error if unvisited
     658             : */
     659           0 : void qh_checkconnect(qhT *qh /* qh.newfacet_list */) {
     660           0 :   facetT *facet, *newfacet, *errfacet= NULL, *neighbor, **neighborp;
     661             : 
     662           0 :   facet= qh->newfacet_list;
     663           0 :   qh_removefacet(qh, facet);
     664           0 :   qh_appendfacet(qh, facet);
     665           0 :   facet->visitid= ++qh->visit_id;
     666           0 :   FORALLfacet_(facet) {
     667           0 :     FOREACHneighbor_(facet) {
     668           0 :       if (neighbor->visitid != qh->visit_id) {
     669           0 :         qh_removefacet(qh, neighbor);
     670           0 :         qh_appendfacet(qh, neighbor);
     671           0 :         neighbor->visitid= qh->visit_id;
     672             :       }
     673             :     }
     674             :   }
     675           0 :   FORALLnew_facets {
     676           0 :     if (newfacet->visitid == qh->visit_id)
     677           0 :       break;
     678           0 :     qh_fprintf(qh, qh->ferr, 6094, "qhull internal error (qh_checkconnect): f%d is not attached to the new facets\n",
     679             :          newfacet->id);
     680           0 :     errfacet= newfacet;
     681             :   }
     682           0 :   if (errfacet)
     683           0 :     qh_errexit(qh, qh_ERRqhull, errfacet, NULL);
     684           0 : } /* checkconnect */
     685             : 
     686             : /*-<a                             href="qh-merge_r.htm#TOC"
     687             :   >-------------------------------</a><a name="checkdelfacet">-</a>
     688             : 
     689             :   qh_checkdelfacet(qh, facet, mergeset )
     690             :     check that mergeset does not reference facet
     691             : 
     692             : */
     693           0 : void qh_checkdelfacet(qhT *qh, facetT *facet, setT *mergeset) {
     694             :   mergeT *merge, **mergep;
     695             : 
     696           0 :   FOREACHmerge_(mergeset) {
     697           0 :     if (merge->facet1 == facet || merge->facet2 == facet) {
     698           0 :       qh_fprintf(qh, qh->ferr, 6390, "qhull internal error (qh_checkdelfacet): cannot delete f%d.  It is referenced by merge f%d f%d mergetype %d\n",
     699           0 :         facet->id, merge->facet1->id, getid_(merge->facet2), merge->mergetype);
     700           0 :       qh_errexit2(qh, qh_ERRqhull, merge->facet1, merge->facet2);
     701             :     }
     702             :   }
     703           0 : } /* checkdelfacet */
     704             : 
     705             : /*-<a                             href="qh-merge_r.htm#TOC"
     706             :   >-------------------------------</a><a name="checkdelridge">-</a>
     707             : 
     708             :   qh_checkdelridge(qh)
     709             :     check that qh_delridge_merge is not needed for deleted ridges
     710             : 
     711             :     notes:
     712             :       called from qh_mergecycle, qh_makenewfacets, qh_attachnewfacets
     713             :       errors if qh.vertex_mergeset is non-empty
     714             :       errors if any visible or new facet has a ridge with r.nonconvex set
     715             :       assumes that vertex.delfacet is not needed
     716             : */
     717           0 : void qh_checkdelridge(qhT *qh /* qh.visible_facets, vertex_mergeset */) {
     718             :   facetT *newfacet, *visible;
     719             :   ridgeT *ridge, **ridgep;
     720             : 
     721           0 :   if (!SETempty_(qh->vertex_mergeset)) {
     722           0 :     qh_fprintf(qh, qh->ferr, 6382, "qhull internal error (qh_checkdelridge): expecting empty qh.vertex_mergeset in order to avoid calling qh_delridge_merge.  Got %d merges\n", qh_setsize(qh, qh->vertex_mergeset));
     723           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
     724             :   }
     725             : 
     726           0 :   FORALLnew_facets {
     727           0 :     FOREACHridge_(newfacet->ridges) {
     728           0 :       if (ridge->nonconvex) {
     729           0 :         qh_fprintf(qh, qh->ferr, 6313, "qhull internal error (qh_checkdelridge): unexpected 'nonconvex' flag for ridge r%d in newfacet f%d.  Otherwise need to call qh_delridge_merge\n",
     730             :            ridge->id, newfacet->id);
     731           0 :         qh_errexit(qh, qh_ERRqhull, newfacet, ridge);
     732             :       }
     733             :     }
     734             :   }
     735             : 
     736           0 :   FORALLvisible_facets {
     737           0 :     FOREACHridge_(visible->ridges) {
     738           0 :       if (ridge->nonconvex) {
     739           0 :         qh_fprintf(qh, qh->ferr, 6385, "qhull internal error (qh_checkdelridge): unexpected 'nonconvex' flag for ridge r%d in visible facet f%d.  Otherwise need to call qh_delridge_merge\n",
     740             :           ridge->id, visible->id);
     741           0 :         qh_errexit(qh, qh_ERRqhull, visible, ridge);
     742             :       }
     743             :     }
     744             :   }
     745           0 : } /* checkdelridge */
     746             : 
     747             : 
     748             : /*-<a                             href="qh-merge_r.htm#TOC"
     749             :   >-------------------------------</a><a name="checkzero">-</a>
     750             : 
     751             :   qh_checkzero(qh, testall )
     752             :     check that facets are clearly convex for qh.DISTround with qh.MERGEexact
     753             : 
     754             :     if testall,
     755             :       test all facets for qh.MERGEexact post-merging
     756             :     else
     757             :       test qh.newfacet_list
     758             : 
     759             :     if qh.MERGEexact,
     760             :       allows coplanar ridges
     761             :       skips convexity test while qh.ZEROall_ok
     762             : 
     763             :   returns:
     764             :     True if all facets !flipped, !dupridge, normal
     765             :          if all horizon facets are simplicial
     766             :          if all vertices are clearly below neighbor
     767             :          if all opposite vertices of horizon are below
     768             :     clears qh.ZEROall_ok if any problems or coplanar facets
     769             : 
     770             :   notes:
     771             :     called by qh_premerge (qh.CHECKzero, 'C-0') and qh_qhull ('Qx')
     772             :     uses qh.vertex_visit
     773             :     horizon facets may define multiple new facets
     774             : 
     775             :   design:
     776             :     for all facets in qh.newfacet_list or qh.facet_list
     777             :       check for flagged faults (flipped, etc.)
     778             :     for all facets in qh.newfacet_list or qh.facet_list
     779             :       for each neighbor of facet
     780             :         skip horizon facets for qh.newfacet_list
     781             :         test the opposite vertex
     782             :       if qh.newfacet_list
     783             :         test the other vertices in the facet's horizon facet
     784             : */
     785       14660 : boolT qh_checkzero(qhT *qh, boolT testall) {
     786             :   facetT *facet, *neighbor;
     787             :   facetT *horizon, *facetlist;
     788             :   int neighbor_i, neighbor_n;
     789             :   vertexT *vertex, **vertexp;
     790             :   realT dist;
     791             : 
     792       14660 :   if (testall)
     793           0 :     facetlist= qh->facet_list;
     794             :   else {
     795       14660 :     facetlist= qh->newfacet_list;
     796       35119 :     FORALLfacet_(facetlist) {
     797       32655 :       horizon= SETfirstt_(facet->neighbors, facetT);
     798       32655 :       if (!horizon->simplicial)
     799        5733 :         goto LABELproblem;
     800       26922 :       if (facet->flipped || facet->dupridge || !facet->normal)
     801        6463 :         goto LABELproblem;
     802             :     }
     803        2464 :     if (qh->MERGEexact && qh->ZEROall_ok) {
     804           0 :       trace2((qh, qh->ferr, 2011, "qh_checkzero: skip convexity check until first pre-merge\n"));
     805           0 :       return True;
     806             :     }
     807             :   }
     808       15583 :   FORALLfacet_(facetlist) {
     809       13120 :     qh->vertex_visit++;
     810       13120 :     horizon= NULL;
     811       52480 :     FOREACHneighbor_i_(qh, facet) {
     812       39360 :       if (!neighbor_i && !testall) {
     813       13120 :         horizon= neighbor;
     814       13120 :         continue; /* horizon facet tested in qh_findhorizon */
     815             :       }
     816       26240 :       vertex= SETelemt_(facet->vertices, neighbor_i, vertexT);
     817       26240 :       vertex->visitid= qh->vertex_visit;
     818       26240 :       zzinc_(Zdistzero);
     819       26240 :       qh_distplane(qh, vertex->point, neighbor, &dist);
     820       26240 :       if (dist >= -2 * qh->DISTround) {  /* need 2x for qh_distround and 'Rn' for qh_checkconvex, same as qh.premerge_centrum */
     821           0 :         qh->ZEROall_ok= False;
     822           0 :         if (!qh->MERGEexact || testall || dist > qh->DISTround)
     823           0 :           goto LABELnonconvex;
     824             :       }
     825             :     }
     826       13120 :     if (!testall && horizon) {
     827       23635 :       FOREACHvertex_(horizon->vertices) {
     828       23635 :         if (vertex->visitid != qh->vertex_visit) {
     829       13120 :           zzinc_(Zdistzero);
     830       13120 :           qh_distplane(qh, vertex->point, facet, &dist);
     831       13120 :           if (dist >= -2 * qh->DISTround) {
     832           1 :             qh->ZEROall_ok= False;
     833           1 :             if (!qh->MERGEexact || dist > qh->DISTround)
     834           1 :               goto LABELnonconvexhorizon;
     835             :           }
     836       13119 :           break;
     837             :         }
     838             :       }
     839             :     }
     840             :   }
     841        2463 :   trace2((qh, qh->ferr, 2012, "qh_checkzero: testall %d, facets are %s\n", testall,
     842             :         (qh->MERGEexact && !testall) ?
     843             :            "not concave, flipped, or dupridge" : "clearly convex"));
     844        2463 :   return True;
     845             : 
     846       12196 :  LABELproblem:
     847       12196 :   qh->ZEROall_ok= False;
     848       12196 :   trace2((qh, qh->ferr, 2013, "qh_checkzero: qh_premerge is needed.  New facet f%d or its horizon f%d is non-simplicial, flipped, dupridge, or mergehorizon\n",
     849             :        facet->id, horizon->id));
     850       12196 :   return False;
     851             : 
     852           0 :  LABELnonconvex:
     853           0 :   trace2((qh, qh->ferr, 2014, "qh_checkzero: facet f%d and f%d are not clearly convex.  v%d dist %.2g\n",
     854             :          facet->id, neighbor->id, vertex->id, dist));
     855           0 :   return False;
     856             : 
     857           1 :  LABELnonconvexhorizon:
     858           1 :   trace2((qh, qh->ferr, 2060, "qh_checkzero: facet f%d and horizon f%d are not clearly convex.  v%d dist %.2g\n",
     859             :       facet->id, horizon->id, vertex->id, dist));
     860           1 :   return False;
     861             : } /* checkzero */
     862             : 
     863             : /*-<a                             href="qh-merge_r.htm#TOC"
     864             :   >-------------------------------</a><a name="compare_anglemerge">-</a>
     865             : 
     866             :   qh_compare_anglemerge( mergeA, mergeB )
     867             :     used by qsort() to order qh.facet_mergeset by mergetype and angle (qh.ANGLEmerge, 'Q1')
     868             :     lower numbered mergetypes done first (MRGcoplanar before MRGconcave)
     869             : 
     870             :   notes:
     871             :     qh_all_merges processes qh.facet_mergeset by qh_setdellast
     872             :     [mar'19] evaluated various options with eg/q_benchmark and merging of pinched vertices (Q14)
     873             : */
     874           0 : int qh_compare_anglemerge(const void *p1, const void *p2) {
     875           0 :   const mergeT *a= *((mergeT *const*)p1), *b= *((mergeT *const*)p2);
     876             : 
     877           0 :   if (a->mergetype != b->mergetype)
     878           0 :     return (a->mergetype < b->mergetype ? 1 : -1); /* select MRGcoplanar (1) before MRGconcave (3) */
     879             :   else
     880           0 :     return (a->angle > b->angle ? 1 : -1);         /* select coplanar merge (1.0) before sharp merge (-0.5) */
     881             : } /* compare_anglemerge */
     882             : 
     883             : /*-<a                             href="qh-merge_r.htm#TOC"
     884             :   >-------------------------------</a><a name="compare_facetmerge">-</a>
     885             : 
     886             :   qh_compare_facetmerge( mergeA, mergeB )
     887             :     used by qsort() to order merges by mergetype, first merge, first
     888             :     lower numbered mergetypes done first (MRGcoplanar before MRGconcave)
     889             :     if same merge type, flat merges are first
     890             : 
     891             :   notes:
     892             :     qh_all_merges processes qh.facet_mergeset by qh_setdellast
     893             :     [mar'19] evaluated various options with eg/q_benchmark and merging of pinched vertices (Q14)
     894             : */
     895           0 : int qh_compare_facetmerge(const void *p1, const void *p2) {
     896           0 :   const mergeT *a= *((mergeT *const*)p1), *b= *((mergeT *const*)p2);
     897             : 
     898           0 :   if (a->mergetype != b->mergetype)
     899           0 :     return (a->mergetype < b->mergetype ? 1 : -1); /* select MRGcoplanar (1) before MRGconcave (3) */
     900           0 :   else if (a->mergetype == MRGanglecoplanar)
     901           0 :     return (a->angle > b->angle ? 1 : -1);         /* if MRGanglecoplanar, select coplanar merge (1.0) before sharp merge (-0.5) */
     902             :   else
     903           0 :     return (a->distance < b->distance ? 1 : -1);   /* select flat (0.0) merge before wide (1e-10) merge */
     904             : } /* compare_facetmerge */
     905             : 
     906             : /*-<a                             href="qh-merge_r.htm#TOC"
     907             :   >-------------------------------</a><a name="comparevisit">-</a>
     908             : 
     909             :   qh_comparevisit( vertexA, vertexB )
     910             :     used by qsort() to order vertices by their visitid
     911             : 
     912             :   notes:
     913             :     only called by qh_find_newvertex
     914             : */
     915           0 : int qh_comparevisit(const void *p1, const void *p2) {
     916           0 :   const vertexT *a= *((vertexT *const*)p1), *b= *((vertexT *const*)p2);
     917             : 
     918           0 :   if (a->visitid > b->visitid)
     919           0 :     return 1;
     920           0 :   return -1;
     921             : } /* comparevisit */
     922             : 
     923             : /*-<a                             href="qh-merge_r.htm#TOC"
     924             :   >-------------------------------</a><a name="copynonconvex">-</a>
     925             : 
     926             :   qh_copynonconvex(qh, atridge )
     927             :     set non-convex flag on other ridges (if any) between same neighbors
     928             : 
     929             :   notes:
     930             :     may be faster if use smaller ridge set
     931             : 
     932             :   design:
     933             :     for each ridge of atridge's top facet
     934             :       if ridge shares the same neighbor
     935             :         set nonconvex flag
     936             : */
     937           0 : void qh_copynonconvex(qhT *qh, ridgeT *atridge) {
     938             :   facetT *facet, *otherfacet;
     939             :   ridgeT *ridge, **ridgep;
     940             : 
     941           0 :   facet= atridge->top;
     942           0 :   otherfacet= atridge->bottom;
     943           0 :   atridge->nonconvex= False;
     944           0 :   FOREACHridge_(facet->ridges) {
     945           0 :     if (otherfacet == ridge->top || otherfacet == ridge->bottom) {
     946           0 :       if (ridge != atridge) {
     947           0 :         ridge->nonconvex= True;
     948           0 :         trace4((qh, qh->ferr, 4020, "qh_copynonconvex: moved nonconvex flag from r%d to r%d between f%d and f%d\n",
     949             :                 atridge->id, ridge->id, facet->id, otherfacet->id));
     950           0 :         break;
     951             :       }
     952             :     }
     953             :   }
     954           0 : } /* copynonconvex */
     955             : 
     956             : /*-<a                             href="qh-merge_r.htm#TOC"
     957             :   >-------------------------------</a><a name="degen_redundant_facet">-</a>
     958             : 
     959             :   qh_degen_redundant_facet(qh, facet )
     960             :     check for a degenerate (too few neighbors) or redundant (subset of vertices) facet
     961             : 
     962             :   notes:
     963             :     called at end of qh_mergefacet, qh_renamevertex, and qh_reducevertices
     964             :     bumps vertex_visit
     965             :     called if a facet was redundant but no longer is (qh_merge_degenredundant)
     966             :     qh_appendmergeset() only appends first reference to facet (i.e., redundant)
     967             :     see: qh_test_redundant_neighbors, qh_maydropneighbor
     968             : 
     969             :   design:
     970             :     test for redundant neighbor
     971             :     test for degenerate facet
     972             : */
     973           1 : void qh_degen_redundant_facet(qhT *qh, facetT *facet) {
     974             :   vertexT *vertex, **vertexp;
     975             :   facetT *neighbor, **neighborp;
     976             : 
     977           1 :   trace3((qh, qh->ferr, 3028, "qh_degen_redundant_facet: test facet f%d for degen/redundant\n",
     978             :           facet->id));
     979           1 :   if (facet->flipped) {
     980           0 :     trace2((qh, qh->ferr, 3074, "qh_degen_redundant_facet: f%d is flipped, will merge later\n", facet->id));
     981           0 :     return;
     982             :   }
     983           5 :   FOREACHneighbor_(facet) {
     984           4 :     if (neighbor->flipped) /* disallow merge of non-flipped into flipped, neighbor will be merged later */
     985           0 :       continue;
     986           4 :     if (neighbor->visible) {
     987           0 :       qh_fprintf(qh, qh->ferr, 6357, "qhull internal error (qh_degen_redundant_facet): facet f%d has deleted neighbor f%d (qh.visible_list)\n",
     988             :         facet->id, neighbor->id);
     989           0 :       qh_errexit2(qh, qh_ERRqhull, facet, neighbor);
     990             :     }
     991           4 :     qh->vertex_visit++;
     992          16 :     FOREACHvertex_(neighbor->vertices)
     993          12 :       vertex->visitid= qh->vertex_visit;
     994           7 :     FOREACHvertex_(facet->vertices) {
     995           7 :       if (vertex->visitid != qh->vertex_visit)
     996           4 :         break;
     997             :     }
     998           4 :     if (!vertex) {
     999           0 :       trace2((qh, qh->ferr, 2015, "qh_degen_redundant_facet: f%d is contained in f%d.  merge\n", facet->id, neighbor->id));
    1000           0 :       qh_appendmergeset(qh, facet, neighbor, MRGredundant, 0.0, 1.0);
    1001           0 :       return;
    1002             :     }
    1003             :   }
    1004           1 :   if (qh_setsize(qh, facet->neighbors) < qh->hull_dim) {
    1005           0 :     qh_appendmergeset(qh, facet, facet, MRGdegen, 0.0, 1.0);
    1006           0 :     trace2((qh, qh->ferr, 2016, "qh_degen_redundant_facet: f%d is degenerate.\n", facet->id));
    1007             :   }
    1008             : } /* degen_redundant_facet */
    1009             : 
    1010             : 
    1011             : /*-<a                             href="qh-merge_r.htm#TOC"
    1012             :   >-------------------------------</a><a name="delridge_merge">-</a>
    1013             : 
    1014             :   qh_delridge_merge(qh, ridge )
    1015             :     delete ridge due to a merge
    1016             : 
    1017             :   notes:
    1018             :     only called by merge_r.c (qh_mergeridges, qh_renameridgevertex)
    1019             :     ridges also freed in qh_freeqhull and qh_mergecycle_ridges
    1020             : 
    1021             :   design:
    1022             :     if needed, moves ridge.nonconvex to another ridge
    1023             :     sets vertex.delridge for qh_reducevertices
    1024             :     deletes ridge from qh.vertex_mergeset
    1025             :     deletes ridge from its neighboring facets
    1026             :     frees up its memory
    1027             : */
    1028       20048 : void qh_delridge_merge(qhT *qh, ridgeT *ridge) {
    1029             :   vertexT *vertex, **vertexp;
    1030             :   mergeT *merge;
    1031             :   int merge_i, merge_n;
    1032             : 
    1033       20048 :   trace3((qh, qh->ferr, 3036, "qh_delridge_merge: delete ridge r%d between f%d and f%d\n",
    1034             :     ridge->id, ridge->top->id, ridge->bottom->id));
    1035       20048 :   if (ridge->nonconvex)
    1036           0 :     qh_copynonconvex(qh, ridge);
    1037       60144 :   FOREACHvertex_(ridge->vertices)
    1038       40096 :     vertex->delridge= True;
    1039       20048 :   FOREACHmerge_i_(qh, qh->vertex_mergeset) {
    1040           0 :     if (merge->ridge1 == ridge || merge->ridge2 == ridge) {
    1041           0 :       trace3((qh, qh->ferr, 3029, "qh_delridge_merge: drop merge of v%d into v%d (dist %2.2g r%d r%d) due to deleted, duplicated ridge r%d\n",
    1042             :         merge->vertex1->id, merge->vertex2->id, merge->distance, merge->ridge1->id, merge->ridge2->id, ridge->id));
    1043           0 :       if (merge->ridge1 == ridge)
    1044           0 :         merge->ridge2->mergevertex= False;
    1045             :       else
    1046           0 :         merge->ridge1->mergevertex= False;
    1047           0 :       qh_setdelnth(qh, qh->vertex_mergeset, merge_i);
    1048           0 :       merge_i--; merge_n--; /* next merge after deleted */
    1049             :     }
    1050             :   }
    1051       20048 :   qh_setdel(ridge->top->ridges, ridge);
    1052       20048 :   qh_setdel(ridge->bottom->ridges, ridge);
    1053       20048 :   qh_delridge(qh, ridge);
    1054       20048 : } /* delridge_merge */
    1055             : 
    1056             : 
    1057             : /*-<a                             href="qh-merge_r.htm#TOC"
    1058             :   >-------------------------------</a><a name="drop_mergevertex">-</a>
    1059             : 
    1060             :   qh_drop_mergevertex(qh, merge )
    1061             : 
    1062             :   clear mergevertex flags for ridges of a vertex merge
    1063             : */
    1064           0 : void qh_drop_mergevertex(qhT *qh, mergeT *merge)
    1065             : {
    1066           0 :   if (merge->mergetype == MRGvertices) {
    1067           0 :     merge->ridge1->mergevertex= False;
    1068           0 :     merge->ridge1->mergevertex2= True;
    1069           0 :     merge->ridge2->mergevertex= False;
    1070           0 :     merge->ridge2->mergevertex2= True;
    1071           0 :     trace3((qh, qh->ferr, 3032, "qh_drop_mergevertex: unset mergevertex for r%d and r%d due to dropped vertex merge v%d to v%d.  Sets mergevertex2\n",
    1072             :       merge->ridge1->id, merge->ridge2->id, merge->vertex1->id, merge->vertex2->id));
    1073             :   }
    1074           0 : } /* drop_mergevertex */
    1075             : 
    1076             : /*-<a                             href="qh-merge_r.htm#TOC"
    1077             :   >-------------------------------</a><a name="find_newvertex">-</a>
    1078             : 
    1079             :   qh_find_newvertex(qh, oldvertex, vertices, ridges )
    1080             :     locate new vertex for renaming old vertex
    1081             :     vertices is a set of possible new vertices
    1082             :       vertices sorted by number of deleted ridges
    1083             : 
    1084             :   returns:
    1085             :     newvertex or NULL
    1086             :       each ridge includes both newvertex and oldvertex
    1087             :     vertices without oldvertex sorted by number of deleted ridges
    1088             :     qh.vertex_visit updated
    1089             :     sets v.seen
    1090             : 
    1091             :   notes:
    1092             :     called by qh_redundant_vertex due to vertex->delridge and qh_rename_sharedvertex
    1093             :     sets vertex->visitid to 0..setsize() for vertices
    1094             :     new vertex is in one of the ridges
    1095             :     renaming will not cause a duplicate ridge
    1096             :     renaming will minimize the number of deleted ridges
    1097             :     newvertex may not be adjacent in the dual (though unlikely)
    1098             : 
    1099             :   design:
    1100             :     for each vertex in vertices
    1101             :       set vertex->visitid to number of ridges
    1102             :     remove unvisited vertices
    1103             :     set qh.vertex_visit above all possible values
    1104             :     sort vertices by number of ridges (minimize ridges that need renaming
    1105             :     add each ridge to qh.hash_table
    1106             :     for each vertex in vertices
    1107             :       find the first vertex that would not cause a duplicate ridge after a rename
    1108             : */
    1109           0 : vertexT *qh_find_newvertex(qhT *qh, vertexT *oldvertex, setT *vertices, setT *ridges) {
    1110             :   vertexT *vertex, **vertexp;
    1111             :   setT *newridges;
    1112             :   ridgeT *ridge, **ridgep;
    1113             :   int size, hashsize;
    1114             :   int hash;
    1115             :   unsigned int maxvisit;
    1116             : 
    1117             : #ifndef qh_NOtrace
    1118           0 :   if (qh->IStracing >= 4) {
    1119           0 :     qh_fprintf(qh, qh->ferr, 8063, "qh_find_newvertex: find new vertex for v%d from ",
    1120             :              oldvertex->id);
    1121           0 :     FOREACHvertex_(vertices)
    1122           0 :       qh_fprintf(qh, qh->ferr, 8064, "v%d ", vertex->id);
    1123           0 :     FOREACHridge_(ridges)
    1124           0 :       qh_fprintf(qh, qh->ferr, 8065, "r%d ", ridge->id);
    1125           0 :     qh_fprintf(qh, qh->ferr, 8066, "\n");
    1126             :   }
    1127             : #endif
    1128           0 :   FOREACHridge_(ridges) {
    1129           0 :     FOREACHvertex_(ridge->vertices)
    1130           0 :       vertex->seen= False;
    1131             :   }
    1132           0 :   FOREACHvertex_(vertices) {
    1133           0 :     vertex->visitid= 0;  /* v.visitid will be number of ridges */
    1134           0 :     vertex->seen= True;
    1135             :   }
    1136           0 :   FOREACHridge_(ridges) {
    1137           0 :     FOREACHvertex_(ridge->vertices) {
    1138           0 :       if (vertex->seen)
    1139           0 :         vertex->visitid++;
    1140             :     }
    1141             :   }
    1142           0 :   FOREACHvertex_(vertices) {
    1143           0 :     if (!vertex->visitid) {
    1144           0 :       qh_setdelnth(qh, vertices, SETindex_(vertices,vertex));
    1145           0 :       vertexp--; /* repeat since deleted this vertex */
    1146             :     }
    1147             :   }
    1148           0 :   maxvisit= (unsigned int)qh_setsize(qh, ridges);
    1149           0 :   maximize_(qh->vertex_visit, maxvisit);
    1150           0 :   if (!qh_setsize(qh, vertices)) {
    1151           0 :     trace4((qh, qh->ferr, 4023, "qh_find_newvertex: vertices not in ridges for v%d\n",
    1152             :             oldvertex->id));
    1153           0 :     return NULL;
    1154             :   }
    1155           0 :   qsort(SETaddr_(vertices, vertexT), (size_t)qh_setsize(qh, vertices),
    1156             :                 sizeof(vertexT *), qh_comparevisit);
    1157             :   /* can now use qh->vertex_visit */
    1158           0 :   if (qh->PRINTstatistics) {
    1159           0 :     size= qh_setsize(qh, vertices);
    1160           0 :     zinc_(Zintersect);
    1161           0 :     zadd_(Zintersecttot, size);
    1162           0 :     zmax_(Zintersectmax, size);
    1163             :   }
    1164           0 :   hashsize= qh_newhashtable(qh, qh_setsize(qh, ridges));
    1165           0 :   FOREACHridge_(ridges)
    1166           0 :     qh_hashridge(qh, qh->hash_table, hashsize, ridge, oldvertex);
    1167           0 :   FOREACHvertex_(vertices) {
    1168           0 :     newridges= qh_vertexridges(qh, vertex, !qh_ALL);
    1169           0 :     FOREACHridge_(newridges) {
    1170           0 :       if (qh_hashridge_find(qh, qh->hash_table, hashsize, ridge, vertex, oldvertex, &hash)) {
    1171           0 :         zinc_(Zvertexridge);
    1172           0 :         break;
    1173             :       }
    1174             :     }
    1175           0 :     qh_settempfree(qh, &newridges);
    1176           0 :     if (!ridge)
    1177           0 :       break;  /* found a rename */
    1178             :   }
    1179           0 :   if (vertex) {
    1180             :     /* counted in qh_renamevertex */
    1181           0 :     trace2((qh, qh->ferr, 2020, "qh_find_newvertex: found v%d for old v%d from %d vertices and %d ridges.\n",
    1182             :       vertex->id, oldvertex->id, qh_setsize(qh, vertices), qh_setsize(qh, ridges)));
    1183             :   }else {
    1184           0 :     zinc_(Zfindfail);
    1185           0 :     trace0((qh, qh->ferr, 14, "qh_find_newvertex: no vertex for renaming v%d (all duplicated ridges) during p%d\n",
    1186             :       oldvertex->id, qh->furthest_id));
    1187             :   }
    1188           0 :   qh_setfree(qh, &qh->hash_table);
    1189           0 :   return vertex;
    1190             : } /* find_newvertex */
    1191             : 
    1192             : /*-<a                             href="qh-geom2_r.htm#TOC"
    1193             :   >-------------------------------</a><a name="findbest_pinchedvertex">-</a>
    1194             : 
    1195             :   qh_findbest_pinchedvertex(qh, merge, apex, nearestp, distp )
    1196             :     Determine the best pinched vertex to rename as its nearest neighboring vertex
    1197             :     Renaming will remove a duplicate MRGdupridge in newfacet_list
    1198             : 
    1199             :   returns:
    1200             :     pinched vertex (either apex or subridge), nearest vertex (subridge or neighbor vertex), and the distance between them
    1201             : 
    1202             :   notes:
    1203             :     only called by qh_getpinchedmerges
    1204             :     assumes qh.VERTEXneighbors
    1205             :     see qh_findbest_ridgevertex
    1206             : 
    1207             :   design:
    1208             :     if the facets have the same vertices
    1209             :       return the nearest vertex pair
    1210             :     else
    1211             :       the subridge is the intersection of the two new facets minus the apex
    1212             :       the subridge consists of qh.hull_dim-2 horizon vertices
    1213             :       the subridge is also a matched ridge for the new facets (its duplicate)
    1214             :       determine the nearest vertex to the apex
    1215             :       determine the nearest pair of subridge vertices
    1216             :       for each vertex in the subridge
    1217             :         determine the nearest neighbor vertex (not in the subridge)
    1218             : */
    1219           0 : vertexT *qh_findbest_pinchedvertex(qhT *qh, mergeT *merge, vertexT *apex, vertexT **nearestp, coordT *distp /* qh.newfacet_list */) {
    1220             :   vertexT *vertex, **vertexp, *vertexA, **vertexAp;
    1221           0 :   vertexT *bestvertex= NULL, *bestpinched= NULL;
    1222             :   setT *subridge, *maybepinched;
    1223           0 :   coordT dist, bestdist= REALmax;
    1224           0 :   coordT pincheddist= (qh->ONEmerge+qh->DISTround)*qh_RATIOpinchedsubridge;
    1225             : 
    1226           0 :   if (!merge->facet1->simplicial || !merge->facet2->simplicial) {
    1227           0 :     qh_fprintf(qh, qh->ferr, 6351, "qhull internal error (qh_findbest_pinchedvertex): expecting merge of adjacent, simplicial new facets.  f%d or f%d is not simplicial\n",
    1228           0 :       merge->facet1->id, merge->facet2->id);
    1229           0 :     qh_errexit2(qh, qh_ERRqhull, merge->facet1, merge->facet2);
    1230             :   }
    1231           0 :   subridge= qh_vertexintersect_new(qh, merge->facet1->vertices, merge->facet2->vertices); /* new setT.  No error_exit() */
    1232           0 :   if (qh_setsize(qh, subridge) == qh->hull_dim) { /* duplicate vertices */
    1233           0 :     bestdist= qh_vertex_bestdist2(qh, subridge, &bestvertex, &bestpinched);
    1234           0 :     if(bestvertex == apex) {
    1235           0 :       bestvertex= bestpinched;
    1236           0 :       bestpinched= apex;
    1237             :     }
    1238             :   }else {
    1239           0 :     qh_setdel(subridge, apex);
    1240           0 :     if (qh_setsize(qh, subridge) != qh->hull_dim - 2) {
    1241           0 :       qh_fprintf(qh, qh->ferr, 6409, "qhull internal error (qh_findbest_pinchedvertex): expecting subridge of qh.hull_dim-2 vertices for the intersection of new facets f%d and f%d minus their apex.  Got %d vertices\n",
    1242           0 :           merge->facet1->id, merge->facet2->id, qh_setsize(qh, subridge));
    1243           0 :       qh_errexit2(qh, qh_ERRqhull, merge->facet1, merge->facet2);
    1244             :     }
    1245           0 :     FOREACHvertex_(subridge) {
    1246           0 :       dist= qh_pointdist(vertex->point, apex->point, qh->hull_dim);
    1247           0 :       if (dist < bestdist) {
    1248           0 :         bestpinched= apex;
    1249           0 :         bestvertex= vertex;
    1250           0 :         bestdist= dist;
    1251             :       }
    1252             :     }
    1253           0 :     if (bestdist > pincheddist) {
    1254           0 :       FOREACHvertex_(subridge) {
    1255           0 :         FOREACHvertexA_(subridge) {
    1256           0 :           if (vertexA->id > vertex->id) { /* once per vertex pair, do not compare addresses */
    1257           0 :             dist= qh_pointdist(vertexA->point, vertex->point, qh->hull_dim);
    1258           0 :             if (dist < bestdist) {
    1259           0 :               bestpinched= vertexA;
    1260           0 :               bestvertex= vertex;
    1261           0 :               bestdist= dist;
    1262             :             }
    1263             :           }
    1264             :         }
    1265             :       }
    1266             :     }
    1267           0 :     if (bestdist > pincheddist) {
    1268           0 :       FOREACHvertexA_(subridge) {
    1269           0 :         maybepinched= qh_neighbor_vertices(qh, vertexA, subridge); /* subridge and apex tested above */
    1270           0 :         FOREACHvertex_(maybepinched) {
    1271           0 :           dist= qh_pointdist(vertex->point, vertexA->point, qh->hull_dim);
    1272           0 :           if (dist < bestdist) {
    1273           0 :             bestvertex= vertex;
    1274           0 :             bestpinched= vertexA;
    1275           0 :             bestdist= dist;
    1276             :           }
    1277             :         }
    1278           0 :         qh_settempfree(qh, &maybepinched);
    1279             :       }
    1280             :     }
    1281             :   }
    1282           0 :   *distp= bestdist;
    1283           0 :   qh_setfree(qh, &subridge); /* qh_err_exit not called since allocated */
    1284           0 :   if (!bestvertex) {  /* should never happen if qh.hull_dim > 2 */
    1285           0 :     qh_fprintf(qh, qh->ferr, 6274, "qhull internal error (qh_findbest_pinchedvertex): did not find best vertex for subridge of dupridge between f%d and f%d, while processing p%d\n", merge->facet1->id, merge->facet2->id, qh->furthest_id);
    1286           0 :     qh_errexit2(qh, qh_ERRqhull, merge->facet1, merge->facet2);
    1287             :   }
    1288           0 :   *nearestp= bestvertex;
    1289           0 :   trace2((qh, qh->ferr, 2061, "qh_findbest_pinchedvertex: best pinched p%d(v%d) and vertex p%d(v%d) are closest (%2.2g) for duplicate subridge between f%d and f%d\n",
    1290             :       qh_pointid(qh, bestpinched->point), bestpinched->id, qh_pointid(qh, bestvertex->point), bestvertex->id, bestdist, merge->facet1->id, merge->facet2->id));
    1291           0 :   return bestpinched;
    1292             : } /* findbest_pinchedvertex */
    1293             : 
    1294             : /*-<a                             href="qh-geom2_r.htm#TOC"
    1295             :   >-------------------------------</a><a name="findbest_ridgevertex">-</a>
    1296             : 
    1297             :   qh_findbest_ridgevertex(qh, ridge, pinchedp, distp )
    1298             :     Determine the best vertex/pinched-vertex to merge for ridges with the same vertices
    1299             : 
    1300             :   returns:
    1301             :     vertex, pinched vertex, and the distance between them
    1302             : 
    1303             :   notes:
    1304             :     assumes qh.hull_dim>=3
    1305             :     see qh_findbest_pinchedvertex
    1306             : 
    1307             : */
    1308           0 : vertexT *qh_findbest_ridgevertex(qhT *qh, ridgeT *ridge, vertexT **pinchedp, coordT *distp) {
    1309             :   vertexT *bestvertex;
    1310             : 
    1311           0 :   *distp= qh_vertex_bestdist2(qh, ridge->vertices, &bestvertex, pinchedp);
    1312           0 :   trace4((qh, qh->ferr, 4069, "qh_findbest_ridgevertex: best pinched p%d(v%d) and vertex p%d(v%d) are closest (%2.2g) for duplicated ridge r%d (same vertices) between f%d and f%d\n",
    1313             :       qh_pointid(qh, (*pinchedp)->point), (*pinchedp)->id, qh_pointid(qh, bestvertex->point), bestvertex->id, *distp, ridge->id, ridge->top->id, ridge->bottom->id));
    1314           0 :   return bestvertex;
    1315             : } /* findbest_ridgevertex */
    1316             : 
    1317             : /*-<a                             href="qh-merge_r.htm#TOC"
    1318             :   >-------------------------------</a><a name="findbest_test">-</a>
    1319             : 
    1320             :   qh_findbest_test(qh, testcentrum, facet, neighbor, &bestfacet, &dist, &mindist, &maxdist )
    1321             :     test neighbor of facet for qh_findbestneighbor()
    1322             :     if testcentrum,
    1323             :       tests centrum (assumes it is defined)
    1324             :     else
    1325             :       tests vertices
    1326             :     initially *bestfacet==NULL and *dist==REALmax
    1327             : 
    1328             :   returns:
    1329             :     if a better facet (i.e., vertices/centrum of facet closer to neighbor)
    1330             :       updates bestfacet, dist, mindist, and maxdist
    1331             : 
    1332             :   notes:
    1333             :     called by qh_findbestneighbor
    1334             :     ignores pairs of flipped facets, unless that's all there is
    1335             : */
    1336           6 : void qh_findbest_test(qhT *qh, boolT testcentrum, facetT *facet, facetT *neighbor,
    1337             :       facetT **bestfacet, realT *distp, realT *mindistp, realT *maxdistp) {
    1338             :   realT dist, mindist, maxdist;
    1339             : 
    1340           6 :   if (facet->flipped && neighbor->flipped && *bestfacet && !(*bestfacet)->flipped)
    1341           0 :     return; /* do not merge flipped into flipped facets */
    1342           6 :   if (testcentrum) {
    1343           0 :     zzinc_(Zbestdist);
    1344           0 :     qh_distplane(qh, facet->center, neighbor, &dist);
    1345           0 :     dist *= qh->hull_dim; /* estimate furthest vertex */
    1346           0 :     if (dist < 0) {
    1347           0 :       maxdist= 0;
    1348           0 :       mindist= dist;
    1349           0 :       dist= -dist;
    1350             :     }else {
    1351           0 :       mindist= 0;
    1352           0 :       maxdist= dist;
    1353             :     }
    1354             :   }else
    1355           6 :     dist= qh_getdistance(qh, facet, neighbor, &mindist, &maxdist);
    1356           6 :   if (dist < *distp) {
    1357           4 :     *bestfacet= neighbor;
    1358           4 :     *mindistp= mindist;
    1359           4 :     *maxdistp= maxdist;
    1360           4 :     *distp= dist;
    1361             :   }
    1362             : } /* findbest_test */
    1363             : 
    1364             : /*-<a                             href="qh-merge_r.htm#TOC"
    1365             :   >-------------------------------</a><a name="findbestneighbor">-</a>
    1366             : 
    1367             :   qh_findbestneighbor(qh, facet, dist, mindist, maxdist )
    1368             :     finds best neighbor (least dist) of a facet for merging
    1369             : 
    1370             :   returns:
    1371             :     returns min and max distances and their max absolute value
    1372             : 
    1373             :   notes:
    1374             :     error if qh_ASvoronoi
    1375             :     avoids merging old into new
    1376             :     assumes ridge->nonconvex only set on one ridge between a pair of facets
    1377             :     could use an early out predicate but not worth it
    1378             : 
    1379             :   design:
    1380             :     if a large facet
    1381             :       will test centrum
    1382             :     else
    1383             :       will test vertices
    1384             :     if a large facet
    1385             :       test nonconvex neighbors for best merge
    1386             :     else
    1387             :       test all neighbors for the best merge
    1388             :     if testing centrum
    1389             :       get distance information
    1390             : */
    1391           2 : facetT *qh_findbestneighbor(qhT *qh, facetT *facet, realT *distp, realT *mindistp, realT *maxdistp) {
    1392           2 :   facetT *neighbor, **neighborp, *bestfacet= NULL;
    1393             :   ridgeT *ridge, **ridgep;
    1394           2 :   boolT nonconvex= True, testcentrum= False;
    1395           2 :   int size= qh_setsize(qh, facet->vertices);
    1396             : 
    1397           2 :   if(qh->CENTERtype==qh_ASvoronoi){
    1398           0 :     qh_fprintf(qh, qh->ferr, 6272, "qhull internal error: cannot call qh_findbestneighor for f%d while qh.CENTERtype is qh_ASvoronoi\n", facet->id);
    1399           0 :     qh_errexit(qh, qh_ERRqhull, facet, NULL);
    1400             :   }
    1401           2 :   *distp= REALmax;
    1402           2 :   if (size > qh_BESTcentrum2 * qh->hull_dim + qh_BESTcentrum) {
    1403           0 :     testcentrum= True;
    1404           0 :     zinc_(Zbestcentrum);
    1405           0 :     if (!facet->center)
    1406           0 :        facet->center= qh_getcentrum(qh, facet);
    1407             :   }
    1408           2 :   if (size > qh->hull_dim + qh_BESTnonconvex) {
    1409           0 :     FOREACHridge_(facet->ridges) {
    1410           0 :       if (ridge->nonconvex) {
    1411           0 :         neighbor= otherfacet_(ridge, facet);
    1412           0 :         qh_findbest_test(qh, testcentrum, facet, neighbor,
    1413             :                           &bestfacet, distp, mindistp, maxdistp);
    1414             :       }
    1415             :     }
    1416             :   }
    1417           2 :   if (!bestfacet) {
    1418           2 :     nonconvex= False;
    1419           8 :     FOREACHneighbor_(facet)
    1420           6 :       qh_findbest_test(qh, testcentrum, facet, neighbor,
    1421             :                         &bestfacet, distp, mindistp, maxdistp);
    1422             :   }
    1423           2 :   if (!bestfacet) {
    1424           0 :     qh_fprintf(qh, qh->ferr, 6095, "qhull internal error (qh_findbestneighbor): no neighbors for f%d\n", facet->id);
    1425           0 :     qh_errexit(qh, qh_ERRqhull, facet, NULL);
    1426             :   }
    1427           2 :   if (testcentrum)
    1428           0 :     qh_getdistance(qh, facet, bestfacet, mindistp, maxdistp);
    1429           2 :   trace3((qh, qh->ferr, 3002, "qh_findbestneighbor: f%d is best neighbor for f%d testcentrum? %d nonconvex? %d dist %2.2g min %2.2g max %2.2g\n",
    1430             :      bestfacet->id, facet->id, testcentrum, nonconvex, *distp, *mindistp, *maxdistp));
    1431           2 :   return(bestfacet);
    1432             : } /* findbestneighbor */
    1433             : 
    1434             : 
    1435             : /*-<a                             href="qh-merge_r.htm#TOC"
    1436             :   >-------------------------------</a><a name="flippedmerges">-</a>
    1437             : 
    1438             :   qh_flippedmerges(qh, facetlist, wasmerge )
    1439             :     merge flipped facets into best neighbor
    1440             :     assumes qh.facet_mergeset at top of temporary stack
    1441             : 
    1442             :   returns:
    1443             :     no flipped facets on facetlist
    1444             :     sets wasmerge if merge occurred
    1445             :     degen/redundant merges passed through
    1446             : 
    1447             :   notes:
    1448             :     othermerges not needed since qh.facet_mergeset is empty before & after
    1449             :       keep it in case of change
    1450             : 
    1451             :   design:
    1452             :     append flipped facets to qh.facetmergeset
    1453             :     for each flipped merge
    1454             :       find best neighbor
    1455             :       merge facet into neighbor
    1456             :       merge degenerate and redundant facets
    1457             :     remove flipped merges from qh.facet_mergeset
    1458             : */
    1459       12197 : void qh_flippedmerges(qhT *qh, facetT *facetlist, boolT *wasmerge) {
    1460             :   facetT *facet, *neighbor, *facet1;
    1461             :   realT dist, mindist, maxdist;
    1462             :   mergeT *merge, **mergep;
    1463             :   setT *othermerges;
    1464       12197 :   int nummerge= 0, numdegen= 0;
    1465             : 
    1466       12197 :   trace4((qh, qh->ferr, 4024, "qh_flippedmerges: begin\n"));
    1467       72484 :   FORALLfacet_(facetlist) {
    1468       60287 :     if (facet->flipped && !facet->visible)
    1469           0 :       qh_appendmergeset(qh, facet, facet, MRGflip, 0.0, 1.0);
    1470             :   }
    1471       12197 :   othermerges= qh_settemppop(qh);
    1472       12197 :   if(othermerges != qh->facet_mergeset) {
    1473           0 :     qh_fprintf(qh, qh->ferr, 6392, "qhull internal error (qh_flippedmerges): facet_mergeset (%d merges) not at top of tempstack (%d merges)\n",
    1474             :         qh_setsize(qh, qh->facet_mergeset), qh_setsize(qh, othermerges));
    1475           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    1476             :   }
    1477       12197 :   qh->facet_mergeset= qh_settemp(qh, qh->TEMPsize);
    1478       12197 :   qh_settemppush(qh, othermerges);
    1479       12197 :   FOREACHmerge_(othermerges) {
    1480           0 :     facet1= merge->facet1;
    1481           0 :     if (merge->mergetype != MRGflip || facet1->visible)
    1482           0 :       continue;
    1483           0 :     if (qh->TRACEmerge-1 == zzval_(Ztotmerge))
    1484           0 :       qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    1485           0 :     neighbor= qh_findbestneighbor(qh, facet1, &dist, &mindist, &maxdist);
    1486           0 :     trace0((qh, qh->ferr, 15, "qh_flippedmerges: merge flipped f%d into f%d dist %2.2g during p%d\n",
    1487             :       facet1->id, neighbor->id, dist, qh->furthest_id));
    1488           0 :     qh_mergefacet(qh, facet1, neighbor, merge->mergetype, &mindist, &maxdist, !qh_MERGEapex);
    1489           0 :     nummerge++;
    1490           0 :     if (qh->PRINTstatistics) {
    1491           0 :       zinc_(Zflipped);
    1492           0 :       wadd_(Wflippedtot, dist);
    1493           0 :       wmax_(Wflippedmax, dist);
    1494             :     }
    1495             :   }
    1496       12197 :   FOREACHmerge_(othermerges) {
    1497           0 :     if (merge->facet1->visible || merge->facet2->visible)
    1498           0 :       qh_memfree(qh, merge, (int)sizeof(mergeT)); /* invalidates merge and othermerges */
    1499             :     else
    1500           0 :       qh_setappend(qh, &qh->facet_mergeset, merge);
    1501             :   }
    1502       12197 :   qh_settempfree(qh, &othermerges);
    1503       12197 :   numdegen += qh_merge_degenredundant(qh); /* somewhat better here than after each flipped merge -- qtest.sh 10 '500 C1,2e-13 D4' 'd Qbb' */
    1504       12197 :   if (nummerge)
    1505           0 :     *wasmerge= True;
    1506       12197 :   trace1((qh, qh->ferr, 1010, "qh_flippedmerges: merged %d flipped and %d degenredundant facets into a good neighbor\n",
    1507             :     nummerge, numdegen));
    1508       12197 : } /* flippedmerges */
    1509             : 
    1510             : 
    1511             : /*-<a                             href="qh-merge_r.htm#TOC"
    1512             :   >-------------------------------</a><a name="forcedmerges">-</a>
    1513             : 
    1514             :   qh_forcedmerges(qh, wasmerge )
    1515             :     merge dupridges
    1516             :     calls qh_check_dupridge to report an error on wide merges
    1517             :     assumes qh_settemppop is qh.facet_mergeset
    1518             : 
    1519             :   returns:
    1520             :     removes all dupridges on facet_mergeset
    1521             :     wasmerge set if merge
    1522             :     qh.facet_mergeset may include non-forced merges(none for now)
    1523             :     qh.degen_mergeset includes degen/redun merges
    1524             : 
    1525             :   notes:
    1526             :     called by qh_premerge
    1527             :     dupridges occur when the horizon is pinched,
    1528             :         i.e. a subridge occurs in more than two horizon ridges.
    1529             :      could rename vertices that pinch the horizon
    1530             :     assumes qh_merge_degenredundant() has not be called
    1531             :     othermerges isn't needed since facet_mergeset is empty afterwards
    1532             :       keep it in case of change
    1533             : 
    1534             :   design:
    1535             :     for each dupridge
    1536             :       find current facets by chasing f.replace links
    1537             :       check for wide merge due to dupridge
    1538             :       determine best direction for facet
    1539             :       merge one facet into the other
    1540             :       remove dupridges from qh.facet_mergeset
    1541             : */
    1542       12197 : void qh_forcedmerges(qhT *qh, boolT *wasmerge) {
    1543             :   facetT *facet1, *facet2, *merging, *merged, *newfacet;
    1544             :   mergeT *merge, **mergep;
    1545             :   realT dist, mindist, maxdist, dist2, mindist2, maxdist2;
    1546             :   setT *othermerges;
    1547       12197 :   int nummerge=0, numflip=0, numdegen= 0;
    1548       12197 :   boolT wasdupridge= False;
    1549             : 
    1550       12197 :   if (qh->TRACEmerge-1 == zzval_(Ztotmerge))
    1551           0 :     qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    1552       12197 :   trace3((qh, qh->ferr, 3054, "qh_forcedmerges: merge dupridges\n"));
    1553       12197 :   othermerges= qh_settemppop(qh); /* was facet_mergeset */
    1554       12197 :   if (qh->facet_mergeset != othermerges ) {
    1555           0 :       qh_fprintf(qh, qh->ferr, 6279, "qhull internal error (qh_forcedmerges): qh_settemppop (size %d) is not qh->facet_mergeset (size %d)\n",
    1556             :           qh_setsize(qh, othermerges), qh_setsize(qh, qh->facet_mergeset));
    1557           0 :       qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    1558             :   }
    1559       12197 :   qh->facet_mergeset= qh_settemp(qh, qh->TEMPsize);
    1560       12197 :   qh_settemppush(qh, othermerges);
    1561       12197 :   FOREACHmerge_(othermerges) {
    1562           0 :     if (merge->mergetype != MRGdupridge)
    1563           0 :         continue;
    1564           0 :     wasdupridge= True;
    1565           0 :     if (qh->TRACEmerge-1 == zzval_(Ztotmerge))
    1566           0 :         qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    1567           0 :     facet1= qh_getreplacement(qh, merge->facet1);  /* must exist, no qh_merge_degenredunant */
    1568           0 :     facet2= qh_getreplacement(qh, merge->facet2);  /* previously merged facet, if any */
    1569           0 :     if (facet1 == facet2)
    1570           0 :       continue;
    1571           0 :     if (!qh_setin(facet2->neighbors, facet1)) {
    1572           0 :       qh_fprintf(qh, qh->ferr, 6096, "qhull internal error (qh_forcedmerges): f%d and f%d had a dupridge but as f%d and f%d they are no longer neighbors\n",
    1573           0 :                merge->facet1->id, merge->facet2->id, facet1->id, facet2->id);
    1574           0 :       qh_errexit2(qh, qh_ERRqhull, facet1, facet2);
    1575             :     }
    1576           0 :     dist= qh_getdistance(qh, facet1, facet2, &mindist, &maxdist);
    1577           0 :     dist2= qh_getdistance(qh, facet2, facet1, &mindist2, &maxdist2);
    1578           0 :     qh_check_dupridge(qh, facet1, dist, facet2, dist2);
    1579           0 :     if (dist < dist2) {
    1580           0 :       if (facet2->flipped && !facet1->flipped && dist2 < qh_WIDEdupridge*(qh->ONEmerge+qh->DISTround)) { /* prefer merge of flipped facet */
    1581           0 :         merging= facet2;
    1582           0 :         merged= facet1;
    1583           0 :         dist= dist2;
    1584           0 :         mindist= mindist2;
    1585           0 :         maxdist= maxdist2;
    1586             :       }else {
    1587           0 :         merging= facet1;
    1588           0 :         merged= facet2;
    1589             :       }
    1590             :     }else {
    1591           0 :       if (facet1->flipped && !facet2->flipped && dist < qh_WIDEdupridge*(qh->ONEmerge+qh->DISTround)) { /* prefer merge of flipped facet */
    1592           0 :         merging= facet1;
    1593           0 :         merged= facet2;
    1594             :       }else {
    1595           0 :         merging= facet2;
    1596           0 :         merged= facet1;
    1597           0 :         dist= dist2;
    1598           0 :         mindist= mindist2;
    1599           0 :         maxdist= maxdist2;
    1600             :       }
    1601             :     }
    1602           0 :     qh_mergefacet(qh, merging, merged, merge->mergetype, &mindist, &maxdist, !qh_MERGEapex);
    1603           0 :     numdegen += qh_merge_degenredundant(qh); /* better here than at end -- qtest.sh 10 '500 C1,2e-13 D4' 'd Qbb' */
    1604           0 :     if (facet1->flipped) {
    1605           0 :       zinc_(Zmergeflipdup);
    1606           0 :       numflip++;
    1607             :     }else
    1608           0 :       nummerge++;
    1609           0 :     if (qh->PRINTstatistics) {
    1610           0 :       zinc_(Zduplicate);
    1611           0 :       wadd_(Wduplicatetot, dist);
    1612           0 :       wmax_(Wduplicatemax, dist);
    1613             :     }
    1614             :   }
    1615       12197 :   FOREACHmerge_(othermerges) {
    1616           0 :     if (merge->mergetype == MRGdupridge)
    1617           0 :       qh_memfree(qh, merge, (int)sizeof(mergeT)); /* invalidates merge and othermerges */
    1618             :     else
    1619           0 :       qh_setappend(qh, &qh->facet_mergeset, merge);
    1620             :   }
    1621       12197 :   qh_settempfree(qh, &othermerges);
    1622       12197 :   if (wasdupridge) {
    1623           0 :     FORALLnew_facets {
    1624           0 :       if (newfacet->dupridge) {
    1625           0 :         newfacet->dupridge= False;
    1626           0 :         newfacet->mergeridge= False;
    1627           0 :         newfacet->mergeridge2= False;
    1628           0 :         if (qh_setsize(qh, newfacet->neighbors) < qh->hull_dim) { /* not tested for MRGdupridge */
    1629           0 :           qh_appendmergeset(qh, newfacet, newfacet, MRGdegen, 0.0, 1.0);
    1630           0 :           trace2((qh, qh->ferr, 2107, "qh_forcedmerges: dupridge f%d is degenerate with fewer than %d neighbors\n",
    1631             :                       newfacet->id, qh->hull_dim));
    1632             :         }
    1633             :       }
    1634             :     }
    1635           0 :     numdegen += qh_merge_degenredundant(qh);
    1636             :   }
    1637       12197 :   if (nummerge || numflip) {
    1638           0 :     *wasmerge= True;
    1639           0 :     trace1((qh, qh->ferr, 1011, "qh_forcedmerges: merged %d facets, %d flipped facets, and %d degenredundant facets across dupridges\n",
    1640             :                   nummerge, numflip, numdegen));
    1641             :   }
    1642       12197 : } /* forcedmerges */
    1643             : 
    1644             : 
    1645             : /*-<a                             href="qh-merge_r.htm#TOC"
    1646             :   >-------------------------------</a><a name="freemergesets">-</a>
    1647             : 
    1648             :   qh_freemergesets(qh )
    1649             :     free the merge sets
    1650             : 
    1651             :   notes:
    1652             :     matches qh_initmergesets
    1653             : */
    1654       14666 : void qh_freemergesets(qhT *qh) {
    1655             : 
    1656       14666 :   if (!qh->facet_mergeset || !qh->degen_mergeset || !qh->vertex_mergeset) {
    1657           0 :     qh_fprintf(qh, qh->ferr, 6388, "qhull internal error (qh_freemergesets): expecting mergesets.  Got a NULL mergeset, qh.facet_mergeset (0x%x), qh.degen_mergeset (0x%x), qh.vertex_mergeset (0x%x)\n",
    1658             :       qh->facet_mergeset, qh->degen_mergeset, qh->vertex_mergeset);
    1659           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    1660             :   }
    1661       14666 :   if (!SETempty_(qh->facet_mergeset) || !SETempty_(qh->degen_mergeset) || !SETempty_(qh->vertex_mergeset)) {
    1662           0 :     qh_fprintf(qh, qh->ferr, 6389, "qhull internal error (qh_freemergesets): expecting empty mergesets.  Got qh.facet_mergeset (%d merges), qh.degen_mergeset (%d merges), qh.vertex_mergeset (%d merges)\n",
    1663             :       qh_setsize(qh, qh->facet_mergeset), qh_setsize(qh, qh->degen_mergeset), qh_setsize(qh, qh->vertex_mergeset));
    1664           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    1665             :   }
    1666       14666 :   qh_settempfree(qh, &qh->facet_mergeset);
    1667       14666 :   qh_settempfree(qh, &qh->vertex_mergeset);
    1668       14666 :   qh_settempfree(qh, &qh->degen_mergeset);
    1669       14666 : } /* freemergesets */
    1670             : 
    1671             : /*-<a                             href="qh-merge_r.htm#TOC"
    1672             :   >-------------------------------</a><a name="getmergeset">-</a>
    1673             : 
    1674             :   qh_getmergeset(qh, facetlist )
    1675             :     determines nonconvex facets on facetlist
    1676             :     tests !tested ridges and nonconvex ridges of !tested facets
    1677             : 
    1678             :   returns:
    1679             :     returns sorted qh.facet_mergeset of facet-neighbor pairs to be merged
    1680             :     all ridges tested
    1681             : 
    1682             :   notes:
    1683             :     facetlist is qh.facet_newlist, use qh_getmergeset_initial for all facets
    1684             :     assumes no nonconvex ridges with both facets tested
    1685             :     uses facet->tested/ridge->tested to prevent duplicate tests
    1686             :     can not limit tests to modified ridges since the centrum changed
    1687             :     uses qh.visit_id
    1688             : 
    1689             :   design:
    1690             :     for each facet on facetlist
    1691             :       for each ridge of facet
    1692             :         if untested ridge
    1693             :           test ridge for convexity
    1694             :           if non-convex
    1695             :             append ridge to qh.facet_mergeset
    1696             :     sort qh.facet_mergeset by mergetype and angle or distance
    1697             : */
    1698           1 : void qh_getmergeset(qhT *qh, facetT *facetlist) {
    1699             :   facetT *facet, *neighbor, **neighborp;
    1700             :   ridgeT *ridge, **ridgep;
    1701             :   int nummerges;
    1702             :   boolT simplicial;
    1703             : 
    1704           1 :   nummerges= qh_setsize(qh, qh->facet_mergeset);
    1705           1 :   trace4((qh, qh->ferr, 4026, "qh_getmergeset: started.\n"));
    1706           1 :   qh->visit_id++;
    1707           7 :   FORALLfacet_(facetlist) {
    1708           6 :     if (facet->tested)
    1709           5 :       continue;
    1710           1 :     facet->visitid= qh->visit_id;
    1711           5 :     FOREACHneighbor_(facet)
    1712           4 :       neighbor->seen= False;
    1713             :     /* facet must be non-simplicial due to merge to qh.facet_newlist */
    1714           5 :     FOREACHridge_(facet->ridges) {
    1715           4 :       if (ridge->tested && !ridge->nonconvex)
    1716           0 :         continue;
    1717             :       /* if r.tested & r.nonconvex, need to retest and append merge */
    1718           4 :       neighbor= otherfacet_(ridge, facet);
    1719           4 :       if (neighbor->seen) { /* another ridge for this facet-neighbor pair was already tested in this loop */
    1720           0 :         ridge->tested= True;
    1721           0 :         ridge->nonconvex= False;   /* only one ridge is marked nonconvex per facet-neighbor pair */
    1722           4 :       }else if (neighbor->visitid != qh->visit_id) {
    1723           4 :         neighbor->seen= True;
    1724           4 :         ridge->nonconvex= False;
    1725           4 :         simplicial= False;
    1726           4 :         if (ridge->simplicialbot && ridge->simplicialtop)
    1727           2 :           simplicial= True;
    1728           4 :         if (qh_test_appendmerge(qh, facet, neighbor, simplicial))
    1729           0 :           ridge->nonconvex= True;
    1730           4 :         ridge->tested= True;
    1731             :       }
    1732             :     }
    1733           1 :     facet->tested= True;
    1734             :   }
    1735           1 :   nummerges= qh_setsize(qh, qh->facet_mergeset);
    1736           1 :   if (qh->ANGLEmerge)
    1737           0 :     qsort(SETaddr_(qh->facet_mergeset, mergeT), (size_t)nummerges, sizeof(mergeT *), qh_compare_anglemerge);
    1738             :   else
    1739           1 :     qsort(SETaddr_(qh->facet_mergeset, mergeT), (size_t)nummerges, sizeof(mergeT *), qh_compare_facetmerge);
    1740           1 :   nummerges += qh_setsize(qh, qh->degen_mergeset);
    1741           1 :   if (qh->POSTmerging) {
    1742           0 :     zadd_(Zmergesettot2, nummerges);
    1743             :   }else {
    1744           1 :     zadd_(Zmergesettot, nummerges);
    1745           1 :     zmax_(Zmergesetmax, nummerges);
    1746             :   }
    1747           1 :   trace2((qh, qh->ferr, 2021, "qh_getmergeset: %d merges found\n", nummerges));
    1748           1 : } /* getmergeset */
    1749             : 
    1750             : 
    1751             : /*-<a                             href="qh-merge_r.htm#TOC"
    1752             :   >-------------------------------</a><a name="getmergeset_initial">-</a>
    1753             : 
    1754             :   qh_getmergeset_initial(qh, facetlist )
    1755             :     determine initial qh.facet_mergeset for facets
    1756             :     tests all facet/neighbor pairs on facetlist
    1757             : 
    1758             :   returns:
    1759             :     sorted qh.facet_mergeset with nonconvex ridges
    1760             :     sets facet->tested, ridge->tested, and ridge->nonconvex
    1761             : 
    1762             :   notes:
    1763             :     uses visit_id, assumes ridge->nonconvex is False
    1764             :     see qh_getmergeset
    1765             : 
    1766             :   design:
    1767             :     for each facet on facetlist
    1768             :       for each untested neighbor of facet
    1769             :         test facet and neighbor for convexity
    1770             :         if non-convex
    1771             :           append merge to qh.facet_mergeset
    1772             :           mark one of the ridges as nonconvex
    1773             :     sort qh.facet_mergeset by mergetype and angle or distance
    1774             : */
    1775       12197 : void qh_getmergeset_initial(qhT *qh, facetT *facetlist) {
    1776             :   facetT *facet, *neighbor, **neighborp;
    1777             :   ridgeT *ridge, **ridgep;
    1778             :   int nummerges;
    1779             :   boolT simplicial;
    1780             : 
    1781       12197 :   qh->visit_id++;
    1782       72484 :   FORALLfacet_(facetlist) {
    1783       60287 :     facet->visitid= qh->visit_id;
    1784      289389 :     FOREACHneighbor_(facet) {
    1785      229102 :       if (neighbor->visitid != qh->visit_id) {
    1786      168815 :         simplicial= False; /* ignores r.simplicialtop/simplicialbot.  Need to test horizon facets */
    1787      168815 :         if (facet->simplicial && neighbor->simplicial)
    1788       59296 :           simplicial= True;
    1789      168815 :         if (qh_test_appendmerge(qh, facet, neighbor, simplicial)) {
    1790           1 :           FOREACHridge_(neighbor->ridges) {
    1791           0 :             if (facet == otherfacet_(ridge, neighbor)) {
    1792           0 :               ridge->nonconvex= True;
    1793           0 :               break;    /* only one ridge is marked nonconvex */
    1794             :             }
    1795             :           }
    1796             :         }
    1797             :       }
    1798             :     }
    1799       60287 :     facet->tested= True;
    1800      199407 :     FOREACHridge_(facet->ridges)
    1801      139120 :       ridge->tested= True;
    1802             :   }
    1803       12197 :   nummerges= qh_setsize(qh, qh->facet_mergeset);
    1804       12197 :   if (qh->ANGLEmerge)
    1805           0 :     qsort(SETaddr_(qh->facet_mergeset, mergeT), (size_t)nummerges, sizeof(mergeT *), qh_compare_anglemerge);
    1806             :   else
    1807       12197 :     qsort(SETaddr_(qh->facet_mergeset, mergeT), (size_t)nummerges, sizeof(mergeT *), qh_compare_facetmerge);
    1808       12197 :   nummerges += qh_setsize(qh, qh->degen_mergeset);
    1809       12197 :   if (qh->POSTmerging) {
    1810           0 :     zadd_(Zmergeinittot2, nummerges);
    1811             :   }else {
    1812       12197 :     zadd_(Zmergeinittot, nummerges);
    1813       12197 :     zmax_(Zmergeinitmax, nummerges);
    1814             :   }
    1815       12197 :   trace2((qh, qh->ferr, 2022, "qh_getmergeset_initial: %d merges found\n", nummerges));
    1816       12197 : } /* getmergeset_initial */
    1817             : 
    1818             : /*-<a                             href="qh-merge_r.htm#TOC"
    1819             :   >-------------------------------</a><a name="getpinchedmerges">-</a>
    1820             : 
    1821             :   qh_getpinchedmerges(qh, apex, maxdist, iscoplanar )
    1822             :     get pinched merges for dupridges in qh.facet_mergeset
    1823             :     qh.NEWtentative==True
    1824             :       qh.newfacet_list with apex
    1825             :       qh.horizon_list is attached to qh.visible_list instead of qh.newfacet_list
    1826             :       maxdist for vertex-facet of a dupridge
    1827             :     qh.facet_mergeset is empty
    1828             :     qh.vertex_mergeset is a temporary set
    1829             : 
    1830             :   returns:
    1831             :     False if nearest vertex would increase facet width by more than maxdist or qh_WIDEpinched
    1832             :     True and iscoplanar, if the pinched vertex is the apex (i.e., make the apex a coplanar point)
    1833             :     True and !iscoplanar, if should merge a pinched vertex of a dupridge
    1834             :       qh.vertex_mergeset contains one or more MRGsubridge with a pinched vertex and a nearby, neighboring vertex
    1835             :     qh.facet_mergeset is empty
    1836             : 
    1837             :   notes:
    1838             :     called by qh_buildcone_mergepinched
    1839             :     hull_dim >= 3
    1840             :     a pinched vertex is in a dupridge and the horizon
    1841             :     selects the pinched vertex that is closest to its neighbor
    1842             : 
    1843             :   design:
    1844             :     for each dupridge
    1845             :         determine the best pinched vertex to be merged into a neighboring vertex
    1846             :         if merging the pinched vertex would produce a wide merge (qh_WIDEpinched)
    1847             :            ignore pinched vertex with a warning, and use qh_merge_degenredundant instead
    1848             :         else
    1849             :            append the pinched vertex to vertex_mergeset for merging
    1850             : */
    1851           0 : boolT qh_getpinchedmerges(qhT *qh, vertexT *apex, coordT maxdupdist, boolT *iscoplanar /* qh.newfacet_list, qh.vertex_mergeset */) {
    1852           0 :   mergeT *merge, **mergep, *bestmerge= NULL;
    1853           0 :   vertexT *nearest, *pinched, *bestvertex= NULL, *bestpinched= NULL;
    1854             :   boolT result;
    1855           0 :   coordT dist, prevdist, bestdist= REALmax/(qh_RATIOcoplanarapex+1.0); /* allow *3.0 */
    1856             :   realT ratio;
    1857             : 
    1858           0 :   trace2((qh, qh->ferr, 2062, "qh_getpinchedmerges: try to merge pinched vertices for dupridges in new facets with apex p%d(v%d) max dupdist %2.2g\n",
    1859             :       qh_pointid(qh, apex->point), apex->id, maxdupdist));
    1860           0 :   *iscoplanar= False;
    1861           0 :   prevdist= fmax_(qh->ONEmerge + qh->DISTround, qh->MINoutside + qh->DISTround);
    1862           0 :   maximize_(prevdist, qh->max_outside);
    1863           0 :   maximize_(prevdist, -qh->min_vertex);
    1864           0 :   qh_mark_dupridges(qh, qh->newfacet_list, !qh_ALL); /* qh.facet_mergeset, creates ridges */
    1865             :   /* qh_mark_dupridges is called a second time in qh_premerge */
    1866           0 :   FOREACHmerge_(qh->facet_mergeset) {  /* read-only */
    1867           0 :     if (merge->mergetype != MRGdupridge) {
    1868           0 :       qh_fprintf(qh, qh->ferr, 6393, "qhull internal error (qh_getpinchedmerges): expecting MRGdupridge from qh_mark_dupridges.  Got merge f%d f%d type %d\n",
    1869           0 :         getid_(merge->facet1), getid_(merge->facet2), merge->mergetype);
    1870           0 :       qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    1871             :     }
    1872             :     /* dist is distance between vertices */
    1873           0 :     pinched= qh_findbest_pinchedvertex(qh, merge, apex, &nearest, &dist /* qh.newfacet_list */);
    1874           0 :     if (pinched == apex && dist < qh_RATIOcoplanarapex*bestdist) { /* prefer coplanar apex since it always works */
    1875           0 :       bestdist= dist/qh_RATIOcoplanarapex;
    1876           0 :       bestmerge= merge;
    1877           0 :       bestpinched= pinched;
    1878           0 :       bestvertex= nearest;
    1879           0 :     }else if (dist < bestdist) {
    1880           0 :       bestdist= dist;
    1881           0 :       bestmerge= merge;
    1882           0 :       bestpinched= pinched;
    1883           0 :       bestvertex= nearest;
    1884             :     }
    1885             :   }
    1886           0 :   result= False;
    1887           0 :   if (bestmerge && bestdist < maxdupdist) {
    1888           0 :     ratio= bestdist / prevdist;
    1889           0 :     if (ratio > qh_WIDEpinched) {
    1890           0 :       if (bestmerge->facet1->mergehorizon || bestmerge->facet2->mergehorizon) { /* e.g., rbox 175 C3,2e-13 t1539182828 | qhull d */
    1891           0 :         trace1((qh, qh->ferr, 1051, "qh_getpinchedmerges: dupridge (MRGdupridge) of coplanar horizon would produce a wide merge (%.0fx) due to pinched vertices v%d and v%d (dist %2.2g) for f%d and f%d.  qh_mergecycle_all will merge one or both facets\n",
    1892             :           ratio, bestpinched->id, bestvertex->id, bestdist, bestmerge->facet1->id, bestmerge->facet2->id));
    1893             :       }else {
    1894           0 :         qh_fprintf(qh, qh->ferr, 7081, "qhull precision warning (qh_getpinchedmerges): pinched vertices v%d and v%d (dist %2.2g, %.0fx) would produce a wide merge for f%d and f%d.  Will merge dupridge instead\n",
    1895           0 :           bestpinched->id, bestvertex->id, bestdist, ratio, bestmerge->facet1->id, bestmerge->facet2->id);
    1896             :       }
    1897             :     }else {
    1898           0 :       if (bestpinched == apex) {
    1899           0 :         trace2((qh, qh->ferr, 2063, "qh_getpinchedmerges: will make the apex a coplanar point.  apex p%d(v%d) is the nearest vertex to v%d on dupridge.  Dist %2.2g\n",
    1900             :           qh_pointid(qh, apex->point), apex->id, bestvertex->id, bestdist*qh_RATIOcoplanarapex));
    1901           0 :         qh->coplanar_apex= apex->point;
    1902           0 :         *iscoplanar= True;
    1903           0 :         result= True;
    1904           0 :       }else if (qh_setin(bestmerge->facet1->vertices, bestpinched) != qh_setin(bestmerge->facet2->vertices, bestpinched)) { /* pinched in one facet but not the other facet */
    1905           0 :         trace2((qh, qh->ferr, 2064, "qh_getpinchedmerges: will merge new facets to resolve dupridge between f%d and f%d with pinched v%d and v%d\n",
    1906             :           bestmerge->facet1->id, bestmerge->facet2->id, bestpinched->id, bestvertex->id));
    1907           0 :         qh_appendvertexmerge(qh, bestpinched, bestvertex, MRGsubridge, bestdist, NULL, NULL);
    1908           0 :         result= True;
    1909             :       }else {
    1910           0 :         trace2((qh, qh->ferr, 2065, "qh_getpinchedmerges: will merge pinched v%d into v%d to resolve dupridge between f%d and f%d\n",
    1911             :           bestpinched->id, bestvertex->id, bestmerge->facet1->id, bestmerge->facet2->id));
    1912           0 :         qh_appendvertexmerge(qh, bestpinched, bestvertex, MRGsubridge, bestdist, NULL, NULL);
    1913           0 :         result= True;
    1914             :       }
    1915             :     }
    1916             :   }
    1917             :   /* delete MRGdupridge, qh_mark_dupridges is called a second time in qh_premerge */
    1918           0 :   while ((merge= (mergeT *)qh_setdellast(qh->facet_mergeset)))
    1919           0 :     qh_memfree(qh, merge, (int)sizeof(mergeT));
    1920           0 :   return result;
    1921             : }/* getpinchedmerges */
    1922             : 
    1923             : /*-<a                             href="qh-merge_r.htm#TOC"
    1924             :   >-------------------------------</a><a name="hasmerge">-</a>
    1925             : 
    1926             :   qh_hasmerge( mergeset, mergetype, facetA, facetB )
    1927             :     True if mergeset has mergetype for facetA and facetB
    1928             : */
    1929           0 : boolT   qh_hasmerge(setT *mergeset, mergeType type, facetT *facetA, facetT *facetB) {
    1930             :   mergeT *merge, **mergep;
    1931             : 
    1932           0 :   FOREACHmerge_(mergeset) {
    1933           0 :     if (merge->mergetype == type) {
    1934           0 :       if (merge->facet1 == facetA && merge->facet2 == facetB)
    1935           0 :         return True;
    1936           0 :       if (merge->facet1 == facetB && merge->facet2 == facetA)
    1937           0 :         return True;
    1938             :     }
    1939             :   }
    1940           0 :   return False;
    1941             : }/* hasmerge */
    1942             : 
    1943             : /*-<a                             href="qh-merge_r.htm#TOC"
    1944             :   >-------------------------------</a><a name="hashridge">-</a>
    1945             : 
    1946             :   qh_hashridge(qh, hashtable, hashsize, ridge, oldvertex )
    1947             :     add ridge to hashtable without oldvertex
    1948             : 
    1949             :   notes:
    1950             :     assumes hashtable is large enough
    1951             : 
    1952             :   design:
    1953             :     determine hash value for ridge without oldvertex
    1954             :     find next empty slot for ridge
    1955             : */
    1956           0 : void qh_hashridge(qhT *qh, setT *hashtable, int hashsize, ridgeT *ridge, vertexT *oldvertex) {
    1957             :   int hash;
    1958             :   ridgeT *ridgeA;
    1959             : 
    1960           0 :   hash= qh_gethash(qh, hashsize, ridge->vertices, qh->hull_dim-1, 0, oldvertex);
    1961             :   while (True) {
    1962           0 :     if (!(ridgeA= SETelemt_(hashtable, hash, ridgeT))) {
    1963           0 :       SETelem_(hashtable, hash)= ridge;
    1964           0 :       break;
    1965           0 :     }else if (ridgeA == ridge)
    1966           0 :       break;
    1967           0 :     if (++hash == hashsize)
    1968           0 :       hash= 0;
    1969             :   }
    1970           0 : } /* hashridge */
    1971             : 
    1972             : 
    1973             : /*-<a                             href="qh-merge_r.htm#TOC"
    1974             :   >-------------------------------</a><a name="hashridge_find">-</a>
    1975             : 
    1976             :   qh_hashridge_find(qh, hashtable, hashsize, ridge, vertex, oldvertex, hashslot )
    1977             :     returns matching ridge without oldvertex in hashtable
    1978             :       for ridge without vertex
    1979             :     if oldvertex is NULL
    1980             :       matches with any one skip
    1981             : 
    1982             :   returns:
    1983             :     matching ridge or NULL
    1984             :     if no match,
    1985             :       if ridge already in   table
    1986             :         hashslot= -1
    1987             :       else
    1988             :         hashslot= next NULL index
    1989             : 
    1990             :   notes:
    1991             :     assumes hashtable is large enough
    1992             :     can't match ridge to itself
    1993             : 
    1994             :   design:
    1995             :     get hash value for ridge without vertex
    1996             :     for each hashslot
    1997             :       return match if ridge matches ridgeA without oldvertex
    1998             : */
    1999           0 : ridgeT *qh_hashridge_find(qhT *qh, setT *hashtable, int hashsize, ridgeT *ridge,
    2000             :               vertexT *vertex, vertexT *oldvertex, int *hashslot) {
    2001             :   int hash;
    2002             :   ridgeT *ridgeA;
    2003             : 
    2004           0 :   *hashslot= 0;
    2005           0 :   zinc_(Zhashridge);
    2006           0 :   hash= qh_gethash(qh, hashsize, ridge->vertices, qh->hull_dim-1, 0, vertex);
    2007           0 :   while ((ridgeA= SETelemt_(hashtable, hash, ridgeT))) {
    2008           0 :     if (ridgeA == ridge)
    2009           0 :       *hashslot= -1;
    2010             :     else {
    2011           0 :       zinc_(Zhashridgetest);
    2012           0 :       if (qh_setequal_except(ridge->vertices, vertex, ridgeA->vertices, oldvertex))
    2013           0 :         return ridgeA;
    2014             :     }
    2015           0 :     if (++hash == hashsize)
    2016           0 :       hash= 0;
    2017             :   }
    2018           0 :   if (!*hashslot)
    2019           0 :     *hashslot= hash;
    2020           0 :   return NULL;
    2021             : } /* hashridge_find */
    2022             : 
    2023             : 
    2024             : /*-<a                             href="qh-merge_r.htm#TOC"
    2025             :   >-------------------------------</a><a name="initmergesets">-</a>
    2026             : 
    2027             :   qh_initmergesets(qh )
    2028             :     initialize the merge sets
    2029             :     if 'all', include qh.degen_mergeset
    2030             : 
    2031             :   notes:
    2032             :     matches qh_freemergesets
    2033             : */
    2034       14666 : void qh_initmergesets(qhT *qh /* qh.facet_mergeset,degen_mergeset,vertex_mergeset */) {
    2035             : 
    2036       14666 :   if (qh->facet_mergeset || qh->degen_mergeset || qh->vertex_mergeset) {
    2037           0 :     qh_fprintf(qh, qh->ferr, 6386, "qhull internal error (qh_initmergesets): expecting NULL mergesets.  Got qh.facet_mergeset (0x%x), qh.degen_mergeset (0x%x), qh.vertex_mergeset (0x%x)\n",
    2038             :       qh->facet_mergeset, qh->degen_mergeset, qh->vertex_mergeset);
    2039           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    2040             :   }
    2041       14666 :   qh->degen_mergeset= qh_settemp(qh, qh->TEMPsize);
    2042       14666 :   qh->vertex_mergeset= qh_settemp(qh, qh->TEMPsize);
    2043       14666 :   qh->facet_mergeset= qh_settemp(qh, qh->TEMPsize); /* last temporary set for qh_forcedmerges */
    2044       14666 : } /* initmergesets */
    2045             : 
    2046             : /*-<a                             href="qh-merge_r.htm#TOC"
    2047             :   >-------------------------------</a><a name="makeridges">-</a>
    2048             : 
    2049             :   qh_makeridges(qh, facet )
    2050             :     creates explicit ridges between simplicial facets
    2051             : 
    2052             :   returns:
    2053             :     facet with ridges and without qh_MERGEridge
    2054             :     ->simplicial is False
    2055             :     if facet was tested, new ridges are tested
    2056             : 
    2057             :   notes:
    2058             :     allows qh_MERGEridge flag
    2059             :     uses existing ridges
    2060             :     duplicate neighbors ok if ridges already exist (qh_mergecycle_ridges)
    2061             : 
    2062             :   see:
    2063             :     qh_mergecycle_ridges()
    2064             :     qh_rename_adjacentvertex for qh_merge_pinchedvertices
    2065             : 
    2066             :   design:
    2067             :     look for qh_MERGEridge neighbors
    2068             :     mark neighbors that already have ridges
    2069             :     for each unprocessed neighbor of facet
    2070             :       create a ridge for neighbor and facet
    2071             :     if any qh_MERGEridge neighbors
    2072             :       delete qh_MERGEridge flags (previously processed by qh_mark_dupridges)
    2073             : */
    2074       40096 : void qh_makeridges(qhT *qh, facetT *facet) {
    2075             :   facetT *neighbor, **neighborp;
    2076             :   ridgeT *ridge, **ridgep;
    2077             :   int neighbor_i, neighbor_n;
    2078       40096 :   boolT toporient, mergeridge= False;
    2079             : 
    2080       40096 :   if (!facet->simplicial)
    2081         804 :     return;
    2082       39292 :   trace4((qh, qh->ferr, 4027, "qh_makeridges: make ridges for f%d\n", facet->id));
    2083       39292 :   facet->simplicial= False;
    2084      157168 :   FOREACHneighbor_(facet) {
    2085      117876 :     if (neighbor == qh_MERGEridge)
    2086           0 :       mergeridge= True;
    2087             :     else
    2088      117876 :       neighbor->seen= False;
    2089             :   }
    2090       92638 :   FOREACHridge_(facet->ridges)
    2091       53346 :     otherfacet_(ridge, facet)->seen= True;
    2092      157168 :   FOREACHneighbor_i_(qh, facet) {
    2093      117876 :     if (neighbor == qh_MERGEridge)
    2094           0 :       continue;  /* fixed by qh_mark_dupridges */
    2095      117876 :     else if (!neighbor->seen) {  /* no current ridges */
    2096       64530 :       ridge= qh_newridge(qh);
    2097       64530 :       ridge->vertices= qh_setnew_delnthsorted(qh, facet->vertices, qh->hull_dim,
    2098             :                                                           neighbor_i, 0);
    2099       64530 :       toporient= (boolT)(facet->toporient ^ (neighbor_i & 0x1));
    2100       64530 :       if (toporient) {
    2101       32125 :         ridge->top= facet;
    2102       32125 :         ridge->bottom= neighbor;
    2103       32125 :         ridge->simplicialtop= True;
    2104       32125 :         ridge->simplicialbot= neighbor->simplicial;
    2105             :       }else {
    2106       32405 :         ridge->top= neighbor;
    2107       32405 :         ridge->bottom= facet;
    2108       32405 :         ridge->simplicialtop= neighbor->simplicial;
    2109       32405 :         ridge->simplicialbot= True;
    2110             :       }
    2111       64530 :       if (facet->tested && !mergeridge)
    2112       12631 :         ridge->tested= True;
    2113             : #if 0 /* this also works */
    2114             :       flip= (facet->toporient ^ neighbor->toporient)^(skip1 & 0x1) ^ (skip2 & 0x1);
    2115             :       if (facet->toporient ^ (skip1 & 0x1) ^ flip) {
    2116             :         ridge->top= neighbor;
    2117             :         ridge->bottom= facet;
    2118             :         ridge->simplicialtop= True;
    2119             :         ridge->simplicialbot= neighbor->simplicial;
    2120             :       }else {
    2121             :         ridge->top= facet;
    2122             :         ridge->bottom= neighbor;
    2123             :         ridge->simplicialtop= neighbor->simplicial;
    2124             :         ridge->simplicialbot= True;
    2125             :       }
    2126             : #endif
    2127       64530 :       qh_setappend(qh, &(facet->ridges), ridge);
    2128       64530 :       trace5((qh, qh->ferr, 5005, "makeridges: appended r%d to ridges for f%d.  Next is ridges for neighbor f%d\n",
    2129             :             ridge->id, facet->id, neighbor->id));
    2130       64530 :       qh_setappend(qh, &(neighbor->ridges), ridge);
    2131       64530 :       if (qh->ridge_id == qh->traceridge_id)
    2132           0 :         qh->traceridge= ridge;
    2133             :     }
    2134             :   }
    2135       39292 :   if (mergeridge) {
    2136           0 :     while (qh_setdel(facet->neighbors, qh_MERGEridge))
    2137             :       ; /* delete each one */
    2138             :   }
    2139             : } /* makeridges */
    2140             : 
    2141             : 
    2142             : /*-<a                             href="qh-merge_r.htm#TOC"
    2143             :   >-------------------------------</a><a name="mark_dupridges">-</a>
    2144             : 
    2145             :   qh_mark_dupridges(qh, facetlist, allmerges )
    2146             :     add duplicated ridges to qh.facet_mergeset
    2147             :     facet-dupridge is true if it contains a subridge shared by more than one new facet
    2148             :     for each such facet, one has a neighbor marked qh_MERGEridge
    2149             :     allmerges is true if merging dupridges
    2150             :     allmerges is false if merging pinched vertices followed by retry addpoint
    2151             :       qh_mark_dupridges will be called again if pinched vertices not found
    2152             : 
    2153             :   returns:
    2154             :     dupridges on qh.facet_mergeset (MRGdupridge)
    2155             :     f.mergeridge and f.mergeridge2 set for facet
    2156             :     f.mergeridge set for neighbor
    2157             :     if allmerges is true
    2158             :       make ridges for facets with dupridges as marked by qh_MERGEridge and both sides facet->dupridge
    2159             :       removes qh_MERGEridge from neighbor sets
    2160             : 
    2161             :   notes:
    2162             :     called by qh_premerge and qh_getpinchedmerges
    2163             :     dupridges are due to duplicate subridges
    2164             :         i.e. a subridge occurs in more than two horizon ridges.
    2165             :         i.e., a ridge has more than two neighboring facets
    2166             :     dupridges occur in at least two cases
    2167             :     1) a pinched horizon with nearly adjacent vertices -> merge the vertices (qh_getpinchedmerges)
    2168             :     2) more than one newfacet for a horizon face -> merge coplanar facets (qh_premerge)
    2169             :     qh_matchdupridge previously identified the furthest apart pair of facets to retain
    2170             :        they must have a matching subridge and the same orientation
    2171             :     only way to set facet->mergeridge and mergeridge2
    2172             :     uses qh.visit_id
    2173             : 
    2174             :   design:
    2175             :     for all facets on facetlist
    2176             :       if facet contains a dupridge
    2177             :         for each neighbor of facet
    2178             :           if neighbor marked qh_MERGEridge (one side of the merge)
    2179             :             set facet->mergeridge
    2180             :           else
    2181             :             if neighbor contains a dupridge
    2182             :             and the back link is qh_MERGEridge
    2183             :               append dupridge to qh.facet_mergeset
    2184             :    exit if !allmerges for repeating qh_mark_dupridges later
    2185             :    for each dupridge
    2186             :      make ridge sets in preparation for merging
    2187             :      remove qh_MERGEridge from neighbor set
    2188             :    for each dupridge
    2189             :      restore the missing neighbor from the neighbor set that was qh_MERGEridge
    2190             :      add the missing ridge for this neighbor
    2191             : */
    2192       12197 : void qh_mark_dupridges(qhT *qh, facetT *facetlist, boolT allmerges) {
    2193             :   facetT *facet, *neighbor, **neighborp;
    2194       12197 :   int nummerge=0;
    2195             :   mergeT *merge, **mergep;
    2196             : 
    2197       12197 :   trace4((qh, qh->ferr, 4028, "qh_mark_dupridges: identify dupridges in facetlist f%d, allmerges? %d\n",
    2198             :     facetlist->id, allmerges));
    2199       72484 :   FORALLfacet_(facetlist) {  /* not necessary for first call */
    2200       60287 :     facet->mergeridge2= False;
    2201       60287 :     facet->mergeridge= False;
    2202             :   }
    2203       72484 :   FORALLfacet_(facetlist) {
    2204       60287 :     if (facet->dupridge) {
    2205           0 :       FOREACHneighbor_(facet) {
    2206           0 :         if (neighbor == qh_MERGEridge) {
    2207           0 :           facet->mergeridge= True;
    2208           0 :           continue;
    2209             :         }
    2210           0 :         if (neighbor->dupridge) {
    2211           0 :           if (!qh_setin(neighbor->neighbors, facet)) { /* i.e., it is qh_MERGEridge, neighbors are distinct */
    2212           0 :             qh_appendmergeset(qh, facet, neighbor, MRGdupridge, 0.0, 1.0);
    2213           0 :             facet->mergeridge2= True;
    2214           0 :             facet->mergeridge= True;
    2215           0 :             nummerge++;
    2216           0 :           }else if (qh_setequal(facet->vertices, neighbor->vertices)) { /* neighbors are the same except for horizon and qh_MERGEridge, see QH7085 */
    2217           0 :             trace3((qh, qh->ferr, 3043, "qh_mark_dupridges): dupridge due to duplicate vertices for subridges f%d and f%d\n",
    2218             :                  facet->id, neighbor->id));
    2219           0 :             qh_appendmergeset(qh, facet, neighbor, MRGdupridge, 0.0, 1.0);
    2220           0 :             facet->mergeridge2= True;
    2221           0 :             facet->mergeridge= True;
    2222           0 :             nummerge++;
    2223           0 :             break; /* same for all neighbors */
    2224             :           }
    2225             :         }
    2226             :       }
    2227             :     }
    2228             :   }
    2229       12197 :   if (!nummerge)
    2230       12197 :     return;
    2231           0 :   if (!allmerges) {
    2232           0 :     trace1((qh, qh->ferr, 1012, "qh_mark_dupridges: found %d duplicated ridges (MRGdupridge) for qh_getpinchedmerges\n", nummerge));
    2233           0 :     return;
    2234             :   }
    2235           0 :   trace1((qh, qh->ferr, 1048, "qh_mark_dupridges: found %d duplicated ridges (MRGdupridge) for qh_premerge.  Prepare facets for merging\n", nummerge));
    2236             :   /* make ridges in preparation for merging */
    2237           0 :   FORALLfacet_(facetlist) {
    2238           0 :     if (facet->mergeridge && !facet->mergeridge2)
    2239           0 :       qh_makeridges(qh, facet);
    2240             :   }
    2241           0 :   trace3((qh, qh->ferr, 3075, "qh_mark_dupridges: restore missing neighbors and ridges due to qh_MERGEridge\n"));
    2242           0 :   FOREACHmerge_(qh->facet_mergeset) {   /* restore the missing neighbors */
    2243           0 :     if (merge->mergetype == MRGdupridge) { /* only between simplicial facets */
    2244           0 :       if (merge->facet2->mergeridge2 && qh_setin(merge->facet2->neighbors, merge->facet1)) {
    2245             :         /* Due to duplicate or multiple subridges, e.g., ../eg/qtest.sh t712682 '200 s W1e-13  C1,1e-13 D5' 'd'
    2246             :             merge->facet1:    - neighboring facets: f27779 f59186 f59186 f59186 MERGEridge f59186
    2247             :             merge->facet2:    - neighboring facets: f27779 f59100 f59100 f59100 f59100 f59100
    2248             :            or, ../eg/qtest.sh 100 '500 s W1e-13 C1,1e-13 D4' 'd'
    2249             :            both facets will be degenerate after merge, consider for special case handling
    2250             :         */
    2251           0 :         qh_fprintf(qh, qh->ferr, 6361, "qhull topological error (qh_mark_dupridges): multiple dupridges for f%d and f%d, including reverse\n",
    2252           0 :           merge->facet1->id, merge->facet2->id);
    2253           0 :         qh_errexit2(qh, qh_ERRtopology, merge->facet1, merge->facet2);
    2254             :       }else
    2255           0 :         qh_setappend(qh, &merge->facet2->neighbors, merge->facet1);
    2256           0 :       qh_makeridges(qh, merge->facet1);   /* and the missing ridges */
    2257             :     }
    2258             :   }
    2259             : } /* mark_dupridges */
    2260             : 
    2261             : /*-<a                             href="qh-merge_r.htm#TOC"
    2262             :   >-------------------------------</a><a name="maybe_duplicateridge">-</a>
    2263             : 
    2264             :   qh_maybe_duplicateridge(qh, ridge )
    2265             :     add MRGvertices if neighboring facet has another ridge with the same vertices
    2266             : 
    2267             :   returns:
    2268             :     adds rename requests to qh.vertex_mergeset
    2269             : 
    2270             :   notes:
    2271             :     called by qh_renamevertex
    2272             :     nop if 2-D
    2273             :     expensive test
    2274             :     Duplicate ridges may lead to new facets with same vertex set (QH7084), will try merging vertices
    2275             :     same as qh_maybe_duplicateridges
    2276             : 
    2277             :   design:
    2278             :     for the two neighbors
    2279             :       if non-simplicial
    2280             :         for each ridge with the same first and last vertices (max id and min id)
    2281             :           if the remaining vertices are the same
    2282             :             get the closest pair of vertices
    2283             :             add to vertex_mergeset for merging
    2284             : */
    2285           0 : void qh_maybe_duplicateridge(qhT *qh, ridgeT *ridgeA) {
    2286             :   ridgeT *ridge, **ridgep;
    2287             :   vertexT *vertex, *pinched;
    2288             :   facetT *neighbor;
    2289             :   coordT dist;
    2290           0 :   int i, k, last= qh->hull_dim-2;
    2291             : 
    2292           0 :   if (qh->hull_dim < 3 )
    2293           0 :     return;
    2294             : 
    2295           0 :   for (neighbor= ridgeA->top, i=0; i<2; neighbor= ridgeA->bottom, i++) {
    2296           0 :     if (!neighbor->simplicial && neighbor->nummerge > 0) { /* skip degenerate neighbors with both new and old vertices that will be merged */
    2297           0 :       FOREACHridge_(neighbor->ridges) {
    2298           0 :         if (ridge != ridgeA && SETfirst_(ridge->vertices) == SETfirst_(ridgeA->vertices)) {
    2299           0 :           if (SETelem_(ridge->vertices, last) == SETelem_(ridgeA->vertices, last)) {
    2300           0 :             for (k=1; k<last; k++) {
    2301           0 :               if (SETelem_(ridge->vertices, k) != SETelem_(ridgeA->vertices, k))
    2302           0 :                 break;
    2303             :             }
    2304           0 :             if (k == last) {
    2305           0 :               vertex= qh_findbest_ridgevertex(qh, ridge, &pinched, &dist);
    2306           0 :               trace2((qh, qh->ferr, 2069, "qh_maybe_duplicateridge: will merge v%d into v%d (dist %2.2g) due to duplicate ridges r%d/r%d with the same vertices.  mergevertex set\n",
    2307             :                 pinched->id, vertex->id, dist, ridgeA->id, ridge->id, ridgeA->top->id, ridgeA->bottom->id, ridge->top->id, ridge->bottom->id));
    2308           0 :               qh_appendvertexmerge(qh, pinched, vertex, MRGvertices, dist, ridgeA, ridge);
    2309           0 :               ridge->mergevertex= True; /* disables check for duplicate vertices in qh_checkfacet */
    2310           0 :               ridgeA->mergevertex= True;
    2311             :             }
    2312             :           }
    2313             :         }
    2314             :       }
    2315             :     }
    2316             :   }
    2317             : } /* maybe_duplicateridge */
    2318             : 
    2319             : /*-<a                             href="qh-merge_r.htm#TOC"
    2320             :   >-------------------------------</a><a name="maybe_duplicateridges">-</a>
    2321             : 
    2322             :   qh_maybe_duplicateridges(qh, facet )
    2323             :     if Q15, add MRGvertices if facet has ridges with the same vertices
    2324             : 
    2325             :   returns:
    2326             :     adds rename requests to qh.vertex_mergeset
    2327             : 
    2328             :   notes:
    2329             :     called at end of qh_mergefacet and qh_mergecycle_all
    2330             :     only enabled if qh.CHECKduplicates ('Q15') and 3-D or more
    2331             :     expensive test, not worth it
    2332             :     same as qh_maybe_duplicateridge
    2333             : 
    2334             :   design:
    2335             :     for all ridge pairs in facet
    2336             :         if the same first and last vertices (max id and min id)
    2337             :           if the remaining vertices are the same
    2338             :             get the closest pair of vertices
    2339             :             add to vertex_mergeset for merging
    2340             : */
    2341       20048 : void qh_maybe_duplicateridges(qhT *qh, facetT *facet) {
    2342             :   facetT *otherfacet;
    2343             :   ridgeT *ridge, *ridge2;
    2344             :   vertexT *vertex, *pinched;
    2345             :   coordT dist;
    2346       20048 :   int ridge_i, ridge_n, i, k, last_v= qh->hull_dim-2;
    2347             : 
    2348       20048 :   if (qh->hull_dim < 3 || !qh->CHECKduplicates)
    2349       20048 :     return;
    2350             : 
    2351           0 :   FOREACHridge_i_(qh, facet->ridges) {
    2352           0 :     otherfacet= otherfacet_(ridge, facet);
    2353           0 :     if (otherfacet->degenerate || otherfacet->redundant || otherfacet->dupridge || otherfacet->flipped) /* will merge */
    2354           0 :       continue;
    2355           0 :     for (i=ridge_i+1; i < ridge_n; i++) {
    2356           0 :       ridge2= SETelemt_(facet->ridges, i, ridgeT);
    2357           0 :       otherfacet= otherfacet_(ridge2, facet);
    2358           0 :       if (otherfacet->degenerate || otherfacet->redundant || otherfacet->dupridge || otherfacet->flipped) /* will merge */
    2359           0 :         continue;
    2360             :       /* optimize qh_setequal(ridge->vertices, ridge2->vertices) */
    2361           0 :       if (SETelem_(ridge->vertices, last_v) == SETelem_(ridge2->vertices, last_v)) { /* SETfirst is likely to be the same */
    2362           0 :         if (SETfirst_(ridge->vertices) == SETfirst_(ridge2->vertices)) {
    2363           0 :           for (k=1; k<last_v; k++) {
    2364           0 :             if (SETelem_(ridge->vertices, k) != SETelem_(ridge2->vertices, k))
    2365           0 :               break;
    2366             :           }
    2367           0 :           if (k == last_v) {
    2368           0 :             vertex= qh_findbest_ridgevertex(qh, ridge, &pinched, &dist);
    2369           0 :             if (ridge->top == ridge2->bottom && ridge->bottom == ridge2->top) {
    2370             :               /* proof that ridges may have opposite orientation */
    2371           0 :               trace2((qh, qh->ferr, 2088, "qh_maybe_duplicateridges: will merge v%d into v%d (dist %2.2g) due to opposite oriented ridges r%d/r%d for f%d and f%d\n",
    2372             :                 pinched->id, vertex->id, dist, ridge->id, ridge2->id, ridge->top->id, ridge->bottom->id));
    2373             :             }else {
    2374           0 :               trace2((qh, qh->ferr, 2083, "qh_maybe_duplicateridges: will merge v%d into v%d (dist %2.2g) due to duplicate ridges with the same vertices r%d/r%d in merged facet f%d\n",
    2375             :                 pinched->id, vertex->id, dist, ridge->id, ridge2->id, facet->id));
    2376             :             }
    2377           0 :             qh_appendvertexmerge(qh, pinched, vertex, MRGvertices, dist, ridge, ridge2);
    2378           0 :             ridge->mergevertex= True; /* disables check for duplicate vertices in qh_checkfacet */
    2379           0 :             ridge2->mergevertex= True;
    2380             :           }
    2381             :         }
    2382             :       }
    2383             :     }
    2384             :   }
    2385             : } /* maybe_duplicateridges */
    2386             : 
    2387             : /*-<a                             href="qh-merge_r.htm#TOC"
    2388             :   >-------------------------------</a><a name="maydropneighbor">-</a>
    2389             : 
    2390             :   qh_maydropneighbor(qh, facet )
    2391             :     drop neighbor relationship if ridge was deleted between a non-simplicial facet and its neighbors
    2392             : 
    2393             :   returns:
    2394             :     for deleted ridges
    2395             :       ridges made for simplicial neighbors
    2396             :       neighbor sets updated
    2397             :       appends degenerate facets to qh.facet_mergeset
    2398             : 
    2399             :   notes:
    2400             :     called by qh_renamevertex
    2401             :     assumes neighbors do not include qh_MERGEridge (qh_makeridges)
    2402             :     won't cause redundant facets since vertex inclusion is the same
    2403             :     may drop vertex and neighbor if no ridge
    2404             :     uses qh.visit_id
    2405             : 
    2406             :   design:
    2407             :     visit all neighbors with ridges
    2408             :     for each unvisited neighbor of facet
    2409             :       delete neighbor and facet from the non-simplicial neighbor sets
    2410             :       if neighbor becomes degenerate
    2411             :         append neighbor to qh.degen_mergeset
    2412             :     if facet is degenerate
    2413             :       append facet to qh.degen_mergeset
    2414             : */
    2415           0 : void qh_maydropneighbor(qhT *qh, facetT *facet) {
    2416             :   ridgeT *ridge, **ridgep;
    2417             :   facetT *neighbor, **neighborp;
    2418             : 
    2419           0 :   qh->visit_id++;
    2420           0 :   trace4((qh, qh->ferr, 4029, "qh_maydropneighbor: test f%d for no ridges to a neighbor\n",
    2421             :           facet->id));
    2422           0 :   if (facet->simplicial) {
    2423           0 :     qh_fprintf(qh, qh->ferr, 6278, "qhull internal error (qh_maydropneighbor): not valid for simplicial f%d while adding furthest p%d\n",
    2424             :       facet->id, qh->furthest_id);
    2425           0 :     qh_errexit(qh, qh_ERRqhull, facet, NULL);
    2426             :   }
    2427           0 :   FOREACHridge_(facet->ridges) {
    2428           0 :     ridge->top->visitid= qh->visit_id;
    2429           0 :     ridge->bottom->visitid= qh->visit_id;
    2430             :   }
    2431           0 :   FOREACHneighbor_(facet) {
    2432           0 :     if (neighbor->visible) {
    2433           0 :       qh_fprintf(qh, qh->ferr, 6358, "qhull internal error (qh_maydropneighbor): facet f%d has deleted neighbor f%d (qh.visible_list)\n",
    2434             :             facet->id, neighbor->id);
    2435           0 :       qh_errexit2(qh, qh_ERRqhull, facet, neighbor);
    2436             :     }
    2437           0 :     if (neighbor->visitid != qh->visit_id) {
    2438           0 :       trace2((qh, qh->ferr, 2104, "qh_maydropneighbor: facets f%d and f%d are no longer neighbors while adding furthest p%d\n",
    2439             :             facet->id, neighbor->id, qh->furthest_id));
    2440           0 :       if (neighbor->simplicial) {
    2441           0 :         qh_fprintf(qh, qh->ferr, 6280, "qhull internal error (qh_maydropneighbor): not valid for simplicial neighbor f%d of f%d while adding furthest p%d\n",
    2442             :             neighbor->id, facet->id, qh->furthest_id);
    2443           0 :         qh_errexit2(qh, qh_ERRqhull, neighbor, facet);
    2444             :       }
    2445           0 :       zinc_(Zdropneighbor);
    2446           0 :       qh_setdel(neighbor->neighbors, facet);
    2447           0 :       if (qh_setsize(qh, neighbor->neighbors) < qh->hull_dim) {
    2448           0 :         zinc_(Zdropdegen);
    2449           0 :         qh_appendmergeset(qh, neighbor, neighbor, MRGdegen, 0.0, qh_ANGLEnone);
    2450           0 :         trace2((qh, qh->ferr, 2023, "qh_maydropneighbors: f%d is degenerate.\n", neighbor->id));
    2451             :       }
    2452           0 :       qh_setdel(facet->neighbors, neighbor);
    2453           0 :       neighborp--;  /* repeat, deleted a neighbor */
    2454             :     }
    2455             :   }
    2456           0 :   if (qh_setsize(qh, facet->neighbors) < qh->hull_dim) {
    2457           0 :     zinc_(Zdropdegen);
    2458           0 :     qh_appendmergeset(qh, facet, facet, MRGdegen, 0.0, qh_ANGLEnone);
    2459           0 :     trace2((qh, qh->ferr, 2024, "qh_maydropneighbors: f%d is degenerate.\n", facet->id));
    2460             :   }
    2461           0 : } /* maydropneighbor */
    2462             : 
    2463             : 
    2464             : /*-<a                             href="qh-merge_r.htm#TOC"
    2465             :   >-------------------------------</a><a name="merge_degenredundant">-</a>
    2466             : 
    2467             :   qh_merge_degenredundant(qh)
    2468             :     merge all degenerate and redundant facets
    2469             :     qh.degen_mergeset contains merges from  qh_test_degen_neighbors, qh_test_redundant_neighbors, and qh_degen_redundant_facet
    2470             : 
    2471             :   returns:
    2472             :     number of merges performed
    2473             :     resets facet->degenerate/redundant
    2474             :     if deleted (visible) facet has no neighbors
    2475             :       sets ->f.replace to NULL
    2476             : 
    2477             :   notes:
    2478             :     redundant merges happen before degenerate ones
    2479             :     merging and renaming vertices can result in degen/redundant facets
    2480             :     check for coplanar and convex neighbors afterwards
    2481             : 
    2482             :   design:
    2483             :     for each merge on qh.degen_mergeset
    2484             :       if redundant merge
    2485             :         if non-redundant facet merged into redundant facet
    2486             :           recheck facet for redundancy
    2487             :         else
    2488             :           merge redundant facet into other facet
    2489             : */
    2490       31569 : int qh_merge_degenredundant(qhT *qh) {
    2491             :   int size;
    2492             :   mergeT *merge;
    2493             :   facetT *bestneighbor, *facet1, *facet2, *facet3;
    2494             :   realT dist, mindist, maxdist;
    2495             :   vertexT *vertex, **vertexp;
    2496       31569 :   int nummerges= 0;
    2497             :   mergeType mergetype;
    2498             :   setT *mergedfacets;
    2499             : 
    2500       31569 :   trace2((qh, qh->ferr, 2095, "qh_merge_degenredundant: merge %d degenerate, redundant, and mirror facets\n",
    2501             :     qh_setsize(qh, qh->degen_mergeset)));
    2502       31569 :   mergedfacets= qh_settemp(qh, qh->TEMPsize);
    2503       31569 :   while ((merge= (mergeT *)qh_setdellast(qh->degen_mergeset))) {
    2504           0 :     facet1= merge->facet1;
    2505           0 :     facet2= merge->facet2;
    2506           0 :     mergetype= merge->mergetype;
    2507           0 :     qh_memfree(qh, merge, (int)sizeof(mergeT)); /* 'merge' is invalidated */
    2508           0 :     if (facet1->visible)
    2509           0 :       continue;
    2510           0 :     facet1->degenerate= False;
    2511           0 :     facet1->redundant= False;
    2512           0 :     if (qh->TRACEmerge-1 == zzval_(Ztotmerge))
    2513           0 :       qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    2514           0 :     if (mergetype == MRGredundant) {
    2515           0 :       zinc_(Zredundant);
    2516           0 :       facet3= qh_getreplacement(qh, facet2); /* the same facet if !facet2.visible */
    2517           0 :       if (!facet3) {
    2518           0 :           qh_fprintf(qh, qh->ferr, 6097, "qhull internal error (qh_merge_degenredunant): f%d is redundant but visible f%d has no replacement\n",
    2519           0 :                facet1->id, getid_(facet2));
    2520           0 :           qh_errexit2(qh, qh_ERRqhull, facet1, facet2);
    2521             :       }
    2522           0 :       qh_setunique(qh, &mergedfacets, facet3);
    2523           0 :       if (facet1 == facet3) {
    2524           0 :         continue;
    2525             :       }
    2526           0 :       trace2((qh, qh->ferr, 2025, "qh_merge_degenredundant: merge redundant f%d into f%d (arg f%d)\n",
    2527             :             facet1->id, facet3->id, facet2->id));
    2528           0 :       qh_mergefacet(qh, facet1, facet3, mergetype, NULL, NULL, !qh_MERGEapex);
    2529             :       /* merge distance is already accounted for */
    2530           0 :       nummerges++;
    2531             :     }else {  /* mergetype == MRGdegen or MRGmirror, other merges may have fixed */
    2532           0 :       if (!(size= qh_setsize(qh, facet1->neighbors))) {
    2533           0 :         zinc_(Zdelfacetdup);
    2534           0 :         trace2((qh, qh->ferr, 2026, "qh_merge_degenredundant: facet f%d has no neighbors.  Deleted\n", facet1->id));
    2535           0 :         qh_willdelete(qh, facet1, NULL);
    2536           0 :         FOREACHvertex_(facet1->vertices) {
    2537           0 :           qh_setdel(vertex->neighbors, facet1);
    2538           0 :           if (!SETfirst_(vertex->neighbors)) {
    2539           0 :             zinc_(Zdegenvertex);
    2540           0 :             trace2((qh, qh->ferr, 2027, "qh_merge_degenredundant: deleted v%d because f%d has no neighbors\n",
    2541             :                  vertex->id, facet1->id));
    2542           0 :             vertex->deleted= True;
    2543           0 :             qh_setappend(qh, &qh->del_vertices, vertex);
    2544             :           }
    2545             :         }
    2546           0 :         nummerges++;
    2547           0 :       }else if (size < qh->hull_dim) {
    2548           0 :         bestneighbor= qh_findbestneighbor(qh, facet1, &dist, &mindist, &maxdist);
    2549           0 :         trace2((qh, qh->ferr, 2028, "qh_merge_degenredundant: facet f%d has %d neighbors, merge into f%d dist %2.2g\n",
    2550             :               facet1->id, size, bestneighbor->id, dist));
    2551           0 :         qh_mergefacet(qh, facet1, bestneighbor, mergetype, &mindist, &maxdist, !qh_MERGEapex);
    2552           0 :         nummerges++;
    2553           0 :         if (qh->PRINTstatistics) {
    2554           0 :           zinc_(Zdegen);
    2555           0 :           wadd_(Wdegentot, dist);
    2556           0 :           wmax_(Wdegenmax, dist);
    2557             :         }
    2558             :       } /* else, another merge fixed the degeneracy and redundancy tested */
    2559             :     }
    2560             :   }
    2561       31569 :   qh_settempfree(qh, &mergedfacets);
    2562       31569 :   return nummerges;
    2563             : } /* merge_degenredundant */
    2564             : 
    2565             : /*-<a                             href="qh-merge_r.htm#TOC"
    2566             :   >-------------------------------</a><a name="merge_nonconvex">-</a>
    2567             : 
    2568             :   qh_merge_nonconvex(qh, facet1, facet2, mergetype )
    2569             :     remove non-convex ridge between facet1 into facet2
    2570             :     mergetype gives why the facet's are non-convex
    2571             : 
    2572             :   returns:
    2573             :     merges one of the facets into the best neighbor
    2574             : 
    2575             :   notes:
    2576             :     mergetype is MRGcoplanar..MRGconvex
    2577             : 
    2578             :   design:
    2579             :     if one of the facets is a new facet
    2580             :       prefer merging new facet into old facet
    2581             :     find best neighbors for both facets
    2582             :     merge the nearest facet into its best neighbor
    2583             :     update the statistics
    2584             : */
    2585           1 : void qh_merge_nonconvex(qhT *qh, facetT *facet1, facetT *facet2, mergeType mergetype) {
    2586             :   facetT *bestfacet, *bestneighbor, *neighbor, *merging, *merged;
    2587             :   realT dist, dist2, mindist, mindist2, maxdist, maxdist2;
    2588             : 
    2589           1 :   if (mergetype < MRGcoplanar || mergetype > MRGconcavecoplanar) {
    2590           0 :     qh_fprintf(qh, qh->ferr, 6398, "qhull internal error (qh_merge_nonconvex): expecting mergetype MRGcoplanar..MRGconcavecoplanar.  Got merge f%d and f%d type %d\n",
    2591             :       facet1->id, facet2->id, mergetype);
    2592           0 :     qh_errexit2(qh, qh_ERRqhull, facet1, facet2);
    2593             :   }
    2594           1 :   if (qh->TRACEmerge-1 == zzval_(Ztotmerge))
    2595           0 :     qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    2596           1 :   trace3((qh, qh->ferr, 3003, "qh_merge_nonconvex: merge #%d for f%d and f%d type %d\n",
    2597             :       zzval_(Ztotmerge) + 1, facet1->id, facet2->id, mergetype));
    2598             :   /* concave or coplanar */
    2599           1 :   if (!facet1->newfacet) {
    2600           0 :     bestfacet= facet2;   /* avoid merging old facet if new is ok */
    2601           0 :     facet2= facet1;
    2602           0 :     facet1= bestfacet;
    2603             :   }else
    2604           1 :     bestfacet= facet1;
    2605           1 :   bestneighbor= qh_findbestneighbor(qh, bestfacet, &dist, &mindist, &maxdist);
    2606           1 :   neighbor= qh_findbestneighbor(qh, facet2, &dist2, &mindist2, &maxdist2);
    2607           1 :   if (dist < dist2) {
    2608           0 :     merging= bestfacet;
    2609           0 :     merged= bestneighbor;
    2610           1 :   }else if (qh->AVOIDold && !facet2->newfacet
    2611           0 :   && ((mindist >= -qh->MAXcoplanar && maxdist <= qh->max_outside)
    2612           0 :        || dist * 1.5 < dist2)) {
    2613           0 :     zinc_(Zavoidold);
    2614           0 :     wadd_(Wavoidoldtot, dist);
    2615           0 :     wmax_(Wavoidoldmax, dist);
    2616           0 :     trace2((qh, qh->ferr, 2029, "qh_merge_nonconvex: avoid merging old facet f%d dist %2.2g.  Use f%d dist %2.2g instead\n",
    2617             :            facet2->id, dist2, facet1->id, dist2));
    2618           0 :     merging= bestfacet;
    2619           0 :     merged= bestneighbor;
    2620             :   }else {
    2621           1 :     merging= facet2;
    2622           1 :     merged= neighbor;
    2623           1 :     dist= dist2;
    2624           1 :     mindist= mindist2;
    2625           1 :     maxdist= maxdist2;
    2626             :   }
    2627           1 :   qh_mergefacet(qh, merging, merged, mergetype, &mindist, &maxdist, !qh_MERGEapex);
    2628             :   /* caller merges qh_degenredundant */
    2629           1 :   if (qh->PRINTstatistics) {
    2630           0 :     if (mergetype == MRGanglecoplanar) {
    2631           0 :       zinc_(Zacoplanar);
    2632           0 :       wadd_(Wacoplanartot, dist);
    2633           0 :       wmax_(Wacoplanarmax, dist);
    2634           0 :     }else if (mergetype == MRGconcave) {
    2635           0 :       zinc_(Zconcave);
    2636           0 :       wadd_(Wconcavetot, dist);
    2637           0 :       wmax_(Wconcavemax, dist);
    2638           0 :     }else if (mergetype == MRGconcavecoplanar) {
    2639           0 :       zinc_(Zconcavecoplanar);
    2640           0 :       wadd_(Wconcavecoplanartot, dist);
    2641           0 :       wmax_(Wconcavecoplanarmax, dist);
    2642             :     }else { /* MRGcoplanar */
    2643           0 :       zinc_(Zcoplanar);
    2644           0 :       wadd_(Wcoplanartot, dist);
    2645           0 :       wmax_(Wcoplanarmax, dist);
    2646             :     }
    2647             :   }
    2648           1 : } /* merge_nonconvex */
    2649             : 
    2650             : /*-<a                             href="qh-merge_r.htm#TOC"
    2651             :   >-------------------------------</a><a name="merge_pinchedvertices">-</a>
    2652             : 
    2653             :   qh_merge_pinchedvertices(qh, apex )
    2654             :     merge pinched vertices in qh.vertex_mergeset to avoid qh_forcedmerges of dupridges
    2655             : 
    2656             :   notes:
    2657             :     only called by qh_all_vertexmerges
    2658             :     hull_dim >= 3
    2659             : 
    2660             :   design:
    2661             :     make vertex neighbors if necessary
    2662             :     for each pinched vertex
    2663             :       determine the ridges for the pinched vertex (make ridges as needed)
    2664             :       merge the pinched vertex into the horizon vertex
    2665             :       merge the degenerate and redundant facets that result
    2666             :     check and resolve new dupridges
    2667             : */
    2668           0 : void qh_merge_pinchedvertices(qhT *qh, int apexpointid /* qh.newfacet_list */) {
    2669             :   mergeT *merge, *mergeA, **mergeAp;
    2670             :   vertexT *vertex, *vertex2;
    2671             :   realT dist;
    2672           0 :   boolT firstmerge= True;
    2673             : 
    2674           0 :   qh_vertexneighbors(qh);
    2675           0 :   if (qh->visible_list || qh->newfacet_list || qh->newvertex_list) {
    2676           0 :     qh_fprintf(qh, qh->ferr, 6402, "qhull internal error (qh_merge_pinchedvertices): qh.visible_list (f%d), newfacet_list (f%d), or newvertex_list (v%d) not empty\n",
    2677           0 :       getid_(qh->visible_list), getid_(qh->newfacet_list), getid_(qh->newvertex_list));
    2678           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    2679             :   }
    2680           0 :   qh->visible_list= qh->newfacet_list= qh->facet_tail;
    2681           0 :   qh->newvertex_list= qh->vertex_tail;
    2682           0 :   qh->isRenameVertex= True; /* disable duplicate ridge vertices check in qh_checkfacet */
    2683           0 :   while ((merge= qh_next_vertexmerge(qh /* qh.vertex_mergeset */))) { /* only one at a time from qh_getpinchedmerges */
    2684           0 :     if (qh->TRACEmerge-1 == zzval_(Ztotmerge))
    2685           0 :       qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    2686           0 :     if (merge->mergetype == MRGsubridge) {
    2687           0 :       zzinc_(Zpinchedvertex);
    2688           0 :       trace1((qh, qh->ferr, 1050, "qh_merge_pinchedvertices: merge one of %d pinched vertices before adding apex p%d.  Try to resolve duplicate ridges in newfacets\n",
    2689             :         qh_setsize(qh, qh->vertex_mergeset)+1, apexpointid));
    2690           0 :       qh_remove_mergetype(qh, qh->vertex_mergeset, MRGsubridge);
    2691             :     }else {
    2692           0 :       zzinc_(Zpinchduplicate);
    2693           0 :       if (firstmerge)
    2694           0 :         trace1((qh, qh->ferr, 1056, "qh_merge_pinchedvertices: merge %d pinched vertices from dupridges in merged facets, apex p%d\n",
    2695             :            qh_setsize(qh, qh->vertex_mergeset)+1, apexpointid));
    2696           0 :       firstmerge= False;
    2697             :     }
    2698           0 :     vertex= merge->vertex1;
    2699           0 :     vertex2= merge->vertex2;
    2700           0 :     dist= merge->distance;
    2701           0 :     qh_memfree(qh, merge, (int)sizeof(mergeT)); /* merge is invalidated */
    2702           0 :     qh_rename_adjacentvertex(qh, vertex, vertex2, dist);
    2703             : #ifndef qh_NOtrace
    2704           0 :     if (qh->IStracing >= 2) {
    2705           0 :       FOREACHmergeA_(qh->degen_mergeset) {
    2706           0 :         if (mergeA->mergetype== MRGdegen) {
    2707           0 :           qh_fprintf(qh, qh->ferr, 2072, "qh_merge_pinchedvertices: merge degenerate f%d into an adjacent facet\n", mergeA->facet1->id);
    2708             :         }else {
    2709           0 :           qh_fprintf(qh, qh->ferr, 2084, "qh_merge_pinchedvertices: merge f%d into f%d mergeType %d\n", mergeA->facet1->id, mergeA->facet2->id, mergeA->mergetype);
    2710             :         }
    2711             :       }
    2712             :     }
    2713             : #endif
    2714           0 :     qh_merge_degenredundant(qh); /* simplicial facets with both old and new vertices */
    2715             :   }
    2716           0 :   qh->isRenameVertex= False;
    2717           0 : }/* merge_pinchedvertices */
    2718             : 
    2719             : /*-<a                             href="qh-merge_r.htm#TOC"
    2720             :   >-------------------------------</a><a name="merge_twisted">-</a>
    2721             : 
    2722             :   qh_merge_twisted(qh, facet1, facet2 )
    2723             :     remove twisted ridge between facet1 into facet2 or report error
    2724             : 
    2725             :   returns:
    2726             :     merges one of the facets into the best neighbor
    2727             : 
    2728             :   notes:
    2729             :     a twisted ridge has opposite vertices that are convex and concave
    2730             : 
    2731             :   design:
    2732             :     find best neighbors for both facets
    2733             :     error if wide merge
    2734             :     merge the nearest facet into its best neighbor
    2735             :     update statistics
    2736             : */
    2737           0 : void qh_merge_twisted(qhT *qh, facetT *facet1, facetT *facet2) {
    2738             :   facetT *neighbor2, *neighbor, *merging, *merged;
    2739             :   vertexT *bestvertex, *bestpinched;
    2740             :   realT dist, dist2, mindist, mindist2, maxdist, maxdist2, mintwisted, bestdist;
    2741             : 
    2742           0 :   if (qh->TRACEmerge-1 == zzval_(Ztotmerge))
    2743           0 :     qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    2744           0 :   trace3((qh, qh->ferr, 3050, "qh_merge_twisted: merge #%d for twisted f%d and f%d\n",
    2745             :       zzval_(Ztotmerge) + 1, facet1->id, facet2->id));
    2746             :   /* twisted */
    2747           0 :   neighbor= qh_findbestneighbor(qh, facet1, &dist, &mindist, &maxdist);
    2748           0 :   neighbor2= qh_findbestneighbor(qh, facet2, &dist2, &mindist2, &maxdist2);
    2749           0 :   mintwisted= qh_RATIOtwisted * qh->ONEmerge;
    2750           0 :   maximize_(mintwisted, facet1->maxoutside);
    2751           0 :   maximize_(mintwisted, facet2->maxoutside);
    2752           0 :   if (dist > mintwisted && dist2 > mintwisted) {
    2753           0 :     bestdist= qh_vertex_bestdist2(qh, facet1->vertices, &bestvertex, &bestpinched);
    2754           0 :     if (bestdist > mintwisted) {
    2755           0 :       qh_fprintf(qh, qh->ferr, 6417, "qhull precision error (qh_merge_twisted): twisted facet f%d does not contain pinched vertices.  Too wide to merge into neighbor.  mindist %2.2g maxdist %2.2g vertexdist %2.2g maxpinched %2.2g neighbor f%d mindist %2.2g maxdist %2.2g\n",
    2756             :         facet1->id, mindist, maxdist, bestdist, mintwisted, facet2->id, mindist2, maxdist2);
    2757             :     }else {
    2758           0 :       qh_fprintf(qh, qh->ferr, 6418, "qhull precision error (qh_merge_twisted): twisted facet f%d with pinched vertices.  Could merge vertices, but too wide to merge into neighbor.   mindist %2.2g maxdist %2.2g vertexdist %2.2g neighbor f%d mindist %2.2g maxdist %2.2g\n",
    2759             :         facet1->id, mindist, maxdist, bestdist, facet2->id, mindist2, maxdist2);
    2760             :     }
    2761           0 :     qh_errexit2(qh, qh_ERRwide, facet1, facet2);
    2762             :   }
    2763           0 :   if (dist < dist2) {
    2764           0 :     merging= facet1;
    2765           0 :     merged= neighbor;
    2766             :   }else {
    2767             :     /* ignores qh.AVOIDold ('Q4') */
    2768           0 :     merging= facet2;
    2769           0 :     merged= neighbor2;
    2770           0 :     dist= dist2;
    2771           0 :     mindist= mindist2;
    2772           0 :     maxdist= maxdist2;
    2773             :   }
    2774           0 :   qh_mergefacet(qh, merging, merged, MRGtwisted, &mindist, &maxdist, !qh_MERGEapex);
    2775             :   /* caller merges qh_degenredundant */
    2776           0 :   zinc_(Ztwisted);
    2777           0 :   wadd_(Wtwistedtot, dist);
    2778           0 :   wmax_(Wtwistedmax, dist);
    2779           0 : } /* merge_twisted */
    2780             : 
    2781             : /*-<a                             href="qh-merge_r.htm#TOC"
    2782             :   >-------------------------------</a><a name="mergecycle">-</a>
    2783             : 
    2784             :   qh_mergecycle(qh, samecycle, newfacet )
    2785             :     merge a cycle of facets starting at samecycle into a newfacet
    2786             :     newfacet is a horizon facet with ->normal
    2787             :     samecycle facets are simplicial from an apex
    2788             : 
    2789             :   returns:
    2790             :     initializes vertex neighbors on first merge
    2791             :     samecycle deleted (placed on qh.visible_list)
    2792             :     newfacet at end of qh.facet_list
    2793             :     deleted vertices on qh.del_vertices
    2794             : 
    2795             :   notes:
    2796             :     only called by qh_mergecycle_all for multiple, same cycle facets
    2797             :     see qh_mergefacet
    2798             : 
    2799             :   design:
    2800             :     make vertex neighbors if necessary
    2801             :     make ridges for newfacet
    2802             :     merge neighbor sets of samecycle into newfacet
    2803             :     merge ridges of samecycle into newfacet
    2804             :     merge vertex neighbors of samecycle into newfacet
    2805             :     make apex of samecycle the apex of newfacet
    2806             :     if newfacet wasn't a new facet
    2807             :       add its vertices to qh.newvertex_list
    2808             :     delete samecycle facets a make newfacet a newfacet
    2809             : */
    2810           0 : void qh_mergecycle(qhT *qh, facetT *samecycle, facetT *newfacet) {
    2811           0 :   int traceonce= False, tracerestore= 0;
    2812             :   vertexT *apex;
    2813             : #ifndef qh_NOtrace
    2814             :   facetT *same;
    2815             : #endif
    2816             : 
    2817           0 :   zzinc_(Ztotmerge);
    2818           0 :   if (qh->REPORTfreq2 && qh->POSTmerging) {
    2819           0 :     if (zzval_(Ztotmerge) > qh->mergereport + qh->REPORTfreq2)
    2820           0 :       qh_tracemerging(qh);
    2821             :   }
    2822             : #ifndef qh_NOtrace
    2823           0 :   if (qh->TRACEmerge == zzval_(Ztotmerge))
    2824           0 :     qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    2825           0 :   trace2((qh, qh->ferr, 2030, "qh_mergecycle: merge #%d for facets from cycle f%d into coplanar horizon f%d\n",
    2826             :         zzval_(Ztotmerge), samecycle->id, newfacet->id));
    2827           0 :   if (newfacet == qh->tracefacet) {
    2828           0 :     tracerestore= qh->IStracing;
    2829           0 :     qh->IStracing= 4;
    2830           0 :     qh_fprintf(qh, qh->ferr, 8068, "qh_mergecycle: ========= trace merge %d of samecycle %d into trace f%d, furthest is p%d\n",
    2831             :                zzval_(Ztotmerge), samecycle->id, newfacet->id,  qh->furthest_id);
    2832           0 :     traceonce= True;
    2833             :   }
    2834           0 :   if (qh->IStracing >=4) {
    2835           0 :     qh_fprintf(qh, qh->ferr, 8069, "  same cycle:");
    2836           0 :     FORALLsame_cycle_(samecycle)
    2837           0 :       qh_fprintf(qh, qh->ferr, 8070, " f%d", same->id);
    2838           0 :     qh_fprintf(qh, qh->ferr, 8071, "\n");
    2839             :   }
    2840           0 :   if (qh->IStracing >=4)
    2841           0 :     qh_errprint(qh, "MERGING CYCLE", samecycle, newfacet, NULL, NULL);
    2842             : #endif /* !qh_NOtrace */
    2843           0 :   if (newfacet->tricoplanar) {
    2844           0 :     if (!qh->TRInormals) {
    2845           0 :       qh_fprintf(qh, qh->ferr, 6224, "qhull internal error (qh_mergecycle): does not work for tricoplanar facets.  Use option 'Q11'\n");
    2846           0 :       qh_errexit(qh, qh_ERRqhull, newfacet, NULL);
    2847             :     }
    2848           0 :     newfacet->tricoplanar= False;
    2849           0 :     newfacet->keepcentrum= False;
    2850             :   }
    2851           0 :   if (qh->CHECKfrequently)
    2852           0 :     qh_checkdelridge(qh);
    2853           0 :   if (!qh->VERTEXneighbors)
    2854           0 :     qh_vertexneighbors(qh);
    2855           0 :   apex= SETfirstt_(samecycle->vertices, vertexT);
    2856           0 :   qh_makeridges(qh, newfacet);
    2857           0 :   qh_mergecycle_neighbors(qh, samecycle, newfacet);
    2858           0 :   qh_mergecycle_ridges(qh, samecycle, newfacet);
    2859           0 :   qh_mergecycle_vneighbors(qh, samecycle, newfacet);
    2860           0 :   if (SETfirstt_(newfacet->vertices, vertexT) != apex)
    2861           0 :     qh_setaddnth(qh, &newfacet->vertices, 0, apex);  /* apex has last id */
    2862           0 :   if (!newfacet->newfacet)
    2863           0 :     qh_newvertices(qh, newfacet->vertices);
    2864           0 :   qh_mergecycle_facets(qh, samecycle, newfacet);
    2865           0 :   qh_tracemerge(qh, samecycle, newfacet, MRGcoplanarhorizon);
    2866             :   /* check for degen_redundant_neighbors after qh_forcedmerges() */
    2867           0 :   if (traceonce) {
    2868           0 :     qh_fprintf(qh, qh->ferr, 8072, "qh_mergecycle: end of trace facet\n");
    2869           0 :     qh->IStracing= tracerestore;
    2870             :   }
    2871           0 : } /* mergecycle */
    2872             : 
    2873             : /*-<a                             href="qh-merge_r.htm#TOC"
    2874             :   >-------------------------------</a><a name="mergecycle_all">-</a>
    2875             : 
    2876             :   qh_mergecycle_all(qh, facetlist, wasmerge )
    2877             :     merge all samecycles of coplanar facets into horizon
    2878             :     don't merge facets with ->mergeridge (these already have ->normal)
    2879             :     all facets are simplicial from apex
    2880             :     all facet->cycledone == False
    2881             : 
    2882             :   returns:
    2883             :     all newfacets merged into coplanar horizon facets
    2884             :     deleted vertices on  qh.del_vertices
    2885             :     sets wasmerge if any merge
    2886             : 
    2887             :   notes:
    2888             :     called by qh_premerge
    2889             :     calls qh_mergecycle for multiple, same cycle facets
    2890             : 
    2891             :   design:
    2892             :     for each facet on facetlist
    2893             :       skip facets with dupridges and normals
    2894             :       check that facet is in a samecycle (->mergehorizon)
    2895             :       if facet only member of samecycle
    2896             :         sets vertex->delridge for all vertices except apex
    2897             :         merge facet into horizon
    2898             :       else
    2899             :         mark all facets in samecycle
    2900             :         remove facets with dupridges from samecycle
    2901             :         merge samecycle into horizon (deletes facets from facetlist)
    2902             : */
    2903       12197 : void qh_mergecycle_all(qhT *qh, facetT *facetlist, boolT *wasmerge) {
    2904             :   facetT *facet, *same, *prev, *horizon, *newfacet;
    2905       12197 :   facetT *samecycle= NULL, *nextfacet, *nextsame;
    2906             :   vertexT *apex, *vertex, **vertexp;
    2907       12197 :   int cycles=0, total=0, facets, nummerge, numdegen= 0;
    2908             : 
    2909       12197 :   trace2((qh, qh->ferr, 2031, "qh_mergecycle_all: merge new facets into coplanar horizon facets.  Bulk merge a cycle of facets with the same horizon facet\n"));
    2910       91892 :   for (facet=facetlist; facet && (nextfacet= facet->next); facet= nextfacet) {
    2911       79695 :     if (facet->normal)
    2912       59648 :       continue;
    2913       20047 :     if (!facet->mergehorizon) {
    2914           0 :       qh_fprintf(qh, qh->ferr, 6225, "qhull internal error (qh_mergecycle_all): f%d without normal\n", facet->id);
    2915           0 :       qh_errexit(qh, qh_ERRqhull, facet, NULL);
    2916             :     }
    2917       20047 :     horizon= SETfirstt_(facet->neighbors, facetT);
    2918       20047 :     if (facet->f.samecycle == facet) {
    2919       20047 :       if (qh->TRACEmerge-1 == zzval_(Ztotmerge))
    2920           0 :         qh->qhmem.IStracing= qh->IStracing= qh->TRACElevel;
    2921       20047 :       zinc_(Zonehorizon);
    2922             :       /* merge distance done in qh_findhorizon */
    2923       20047 :       apex= SETfirstt_(facet->vertices, vertexT);
    2924       80188 :       FOREACHvertex_(facet->vertices) {
    2925       60141 :         if (vertex != apex)
    2926       40094 :           vertex->delridge= True;
    2927             :       }
    2928       20047 :       horizon->f.newcycle= NULL;
    2929       20047 :       qh_mergefacet(qh, facet, horizon, MRGcoplanarhorizon, NULL, NULL, qh_MERGEapex);
    2930             :     }else {
    2931           0 :       samecycle= facet;
    2932           0 :       facets= 0;
    2933           0 :       prev= facet;
    2934           0 :       for (same= facet->f.samecycle; same;  /* FORALLsame_cycle_(facet) */
    2935           0 :            same= (same == facet ? NULL :nextsame)) { /* ends at facet */
    2936           0 :         nextsame= same->f.samecycle;
    2937           0 :         if (same->cycledone || same->visible)
    2938           0 :           qh_infiniteloop(qh, same);
    2939           0 :         same->cycledone= True;
    2940           0 :         if (same->normal) {
    2941           0 :           prev->f.samecycle= same->f.samecycle; /* unlink ->mergeridge */
    2942           0 :           same->f.samecycle= NULL;
    2943             :         }else {
    2944           0 :           prev= same;
    2945           0 :           facets++;
    2946             :         }
    2947             :       }
    2948           0 :       while (nextfacet && nextfacet->cycledone)  /* will delete samecycle */
    2949           0 :         nextfacet= nextfacet->next;
    2950           0 :       horizon->f.newcycle= NULL;
    2951           0 :       qh_mergecycle(qh, samecycle, horizon);
    2952           0 :       nummerge= horizon->nummerge + facets;
    2953           0 :       if (nummerge > qh_MAXnummerge)
    2954           0 :         horizon->nummerge= qh_MAXnummerge;
    2955             :       else
    2956           0 :         horizon->nummerge= (short unsigned int)nummerge; /* limited to 9 bits by qh_MAXnummerge, -Wconversion */
    2957           0 :       zzinc_(Zcyclehorizon);
    2958           0 :       total += facets;
    2959           0 :       zzadd_(Zcyclefacettot, facets);
    2960           0 :       zmax_(Zcyclefacetmax, facets);
    2961             :     }
    2962       20047 :     cycles++;
    2963             :   }
    2964       12197 :   if (cycles) {
    2965       55564 :     FORALLnew_facets {
    2966             :       /* qh_maybe_duplicateridges postponed since qh_mergecycle_ridges deletes ridges without calling qh_delridge_merge */
    2967       45879 :       if (newfacet->coplanarhorizon) {
    2968       20047 :         qh_test_redundant_neighbors(qh, newfacet);
    2969       20047 :         qh_maybe_duplicateridges(qh, newfacet);
    2970       20047 :         newfacet->coplanarhorizon= False;
    2971             :       }
    2972             :     }
    2973        9685 :     numdegen += qh_merge_degenredundant(qh);
    2974        9685 :     *wasmerge= True;
    2975        9685 :     trace1((qh, qh->ferr, 1013, "qh_mergecycle_all: merged %d same cycles or facets into coplanar horizons and %d degenredundant facets\n",
    2976             :       cycles, numdegen));
    2977             :   }
    2978       12197 : } /* mergecycle_all */
    2979             : 
    2980             : /*-<a                             href="qh-merge_r.htm#TOC"
    2981             :   >-------------------------------</a><a name="mergecycle_facets">-</a>
    2982             : 
    2983             :   qh_mergecycle_facets(qh, samecycle, newfacet )
    2984             :     finish merge of samecycle into newfacet
    2985             : 
    2986             :   returns:
    2987             :     samecycle prepended to visible_list for later deletion and partitioning
    2988             :       each facet->f.replace == newfacet
    2989             : 
    2990             :     newfacet moved to end of qh.facet_list
    2991             :       makes newfacet a newfacet (get's facet1->id if it was old)
    2992             :       sets newfacet->newmerge
    2993             :       clears newfacet->center (unless merging into a large facet)
    2994             :       clears newfacet->tested and ridge->tested for facet1
    2995             : 
    2996             :     adds neighboring facets to facet_mergeset if redundant or degenerate
    2997             : 
    2998             :   design:
    2999             :     make newfacet a new facet and set its flags
    3000             :     move samecycle facets to qh.visible_list for later deletion
    3001             :     unless newfacet is large
    3002             :       remove its centrum
    3003             : */
    3004           0 : void qh_mergecycle_facets(qhT *qh, facetT *samecycle, facetT *newfacet) {
    3005             :   facetT *same, *next;
    3006             : 
    3007           0 :   trace4((qh, qh->ferr, 4030, "qh_mergecycle_facets: make newfacet new and samecycle deleted\n"));
    3008           0 :   qh_removefacet(qh, newfacet);  /* append as a newfacet to end of qh->facet_list */
    3009           0 :   qh_appendfacet(qh, newfacet);
    3010           0 :   newfacet->newfacet= True;
    3011           0 :   newfacet->simplicial= False;
    3012           0 :   newfacet->newmerge= True;
    3013             : 
    3014           0 :   for (same= samecycle->f.samecycle; same; same= (same == samecycle ?  NULL : next)) {
    3015           0 :     next= same->f.samecycle;  /* reused by willdelete */
    3016           0 :     qh_willdelete(qh, same, newfacet);
    3017             :   }
    3018           0 :   if (newfacet->center
    3019           0 :       && qh_setsize(qh, newfacet->vertices) <= qh->hull_dim + qh_MAXnewcentrum) {
    3020           0 :     qh_memfree(qh, newfacet->center, qh->normal_size);
    3021           0 :     newfacet->center= NULL;
    3022             :   }
    3023           0 :   trace3((qh, qh->ferr, 3004, "qh_mergecycle_facets: merged facets from cycle f%d into f%d\n",
    3024             :              samecycle->id, newfacet->id));
    3025           0 : } /* mergecycle_facets */
    3026             : 
    3027             : /*-<a                             href="qh-merge_r.htm#TOC"
    3028             :   >-------------------------------</a><a name="mergecycle_neighbors">-</a>
    3029             : 
    3030             :   qh_mergecycle_neighbors(qh, samecycle, newfacet )
    3031             :     add neighbors for samecycle facets to newfacet
    3032             : 
    3033             :   returns:
    3034             :     newfacet with updated neighbors and vice-versa
    3035             :     newfacet has ridges
    3036             :     all neighbors of newfacet marked with qh.visit_id
    3037             :     samecycle facets marked with qh.visit_id-1
    3038             :     ridges updated for simplicial neighbors of samecycle with a ridge
    3039             : 
    3040             :   notes:
    3041             :     assumes newfacet not in samecycle
    3042             :     usually, samecycle facets are new, simplicial facets without internal ridges
    3043             :       not so if horizon facet is coplanar to two different samecycles
    3044             : 
    3045             :   see:
    3046             :     qh_mergeneighbors()
    3047             : 
    3048             :   design:
    3049             :     check samecycle
    3050             :     delete neighbors from newfacet that are also in samecycle
    3051             :     for each neighbor of a facet in samecycle
    3052             :       if neighbor is simplicial
    3053             :         if first visit
    3054             :           move the neighbor relation to newfacet
    3055             :           update facet links for its ridges
    3056             :         else
    3057             :           make ridges for neighbor
    3058             :           remove samecycle reference
    3059             :       else
    3060             :         update neighbor sets
    3061             : */
    3062           0 : void qh_mergecycle_neighbors(qhT *qh, facetT *samecycle, facetT *newfacet) {
    3063             :   facetT *same, *neighbor, **neighborp;
    3064           0 :   int delneighbors= 0, newneighbors= 0;
    3065             :   unsigned int samevisitid;
    3066             :   ridgeT *ridge, **ridgep;
    3067             : 
    3068           0 :   samevisitid= ++qh->visit_id;
    3069           0 :   FORALLsame_cycle_(samecycle) {
    3070           0 :     if (same->visitid == samevisitid || same->visible)
    3071           0 :       qh_infiniteloop(qh, samecycle);
    3072           0 :     same->visitid= samevisitid;
    3073             :   }
    3074           0 :   newfacet->visitid= ++qh->visit_id;
    3075           0 :   trace4((qh, qh->ferr, 4031, "qh_mergecycle_neighbors: delete shared neighbors from newfacet\n"));
    3076           0 :   FOREACHneighbor_(newfacet) {
    3077           0 :     if (neighbor->visitid == samevisitid) {
    3078           0 :       SETref_(neighbor)= NULL;  /* samecycle neighbors deleted */
    3079           0 :       delneighbors++;
    3080             :     }else
    3081           0 :       neighbor->visitid= qh->visit_id;
    3082             :   }
    3083           0 :   qh_setcompact(qh, newfacet->neighbors);
    3084             : 
    3085           0 :   trace4((qh, qh->ferr, 4032, "qh_mergecycle_neighbors: update neighbors\n"));
    3086           0 :   FORALLsame_cycle_(samecycle) {
    3087           0 :     FOREACHneighbor_(same) {
    3088           0 :       if (neighbor->visitid == samevisitid)
    3089           0 :         continue;
    3090           0 :       if (neighbor->simplicial) {
    3091           0 :         if (neighbor->visitid != qh->visit_id) {
    3092           0 :           qh_setappend(qh, &newfacet->neighbors, neighbor);
    3093           0 :           qh_setreplace(qh, neighbor->neighbors, same, newfacet);
    3094           0 :           newneighbors++;
    3095           0 :           neighbor->visitid= qh->visit_id;
    3096           0 :           FOREACHridge_(neighbor->ridges) { /* update ridge in case of qh_makeridges */
    3097           0 :             if (ridge->top == same) {
    3098           0 :               ridge->top= newfacet;
    3099           0 :               break;
    3100           0 :             }else if (ridge->bottom == same) {
    3101           0 :               ridge->bottom= newfacet;
    3102           0 :               break;
    3103             :             }
    3104             :           }
    3105             :         }else {
    3106           0 :           qh_makeridges(qh, neighbor);
    3107           0 :           qh_setdel(neighbor->neighbors, same);
    3108             :           /* same can't be horizon facet for neighbor */
    3109             :         }
    3110             :       }else { /* non-simplicial neighbor */
    3111           0 :         qh_setdel(neighbor->neighbors, same);
    3112           0 :         if (neighbor->visitid != qh->visit_id) {
    3113           0 :           qh_setappend(qh, &neighbor->neighbors, newfacet);
    3114           0 :           qh_setappend(qh, &newfacet->neighbors, neighbor);
    3115           0 :           neighbor->visitid= qh->visit_id;
    3116           0 :           newneighbors++;
    3117             :         }
    3118             :       }
    3119             :     }
    3120             :   }
    3121           0 :   trace2((qh, qh->ferr, 2032, "qh_mergecycle_neighbors: deleted %d neighbors and added %d\n",
    3122             :              delneighbors, newneighbors));
    3123           0 : } /* mergecycle_neighbors */
    3124             : 
    3125             : /*-<a                             href="qh-merge_r.htm#TOC"
    3126             :   >-------------------------------</a><a name="mergecycle_ridges">-</a>
    3127             : 
    3128             :   qh_mergecycle_ridges(qh, samecycle, newfacet )
    3129             :     add ridges/neighbors for facets in samecycle to newfacet
    3130             :     all new/old neighbors of newfacet marked with qh.visit_id
    3131             :     facets in samecycle marked with qh.visit_id-1
    3132             :     newfacet marked with qh.visit_id
    3133             : 
    3134             :   returns:
    3135             :     newfacet has merged ridges
    3136             : 
    3137             :   notes:
    3138             :     ridge already updated for simplicial neighbors of samecycle with a ridge
    3139             :     qh_checkdelridge called by qh_mergecycle
    3140             : 
    3141             :   see:
    3142             :     qh_mergeridges()
    3143             :     qh_makeridges()
    3144             : 
    3145             :   design:
    3146             :     remove ridges between newfacet and samecycle
    3147             :     for each facet in samecycle
    3148             :       for each ridge in facet
    3149             :         update facet pointers in ridge
    3150             :         skip ridges processed in qh_mergecycle_neighors
    3151             :         free ridges between newfacet and samecycle
    3152             :         free ridges between facets of samecycle (on 2nd visit)
    3153             :         append remaining ridges to newfacet
    3154             :       if simplicial facet
    3155             :         for each neighbor of facet
    3156             :           if simplicial facet
    3157             :           and not samecycle facet or newfacet
    3158             :             make ridge between neighbor and newfacet
    3159             : */
    3160           0 : void qh_mergecycle_ridges(qhT *qh, facetT *samecycle, facetT *newfacet) {
    3161           0 :   facetT *same, *neighbor= NULL;
    3162           0 :   int numold=0, numnew=0;
    3163             :   int neighbor_i, neighbor_n;
    3164             :   unsigned int samevisitid;
    3165             :   ridgeT *ridge, **ridgep;
    3166             :   boolT toporient;
    3167             :   void **freelistp; /* used if !qh_NOmem by qh_memfree_() */
    3168             : 
    3169           0 :   trace4((qh, qh->ferr, 4033, "qh_mergecycle_ridges: delete shared ridges from newfacet\n"));
    3170           0 :   samevisitid= qh->visit_id -1;
    3171           0 :   FOREACHridge_(newfacet->ridges) {
    3172           0 :     neighbor= otherfacet_(ridge, newfacet);
    3173           0 :     if (neighbor->visitid == samevisitid)
    3174           0 :       SETref_(ridge)= NULL; /* ridge free'd below */
    3175             :   }
    3176           0 :   qh_setcompact(qh, newfacet->ridges);
    3177             : 
    3178           0 :   trace4((qh, qh->ferr, 4034, "qh_mergecycle_ridges: add ridges to newfacet\n"));
    3179           0 :   FORALLsame_cycle_(samecycle) {
    3180           0 :     FOREACHridge_(same->ridges) {
    3181           0 :       if (ridge->top == same) {
    3182           0 :         ridge->top= newfacet;
    3183           0 :         neighbor= ridge->bottom;
    3184           0 :       }else if (ridge->bottom == same) {
    3185           0 :         ridge->bottom= newfacet;
    3186           0 :         neighbor= ridge->top;
    3187           0 :       }else if (ridge->top == newfacet || ridge->bottom == newfacet) {
    3188           0 :         qh_setappend(qh, &newfacet->ridges, ridge);
    3189           0 :         numold++;  /* already set by qh_mergecycle_neighbors */
    3190           0 :         continue;
    3191             :       }else {
    3192           0 :         qh_fprintf(qh, qh->ferr, 6098, "qhull internal error (qh_mergecycle_ridges): bad ridge r%d\n", ridge->id);
    3193           0 :         qh_errexit(qh, qh_ERRqhull, NULL, ridge);
    3194             :       }
    3195           0 :       if (neighbor == newfacet) {
    3196           0 :         if (qh->traceridge == ridge)
    3197           0 :           qh->traceridge= NULL;
    3198           0 :         qh_setfree(qh, &(ridge->vertices));
    3199           0 :         qh_memfree_(qh, ridge, (int)sizeof(ridgeT), freelistp);
    3200           0 :         numold++;
    3201           0 :       }else if (neighbor->visitid == samevisitid) {
    3202           0 :         qh_setdel(neighbor->ridges, ridge);
    3203           0 :         if (qh->traceridge == ridge)
    3204           0 :           qh->traceridge= NULL;
    3205           0 :         qh_setfree(qh, &(ridge->vertices));
    3206           0 :         qh_memfree_(qh, ridge, (int)sizeof(ridgeT), freelistp);
    3207           0 :         numold++;
    3208             :       }else {
    3209           0 :         qh_setappend(qh, &newfacet->ridges, ridge);
    3210           0 :         numold++;
    3211             :       }
    3212             :     }
    3213           0 :     if (same->ridges)
    3214           0 :       qh_settruncate(qh, same->ridges, 0);
    3215           0 :     if (!same->simplicial)
    3216           0 :       continue;
    3217           0 :     FOREACHneighbor_i_(qh, same) {       /* note: !newfact->simplicial */
    3218           0 :       if (neighbor->visitid != samevisitid && neighbor->simplicial) {
    3219           0 :         ridge= qh_newridge(qh);
    3220           0 :         ridge->vertices= qh_setnew_delnthsorted(qh, same->vertices, qh->hull_dim,
    3221             :                                                           neighbor_i, 0);
    3222           0 :         toporient= (boolT)(same->toporient ^ (neighbor_i & 0x1));
    3223           0 :         if (toporient) {
    3224           0 :           ridge->top= newfacet;
    3225           0 :           ridge->bottom= neighbor;
    3226           0 :           ridge->simplicialbot= True;
    3227             :         }else {
    3228           0 :           ridge->top= neighbor;
    3229           0 :           ridge->bottom= newfacet;
    3230           0 :           ridge->simplicialtop= True;
    3231             :         }
    3232           0 :         qh_setappend(qh, &(newfacet->ridges), ridge);
    3233           0 :         qh_setappend(qh, &(neighbor->ridges), ridge);
    3234           0 :         if (qh->ridge_id == qh->traceridge_id)
    3235           0 :           qh->traceridge= ridge;
    3236           0 :         numnew++;
    3237             :       }
    3238             :     }
    3239             :   }
    3240             : 
    3241           0 :   trace2((qh, qh->ferr, 2033, "qh_mergecycle_ridges: found %d old ridges and %d new ones\n",
    3242             :              numold, numnew));
    3243           0 : } /* mergecycle_ridges */
    3244             : 
    3245             : /*-<a                             href="qh-merge_r.htm#TOC"
    3246             :   >-------------------------------</a><a name="mergecycle_vneighbors">-</a>
    3247             : 
    3248             :   qh_mergecycle_vneighbors(qh, samecycle, newfacet )
    3249             :     create vertex neighbors for newfacet from vertices of facets in samecycle
    3250             :     samecycle marked with visitid == qh.visit_id - 1
    3251             : 
    3252             :   returns:
    3253             :     newfacet vertices with updated neighbors
    3254             :     marks newfacet with qh.visit_id-1
    3255             :     deletes vertices that are merged away
    3256             :     sets delridge on all vertices (faster here than in mergecycle_ridges)
    3257             : 
    3258             :   see:
    3259             :     qh_mergevertex_neighbors()
    3260             : 
    3261             :   design:
    3262             :     for each vertex of samecycle facet
    3263             :       set vertex->delridge
    3264             :       delete samecycle facets from vertex neighbors
    3265             :       append newfacet to vertex neighbors
    3266             :       if vertex only in newfacet
    3267             :         delete it from newfacet
    3268             :         add it to qh.del_vertices for later deletion
    3269             : */
    3270           0 : void qh_mergecycle_vneighbors(qhT *qh, facetT *samecycle, facetT *newfacet) {
    3271             :   facetT *neighbor, **neighborp;
    3272             :   unsigned int mergeid;
    3273             :   vertexT *vertex, **vertexp, *apex;
    3274             :   setT *vertices;
    3275             : 
    3276           0 :   trace4((qh, qh->ferr, 4035, "qh_mergecycle_vneighbors: update vertex neighbors for newfacet\n"));
    3277           0 :   mergeid= qh->visit_id - 1;
    3278           0 :   newfacet->visitid= mergeid;
    3279           0 :   vertices= qh_basevertices(qh, samecycle); /* temp */
    3280           0 :   apex= SETfirstt_(samecycle->vertices, vertexT);
    3281           0 :   qh_setappend(qh, &vertices, apex);
    3282           0 :   FOREACHvertex_(vertices) {
    3283           0 :     vertex->delridge= True;
    3284           0 :     FOREACHneighbor_(vertex) {
    3285           0 :       if (neighbor->visitid == mergeid)
    3286           0 :         SETref_(neighbor)= NULL;
    3287             :     }
    3288           0 :     qh_setcompact(qh, vertex->neighbors);
    3289           0 :     qh_setappend(qh, &vertex->neighbors, newfacet);
    3290           0 :     if (!SETsecond_(vertex->neighbors)) {
    3291           0 :       zinc_(Zcyclevertex);
    3292           0 :       trace2((qh, qh->ferr, 2034, "qh_mergecycle_vneighbors: deleted v%d when merging cycle f%d into f%d\n",
    3293             :         vertex->id, samecycle->id, newfacet->id));
    3294           0 :       qh_setdelsorted(newfacet->vertices, vertex);
    3295           0 :       vertex->deleted= True;
    3296           0 :       qh_setappend(qh, &qh->del_vertices, vertex);
    3297             :     }
    3298             :   }
    3299           0 :   qh_settempfree(qh, &vertices);
    3300           0 :   trace3((qh, qh->ferr, 3005, "qh_mergecycle_vneighbors: merged vertices from cycle f%d into f%d\n",
    3301             :              samecycle->id, newfacet->id));
    3302           0 : } /* mergecycle_vneighbors */
    3303             : 
    3304             : /*-<a                             href="qh-merge_r.htm#TOC"
    3305             :   >-------------------------------</a><a name="mergefacet">-</a>
    3306             : 
    3307             :   qh_mergefacet(qh, facet1, facet2, mergetype, mindist, maxdist, mergeapex )
    3308             :     merges facet1 into facet2
    3309             :     mergeapex==qh_MERGEapex if merging new facet into coplanar horizon (optimizes qh_mergesimplex)
    3310             : 
    3311             :   returns:
    3312             :     qh.max_outside and qh.min_vertex updated
    3313             :     initializes vertex neighbors on first merge
    3314             : 
    3315             :   note:
    3316             :     mergetype only used for logging and error reporting
    3317             : 
    3318             :   returns:
    3319             :     facet2 contains facet1's vertices, neighbors, and ridges
    3320             :       facet2 moved to end of qh.facet_list
    3321             :       makes facet2 a newfacet
    3322             :       sets facet2->newmerge set
    3323             :       clears facet2->center (unless merging into a large facet)
    3324             :       clears facet2->tested and ridge->tested for facet1
    3325             : 
    3326             :     facet1 prepended to visible_list for later deletion and partitioning
    3327             :       facet1->f.replace == facet2
    3328             : 
    3329             :     adds neighboring facets to facet_mergeset if redundant or degenerate
    3330             : 
    3331             :   notes:
    3332             :     when done, tests facet1 and facet2 for degenerate or redundant neighbors and dupridges
    3333             :     mindist/maxdist may be NULL (only if both NULL)
    3334             :     traces merge if fmax_(maxdist,-mindist) > TRACEdist
    3335             : 
    3336             :   see:
    3337             :     qh_mergecycle()
    3338             : 
    3339             :   design:
    3340             :     trace merge and check for degenerate simplex
    3341             :     make ridges for both facets
    3342             :     update qh.max_outside, qh.max_vertex, qh.min_vertex
    3343             :     update facet2->maxoutside and keepcentrum
    3344             :     update facet2->nummerge
    3345             :     update tested flags for facet2
    3346             :     if facet1 is simplicial
    3347             :       merge facet1 into facet2
    3348             :     else
    3349             :       merge facet1's neighbors into facet2
    3350             :       merge facet1's ridges into facet2
    3351             :       merge facet1's vertices into facet2
    3352             :       merge facet1's vertex neighbors into facet2
    3353             :       add facet2's vertices to qh.new_vertexlist
    3354             :     move facet2 to end of qh.newfacet_list
    3355             :     unless MRGcoplanarhorizon
    3356             :       test facet2 for redundant neighbors
    3357             :       test facet1 for degenerate neighbors
    3358             :       test for redundant facet2
    3359             :       maybe test for duplicate ridges ('Q15')
    3360             :     move facet1 to qh.visible_list for later deletion
    3361             : */
    3362       20048 : void qh_mergefacet(qhT *qh, facetT *facet1, facetT *facet2, mergeType mergetype, realT *mindist, realT *maxdist, boolT mergeapex) {
    3363       20048 :   boolT traceonce= False;
    3364             :   vertexT *vertex, **vertexp;
    3365             :   realT mintwisted, vertexdist;
    3366             :   realT onemerge;
    3367       20048 :   int tracerestore=0, nummerge;
    3368             :   const char *mergename;
    3369             : 
    3370       20048 :   if(mergetype > 0 && mergetype < sizeof(mergetypes)/sizeof(char *))
    3371       20048 :     mergename= mergetypes[mergetype];
    3372             :   else
    3373           0 :     mergename= mergetypes[MRGnone];
    3374       20048 :   if (facet1->tricoplanar || facet2->tricoplanar) {
    3375           0 :     if (!qh->TRInormals) {
    3376           0 :       qh_fprintf(qh, qh->ferr, 6226, "qhull internal error (qh_mergefacet): merge f%d into f%d for mergetype %d (%s) does not work for tricoplanar facets.  Use option 'Q11'\n",
    3377             :         facet1->id, facet2->id, mergetype, mergename);
    3378           0 :       qh_errexit2(qh, qh_ERRqhull, facet1, facet2);
    3379             :     }
    3380           0 :     if (facet2->tricoplanar) {
    3381           0 :       facet2->tricoplanar= False;
    3382           0 :       facet2->keepcentrum= False;
    3383             :     }
    3384             :   }
    3385       20048 :   zzinc_(Ztotmerge);
    3386       20048 :   if (qh->REPORTfreq2 && qh->POSTmerging) {
    3387           0 :     if (zzval_(Ztotmerge) > qh->mergereport + qh->REPORTfreq2)
    3388           0 :       qh_tracemerging(qh);
    3389             :   }
    3390             : #ifndef qh_NOtrace
    3391       20048 :   if (qh->build_cnt >= qh->RERUN) {
    3392       20048 :     if (mindist && (-*mindist > qh->TRACEdist || *maxdist > qh->TRACEdist)) {
    3393           0 :       tracerestore= 0;
    3394           0 :       qh->IStracing= qh->TRACElevel;
    3395           0 :       traceonce= True;
    3396           0 :       qh_fprintf(qh, qh->ferr, 8075, "qh_mergefacet: ========= trace wide merge #%d(%2.2g) for f%d into f%d for mergetype %d (%s), last point was p%d\n",
    3397           0 :           zzval_(Ztotmerge), fmax_(-*mindist, *maxdist), facet1->id, facet2->id, mergetype, mergename, qh->furthest_id);
    3398       20048 :     }else if (facet1 == qh->tracefacet || facet2 == qh->tracefacet) {
    3399           0 :       tracerestore= qh->IStracing;
    3400           0 :       qh->IStracing= 4;
    3401           0 :       traceonce= True;
    3402           0 :       qh_fprintf(qh, qh->ferr, 8076, "qh_mergefacet: ========= trace merge #%d for f%d into f%d for mergetype %d (%s), furthest is p%d\n",
    3403             :                  zzval_(Ztotmerge), facet1->id, facet2->id, mergetype, mergename, qh->furthest_id);
    3404             :     }
    3405             :   }
    3406       20048 :   if (qh->IStracing >= 2) {
    3407           0 :     realT mergemin= -2;
    3408           0 :     realT mergemax= -2;
    3409             : 
    3410           0 :     if (mindist) {
    3411           0 :       mergemin= *mindist;
    3412           0 :       mergemax= *maxdist;
    3413             :     }
    3414           0 :     qh_fprintf(qh, qh->ferr, 2081, "qh_mergefacet: #%d merge f%d into f%d for merge for mergetype %d (%s), mindist= %2.2g, maxdist= %2.2g, max_outside %2.2g\n",
    3415             :     zzval_(Ztotmerge), facet1->id, facet2->id, mergetype, mergename, mergemin, mergemax, qh->max_outside);
    3416             :   }
    3417             : #endif /* !qh_NOtrace */
    3418       20048 :   if(!qh->ALLOWwide && mindist) {
    3419           1 :     mintwisted= qh_WIDEmaxoutside * qh->ONEmerge;  /* same as qh_merge_twisted and qh_check_maxout (poly2) */
    3420           1 :     maximize_(mintwisted, facet1->maxoutside);
    3421           1 :     maximize_(mintwisted, facet2->maxoutside);
    3422           1 :     if (*maxdist > mintwisted || -*mindist > mintwisted) {
    3423           0 :       vertexdist= qh_vertex_bestdist(qh, facet1->vertices);
    3424           0 :       onemerge= qh->ONEmerge + qh->DISTround;
    3425           0 :       if (vertexdist > mintwisted) {
    3426           0 :         qh_fprintf(qh, qh->ferr, 6347, "qhull precision error (qh_mergefacet): wide merge for facet f%d into f%d for mergetype %d (%s).  maxdist %2.2g (%.1fx) mindist %2.2g (%.1fx) vertexdist %2.2g  Allow with 'Q12' (allow-wide)\n",
    3427           0 :           facet1->id, facet2->id, mergetype, mergename, *maxdist, *maxdist/onemerge, *mindist, -*mindist/onemerge, vertexdist);
    3428             :       }else {
    3429           0 :         qh_fprintf(qh, qh->ferr, 6348, "qhull precision error (qh_mergefacet): wide merge for pinched facet f%d into f%d for mergetype %d (%s).  maxdist %2.2g (%.fx) mindist %2.2g (%.1fx) vertexdist %2.2g  Allow with 'Q12' (allow-wide)\n",
    3430           0 :           facet1->id, facet2->id, mergetype, mergename, *maxdist, *maxdist/onemerge, *mindist, -*mindist/onemerge, vertexdist);
    3431             :       }
    3432           0 :       qh_errexit2(qh, qh_ERRwide, facet1, facet2);
    3433             :     }
    3434             :   }
    3435       20048 :   if (facet1 == facet2 || facet1->visible || facet2->visible) {
    3436           0 :     qh_fprintf(qh, qh->ferr, 6099, "qhull internal error (qh_mergefacet): either f%d and f%d are the same or one is a visible facet, mergetype %d (%s)\n",
    3437             :              facet1->id, facet2->id, mergetype, mergename);
    3438           0 :     qh_errexit2(qh, qh_ERRqhull, facet1, facet2);
    3439             :   }
    3440       20048 :   if (qh->num_facets - qh->num_visible <= qh->hull_dim + 1) {
    3441           0 :     qh_fprintf(qh, qh->ferr, 6227, "qhull topology error: Only %d facets remain.  The input is too degenerate or the convexity constraints are too strong.\n", 
    3442           0 :           qh->hull_dim+1);
    3443           0 :     if (qh->hull_dim >= 5 && !qh->MERGEexact)
    3444           0 :       qh_fprintf(qh, qh->ferr, 8079, "    Option 'Qx' may avoid this problem.\n");
    3445           0 :     qh_errexit(qh, qh_ERRtopology, NULL, NULL);
    3446             :   }
    3447       20048 :   if (!qh->VERTEXneighbors)
    3448           3 :     qh_vertexneighbors(qh);
    3449       20048 :   qh_makeridges(qh, facet1);
    3450       20048 :   qh_makeridges(qh, facet2);
    3451       20048 :   if (qh->IStracing >=4)
    3452           0 :     qh_errprint(qh, "MERGING", facet1, facet2, NULL, NULL);
    3453       20048 :   if (mindist) {
    3454           1 :     maximize_(qh->max_outside, *maxdist);
    3455           1 :     maximize_(qh->max_vertex, *maxdist);
    3456             : #if qh_MAXoutside
    3457           1 :     maximize_(facet2->maxoutside, *maxdist);
    3458             : #endif
    3459           1 :     minimize_(qh->min_vertex, *mindist);
    3460           1 :     if (!facet2->keepcentrum
    3461           1 :     && (*maxdist > qh->WIDEfacet || *mindist < -qh->WIDEfacet)) {
    3462           0 :       facet2->keepcentrum= True;
    3463           0 :       zinc_(Zwidefacet);
    3464             :     }
    3465             :   }
    3466       20048 :   nummerge= facet1->nummerge + facet2->nummerge + 1;
    3467       20048 :   if (nummerge >= qh_MAXnummerge)
    3468           0 :     facet2->nummerge= qh_MAXnummerge;
    3469             :   else
    3470       20048 :     facet2->nummerge= (short unsigned int)nummerge; /* limited to 9 bits by qh_MAXnummerge, -Wconversion */
    3471       20048 :   facet2->newmerge= True;
    3472       20048 :   facet2->dupridge= False;
    3473       20048 :   qh_updatetested(qh, facet1, facet2);
    3474       20048 :   if (qh->hull_dim > 2 && qh_setsize(qh, facet1->vertices) == qh->hull_dim)
    3475       20048 :     qh_mergesimplex(qh, facet1, facet2, mergeapex);
    3476             :   else {
    3477           0 :     qh->vertex_visit++;
    3478           0 :     FOREACHvertex_(facet2->vertices)
    3479           0 :       vertex->visitid= qh->vertex_visit;
    3480           0 :     if (qh->hull_dim == 2)
    3481           0 :       qh_mergefacet2d(qh, facet1, facet2);
    3482             :     else {
    3483           0 :       qh_mergeneighbors(qh, facet1, facet2);
    3484           0 :       qh_mergevertices(qh, facet1->vertices, &facet2->vertices);
    3485             :     }
    3486           0 :     qh_mergeridges(qh, facet1, facet2);
    3487           0 :     qh_mergevertex_neighbors(qh, facet1, facet2);
    3488           0 :     if (!facet2->newfacet)
    3489           0 :       qh_newvertices(qh, facet2->vertices);
    3490             :   }
    3491       20048 :   if (facet2->coplanarhorizon) {
    3492       20047 :     zinc_(Zmergeintocoplanar);
    3493           1 :   }else if (!facet2->newfacet) {
    3494           0 :     zinc_(Zmergeintohorizon);
    3495           1 :   }else if (!facet1->newfacet && facet2->newfacet) {
    3496           1 :     zinc_(Zmergehorizon);
    3497             :   }else {
    3498           0 :     zinc_(Zmergenew);
    3499             :   }
    3500       20048 :   qh_removefacet(qh, facet2);  /* append as a newfacet to end of qh->facet_list */
    3501       20048 :   qh_appendfacet(qh, facet2);
    3502       20048 :   facet2->newfacet= True;
    3503       20048 :   facet2->tested= False;
    3504       20048 :   qh_tracemerge(qh, facet1, facet2, mergetype);
    3505       20048 :   if (traceonce) {
    3506           0 :     qh_fprintf(qh, qh->ferr, 8080, "qh_mergefacet: end of wide tracing\n");
    3507           0 :     qh->IStracing= tracerestore;
    3508             :   }
    3509       20048 :   if (mergetype != MRGcoplanarhorizon) {
    3510           1 :     trace3((qh, qh->ferr, 3076, "qh_mergefacet: check f%d and f%d for redundant and degenerate neighbors\n",
    3511             :         facet1->id, facet2->id));
    3512           1 :     qh_test_redundant_neighbors(qh, facet2);
    3513           1 :     qh_test_degen_neighbors(qh, facet1);  /* after qh_test_redundant_neighbors since MRGdegen more difficult than MRGredundant
    3514             :                                              and before qh_willdelete which clears facet1.neighbors */
    3515           1 :     qh_degen_redundant_facet(qh, facet2); /* may occur in qh_merge_pinchedvertices, e.g., rbox 175 C3,2e-13 D4 t1545228104 | qhull d */
    3516           1 :     qh_maybe_duplicateridges(qh, facet2);
    3517             :   }
    3518       20048 :   qh_willdelete(qh, facet1, facet2);
    3519       20048 : } /* mergefacet */
    3520             : 
    3521             : 
    3522             : /*-<a                             href="qh-merge_r.htm#TOC"
    3523             :   >-------------------------------</a><a name="mergefacet2d">-</a>
    3524             : 
    3525             :   qh_mergefacet2d(qh, facet1, facet2 )
    3526             :     in 2d, merges neighbors and vertices of facet1 into facet2
    3527             : 
    3528             :   returns:
    3529             :     build ridges for neighbors if necessary
    3530             :     facet2 looks like a simplicial facet except for centrum, ridges
    3531             :       neighbors are opposite the corresponding vertex
    3532             :       maintains orientation of facet2
    3533             : 
    3534             :   notes:
    3535             :     qh_mergefacet() retains non-simplicial structures
    3536             :       they are not needed in 2d, but later routines may use them
    3537             :     preserves qh.vertex_visit for qh_mergevertex_neighbors()
    3538             : 
    3539             :   design:
    3540             :     get vertices and neighbors
    3541             :     determine new vertices and neighbors
    3542             :     set new vertices and neighbors and adjust orientation
    3543             :     make ridges for new neighbor if needed
    3544             : */
    3545           0 : void qh_mergefacet2d(qhT *qh, facetT *facet1, facetT *facet2) {
    3546             :   vertexT *vertex1A, *vertex1B, *vertex2A, *vertex2B, *vertexA, *vertexB;
    3547             :   facetT *neighbor1A, *neighbor1B, *neighbor2A, *neighbor2B, *neighborA, *neighborB;
    3548             : 
    3549           0 :   vertex1A= SETfirstt_(facet1->vertices, vertexT);
    3550           0 :   vertex1B= SETsecondt_(facet1->vertices, vertexT);
    3551           0 :   vertex2A= SETfirstt_(facet2->vertices, vertexT);
    3552           0 :   vertex2B= SETsecondt_(facet2->vertices, vertexT);
    3553           0 :   neighbor1A= SETfirstt_(facet1->neighbors, facetT);
    3554           0 :   neighbor1B= SETsecondt_(facet1->neighbors, facetT);
    3555           0 :   neighbor2A= SETfirstt_(facet2->neighbors, facetT);
    3556           0 :   neighbor2B= SETsecondt_(facet2->neighbors, facetT);
    3557           0 :   if (vertex1A == vertex2A) {
    3558           0 :     vertexA= vertex1B;
    3559           0 :     vertexB= vertex2B;
    3560           0 :     neighborA= neighbor2A;
    3561           0 :     neighborB= neighbor1A;
    3562           0 :   }else if (vertex1A == vertex2B) {
    3563           0 :     vertexA= vertex1B;
    3564           0 :     vertexB= vertex2A;
    3565           0 :     neighborA= neighbor2B;
    3566           0 :     neighborB= neighbor1A;
    3567           0 :   }else if (vertex1B == vertex2A) {
    3568           0 :     vertexA= vertex1A;
    3569           0 :     vertexB= vertex2B;
    3570           0 :     neighborA= neighbor2A;
    3571           0 :     neighborB= neighbor1B;
    3572             :   }else { /* 1B == 2B */
    3573           0 :     vertexA= vertex1A;
    3574           0 :     vertexB= vertex2A;
    3575           0 :     neighborA= neighbor2B;
    3576           0 :     neighborB= neighbor1B;
    3577             :   }
    3578             :   /* vertexB always from facet2, neighborB always from facet1 */
    3579           0 :   if (vertexA->id > vertexB->id) {
    3580           0 :     SETfirst_(facet2->vertices)= vertexA;
    3581           0 :     SETsecond_(facet2->vertices)= vertexB;
    3582           0 :     if (vertexB == vertex2A)
    3583           0 :       facet2->toporient= !facet2->toporient;
    3584           0 :     SETfirst_(facet2->neighbors)= neighborA;
    3585           0 :     SETsecond_(facet2->neighbors)= neighborB;
    3586             :   }else {
    3587           0 :     SETfirst_(facet2->vertices)= vertexB;
    3588           0 :     SETsecond_(facet2->vertices)= vertexA;
    3589           0 :     if (vertexB == vertex2B)
    3590           0 :       facet2->toporient= !facet2->toporient;
    3591           0 :     SETfirst_(facet2->neighbors)= neighborB;
    3592           0 :     SETsecond_(facet2->neighbors)= neighborA;
    3593             :   }
    3594             :   /* qh_makeridges not needed since neighborB is not degenerate */
    3595           0 :   qh_setreplace(qh, neighborB->neighbors, facet1, facet2);
    3596           0 :   trace4((qh, qh->ferr, 4036, "qh_mergefacet2d: merged v%d and neighbor f%d of f%d into f%d\n",
    3597             :        vertexA->id, neighborB->id, facet1->id, facet2->id));
    3598           0 : } /* mergefacet2d */
    3599             : 
    3600             : 
    3601             : /*-<a                             href="qh-merge_r.htm#TOC"
    3602             :   >-------------------------------</a><a name="mergeneighbors">-</a>
    3603             : 
    3604             :   qh_mergeneighbors(qh, facet1, facet2 )
    3605             :     merges the neighbors of facet1 into facet2
    3606             : 
    3607             :   notes:
    3608             :     only called by qh_mergefacet
    3609             :     qh.hull_dim >= 3
    3610             :     see qh_mergecycle_neighbors
    3611             : 
    3612             :   design:
    3613             :     for each neighbor of facet1
    3614             :       if neighbor is also a neighbor of facet2
    3615             :         if neighbor is simplicial
    3616             :           make ridges for later deletion as a degenerate facet
    3617             :         update its neighbor set
    3618             :       else
    3619             :         move the neighbor relation to facet2
    3620             :     remove the neighbor relation for facet1 and facet2
    3621             : */
    3622           0 : void qh_mergeneighbors(qhT *qh, facetT *facet1, facetT *facet2) {
    3623             :   facetT *neighbor, **neighborp;
    3624             : 
    3625           0 :   trace4((qh, qh->ferr, 4037, "qh_mergeneighbors: merge neighbors of f%d and f%d\n",
    3626             :           facet1->id, facet2->id));
    3627           0 :   qh->visit_id++;
    3628           0 :   FOREACHneighbor_(facet2) {
    3629           0 :     neighbor->visitid= qh->visit_id;
    3630             :   }
    3631           0 :   FOREACHneighbor_(facet1) {
    3632           0 :     if (neighbor->visitid == qh->visit_id) {
    3633           0 :       if (neighbor->simplicial)    /* is degen, needs ridges */
    3634           0 :         qh_makeridges(qh, neighbor);
    3635           0 :       if (SETfirstt_(neighbor->neighbors, facetT) != facet1) /*keep newfacet->horizon*/
    3636           0 :         qh_setdel(neighbor->neighbors, facet1);
    3637             :       else {
    3638           0 :         qh_setdel(neighbor->neighbors, facet2);
    3639           0 :         qh_setreplace(qh, neighbor->neighbors, facet1, facet2);
    3640             :       }
    3641           0 :     }else if (neighbor != facet2) {
    3642           0 :       qh_setappend(qh, &(facet2->neighbors), neighbor);
    3643           0 :       qh_setreplace(qh, neighbor->neighbors, facet1, facet2);
    3644             :     }
    3645             :   }
    3646           0 :   qh_setdel(facet1->neighbors, facet2);  /* here for makeridges */
    3647           0 :   qh_setdel(facet2->neighbors, facet1);
    3648           0 : } /* mergeneighbors */
    3649             : 
    3650             : 
    3651             : /*-<a                             href="qh-merge_r.htm#TOC"
    3652             :   >-------------------------------</a><a name="mergeridges">-</a>
    3653             : 
    3654             :   qh_mergeridges(qh, facet1, facet2 )
    3655             :     merges the ridge set of facet1 into facet2
    3656             : 
    3657             :   returns:
    3658             :     may delete all ridges for a vertex
    3659             :     sets vertex->delridge on deleted ridges
    3660             : 
    3661             :   see:
    3662             :     qh_mergecycle_ridges()
    3663             : 
    3664             :   design:
    3665             :     delete ridges between facet1 and facet2
    3666             :       mark (delridge) vertices on these ridges for later testing
    3667             :     for each remaining ridge
    3668             :       rename facet1 to facet2
    3669             : */
    3670           0 : void qh_mergeridges(qhT *qh, facetT *facet1, facetT *facet2) {
    3671             :   ridgeT *ridge, **ridgep;
    3672             : 
    3673           0 :   trace4((qh, qh->ferr, 4038, "qh_mergeridges: merge ridges of f%d into f%d\n",
    3674             :           facet1->id, facet2->id));
    3675           0 :   FOREACHridge_(facet2->ridges) {
    3676           0 :     if ((ridge->top == facet1) || (ridge->bottom == facet1)) {
    3677             :       /* ridge.nonconvex is irrelevant due to merge */
    3678           0 :       qh_delridge_merge(qh, ridge);  /* expensive in high-d, could rebuild */
    3679           0 :       ridgep--; /* deleted this ridge, repeat with next ridge*/
    3680             :     }
    3681             :   }
    3682           0 :   FOREACHridge_(facet1->ridges) {
    3683           0 :     if (ridge->top == facet1) {
    3684           0 :       ridge->top= facet2;
    3685           0 :       ridge->simplicialtop= False;
    3686             :     }else { /* ridge.bottom is facet1 */
    3687           0 :       ridge->bottom= facet2;
    3688           0 :       ridge->simplicialbot= False;
    3689             :     }
    3690           0 :     qh_setappend(qh, &(facet2->ridges), ridge);
    3691             :   }
    3692           0 : } /* mergeridges */
    3693             : 
    3694             : 
    3695             : /*-<a                             href="qh-merge_r.htm#TOC"
    3696             :   >-------------------------------</a><a name="mergesimplex">-</a>
    3697             : 
    3698             :   qh_mergesimplex(qh, facet1, facet2, mergeapex )
    3699             :     merge simplicial facet1 into facet2
    3700             :     mergeapex==qh_MERGEapex if merging samecycle into horizon facet
    3701             :       vertex id is latest (most recently created)
    3702             :     facet1 may be contained in facet2
    3703             :     ridges exist for both facets
    3704             : 
    3705             :   returns:
    3706             :     facet2 with updated vertices, ridges, neighbors
    3707             :     updated neighbors for facet1's vertices
    3708             :     facet1 not deleted
    3709             :     sets vertex->delridge on deleted ridges
    3710             : 
    3711             :   notes:
    3712             :     special case code since this is the most common merge
    3713             :     called from qh_mergefacet()
    3714             : 
    3715             :   design:
    3716             :     if qh_MERGEapex
    3717             :       add vertices of facet2 to qh.new_vertexlist if necessary
    3718             :       add apex to facet2
    3719             :     else
    3720             :       for each ridge between facet1 and facet2
    3721             :         set vertex->delridge
    3722             :       determine the apex for facet1 (i.e., vertex to be merged)
    3723             :       unless apex already in facet2
    3724             :         insert apex into vertices for facet2
    3725             :       add vertices of facet2 to qh.new_vertexlist if necessary
    3726             :       add apex to qh.new_vertexlist if necessary
    3727             :       for each vertex of facet1
    3728             :         if apex
    3729             :           rename facet1 to facet2 in its vertex neighbors
    3730             :         else
    3731             :           delete facet1 from vertex neighbors
    3732             :           if only in facet2
    3733             :             add vertex to qh.del_vertices for later deletion
    3734             :       for each ridge of facet1
    3735             :         delete ridges between facet1 and facet2
    3736             :         append other ridges to facet2 after renaming facet to facet2
    3737             : */
    3738       20048 : void qh_mergesimplex(qhT *qh, facetT *facet1, facetT *facet2, boolT mergeapex) {
    3739             :   vertexT *vertex, **vertexp, *opposite;
    3740             :   ridgeT *ridge, **ridgep;
    3741       20048 :   boolT isnew= False;
    3742             :   facetT *neighbor, **neighborp, *otherfacet;
    3743             : 
    3744       20048 :   if (mergeapex) {
    3745       20047 :     opposite= SETfirstt_(facet1->vertices, vertexT); /* apex is opposite facet2.  It has the last vertex id */
    3746       20047 :     trace4((qh, qh->ferr, 4086, "qh_mergesimplex: merge apex v%d of f%d into facet f%d\n",
    3747             :       opposite->id, facet1->id, facet2->id));
    3748       20047 :     if (!facet2->newfacet)
    3749       20047 :       qh_newvertices(qh, facet2->vertices);  /* apex, the first vertex, is already new */
    3750       20047 :     if (SETfirstt_(facet2->vertices, vertexT) != opposite) {
    3751       20047 :       qh_setaddnth(qh, &facet2->vertices, 0, opposite);
    3752       20047 :       isnew= True;
    3753             :     }
    3754             :   }else {
    3755           1 :     zinc_(Zmergesimplex);
    3756           4 :     FOREACHvertex_(facet1->vertices)
    3757           3 :       vertex->seen= False;
    3758           3 :     FOREACHridge_(facet1->ridges) {
    3759           3 :       if (otherfacet_(ridge, facet1) == facet2) {
    3760           3 :         FOREACHvertex_(ridge->vertices) {
    3761           2 :           vertex->seen= True;
    3762           2 :           vertex->delridge= True;
    3763             :         }
    3764           1 :         break;
    3765             :       }
    3766             :     }
    3767           3 :     FOREACHvertex_(facet1->vertices) {
    3768           3 :       if (!vertex->seen)
    3769           1 :         break;  /* must occur */
    3770             :     }
    3771           1 :     opposite= vertex;
    3772           1 :     trace4((qh, qh->ferr, 4039, "qh_mergesimplex: merge opposite v%d of f%d into facet f%d\n",
    3773             :           opposite->id, facet1->id, facet2->id));
    3774           1 :     isnew= qh_addfacetvertex(qh, facet2, opposite);
    3775           1 :     if (!facet2->newfacet)
    3776           0 :       qh_newvertices(qh, facet2->vertices);
    3777           1 :     else if (!opposite->newfacet) {
    3778           1 :       qh_removevertex(qh, opposite);
    3779           1 :       qh_appendvertex(qh, opposite);
    3780             :     }
    3781             :   }
    3782       20048 :   trace4((qh, qh->ferr, 4040, "qh_mergesimplex: update vertex neighbors of f%d\n",
    3783             :           facet1->id));
    3784       80192 :   FOREACHvertex_(facet1->vertices) {
    3785       60144 :     if (vertex == opposite && isnew)
    3786       20048 :       qh_setreplace(qh, vertex->neighbors, facet1, facet2);
    3787             :     else {
    3788       40096 :       qh_setdel(vertex->neighbors, facet1);
    3789       40096 :       if (!SETsecond_(vertex->neighbors))
    3790           0 :         qh_mergevertex_del(qh, vertex, facet1, facet2);
    3791             :     }
    3792             :   }
    3793       20048 :   trace4((qh, qh->ferr, 4041, "qh_mergesimplex: merge ridges and neighbors of f%d into f%d\n",
    3794             :           facet1->id, facet2->id));
    3795       20048 :   qh->visit_id++;
    3796      108386 :   FOREACHneighbor_(facet2)
    3797       88338 :     neighbor->visitid= qh->visit_id;
    3798       80192 :   FOREACHridge_(facet1->ridges) {
    3799       60144 :     otherfacet= otherfacet_(ridge, facet1);
    3800       60144 :     if (otherfacet == facet2) {
    3801             :       /* ridge.nonconvex is irrelevant due to merge */
    3802       20048 :       qh_delridge_merge(qh, ridge);  /* expensive in high-d, could rebuild */
    3803       20048 :       ridgep--; /* deleted this ridge, repeat with next ridge*/
    3804       20048 :       qh_setdel(facet2->neighbors, facet1); /* a simplicial facet may have duplicate neighbors, need to delete each one */
    3805       40096 :     }else if (otherfacet->dupridge && !qh_setin(otherfacet->neighbors, facet1)) {
    3806           0 :       qh_fprintf(qh, qh->ferr, 6356, "qhull topology error (qh_mergesimplex): f%d is a dupridge of f%d, cannot merge f%d into f%d\n",
    3807             :         facet1->id, otherfacet->id, facet1->id, facet2->id);
    3808           0 :       qh_errexit2(qh, qh_ERRqhull, facet1, otherfacet);
    3809             :     }else {
    3810       40096 :       trace4((qh, qh->ferr, 4059, "qh_mergesimplex: move r%d with f%d to f%d, new neighbor? %d, maybe horizon? %d\n",
    3811             :         ridge->id, otherfacet->id, facet2->id, (otherfacet->visitid != qh->visit_id), (SETfirstt_(otherfacet->neighbors, facetT) == facet1)));
    3812       40096 :       qh_setappend(qh, &facet2->ridges, ridge);
    3813       40096 :       if (otherfacet->visitid != qh->visit_id) {
    3814       40096 :         qh_setappend(qh, &facet2->neighbors, otherfacet);
    3815       40096 :         qh_setreplace(qh, otherfacet->neighbors, facet1, facet2);
    3816       40096 :         otherfacet->visitid= qh->visit_id;
    3817             :       }else {
    3818           0 :         if (otherfacet->simplicial)    /* is degen, needs ridges */
    3819           0 :           qh_makeridges(qh, otherfacet);
    3820           0 :         if (SETfirstt_(otherfacet->neighbors, facetT) == facet1) {
    3821             :           /* keep new, otherfacet->neighbors->horizon */
    3822           0 :           qh_setdel(otherfacet->neighbors, facet2);
    3823           0 :           qh_setreplace(qh, otherfacet->neighbors, facet1, facet2);
    3824             :         }else {
    3825             :           /* facet2 is already a neighbor of otherfacet, by f.visitid */
    3826           0 :           qh_setdel(otherfacet->neighbors, facet1);
    3827             :         }
    3828             :       }
    3829       40096 :       if (ridge->top == facet1) { /* wait until after qh_makeridges */
    3830       20048 :         ridge->top= facet2;
    3831       20048 :         ridge->simplicialtop= False;
    3832             :       }else {
    3833       20048 :         ridge->bottom= facet2;
    3834       20048 :         ridge->simplicialbot= False;
    3835             :       }
    3836             :     }
    3837             :   }
    3838       20048 :   trace3((qh, qh->ferr, 3006, "qh_mergesimplex: merged simplex f%d v%d into facet f%d\n",
    3839             :           facet1->id, opposite->id, facet2->id));
    3840       20048 : } /* mergesimplex */
    3841             : 
    3842             : /*-<a                             href="qh-merge_r.htm#TOC"
    3843             :   >-------------------------------</a><a name="mergevertex_del">-</a>
    3844             : 
    3845             :   qh_mergevertex_del(qh, vertex, facet1, facet2 )
    3846             :     delete a vertex because of merging facet1 into facet2
    3847             : 
    3848             :   returns:
    3849             :     deletes vertex from facet2
    3850             :     adds vertex to qh.del_vertices for later deletion
    3851             : */
    3852           0 : void qh_mergevertex_del(qhT *qh, vertexT *vertex, facetT *facet1, facetT *facet2) {
    3853             : 
    3854           0 :   zinc_(Zmergevertex);
    3855           0 :   trace2((qh, qh->ferr, 2035, "qh_mergevertex_del: deleted v%d when merging f%d into f%d\n",
    3856             :           vertex->id, facet1->id, facet2->id));
    3857           0 :   qh_setdelsorted(facet2->vertices, vertex);
    3858           0 :   vertex->deleted= True;
    3859           0 :   qh_setappend(qh, &qh->del_vertices, vertex);
    3860           0 : } /* mergevertex_del */
    3861             : 
    3862             : /*-<a                             href="qh-merge_r.htm#TOC"
    3863             :   >-------------------------------</a><a name="mergevertex_neighbors">-</a>
    3864             : 
    3865             :   qh_mergevertex_neighbors(qh, facet1, facet2 )
    3866             :     merge the vertex neighbors of facet1 to facet2
    3867             : 
    3868             :   returns:
    3869             :     if vertex is current qh.vertex_visit
    3870             :       deletes facet1 from vertex->neighbors
    3871             :     else
    3872             :       renames facet1 to facet2 in vertex->neighbors
    3873             :     deletes vertices if only one neighbor
    3874             : 
    3875             :   notes:
    3876             :     assumes vertex neighbor sets are good
    3877             : */
    3878           0 : void qh_mergevertex_neighbors(qhT *qh, facetT *facet1, facetT *facet2) {
    3879             :   vertexT *vertex, **vertexp;
    3880             : 
    3881           0 :   trace4((qh, qh->ferr, 4042, "qh_mergevertex_neighbors: merge vertex neighborset for f%d into f%d\n",
    3882             :           facet1->id, facet2->id));
    3883           0 :   if (qh->tracevertex) {
    3884           0 :     qh_fprintf(qh, qh->ferr, 8081, "qh_mergevertex_neighbors: of f%d into f%d at furthest p%d f0= %p\n",
    3885           0 :              facet1->id, facet2->id, qh->furthest_id, qh->tracevertex->neighbors->e[0].p);
    3886           0 :     qh_errprint(qh, "TRACE", NULL, NULL, NULL, qh->tracevertex);
    3887             :   }
    3888           0 :   FOREACHvertex_(facet1->vertices) {
    3889           0 :     if (vertex->visitid != qh->vertex_visit)
    3890           0 :       qh_setreplace(qh, vertex->neighbors, facet1, facet2);
    3891             :     else {
    3892           0 :       qh_setdel(vertex->neighbors, facet1);
    3893           0 :       if (!SETsecond_(vertex->neighbors))
    3894           0 :         qh_mergevertex_del(qh, vertex, facet1, facet2);
    3895             :     }
    3896             :   }
    3897           0 :   if (qh->tracevertex)
    3898           0 :     qh_errprint(qh, "TRACE", NULL, NULL, NULL, qh->tracevertex);
    3899           0 : } /* mergevertex_neighbors */
    3900             : 
    3901             : 
    3902             : /*-<a                             href="qh-merge_r.htm#TOC"
    3903             :   >-------------------------------</a><a name="mergevertices">-</a>
    3904             : 
    3905             :   qh_mergevertices(qh, vertices1, vertices2 )
    3906             :     merges the vertex set of facet1 into facet2
    3907             : 
    3908             :   returns:
    3909             :     replaces vertices2 with merged set
    3910             :     preserves vertex_visit for qh_mergevertex_neighbors
    3911             :     updates qh.newvertex_list
    3912             : 
    3913             :   design:
    3914             :     create a merged set of both vertices (in inverse id order)
    3915             : */
    3916           0 : void qh_mergevertices(qhT *qh, setT *vertices1, setT **vertices2) {
    3917           0 :   int newsize= qh_setsize(qh, vertices1)+qh_setsize(qh, *vertices2) - qh->hull_dim + 1;
    3918             :   setT *mergedvertices;
    3919           0 :   vertexT *vertex, **vertexp, **vertex2= SETaddr_(*vertices2, vertexT);
    3920             : 
    3921           0 :   mergedvertices= qh_settemp(qh, newsize);
    3922           0 :   FOREACHvertex_(vertices1) {
    3923           0 :     if (!*vertex2 || vertex->id > (*vertex2)->id)
    3924           0 :       qh_setappend(qh, &mergedvertices, vertex);
    3925             :     else {
    3926           0 :       while (*vertex2 && (*vertex2)->id > vertex->id)
    3927           0 :         qh_setappend(qh, &mergedvertices, *vertex2++);
    3928           0 :       if (!*vertex2 || (*vertex2)->id < vertex->id)
    3929           0 :         qh_setappend(qh, &mergedvertices, vertex);
    3930             :       else
    3931           0 :         qh_setappend(qh, &mergedvertices, *vertex2++);
    3932             :     }
    3933             :   }
    3934           0 :   while (*vertex2)
    3935           0 :     qh_setappend(qh, &mergedvertices, *vertex2++);
    3936           0 :   if (newsize < qh_setsize(qh, mergedvertices)) {
    3937           0 :     qh_fprintf(qh, qh->ferr, 6100, "qhull internal error (qh_mergevertices): facets did not share a ridge\n");
    3938           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    3939             :   }
    3940           0 :   qh_setfree(qh, vertices2);
    3941           0 :   *vertices2= mergedvertices;
    3942           0 :   qh_settemppop(qh);
    3943           0 : } /* mergevertices */
    3944             : 
    3945             : 
    3946             : /*-<a                             href="qh-merge_r.htm#TOC"
    3947             :   >-------------------------------</a><a name="neighbor_intersections">-</a>
    3948             : 
    3949             :   qh_neighbor_intersections(qh, vertex )
    3950             :     return intersection of all vertices in vertex->neighbors except for vertex
    3951             : 
    3952             :   returns:
    3953             :     returns temporary set of vertices
    3954             :     does not include vertex
    3955             :     NULL if a neighbor is simplicial
    3956             :     NULL if empty set
    3957             : 
    3958             :   notes:
    3959             :     only called by qh_redundant_vertex for qh_reducevertices
    3960             :       so f.vertices does not contain extraneous vertices that are not in f.ridges
    3961             :     used for renaming vertices
    3962             : 
    3963             :   design:
    3964             :     initialize the intersection set with vertices of the first two neighbors
    3965             :     delete vertex from the intersection
    3966             :     for each remaining neighbor
    3967             :       intersect its vertex set with the intersection set
    3968             :       return NULL if empty
    3969             :     return the intersection set
    3970             : */
    3971           0 : setT *qh_neighbor_intersections(qhT *qh, vertexT *vertex) {
    3972             :   facetT *neighbor, **neighborp, *neighborA, *neighborB;
    3973             :   setT *intersect;
    3974             :   int neighbor_i, neighbor_n;
    3975             : 
    3976           0 :   FOREACHneighbor_(vertex) {
    3977           0 :     if (neighbor->simplicial)
    3978           0 :       return NULL;
    3979             :   }
    3980           0 :   neighborA= SETfirstt_(vertex->neighbors, facetT);
    3981           0 :   neighborB= SETsecondt_(vertex->neighbors, facetT);
    3982           0 :   zinc_(Zintersectnum);
    3983           0 :   if (!neighborA)
    3984           0 :     return NULL;
    3985           0 :   if (!neighborB)
    3986           0 :     intersect= qh_setcopy(qh, neighborA->vertices, 0);
    3987             :   else
    3988           0 :     intersect= qh_vertexintersect_new(qh, neighborA->vertices, neighborB->vertices);
    3989           0 :   qh_settemppush(qh, intersect);
    3990           0 :   qh_setdelsorted(intersect, vertex);
    3991           0 :   FOREACHneighbor_i_(qh, vertex) {
    3992           0 :     if (neighbor_i >= 2) {
    3993           0 :       zinc_(Zintersectnum);
    3994           0 :       qh_vertexintersect(qh, &intersect, neighbor->vertices);
    3995           0 :       if (!SETfirst_(intersect)) {
    3996           0 :         zinc_(Zintersectfail);
    3997           0 :         qh_settempfree(qh, &intersect);
    3998           0 :         return NULL;
    3999             :       }
    4000             :     }
    4001             :   }
    4002           0 :   trace3((qh, qh->ferr, 3007, "qh_neighbor_intersections: %d vertices in neighbor intersection of v%d\n",
    4003             :           qh_setsize(qh, intersect), vertex->id));
    4004           0 :   return intersect;
    4005             : } /* neighbor_intersections */
    4006             : 
    4007             : /*-<a                             href="qh-merge_r.htm#TOC"
    4008             :   >-------------------------------</a><a name="neighbor_vertices">-</a>
    4009             : 
    4010             :   qh_neighbor_vertices(qh, vertex )
    4011             :     return neighboring vertices for a vertex (not in subridge)
    4012             :     assumes vertices have full vertex->neighbors
    4013             : 
    4014             :   returns:
    4015             :     temporary set of vertices
    4016             : 
    4017             :   notes:
    4018             :     updates qh.visit_id and qh.vertex_visit
    4019             :     similar to qh_vertexridges
    4020             : 
    4021             : */
    4022           0 : setT *qh_neighbor_vertices(qhT *qh, vertexT *vertexA, setT *subridge) {
    4023             :   facetT *neighbor, **neighborp;
    4024             :   vertexT *vertex, **vertexp;
    4025           0 :   setT *vertices= qh_settemp(qh, qh->TEMPsize);
    4026             : 
    4027           0 :   qh->visit_id++;
    4028           0 :   FOREACHneighbor_(vertexA)
    4029           0 :     neighbor->visitid= qh->visit_id;
    4030           0 :   qh->vertex_visit++;
    4031           0 :   vertexA->visitid= qh->vertex_visit;
    4032           0 :   FOREACHvertex_(subridge) {
    4033           0 :     vertex->visitid= qh->vertex_visit;
    4034             :   }
    4035           0 :   FOREACHneighbor_(vertexA) {
    4036           0 :     if (*neighborp)   /* no new ridges in last neighbor */
    4037           0 :       qh_neighbor_vertices_facet(qh, vertexA, neighbor, &vertices);
    4038             :   }
    4039           0 :   trace3((qh, qh->ferr, 3035, "qh_neighbor_vertices: %d non-subridge, vertex neighbors for v%d\n",
    4040             :     qh_setsize(qh, vertices), vertexA->id));
    4041           0 :   return vertices;
    4042             : } /* neighbor_vertices */
    4043             : 
    4044             : /*-<a                             href="qh-merge_r.htm#TOC"
    4045             :   >-------------------------------</a><a name="neighbor_vertices_facet">-</a>
    4046             : 
    4047             :   qh_neighbor_vertices_facet(qh, vertex, facet, vertices )
    4048             :     add neighboring vertices on ridges for vertex in facet
    4049             :     neighbor->visitid==qh.visit_id if it hasn't been visited
    4050             :     v.visitid==qh.vertex_visit if it is already in vertices
    4051             : 
    4052             :   returns:
    4053             :     vertices updated
    4054             :     sets facet->visitid to qh.visit_id-1
    4055             : 
    4056             :   notes:
    4057             :     only called by qh_neighbor_vertices
    4058             :     similar to qh_vertexridges_facet
    4059             : 
    4060             :   design:
    4061             :     for each ridge of facet
    4062             :       if ridge of visited neighbor (i.e., unprocessed)
    4063             :         if vertex in ridge
    4064             :           append unprocessed vertices of ridge
    4065             :     mark facet processed
    4066             : */
    4067           0 : void qh_neighbor_vertices_facet(qhT *qh, vertexT *vertexA, facetT *facet, setT **vertices) {
    4068             :   ridgeT *ridge, **ridgep;
    4069             :   facetT *neighbor;
    4070             :   vertexT *second, *last, *vertex, **vertexp;
    4071           0 :   int last_i= qh->hull_dim-2, count= 0;
    4072             :   boolT isridge;
    4073             : 
    4074           0 :   if (facet->simplicial) {
    4075           0 :     FOREACHvertex_(facet->vertices) {
    4076           0 :       if (vertex->visitid != qh->vertex_visit) {
    4077           0 :         vertex->visitid= qh->vertex_visit;
    4078           0 :         qh_setappend(qh, vertices, vertex);
    4079           0 :         count++;
    4080             :       }
    4081             :     }
    4082             :   }else {
    4083           0 :     FOREACHridge_(facet->ridges) {
    4084           0 :       neighbor= otherfacet_(ridge, facet);
    4085           0 :       if (neighbor->visitid == qh->visit_id) {
    4086           0 :         isridge= False;
    4087           0 :         if (SETfirst_(ridge->vertices) == vertexA) {
    4088           0 :           isridge= True;
    4089           0 :         }else if (last_i > 2) {
    4090           0 :           second= SETsecondt_(ridge->vertices, vertexT);
    4091           0 :           last= SETelemt_(ridge->vertices, last_i, vertexT);
    4092           0 :           if (second->id >= vertexA->id && last->id <= vertexA->id) { /* vertices inverse sorted by id */
    4093           0 :             if (second == vertexA || last == vertexA)
    4094           0 :               isridge= True;
    4095           0 :             else if (qh_setin(ridge->vertices, vertexA))
    4096           0 :               isridge= True;
    4097             :           }
    4098           0 :         }else if (SETelem_(ridge->vertices, last_i) == vertexA) {
    4099           0 :           isridge= True;
    4100           0 :         }else if (last_i > 1 && SETsecond_(ridge->vertices) == vertexA) {
    4101           0 :           isridge= True;
    4102             :         }
    4103           0 :         if (isridge) {
    4104           0 :           FOREACHvertex_(ridge->vertices) {
    4105           0 :             if (vertex->visitid != qh->vertex_visit) {
    4106           0 :               vertex->visitid= qh->vertex_visit;
    4107           0 :               qh_setappend(qh, vertices, vertex);
    4108           0 :               count++;
    4109             :             }
    4110             :           }
    4111             :         }
    4112             :       }
    4113             :     }
    4114             :   }
    4115           0 :   facet->visitid= qh->visit_id-1;
    4116           0 :   if (count) {
    4117           0 :     trace4((qh, qh->ferr, 4079, "qh_neighbor_vertices_facet: found %d vertex neighbors for v%d in f%d (simplicial? %d)\n",
    4118             :       count, vertexA->id, facet->id, facet->simplicial));
    4119             :   }
    4120           0 : } /* neighbor_vertices_facet */
    4121             : 
    4122             : 
    4123             : /*-<a                             href="qh-merge_r.htm#TOC"
    4124             :   >-------------------------------</a><a name="newvertices">-</a>
    4125             : 
    4126             :   qh_newvertices(qh, vertices )
    4127             :     add vertices to end of qh.vertex_list (marks as new vertices)
    4128             : 
    4129             :   returns:
    4130             :     vertices on qh.newvertex_list
    4131             :     vertex->newfacet set
    4132             : */
    4133       20047 : void qh_newvertices(qhT *qh, setT *vertices) {
    4134             :   vertexT *vertex, **vertexp;
    4135             : 
    4136      108382 :   FOREACHvertex_(vertices) {
    4137       88335 :     if (!vertex->newfacet) {
    4138       48241 :       qh_removevertex(qh, vertex);
    4139       48241 :       qh_appendvertex(qh, vertex);
    4140             :     }
    4141             :   }
    4142       20047 : } /* newvertices */
    4143             : 
    4144             : /*-<a                             href="qh-merge_r.htm#TOC"
    4145             :   >-------------------------------</a><a name="next_vertexmerge">-</a>
    4146             : 
    4147             :   qh_next_vertexmerge(qh )
    4148             :     return next vertex merge from qh.vertex_mergeset
    4149             : 
    4150             :   returns:
    4151             :     vertex merge either MRGvertices or MRGsubridge
    4152             :     drops merges of deleted vertices
    4153             : 
    4154             :   notes:
    4155             :     called from qh_merge_pinchedvertices
    4156             : */
    4157           0 : mergeT *qh_next_vertexmerge(qhT *qh /* qh.vertex_mergeset */) {
    4158             :   mergeT *merge;
    4159           0 :   int merge_i, merge_n, best_i= -1;
    4160           0 :   realT bestdist= REALmax;
    4161             : 
    4162           0 :   FOREACHmerge_i_(qh, qh->vertex_mergeset) {
    4163           0 :     if (!merge->vertex1 || !merge->vertex2) {
    4164           0 :       qh_fprintf(qh, qh->ferr, 6299, "qhull internal error (qh_next_vertexmerge): expecting two vertices for vertex merge.  Got v%d v%d and optional f%d\n",
    4165           0 :         getid_(merge->vertex1), getid_(merge->vertex2), getid_(merge->facet1));
    4166           0 :       qh_errexit(qh, qh_ERRqhull, merge->facet1, NULL);
    4167             :     }
    4168           0 :     if (merge->vertex1->deleted || merge->vertex2->deleted) {
    4169           0 :       trace3((qh, qh->ferr, 3030, "qh_next_vertexmerge: drop merge of v%d (del? %d) into v%d (del? %d) due to deleted vertex of r%d and r%d\n",
    4170             :         merge->vertex1->id, merge->vertex1->deleted, merge->vertex2->id, merge->vertex2->deleted, getid_(merge->ridge1), getid_(merge->ridge2)));
    4171           0 :       qh_drop_mergevertex(qh, merge);
    4172           0 :       qh_setdelnth(qh, qh->vertex_mergeset, merge_i);
    4173           0 :       merge_i--; merge_n--;
    4174           0 :       qh_memfree(qh, merge, (int)sizeof(mergeT));
    4175           0 :     }else if (merge->distance < bestdist) {
    4176           0 :       bestdist= merge->distance;
    4177           0 :       best_i= merge_i;
    4178             :     }
    4179             :   }
    4180           0 :   merge= NULL;
    4181           0 :   if (best_i >= 0) {
    4182           0 :     merge= SETelemt_(qh->vertex_mergeset, best_i, mergeT);
    4183           0 :     if (bestdist/qh->ONEmerge > qh_WIDEpinched) {
    4184           0 :       if (merge->mergetype==MRGvertices) {
    4185           0 :         if (merge->ridge1->top == merge->ridge2->bottom && merge->ridge1->bottom == merge->ridge2->top)
    4186           0 :           qh_fprintf(qh, qh->ferr, 6391, "qhull topology error (qh_next_vertexmerge): no nearly adjacent vertices to resolve opposite oriented ridges r%d and r%d in f%d and f%d.  Nearest v%d and v%d dist %2.2g (%.1fx)\n",
    4187           0 :             merge->ridge1->id, merge->ridge2->id, merge->ridge1->top->id, merge->ridge1->bottom->id, merge->vertex1->id, merge->vertex2->id, bestdist, bestdist/qh->ONEmerge);
    4188             :         else
    4189           0 :           qh_fprintf(qh, qh->ferr, 6381, "qhull topology error (qh_next_vertexmerge): no nearly adjacent vertices to resolve duplicate ridges r%d and r%d.  Nearest v%d and v%d dist %2.2g (%.1fx)\n",
    4190           0 :             merge->ridge1->id, merge->ridge2->id, merge->vertex1->id, merge->vertex2->id, bestdist, bestdist/qh->ONEmerge);
    4191             :       }else {
    4192           0 :         qh_fprintf(qh, qh->ferr, 6208, "qhull topology error (qh_next_vertexmerge): no nearly adjacent vertices to resolve dupridge.  Nearest v%d and v%d dist %2.2g (%.1fx)\n",
    4193           0 :           merge->vertex1->id, merge->vertex2->id, bestdist, bestdist/qh->ONEmerge);
    4194             :       }
    4195             :       /* it may be possible to find a different vertex, after other vertex merges have occurred */
    4196           0 :       qh_errexit(qh, qh_ERRtopology, NULL, merge->ridge1);
    4197             :     }
    4198           0 :     qh_setdelnth(qh, qh->vertex_mergeset, best_i);
    4199             :   }
    4200           0 :   return merge;
    4201             : } /* next_vertexmerge */
    4202             : 
    4203             : /*-<a                             href="qh-merge_r.htm#TOC"
    4204             :   >-------------------------------</a><a name="opposite_horizonfacet">-</a>
    4205             : 
    4206             :   qh_opposite_horizonfacet(qh, merge, opposite )
    4207             :     return horizon facet for one of the merge facets, and its opposite vertex across the ridge
    4208             :     assumes either facet1 or facet2 of merge is 'mergehorizon'
    4209             :     assumes both facets are simplicial facets on qh.new_facetlist
    4210             : 
    4211             :   returns:
    4212             :     horizon facet and opposite vertex
    4213             : 
    4214             :   notes:
    4215             :     called by qh_getpinchedmerges
    4216             : */
    4217           0 : facetT *qh_opposite_horizonfacet(qhT *qh, mergeT *merge, vertexT **opposite) {
    4218             :   facetT *facet, *horizon, *otherfacet;
    4219             :   int neighbor_i;
    4220             : 
    4221           0 :   if (!merge->facet1->simplicial || !merge->facet2->simplicial || (!merge->facet1->mergehorizon && !merge->facet2->mergehorizon)) {
    4222           0 :     qh_fprintf(qh, qh->ferr, 6273, "qhull internal error (qh_opposite_horizonfacet): expecting merge of simplicial facets, at least one of which is mergehorizon.  Either simplicial or mergehorizon is wrong\n");
    4223           0 :     qh_errexit2(qh, qh_ERRqhull, merge->facet1, merge->facet2);
    4224             :   }
    4225           0 :   if (merge->facet1->mergehorizon) {
    4226           0 :     facet= merge->facet1;
    4227           0 :     otherfacet= merge->facet2;
    4228             :   }else {
    4229           0 :     facet= merge->facet2;
    4230           0 :     otherfacet= merge->facet1;
    4231             :   }
    4232           0 :   horizon= SETfirstt_(facet->neighbors, facetT);
    4233           0 :   neighbor_i= qh_setindex(otherfacet->neighbors, facet);
    4234           0 :   if (neighbor_i==-1)
    4235           0 :     neighbor_i= qh_setindex(otherfacet->neighbors, qh_MERGEridge);
    4236           0 :   if (neighbor_i==-1) {
    4237           0 :     qh_fprintf(qh, qh->ferr, 6238, "qhull internal error (qh_opposite_horizonfacet): merge facet f%d not connected to mergehorizon f%d\n",
    4238             :       otherfacet->id, facet->id);
    4239           0 :     qh_errexit2(qh, qh_ERRqhull, otherfacet, facet);
    4240             :   }
    4241           0 :   *opposite= SETelemt_(otherfacet->vertices, neighbor_i, vertexT);
    4242           0 :   return horizon;
    4243             : } /* opposite_horizonfacet */
    4244             : 
    4245             : 
    4246             : /*-<a                             href="qh-merge_r.htm#TOC"
    4247             :   >-------------------------------</a><a name="reducevertices">-</a>
    4248             : 
    4249             :   qh_reducevertices(qh)
    4250             :     reduce extra vertices, shared vertices, and redundant vertices
    4251             :     facet->newmerge is set if merged since last call
    4252             :     vertex->delridge is set if vertex was on a deleted ridge
    4253             :     if !qh.MERGEvertices, only removes extra vertices
    4254             : 
    4255             :   returns:
    4256             :     True if also merged degen_redundant facets
    4257             :     vertices are renamed if possible
    4258             :     clears facet->newmerge and vertex->delridge
    4259             : 
    4260             :   notes:
    4261             :     called by qh_all_merges and qh_postmerge
    4262             :     ignored if 2-d
    4263             : 
    4264             :   design:
    4265             :     merge any degenerate or redundant facets
    4266             :     repeat until no more degenerate or redundant facets
    4267             :       for each newly merged facet
    4268             :         remove extra vertices
    4269             :       if qh.MERGEvertices
    4270             :         for each newly merged facet
    4271             :           for each vertex
    4272             :             if vertex was on a deleted ridge
    4273             :               rename vertex if it is shared
    4274             :         for each new, undeleted vertex
    4275             :           remove delridge flag
    4276             :           if vertex is redundant
    4277             :             merge degenerate or redundant facets
    4278             : */
    4279        9686 : boolT qh_reducevertices(qhT *qh) {
    4280        9686 :   int numshare=0, numrename= 0;
    4281        9686 :   boolT degenredun= False;
    4282             :   facetT *newfacet;
    4283             :   vertexT *vertex, **vertexp;
    4284             : 
    4285        9686 :   if (qh->hull_dim == 2)
    4286           0 :     return False;
    4287        9686 :   trace2((qh, qh->ferr, 2101, "qh_reducevertices: reduce extra vertices, shared vertices, and redundant vertices\n"));
    4288        9686 :   if (qh_merge_degenredundant(qh))
    4289           0 :     degenredun= True;
    4290        9686 : LABELrestart:
    4291       55571 :   FORALLnew_facets {
    4292       45885 :     if (newfacet->newmerge) {
    4293       20048 :       if (!qh->MERGEvertices)
    4294           0 :         newfacet->newmerge= False;
    4295       20048 :       if (qh_remove_extravertices(qh, newfacet)) {
    4296           0 :         qh_degen_redundant_facet(qh, newfacet);
    4297           0 :         if (qh_merge_degenredundant(qh)) {
    4298           0 :           degenredun= True;
    4299           0 :           goto LABELrestart;
    4300             :         }
    4301             :       }
    4302             :     }
    4303             :   }
    4304        9686 :   if (!qh->MERGEvertices)
    4305           0 :     return False;
    4306       55571 :   FORALLnew_facets {
    4307       45885 :     if (newfacet->newmerge) {
    4308       20048 :       newfacet->newmerge= False;
    4309      128434 :       FOREACHvertex_(newfacet->vertices) {
    4310      108386 :         if (vertex->delridge) {
    4311       40096 :           if (qh_rename_sharedvertex(qh, vertex, newfacet)) {
    4312           0 :             numshare++;
    4313           0 :             if (qh_merge_degenredundant(qh)) {
    4314           0 :               degenredun= True;
    4315           0 :               goto LABELrestart;
    4316             :             }
    4317           0 :             vertexp--; /* repeat since deleted vertex */
    4318             :           }
    4319             :         }
    4320             :       }
    4321             :     }
    4322             :   }
    4323      113499 :   FORALLvertex_(qh->newvertex_list) {
    4324      103813 :     if (vertex->delridge && !vertex->deleted) {
    4325       29603 :       vertex->delridge= False;
    4326       29603 :       if (qh->hull_dim >= 4 && qh_redundant_vertex(qh, vertex)) {
    4327           0 :         numrename++;
    4328           0 :         if (qh_merge_degenredundant(qh)) {
    4329           0 :           degenredun= True;
    4330           0 :           goto LABELrestart;
    4331             :         }
    4332             :       }
    4333             :     }
    4334             :   }
    4335        9686 :   trace1((qh, qh->ferr, 1014, "qh_reducevertices: renamed %d shared vertices and %d redundant vertices. Degen? %d\n",
    4336             :           numshare, numrename, degenredun));
    4337        9686 :   return degenredun;
    4338             : } /* reducevertices */
    4339             : 
    4340             : /*-<a                             href="qh-merge_r.htm#TOC"
    4341             :   >-------------------------------</a><a name="redundant_vertex">-</a>
    4342             : 
    4343             :   qh_redundant_vertex(qh, vertex )
    4344             :     rename a redundant vertex if qh_find_newvertex succeeds
    4345             :     assumes vertices have full vertex->neighbors
    4346             : 
    4347             :   returns:
    4348             :     if find a replacement vertex
    4349             :       returns new vertex
    4350             :       qh_renamevertex sets vertex->deleted for redundant vertex
    4351             : 
    4352             :   notes:
    4353             :     only called by qh_reducevertices for vertex->delridge and hull_dim >= 4
    4354             :     may add degenerate facets to qh.facet_mergeset
    4355             :     doesn't change vertex->neighbors or create redundant facets
    4356             : 
    4357             :   design:
    4358             :     intersect vertices of all facet neighbors of vertex
    4359             :     determine ridges for these vertices
    4360             :     if find a new vertex for vertex among these ridges and vertices
    4361             :       rename vertex to the new vertex
    4362             : */
    4363           0 : vertexT *qh_redundant_vertex(qhT *qh, vertexT *vertex) {
    4364           0 :   vertexT *newvertex= NULL;
    4365             :   setT *vertices, *ridges;
    4366             : 
    4367           0 :   trace3((qh, qh->ferr, 3008, "qh_redundant_vertex: check if v%d from a deleted ridge can be renamed\n", vertex->id));
    4368           0 :   if ((vertices= qh_neighbor_intersections(qh, vertex))) {
    4369           0 :     ridges= qh_vertexridges(qh, vertex, !qh_ALL);
    4370           0 :     if ((newvertex= qh_find_newvertex(qh, vertex, vertices, ridges))) {
    4371           0 :       zinc_(Zrenameall);
    4372           0 :       qh_renamevertex(qh, vertex, newvertex, ridges, NULL, NULL); /* ridges invalidated */
    4373             :     }
    4374           0 :     qh_settempfree(qh, &ridges);
    4375           0 :     qh_settempfree(qh, &vertices);
    4376             :   }
    4377           0 :   return newvertex;
    4378             : } /* redundant_vertex */
    4379             : 
    4380             : /*-<a                             href="qh-merge_r.htm#TOC"
    4381             :   >-------------------------------</a><a name="remove_extravertices">-</a>
    4382             : 
    4383             :   qh_remove_extravertices(qh, facet )
    4384             :     remove extra vertices from non-simplicial facets
    4385             : 
    4386             :   returns:
    4387             :     returns True if it finds them
    4388             :       deletes facet from vertex neighbors
    4389             :       facet may be redundant (test with qh_degen_redundant)
    4390             : 
    4391             :   notes:
    4392             :     called by qh_renamevertex and qh_reducevertices
    4393             :     a merge (qh_reducevertices) or qh_renamevertex may drop all ridges for a vertex in a facet
    4394             : 
    4395             :   design:
    4396             :     for each vertex in facet
    4397             :       if vertex not in a ridge (i.e., no longer used)
    4398             :         delete vertex from facet
    4399             :         delete facet from vertex's neighbors
    4400             :         unless vertex in another facet
    4401             :           add vertex to qh.del_vertices for later deletion
    4402             : */
    4403       20048 : boolT qh_remove_extravertices(qhT *qh, facetT *facet) {
    4404             :   ridgeT *ridge, **ridgep;
    4405             :   vertexT *vertex, **vertexp;
    4406       20048 :   boolT foundrem= False;
    4407             : 
    4408       20048 :   if (facet->simplicial) {
    4409           0 :     return False;
    4410             :   }
    4411       20048 :   trace4((qh, qh->ferr, 4043, "qh_remove_extravertices: test non-simplicial f%d for extra vertices\n",
    4412             :           facet->id));
    4413      128434 :   FOREACHvertex_(facet->vertices)
    4414      108386 :     vertex->seen= False;
    4415      128434 :   FOREACHridge_(facet->ridges) {
    4416      325158 :     FOREACHvertex_(ridge->vertices)
    4417      216772 :       vertex->seen= True;
    4418             :   }
    4419      128434 :   FOREACHvertex_(facet->vertices) {
    4420      108386 :     if (!vertex->seen) {
    4421           0 :       foundrem= True;
    4422           0 :       zinc_(Zremvertex);
    4423           0 :       qh_setdelsorted(facet->vertices, vertex);
    4424           0 :       qh_setdel(vertex->neighbors, facet);
    4425           0 :       if (!qh_setsize(qh, vertex->neighbors)) {
    4426           0 :         vertex->deleted= True;
    4427           0 :         qh_setappend(qh, &qh->del_vertices, vertex);
    4428           0 :         zinc_(Zremvertexdel);
    4429           0 :         trace2((qh, qh->ferr, 2036, "qh_remove_extravertices: v%d deleted because it's lost all ridges\n", vertex->id));
    4430             :       }else
    4431           0 :         trace3((qh, qh->ferr, 3009, "qh_remove_extravertices: v%d removed from f%d because it's lost all ridges\n", vertex->id, facet->id));
    4432           0 :       vertexp--; /*repeat*/
    4433             :     }
    4434             :   }
    4435       20048 :   return foundrem;
    4436             : } /* remove_extravertices */
    4437             : 
    4438             : /*-<a                             href="qh-merge_r.htm#TOC"
    4439             :   >-------------------------------</a><a name="remove_mergetype">-</a>
    4440             : 
    4441             :   qh_remove_mergetype(qh, mergeset, mergetype )
    4442             :     Remove mergetype merges from mergeset
    4443             : 
    4444             :   notes:
    4445             :     Does not preserve order
    4446             : */
    4447           0 : void qh_remove_mergetype(qhT *qh, setT *mergeset, mergeType type) {
    4448             :   mergeT *merge;
    4449             :   int merge_i, merge_n;
    4450             : 
    4451           0 :   FOREACHmerge_i_(qh, mergeset) {
    4452           0 :     if (merge->mergetype == type) {
    4453           0 :         trace3((qh, qh->ferr, 3037, "qh_remove_mergetype: remove merge f%d f%d v%d v%d r%d r%d dist %2.2g type %d",
    4454             :             getid_(merge->facet1), getid_(merge->facet2), getid_(merge->vertex1), getid_(merge->vertex2), getid_(merge->ridge1), getid_(merge->ridge2), merge->distance, type));
    4455           0 :         qh_setdelnth(qh, mergeset, merge_i);
    4456           0 :         merge_i--; merge_n--;  /* repeat with next merge */
    4457             :     }
    4458             :   }
    4459           0 : } /* remove_mergetype */
    4460             : 
    4461             : /*-<a                             href="qh-merge_r.htm#TOC"
    4462             :   >-------------------------------</a><a name="rename_adjacentvertex">-</a>
    4463             : 
    4464             :   qh_rename_adjacentvertex(qh, oldvertex, newvertex )
    4465             :     renames oldvertex as newvertex.  Must be adjacent (i.e., in the same subridge)
    4466             :     no-op if either vertex is deleted
    4467             : 
    4468             :   notes:
    4469             :     called from qh_merge_pinchedvertices
    4470             : 
    4471             :   design:
    4472             :     for all neighbors of oldvertex
    4473             :       if simplicial, rename oldvertex to newvertex and drop if degenerate
    4474             :       if needed, add oldvertex neighbor to newvertex
    4475             :     determine ridges for oldvertex
    4476             :     rename oldvertex as newvertex in ridges (qh_renamevertex)
    4477             : */
    4478           0 : void qh_rename_adjacentvertex(qhT *qh, vertexT *oldvertex, vertexT *newvertex, realT dist) {
    4479             :   setT *ridges;
    4480           0 :   facetT *neighbor, **neighborp, *maxfacet= NULL;
    4481             :   ridgeT *ridge, **ridgep;
    4482           0 :   boolT istrace= False;
    4483           0 :   int oldsize= qh_setsize(qh, oldvertex->neighbors);
    4484           0 :   int newsize= qh_setsize(qh, newvertex->neighbors);
    4485           0 :   coordT maxdist2= -REALmax, dist2;
    4486             : 
    4487           0 :   if (qh->IStracing >= 4 || oldvertex->id == qh->tracevertex_id || newvertex->id == qh->tracevertex_id) {
    4488           0 :     istrace= True;
    4489             :   }
    4490           0 :   zzinc_(Ztotmerge);
    4491           0 :   if (istrace) {
    4492           0 :     qh_fprintf(qh, qh->ferr, 2071, "qh_rename_adjacentvertex: merge #%d rename v%d (%d neighbors) to v%d (%d neighbors) dist %2.2g\n",
    4493             :       zzval_(Ztotmerge), oldvertex->id, oldsize, newvertex->id, newsize, dist);
    4494             :   }
    4495           0 :   if (oldvertex->deleted || newvertex->deleted) {
    4496           0 :     if (istrace || qh->IStracing >= 2) {
    4497           0 :       qh_fprintf(qh, qh->ferr, 2072, "qh_rename_adjacentvertex: ignore rename.  Either v%d (%d) or v%d (%d) is deleted\n",
    4498           0 :         oldvertex->id, oldvertex->deleted, newvertex->id, newvertex->deleted);
    4499             :     }
    4500           0 :     return;
    4501             :   }
    4502           0 :   if (oldsize == 0 || newsize == 0) {
    4503           0 :     qh_fprintf(qh, qh->ferr, 2072, "qhull internal error (qh_rename_adjacentvertex): expecting neighbor facets for v%d and v%d.  Got %d and %d neighbors resp.\n",
    4504             :       oldvertex->id, newvertex->id, oldsize, newsize);
    4505           0 :       qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    4506             :   }
    4507           0 :   FOREACHneighbor_(oldvertex) {
    4508           0 :     if (neighbor->simplicial) {
    4509           0 :       if (qh_setin(neighbor->vertices, newvertex)) {
    4510           0 :         if (istrace || qh->IStracing >= 2) {
    4511           0 :           qh_fprintf(qh, qh->ferr, 2070, "qh_rename_adjacentvertex: simplicial f%d contains old v%d and new v%d.  Will be marked degenerate by qh_renamevertex\n",
    4512             :             neighbor->id, oldvertex->id, newvertex->id);
    4513             :         }
    4514           0 :         qh_makeridges(qh, neighbor); /* no longer simplicial, nummerge==0, skipped by qh_maybe_duplicateridge */
    4515             :       }else {
    4516           0 :         qh_replacefacetvertex(qh, neighbor, oldvertex, newvertex);
    4517           0 :         qh_setunique(qh, &newvertex->neighbors, neighbor);
    4518           0 :         qh_newvertices(qh, neighbor->vertices);  /* for qh_update_vertexneighbors of vertex neighbors */
    4519             :       }
    4520             :     }
    4521             :   }
    4522           0 :   ridges= qh_vertexridges(qh, oldvertex, qh_ALL);
    4523           0 :   if (istrace) {
    4524           0 :     FOREACHridge_(ridges) {
    4525           0 :       qh_printridge(qh, qh->ferr, ridge);
    4526             :     }
    4527             :   }
    4528           0 :   FOREACHneighbor_(oldvertex) {
    4529           0 :     if (!neighbor->simplicial){
    4530           0 :       qh_addfacetvertex(qh, neighbor, newvertex);
    4531           0 :       qh_setunique(qh, &newvertex->neighbors, neighbor);
    4532           0 :       qh_newvertices(qh, neighbor->vertices);  /* for qh_update_vertexneighbors of vertex neighbors */
    4533           0 :       if (qh->newfacet_list == qh->facet_tail) {
    4534           0 :         qh_removefacet(qh, neighbor);  /* add a neighbor to newfacet_list so that qh_partitionvisible has a newfacet */
    4535           0 :         qh_appendfacet(qh, neighbor);
    4536           0 :         neighbor->newfacet= True;
    4537             :       }
    4538             :     }
    4539             :   }
    4540           0 :   qh_renamevertex(qh, oldvertex, newvertex, ridges, NULL, NULL);  /* ridges invalidated */
    4541           0 :   if (oldvertex->deleted && !oldvertex->partitioned) {
    4542           0 :     FOREACHneighbor_(newvertex) {
    4543           0 :       if (!neighbor->visible) {
    4544           0 :         qh_distplane(qh, oldvertex->point, neighbor, &dist2);
    4545           0 :         if (dist2>maxdist2) {
    4546           0 :           maxdist2= dist2;
    4547           0 :           maxfacet= neighbor;
    4548             :         }
    4549             :       }
    4550             :     }
    4551           0 :     trace2((qh, qh->ferr, 2096, "qh_rename_adjacentvertex: partition old p%d(v%d) as a coplanar point for furthest f%d dist %2.2g.  Maybe repartition later (QH0031)\n",
    4552             :       qh_pointid(qh, oldvertex->point), oldvertex->id, maxfacet->id, maxdist2))
    4553           0 :     qh_partitioncoplanar(qh, oldvertex->point, maxfacet, NULL, !qh_ALL);  /* faster with maxdist2, otherwise duplicates distance tests from maxdist2/dist2 */
    4554           0 :     oldvertex->partitioned= True;
    4555             :   }
    4556           0 :   qh_settempfree(qh, &ridges);
    4557             : } /* rename_adjacentvertex */
    4558             : 
    4559             : /*-<a                             href="qh-merge_r.htm#TOC"
    4560             :   >-------------------------------</a><a name="rename_sharedvertex">-</a>
    4561             : 
    4562             :   qh_rename_sharedvertex(qh, vertex, facet )
    4563             :     detect and rename if shared vertex in facet
    4564             :     vertices have full ->neighbors
    4565             : 
    4566             :   returns:
    4567             :     newvertex or NULL
    4568             :     the vertex may still exist in other facets (i.e., a neighbor was pinched)
    4569             :     does not change facet->neighbors
    4570             :     updates vertex->neighbors
    4571             : 
    4572             :   notes:
    4573             :     only called by qh_reducevertices after qh_remove_extravertices
    4574             :        so f.vertices does not contain extraneous vertices
    4575             :     a shared vertex for a facet is only in ridges to one neighbor
    4576             :     this may undo a pinched facet
    4577             : 
    4578             :     it does not catch pinches involving multiple facets.  These appear
    4579             :       to be difficult to detect, since an exhaustive search is too expensive.
    4580             : 
    4581             :   design:
    4582             :     if vertex only has two neighbors
    4583             :       determine the ridges that contain the vertex
    4584             :       determine the vertices shared by both neighbors
    4585             :       if can find a new vertex in this set
    4586             :         rename the vertex to the new vertex
    4587             : */
    4588       40096 : vertexT *qh_rename_sharedvertex(qhT *qh, vertexT *vertex, facetT *facet) {
    4589       40096 :   facetT *neighbor, **neighborp, *neighborA= NULL;
    4590             :   setT *vertices, *ridges;
    4591       40096 :   vertexT *newvertex= NULL;
    4592             : 
    4593       40096 :   if (qh_setsize(qh, vertex->neighbors) == 2) {
    4594           0 :     neighborA= SETfirstt_(vertex->neighbors, facetT);
    4595           0 :     if (neighborA == facet)
    4596           0 :       neighborA= SETsecondt_(vertex->neighbors, facetT);
    4597       40096 :   }else if (qh->hull_dim == 3)
    4598       40096 :     return NULL;
    4599             :   else {
    4600           0 :     qh->visit_id++;
    4601           0 :     FOREACHneighbor_(facet)
    4602           0 :       neighbor->visitid= qh->visit_id;
    4603           0 :     FOREACHneighbor_(vertex) {
    4604           0 :       if (neighbor->visitid == qh->visit_id) {
    4605           0 :         if (neighborA)
    4606           0 :           return NULL;
    4607           0 :         neighborA= neighbor;
    4608             :       }
    4609             :     }
    4610             :   }
    4611           0 :   if (!neighborA) {
    4612           0 :     qh_fprintf(qh, qh->ferr, 6101, "qhull internal error (qh_rename_sharedvertex): v%d's neighbors not in f%d\n",
    4613             :         vertex->id, facet->id);
    4614           0 :     qh_errprint(qh, "ERRONEOUS", facet, NULL, NULL, vertex);
    4615           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL);
    4616             :   }
    4617           0 :   if (neighborA) { /* avoid warning */
    4618             :     /* the vertex is shared by facet and neighborA */
    4619           0 :     ridges= qh_settemp(qh, qh->TEMPsize);
    4620           0 :     neighborA->visitid= ++qh->visit_id;
    4621           0 :     qh_vertexridges_facet(qh, vertex, facet, &ridges);
    4622           0 :     trace2((qh, qh->ferr, 2037, "qh_rename_sharedvertex: p%d(v%d) is shared by f%d(%d ridges) and f%d\n",
    4623             :       qh_pointid(qh, vertex->point), vertex->id, facet->id, qh_setsize(qh, ridges), neighborA->id));
    4624           0 :     zinc_(Zintersectnum);
    4625           0 :     vertices= qh_vertexintersect_new(qh, facet->vertices, neighborA->vertices);
    4626           0 :     qh_setdel(vertices, vertex);
    4627           0 :     qh_settemppush(qh, vertices);
    4628           0 :     if ((newvertex= qh_find_newvertex(qh, vertex, vertices, ridges)))
    4629           0 :       qh_renamevertex(qh, vertex, newvertex, ridges, facet, neighborA);  /* ridges invalidated */
    4630           0 :     qh_settempfree(qh, &vertices);
    4631           0 :     qh_settempfree(qh, &ridges);
    4632             :   }
    4633           0 :   return newvertex;
    4634             : } /* rename_sharedvertex */
    4635             : 
    4636             : /*-<a                             href="qh-merge_r.htm#TOC"
    4637             :   >-------------------------------</a><a name="renameridgevertex">-</a>
    4638             : 
    4639             :   qh_renameridgevertex(qh, ridge, oldvertex, newvertex )
    4640             :     renames oldvertex as newvertex in ridge
    4641             : 
    4642             :   returns:
    4643             :     True if renames oldvertex
    4644             :     False if deleted the ridge
    4645             : 
    4646             :   notes:
    4647             :     called by qh_renamevertex
    4648             :     caller sets newvertex->delridge for deleted ridges (qh_reducevertices)
    4649             : 
    4650             :   design:
    4651             :     delete oldvertex from ridge
    4652             :     if newvertex already in ridge
    4653             :       copy ridge->noconvex to another ridge if possible
    4654             :       delete the ridge
    4655             :     else
    4656             :       insert newvertex into the ridge
    4657             :       adjust the ridge's orientation
    4658             : */
    4659           0 : boolT qh_renameridgevertex(qhT *qh, ridgeT *ridge, vertexT *oldvertex, vertexT *newvertex) {
    4660           0 :   int nth= 0, oldnth;
    4661             :   facetT *temp;
    4662             :   vertexT *vertex, **vertexp;
    4663             : 
    4664           0 :   oldnth= qh_setindex(ridge->vertices, oldvertex);
    4665           0 :   if (oldnth < 0) {
    4666           0 :     qh_fprintf(qh, qh->ferr, 6424, "qhull internal error (qh_renameridgevertex): oldvertex v%d not found in r%d.  Cannot rename to v%d\n",
    4667             :         oldvertex->id, ridge->id, newvertex->id);
    4668           0 :     qh_errexit(qh, qh_ERRqhull, NULL, ridge);
    4669             :   }
    4670           0 :   qh_setdelnthsorted(qh, ridge->vertices, oldnth);
    4671           0 :   FOREACHvertex_(ridge->vertices) {
    4672           0 :     if (vertex == newvertex) {
    4673           0 :       zinc_(Zdelridge);
    4674           0 :       if (ridge->nonconvex) /* only one ridge has nonconvex set */
    4675           0 :         qh_copynonconvex(qh, ridge);
    4676           0 :       trace2((qh, qh->ferr, 2038, "qh_renameridgevertex: ridge r%d deleted.  It contained both v%d and v%d\n",
    4677             :         ridge->id, oldvertex->id, newvertex->id));
    4678           0 :       qh_delridge_merge(qh, ridge); /* ridge.vertices deleted */
    4679           0 :       return False;
    4680             :     }
    4681           0 :     if (vertex->id < newvertex->id)
    4682           0 :       break;
    4683           0 :     nth++;
    4684             :   }
    4685           0 :   qh_setaddnth(qh, &ridge->vertices, nth, newvertex);
    4686           0 :   ridge->simplicialtop= False;
    4687           0 :   ridge->simplicialbot= False;
    4688           0 :   if (abs(oldnth - nth)%2) {
    4689           0 :     trace3((qh, qh->ferr, 3010, "qh_renameridgevertex: swapped the top and bottom of ridge r%d\n",
    4690             :             ridge->id));
    4691           0 :     temp= ridge->top;
    4692           0 :     ridge->top= ridge->bottom;
    4693           0 :     ridge->bottom= temp;
    4694             :   }
    4695           0 :   return True;
    4696             : } /* renameridgevertex */
    4697             : 
    4698             : 
    4699             : /*-<a                             href="qh-merge_r.htm#TOC"
    4700             :   >-------------------------------</a><a name="renamevertex">-</a>
    4701             : 
    4702             :   qh_renamevertex(qh, oldvertex, newvertex, ridges, oldfacet, neighborA )
    4703             :     renames oldvertex as newvertex in ridges of non-simplicial neighbors
    4704             :     set oldfacet/neighborA if oldvertex is shared between two facets (qh_rename_sharedvertex)
    4705             :     otherwise qh_redundant_vertex or qh_rename_adjacentvertex
    4706             : 
    4707             :   returns:
    4708             :     if oldfacet and multiple neighbors, oldvertex may still exist afterwards
    4709             :     otherwise sets oldvertex->deleted for later deletion
    4710             :     one or more ridges maybe deleted
    4711             :     ridges is invalidated
    4712             :     merges may be added to degen_mergeset via qh_maydropneighbor or qh_degen_redundant_facet
    4713             : 
    4714             :   notes:
    4715             :     qh_rename_sharedvertex can not change neighbors of newvertex (since it's a subset)
    4716             :     qh_redundant_vertex due to vertex->delridge for qh_reducevertices
    4717             :     qh_rename_adjacentvertex for complete renames
    4718             : 
    4719             :   design:
    4720             :     for each ridge in ridges
    4721             :       rename oldvertex to newvertex and delete degenerate ridges
    4722             :     if oldfacet not defined
    4723             :       for each non-simplicial neighbor of oldvertex
    4724             :         delete oldvertex from neighbor's vertices
    4725             :         remove extra vertices from neighbor
    4726             :       add oldvertex to qh.del_vertices
    4727             :     else if oldvertex only between oldfacet and neighborA
    4728             :       delete oldvertex from oldfacet and neighborA
    4729             :       add oldvertex to qh.del_vertices
    4730             :     else oldvertex is in oldfacet and neighborA and other facets (i.e., pinched)
    4731             :       delete oldvertex from oldfacet
    4732             :       delete oldfacet from old vertex's neighbors
    4733             :       remove extra vertices (e.g., oldvertex) from neighborA
    4734             : */
    4735           0 : void qh_renamevertex(qhT *qh, vertexT *oldvertex, vertexT *newvertex, setT *ridges, facetT *oldfacet, facetT *neighborA) {
    4736             :   facetT *neighbor, **neighborp;
    4737             :   ridgeT *ridge, **ridgep;
    4738             :   int topsize, bottomsize;
    4739           0 :   boolT istrace= False;
    4740             : 
    4741             : #ifndef qh_NOtrace
    4742           0 :   if (qh->IStracing >= 2 || oldvertex->id == qh->tracevertex_id ||
    4743           0 :         newvertex->id == qh->tracevertex_id) {
    4744           0 :     istrace= True;
    4745           0 :     qh_fprintf(qh, qh->ferr, 2086, "qh_renamevertex: rename v%d to v%d in %d ridges with old f%d and neighbor f%d\n",
    4746           0 :       oldvertex->id, newvertex->id, qh_setsize(qh, ridges), getid_(oldfacet), getid_(neighborA));
    4747             :   }
    4748             : #endif
    4749           0 :   FOREACHridge_(ridges) {
    4750           0 :     if (qh_renameridgevertex(qh, ridge, oldvertex, newvertex)) { /* ridge is deleted if False, invalidating ridges */
    4751           0 :       topsize= qh_setsize(qh, ridge->top->vertices);
    4752           0 :       bottomsize= qh_setsize(qh, ridge->bottom->vertices);
    4753           0 :       if (topsize < qh->hull_dim || (topsize == qh->hull_dim && !ridge->top->simplicial && qh_setin(ridge->top->vertices, newvertex))) {
    4754           0 :         trace4((qh, qh->ferr, 4070, "qh_renamevertex: ignore duplicate check for r%d.  top f%d (size %d) will be degenerate after rename v%d to v%d\n",
    4755             :           ridge->id, ridge->top->id, topsize, oldvertex->id, newvertex->id));
    4756           0 :       }else if (bottomsize < qh->hull_dim || (bottomsize == qh->hull_dim && !ridge->bottom->simplicial && qh_setin(ridge->bottom->vertices, newvertex))) {
    4757           0 :         trace4((qh, qh->ferr, 4071, "qh_renamevertex: ignore duplicate check for r%d.  bottom f%d (size %d) will be degenerate after rename v%d to v%d\n",
    4758             :           ridge->id, ridge->bottom->id, bottomsize, oldvertex->id, newvertex->id));
    4759             :       }else
    4760           0 :         qh_maybe_duplicateridge(qh, ridge);
    4761             :     }
    4762             :   }
    4763           0 :   if (!oldfacet) {
    4764             :     /* stat Zrenameall or Zpinchduplicate */
    4765           0 :     if (istrace)
    4766           0 :       qh_fprintf(qh, qh->ferr, 2087, "qh_renamevertex: renaming v%d to v%d in several facets for qh_redundant_vertex or MRGsubridge\n",
    4767             :                oldvertex->id, newvertex->id);
    4768           0 :     FOREACHneighbor_(oldvertex) {
    4769           0 :       if (neighbor->simplicial) {
    4770           0 :         qh_degen_redundant_facet(qh, neighbor); /* e.g., rbox 175 C3,2e-13 D4 t1545235541 | qhull d */
    4771             :       }else {
    4772           0 :         if (istrace)
    4773           0 :           qh_fprintf(qh, qh->ferr, 4080, "qh_renamevertex: rename vertices in non-simplicial neighbor f%d of v%d\n", neighbor->id, oldvertex->id);
    4774           0 :         qh_maydropneighbor(qh, neighbor);
    4775           0 :         qh_setdelsorted(neighbor->vertices, oldvertex); /* if degenerate, qh_degen_redundant_facet will add to mergeset */
    4776           0 :         if (qh_remove_extravertices(qh, neighbor))
    4777           0 :           neighborp--; /* neighbor deleted from oldvertex neighborset */
    4778           0 :         qh_degen_redundant_facet(qh, neighbor); /* either direction may be redundant, faster if combine? */
    4779           0 :         qh_test_redundant_neighbors(qh, neighbor);
    4780           0 :         qh_test_degen_neighbors(qh, neighbor);
    4781             :       }
    4782             :     }
    4783           0 :     if (!oldvertex->deleted) {
    4784           0 :       oldvertex->deleted= True;
    4785           0 :       qh_setappend(qh, &qh->del_vertices, oldvertex);
    4786             :     }
    4787           0 :   }else if (qh_setsize(qh, oldvertex->neighbors) == 2) {
    4788           0 :     zinc_(Zrenameshare);
    4789           0 :     if (istrace)
    4790           0 :       qh_fprintf(qh, qh->ferr, 3039, "qh_renamevertex: renaming v%d to v%d in oldfacet f%d for qh_rename_sharedvertex\n",
    4791             :                oldvertex->id, newvertex->id, oldfacet->id);
    4792           0 :     FOREACHneighbor_(oldvertex) {
    4793           0 :       qh_setdelsorted(neighbor->vertices, oldvertex);
    4794           0 :       qh_degen_redundant_facet(qh, neighbor);
    4795             :     }
    4796           0 :     oldvertex->deleted= True;
    4797           0 :     qh_setappend(qh, &qh->del_vertices, oldvertex);
    4798             :   }else {
    4799           0 :     zinc_(Zrenamepinch);
    4800           0 :     if (istrace || qh->IStracing >= 1)
    4801           0 :       qh_fprintf(qh, qh->ferr, 3040, "qh_renamevertex: renaming pinched v%d to v%d between f%d and f%d\n",
    4802             :                oldvertex->id, newvertex->id, oldfacet->id, neighborA->id);
    4803           0 :     qh_setdelsorted(oldfacet->vertices, oldvertex);
    4804           0 :     qh_setdel(oldvertex->neighbors, oldfacet);
    4805           0 :     if (qh_remove_extravertices(qh, neighborA))
    4806           0 :       qh_degen_redundant_facet(qh, neighborA);
    4807             :   }
    4808           0 :   if (oldfacet)
    4809           0 :     qh_degen_redundant_facet(qh, oldfacet);
    4810           0 : } /* renamevertex */
    4811             : 
    4812             : /*-<a                             href="qh-merge_r.htm#TOC"
    4813             :   >-------------------------------</a><a name="test_appendmerge">-</a>
    4814             : 
    4815             :   qh_test_appendmerge(qh, facet, neighbor, simplicial )
    4816             :     test convexity and append to qh.facet_mergeset if non-convex
    4817             :     if pre-merging,
    4818             :       no-op if qh.SKIPconvex, or qh.MERGEexact and coplanar
    4819             :     if simplicial, assumes centrum test is valid (e.g., adjacent, simplicial new facets)
    4820             : 
    4821             :   returns:
    4822             :     true if appends facet/neighbor to qh.facet_mergeset
    4823             :     sets facet->center as needed
    4824             :     does not change facet->seen
    4825             : 
    4826             :   notes:
    4827             :     called from qh_getmergeset_initial, qh_getmergeset, and qh_test_vneighbors
    4828             :     must be at least as strong as qh_checkconvex (poly2_r.c)
    4829             :     assumes !f.flipped
    4830             : 
    4831             :   design:
    4832             :     exit if qh.SKIPconvex ('Q0') and !qh.POSTmerging
    4833             :     if qh.cos_max ('An') is defined and merging coplanars
    4834             :       if the angle between facet normals is too shallow
    4835             :         append an angle-coplanar merge to qh.mergeset
    4836             :         return True
    4837             :     test convexity of facet and neighbor
    4838             : */
    4839      168819 : boolT qh_test_appendmerge(qhT *qh, facetT *facet, facetT *neighbor, boolT simplicial) {
    4840      168819 :   realT angle= -REALmax;
    4841      168819 :   boolT okangle= False;
    4842             : 
    4843      168819 :   if (qh->SKIPconvex && !qh->POSTmerging)
    4844           0 :     return False;
    4845      168819 :   if (qh->cos_max < REALmax/2 && (!qh->MERGEexact || qh->POSTmerging)) {
    4846           0 :     angle= qh_getangle(qh, facet->normal, neighbor->normal);
    4847           0 :     okangle= True;
    4848           0 :     zinc_(Zangletests);
    4849           0 :     if (angle > qh->cos_max) {
    4850           0 :       zinc_(Zcoplanarangle);
    4851           0 :       qh_appendmergeset(qh, facet, neighbor, MRGanglecoplanar, 0.0, angle);
    4852           0 :       trace2((qh, qh->ferr, 2039, "qh_test_appendmerge: coplanar angle %4.4g between f%d and f%d\n",
    4853             :          angle, facet->id, neighbor->id));
    4854           0 :       return True;
    4855             :     }
    4856             :   }
    4857      168819 :   if (simplicial || qh->hull_dim <= 3)
    4858      168819 :     return qh_test_centrum_merge(qh, facet, neighbor, angle, okangle);
    4859             :   else
    4860           0 :     return qh_test_nonsimplicial_merge(qh, facet, neighbor, angle, okangle);
    4861             : } /* test_appendmerge */
    4862             : 
    4863             : /*-<a                             href="qh-merge_r.htm#TOC"
    4864             :   >-------------------------------</a><a name="test_centrum_merge">-</a>
    4865             : 
    4866             :   qh_test_centrum_merge(qh, facet, neighbor, angle, okangle )
    4867             :     test centrum convexity and append non-convex facets to qh.facet_mergeset
    4868             :     'angle' is angle between facets if okangle is true, otherwise use 0.0
    4869             : 
    4870             :   returns:
    4871             :     true if append facet/neighbor to qh.facet_mergeset
    4872             :     sets facet->center as needed
    4873             :     does not change facet->seen
    4874             : 
    4875             :   notes:
    4876             :     called from test_appendmerge if adjacent simplicial facets or 2-d/3-d
    4877             :     at least as strict as qh_checkconvex, including qh.DISTround ('En' and 'Rn')
    4878             : 
    4879             :   design:
    4880             :     make facet's centrum if needed
    4881             :     if facet's centrum is above the neighbor (qh.centrum_radius)
    4882             :       set isconcave
    4883             : 
    4884             :     if facet's centrum is not below the neighbor (-qh.centrum_radius)
    4885             :       set iscoplanar
    4886             :     make neighbor's centrum if needed
    4887             :     if neighbor's centrum is above the facet
    4888             :       set isconcave
    4889             :     else if neighbor's centrum is not below the facet
    4890             :       set iscoplanar
    4891             :     if isconcave or iscoplanar and merging coplanars
    4892             :       get angle if needed (qh.ANGLEmerge 'An')
    4893             :       append concave-coplanar, concave ,or coplanar merge to qh.mergeset
    4894             : */
    4895      168819 : boolT qh_test_centrum_merge(qhT *qh, facetT *facet, facetT *neighbor, realT angle, boolT okangle) {
    4896             :   coordT dist, dist2, mergedist;
    4897      168819 :   boolT isconcave= False, iscoplanar= False;
    4898             : 
    4899      168819 :   if (!facet->center)
    4900       17491 :     facet->center= qh_getcentrum(qh, facet);
    4901      168819 :   zzinc_(Zcentrumtests);
    4902      168819 :   qh_distplane(qh, facet->center, neighbor, &dist);
    4903      168819 :   if (dist > qh->centrum_radius)
    4904           0 :     isconcave= True;
    4905      168819 :   else if (dist >= -qh->centrum_radius)
    4906           1 :     iscoplanar= True;
    4907      168819 :   if (!neighbor->center)
    4908       48425 :     neighbor->center= qh_getcentrum(qh, neighbor);
    4909      168819 :   zzinc_(Zcentrumtests);
    4910      168819 :   qh_distplane(qh, neighbor->center, facet, &dist2);
    4911      168819 :   if (dist2 > qh->centrum_radius)
    4912           0 :     isconcave= True;
    4913      168819 :   else if (!iscoplanar && dist2 >= -qh->centrum_radius)
    4914           0 :     iscoplanar= True;
    4915      168819 :   if (!isconcave && (!iscoplanar || (qh->MERGEexact && !qh->POSTmerging)))
    4916      168818 :     return False;
    4917           1 :   if (!okangle && qh->ANGLEmerge) {
    4918           0 :     angle= qh_getangle(qh, facet->normal, neighbor->normal);
    4919           0 :     zinc_(Zangletests);
    4920             :   }
    4921           1 :   if (isconcave && iscoplanar) {
    4922           0 :     zinc_(Zconcavecoplanarridge);
    4923           0 :     if (dist > dist2)
    4924           0 :       qh_appendmergeset(qh, facet, neighbor, MRGconcavecoplanar, dist, angle);
    4925             :     else
    4926           0 :       qh_appendmergeset(qh, neighbor, facet, MRGconcavecoplanar, dist2, angle);
    4927           0 :     trace0((qh, qh->ferr, 36, "qh_test_centrum_merge: concave f%d to coplanar f%d, dist %4.4g and reverse dist %4.4g, angle %4.4g during p%d\n",
    4928             :            facet->id, neighbor->id, dist, dist2, angle, qh->furthest_id));
    4929           1 :   }else if (isconcave) {
    4930           0 :     mergedist= fmax_(dist, dist2);
    4931           0 :     zinc_(Zconcaveridge);
    4932           0 :     qh_appendmergeset(qh, facet, neighbor, MRGconcave, mergedist, angle);
    4933           0 :     trace0((qh, qh->ferr, 37, "qh_test_centrum_merge: concave f%d to f%d, dist %4.4g and reverse dist %4.4g, angle %4.4g during p%d\n",
    4934             :       facet->id, neighbor->id, dist, dist2, angle, qh->furthest_id));
    4935             :   }else /* iscoplanar */ {
    4936           1 :     mergedist= fmin_(fabs_(dist), fabs_(dist2));
    4937           1 :     zinc_(Zcoplanarcentrum);
    4938           1 :     qh_appendmergeset(qh, facet, neighbor, MRGcoplanar, mergedist, angle);
    4939           1 :     trace2((qh, qh->ferr, 2097, "qh_test_centrum_merge: coplanar f%d to f%d dist %4.4g, reverse dist %4.4g angle %4.4g\n",
    4940             :               facet->id, neighbor->id, dist, dist2, angle));
    4941             :   }
    4942           1 :   return True;
    4943             : } /* test_centrum_merge */
    4944             : 
    4945             : /*-<a                             href="qh-merge_r.htm#TOC"
    4946             :   >-------------------------------</a><a name="test_degen_neighbors">-</a>
    4947             : 
    4948             :   qh_test_degen_neighbors(qh, facet )
    4949             :     append degenerate neighbors to qh.degen_mergeset
    4950             : 
    4951             :   notes:
    4952             :   called at end of qh_mergefacet() and qh_renamevertex()
    4953             :   call after test_redundant_facet() since MRGredundant is less expensive then MRGdegen
    4954             :     a degenerate facet has fewer than hull_dim neighbors
    4955             :     see: qh_merge_degenredundant()
    4956             : 
    4957             : */
    4958           1 : void qh_test_degen_neighbors(qhT *qh, facetT *facet) {
    4959             :   facetT *neighbor, **neighborp;
    4960             :   int size;
    4961             : 
    4962           1 :   trace4((qh, qh->ferr, 4073, "qh_test_degen_neighbors: test for degenerate neighbors of f%d\n", facet->id));
    4963           4 :   FOREACHneighbor_(facet) {
    4964           3 :     if (neighbor->visible) {
    4965           0 :       qh_fprintf(qh, qh->ferr, 6359, "qhull internal error (qh_test_degen_neighbors): facet f%d has deleted neighbor f%d (qh.visible_list)\n",
    4966             :         facet->id, neighbor->id);
    4967           0 :       qh_errexit2(qh, qh_ERRqhull, facet, neighbor);
    4968             :     }
    4969           3 :     if (neighbor->degenerate || neighbor->redundant || neighbor->dupridge) /* will merge or delete */
    4970           0 :       continue;
    4971             :     /* merge flipped-degenerate facet before flipped facets */
    4972           3 :     if ((size= qh_setsize(qh, neighbor->neighbors)) < qh->hull_dim) {
    4973           0 :       qh_appendmergeset(qh, neighbor, neighbor, MRGdegen, 0.0, 1.0);
    4974           0 :       trace2((qh, qh->ferr, 2019, "qh_test_degen_neighbors: f%d is degenerate with %d neighbors.  Neighbor of f%d.\n", neighbor->id, size, facet->id));
    4975             :     }
    4976             :   }
    4977           1 : } /* test_degen_neighbors */
    4978             : 
    4979             : 
    4980             : /*-<a                             href="qh-merge_r.htm#TOC"
    4981             :   >-------------------------------</a><a name="test_nonsimplicial_merge">-</a>
    4982             : 
    4983             :   qh_test_nonsimplicial_merge(qh, facet, neighbor, angle, okangle )
    4984             :     test centrum and vertex convexity and append non-convex or redundant facets to qh.facet_mergeset
    4985             :     'angle' is angle between facets if okangle is true, otherwise use 0.0
    4986             :     skips coplanar merges if pre-merging with qh.MERGEexact ('Qx')
    4987             : 
    4988             :   returns:
    4989             :     true if appends facet/neighbor to qh.facet_mergeset
    4990             :     sets facet->center as needed
    4991             :     does not change facet->seen
    4992             : 
    4993             :   notes:
    4994             :     only called from test_appendmerge if a non-simplicial facet and at least 4-d
    4995             :     at least as strict as qh_checkconvex, including qh.DISTround ('En' and 'Rn')
    4996             :       centrums must be < -qh.centrum_radius
    4997             :     tests vertices as well as centrums since a facet may be twisted relative to its neighbor
    4998             : 
    4999             :   design:
    5000             :     set precision constants for maxoutside, clearlyconcave, minvertex, and coplanarcentrum
    5001             :       use maxoutside for coplanarcentrum if premerging with 'Qx' and qh_MAXcoplanarcentrum merges
    5002             :       otherwise use qh.centrum_radious for coplanarcentrum
    5003             :     make facet and neighbor centrums if needed
    5004             :     isconcave if a centrum is above neighbor (coplanarcentrum)
    5005             :     iscoplanar if a centrum is not below neighbor (-qh.centrum_radius)
    5006             :     maybeconvex if a centrum is clearly below neighbor (-clearyconvex)
    5007             :     return False if both centrums clearly below neighbor (-clearyconvex)
    5008             :     return MRGconcave if isconcave
    5009             : 
    5010             :     facets are neither clearly convex nor clearly concave
    5011             :     test vertices as well as centrums
    5012             :     if maybeconvex
    5013             :       determine mindist and maxdist for vertices of the other facet
    5014             :       maybe MRGredundant
    5015             :     otherwise
    5016             :       determine mindist and maxdist for vertices of either facet
    5017             :       maybe MRGredundant
    5018             :       maybeconvex if a vertex is clearly below neighbor (-clearconvex)
    5019             : 
    5020             :     vertices are concave if dist > clearlyconcave
    5021             :     vertices are twisted if dist > maxoutside (isconcave and maybeconvex)
    5022             :     return False if not concave and pre-merge of 'Qx' (qh.MERGEexact)
    5023             :     vertices are coplanar if dist in -minvertex..maxoutside
    5024             :     if !isconcave, vertices are coplanar if dist >= -qh.MAXcoplanar (n*qh.premerge_centrum)
    5025             : 
    5026             :     return False if neither concave nor coplanar
    5027             :     return MRGtwisted if isconcave and maybeconvex
    5028             :     return MRGconcavecoplanar if isconcave and isconvex
    5029             :     return MRGconcave if isconcave
    5030             :     return MRGcoplanar if iscoplanar
    5031             : */
    5032           0 : boolT qh_test_nonsimplicial_merge(qhT *qh, facetT *facet, facetT *neighbor, realT angle, boolT okangle) {
    5033             :   coordT dist, mindist, maxdist, mindist2, maxdist2, dist2, maxoutside, clearlyconcave, minvertex, clearlyconvex, mergedist, coplanarcentrum;
    5034           0 :   boolT isconcave= False, iscoplanar= False, maybeconvex= False, isredundant= False;
    5035           0 :   vertexT *maxvertex= NULL, *maxvertex2= NULL;
    5036             : 
    5037           0 :   maxoutside= fmax_(neighbor->maxoutside, qh->ONEmerge + qh->DISTround);
    5038           0 :   maxoutside= fmax_(maxoutside, facet->maxoutside);
    5039           0 :   clearlyconcave= qh_RATIOconcavehorizon * maxoutside;
    5040           0 :   minvertex= fmax_(-qh->min_vertex, qh->MAXcoplanar); /* non-negative, not available per facet, not used for iscoplanar */
    5041           0 :   clearlyconvex= qh_RATIOconvexmerge * minvertex; /* must be convex for MRGtwisted */
    5042           0 :   if (qh->MERGEexact && !qh->POSTmerging && (facet->nummerge > qh_MAXcoplanarcentrum || neighbor->nummerge > qh_MAXcoplanarcentrum))
    5043           0 :     coplanarcentrum= maxoutside;
    5044             :   else
    5045           0 :     coplanarcentrum= qh->centrum_radius;
    5046             : 
    5047           0 :   if (!facet->center)
    5048           0 :     facet->center= qh_getcentrum(qh, facet);
    5049           0 :   zzinc_(Zcentrumtests);
    5050           0 :   qh_distplane(qh, facet->center, neighbor, &dist);
    5051           0 :   if (dist > coplanarcentrum)
    5052           0 :     isconcave= True;
    5053           0 :   else if (dist >= -qh->centrum_radius)
    5054           0 :     iscoplanar= True;
    5055           0 :   else if (dist < -clearlyconvex)
    5056           0 :     maybeconvex= True;
    5057           0 :   if (!neighbor->center)
    5058           0 :     neighbor->center= qh_getcentrum(qh, neighbor);
    5059           0 :   zzinc_(Zcentrumtests);
    5060           0 :   qh_distplane(qh, neighbor->center, facet, &dist2);
    5061           0 :   if (dist2 > coplanarcentrum)
    5062           0 :     isconcave= True;
    5063           0 :   else if (dist2 >= -qh->centrum_radius)
    5064           0 :     iscoplanar= True;
    5065           0 :   else if (dist2 < -clearlyconvex) {
    5066           0 :     if (maybeconvex)
    5067           0 :       return False; /* both centrums clearly convex */
    5068           0 :     maybeconvex= True;
    5069             :   }
    5070           0 :   if (isconcave) {
    5071           0 :     if (!okangle && qh->ANGLEmerge) {
    5072           0 :       angle= qh_getangle(qh, facet->normal, neighbor->normal);
    5073           0 :       zinc_(Zangletests);
    5074             :     }
    5075           0 :     mergedist= fmax_(dist, dist2);
    5076           0 :     zinc_(Zconcaveridge);
    5077           0 :     qh_appendmergeset(qh, facet, neighbor, MRGconcave, mergedist, angle);
    5078           0 :     trace0((qh, qh->ferr, 18, "qh_test_nonsimplicial_merge: concave centrum for f%d or f%d, dist %4.4g and reverse dist %4.4g, angle %4.4g during p%d\n",
    5079             :       facet->id, neighbor->id, dist, dist2, angle, qh->furthest_id));
    5080           0 :     return True;
    5081             :   }
    5082             :   /* neither clearly convex nor clearly concave, test vertices as well as centrums */
    5083           0 :   if (maybeconvex) {
    5084           0 :     if (dist < -clearlyconvex) {
    5085           0 :       maxdist= dist;  /* facet centrum clearly convex, no need to test its vertex distance */
    5086           0 :       mindist= dist;
    5087           0 :       maxvertex2= qh_furthestvertex(qh, neighbor, facet, &maxdist2, &mindist2);
    5088           0 :       if (!maxvertex2) {
    5089           0 :         qh_appendmergeset(qh, neighbor, facet, MRGredundant, maxdist2, qh_ANGLEnone);
    5090           0 :         isredundant= True;
    5091             :       }
    5092             :     }else { /* dist2 < -clearlyconvex */
    5093           0 :       maxdist2= dist2;   /* neighbor centrum clearly convex, no need to test its vertex distance */
    5094           0 :       mindist2= dist2;
    5095           0 :       maxvertex= qh_furthestvertex(qh, facet, neighbor, &maxdist, &mindist);
    5096           0 :       if (!maxvertex) {
    5097           0 :         qh_appendmergeset(qh, facet, neighbor, MRGredundant, maxdist, qh_ANGLEnone);
    5098           0 :         isredundant= True;
    5099             :       }
    5100             :     }
    5101             :   }else {
    5102           0 :     maxvertex= qh_furthestvertex(qh, facet, neighbor, &maxdist, &mindist);
    5103           0 :     if (maxvertex) {
    5104           0 :       maxvertex2= qh_furthestvertex(qh, neighbor, facet, &maxdist2, &mindist2);
    5105           0 :       if (!maxvertex2) {
    5106           0 :         qh_appendmergeset(qh, neighbor, facet, MRGredundant, maxdist2, qh_ANGLEnone);
    5107           0 :         isredundant= True;
    5108           0 :       }else if (mindist < -clearlyconvex || mindist2 < -clearlyconvex)
    5109           0 :         maybeconvex= True;
    5110             :     }else { /* !maxvertex */
    5111           0 :       qh_appendmergeset(qh, facet, neighbor, MRGredundant, maxdist, qh_ANGLEnone);
    5112           0 :       isredundant= True;
    5113             :     }
    5114             :   }
    5115           0 :   if (isredundant) {
    5116           0 :     zinc_(Zredundantmerge);
    5117           0 :     return True;
    5118             :   }
    5119             : 
    5120           0 :   if (maxdist > clearlyconcave || maxdist2 > clearlyconcave)
    5121           0 :     isconcave= True;
    5122           0 :   else if (maybeconvex) {
    5123           0 :     if (maxdist > maxoutside || maxdist2 > maxoutside)
    5124           0 :       isconcave= True;  /* MRGtwisted */
    5125             :   }
    5126           0 :   if (!isconcave && qh->MERGEexact && !qh->POSTmerging)
    5127           0 :     return False;
    5128           0 :   if (isconcave && !iscoplanar) {
    5129           0 :     if (maxdist < maxoutside && (-qh->MAXcoplanar || (maxdist2 < maxoutside && mindist2 >= -qh->MAXcoplanar)))
    5130           0 :       iscoplanar= True; /* MRGconcavecoplanar */
    5131           0 :   }else if (!iscoplanar) {
    5132           0 :     if (mindist >= -qh->MAXcoplanar || mindist2 >= -qh->MAXcoplanar)
    5133           0 :       iscoplanar= True;  /* MRGcoplanar */
    5134             :   }
    5135           0 :   if (!isconcave && !iscoplanar)
    5136           0 :     return False;
    5137           0 :   if (!okangle && qh->ANGLEmerge) {
    5138           0 :     angle= qh_getangle(qh, facet->normal, neighbor->normal);
    5139           0 :     zinc_(Zangletests);
    5140             :   }
    5141           0 :   if (isconcave && maybeconvex) {
    5142           0 :     zinc_(Ztwistedridge);
    5143           0 :     if (maxdist > maxdist2)
    5144           0 :       qh_appendmergeset(qh, facet, neighbor, MRGtwisted, maxdist, angle);
    5145             :     else
    5146           0 :       qh_appendmergeset(qh, neighbor, facet, MRGtwisted, maxdist2, angle);
    5147           0 :     trace0((qh, qh->ferr, 27, "qh_test_nonsimplicial_merge: twisted concave f%d v%d to f%d v%d, dist %4.4g and reverse dist %4.4g, angle %4.4g during p%d\n",
    5148             :            facet->id, getid_(maxvertex), neighbor->id, getid_(maxvertex2), maxdist, maxdist2, angle, qh->furthest_id));
    5149           0 :   }else if (isconcave && iscoplanar) {
    5150           0 :     zinc_(Zconcavecoplanarridge);
    5151           0 :     if (maxdist > maxdist2)
    5152           0 :       qh_appendmergeset(qh, facet, neighbor, MRGconcavecoplanar, maxdist, angle);
    5153             :     else
    5154           0 :       qh_appendmergeset(qh, neighbor, facet, MRGconcavecoplanar, maxdist2, angle);
    5155           0 :     trace0((qh, qh->ferr, 28, "qh_test_nonsimplicial_merge: concave coplanar f%d v%d to f%d v%d, dist %4.4g and reverse dist %4.4g, angle %4.4g during p%d\n",
    5156             :       facet->id, getid_(maxvertex), neighbor->id, getid_(maxvertex2), maxdist, maxdist2, angle, qh->furthest_id));
    5157           0 :   }else if (isconcave) {
    5158           0 :     mergedist= fmax_(maxdist, maxdist2);
    5159           0 :     zinc_(Zconcaveridge);
    5160           0 :     qh_appendmergeset(qh, facet, neighbor, MRGconcave, mergedist, angle);
    5161           0 :     trace0((qh, qh->ferr, 29, "qh_test_nonsimplicial_merge: concave f%d v%d to f%d v%d, dist %4.4g and reverse dist %4.4g, angle %4.4g during p%d\n",
    5162             :       facet->id, getid_(maxvertex), neighbor->id, getid_(maxvertex2), maxdist, maxdist2, angle, qh->furthest_id));
    5163             :   }else /* iscoplanar */ {
    5164           0 :     mergedist= fmax_(fmax_(maxdist, maxdist2), fmax_(-mindist, -mindist2));
    5165           0 :     zinc_(Zcoplanarcentrum);
    5166           0 :     qh_appendmergeset(qh, facet, neighbor, MRGcoplanar, mergedist, angle);
    5167           0 :     trace2((qh, qh->ferr, 2099, "qh_test_nonsimplicial_merge: coplanar f%d v%d to f%d v%d, dist %4.4g and reverse dist %4.4g, angle %4.4g during p%d\n",
    5168             :       facet->id, getid_(maxvertex), neighbor->id, getid_(maxvertex2), maxdist, maxdist2, angle, qh->furthest_id));
    5169             :   }
    5170           0 :   return True;
    5171             : } /* test_nonsimplicial_merge */
    5172             : 
    5173             : /*-<a                             href="qh-merge_r.htm#TOC"
    5174             :   >-------------------------------</a><a name="test_redundant_neighbors">-</a>
    5175             : 
    5176             :   qh_test_redundant_neighbors(qh, facet )
    5177             :     append degenerate facet or its redundant neighbors to qh.degen_mergeset
    5178             : 
    5179             :   returns:
    5180             :     bumps vertex_visit
    5181             : 
    5182             :   notes:
    5183             :     called at end of qh_mergefacet(), qh_mergecycle_all(), and qh_renamevertex
    5184             :     call before qh_test_degen_neighbors (MRGdegen are more likely to cause problems)
    5185             :     a redundant neighbor's vertices is a subset of the facet's vertices
    5186             :     with pinched and flipped facets, a redundant neighbor may have a wildly different normal
    5187             : 
    5188             :     see qh_merge_degenredundant() and qh_-_facet()
    5189             : 
    5190             :   design:
    5191             :     if facet is degenerate
    5192             :        appends facet to degen_mergeset
    5193             :     else
    5194             :        appends redundant neighbors of facet to degen_mergeset
    5195             : */
    5196       20048 : void qh_test_redundant_neighbors(qhT *qh, facetT *facet) {
    5197             :   vertexT *vertex, **vertexp;
    5198             :   facetT *neighbor, **neighborp;
    5199             :   int size;
    5200             : 
    5201       20048 :   trace4((qh, qh->ferr, 4022, "qh_test_redundant_neighbors: test neighbors of f%d vertex_visit %d\n",
    5202             :           facet->id, qh->vertex_visit+1));
    5203       20048 :   if ((size= qh_setsize(qh, facet->neighbors)) < qh->hull_dim) {
    5204           0 :     qh_appendmergeset(qh, facet, facet, MRGdegen, 0.0, 1.0);
    5205           0 :     trace2((qh, qh->ferr, 2017, "qh_test_redundant_neighbors: f%d is degenerate with %d neighbors.\n", facet->id, size));
    5206             :   }else {
    5207       20048 :     qh->vertex_visit++;
    5208      128434 :     FOREACHvertex_(facet->vertices)
    5209      108386 :       vertex->visitid= qh->vertex_visit;
    5210      128434 :     FOREACHneighbor_(facet) {
    5211      108386 :       if (neighbor->visible) {
    5212           0 :         qh_fprintf(qh, qh->ferr, 6360, "qhull internal error (qh_test_redundant_neighbors): facet f%d has deleted neighbor f%d (qh.visible_list)\n",
    5213             :           facet->id, neighbor->id);
    5214           0 :         qh_errexit2(qh, qh_ERRqhull, facet, neighbor);
    5215             :       }
    5216      108386 :       if (neighbor->degenerate || neighbor->redundant || neighbor->dupridge) /* will merge or delete */
    5217           0 :         continue;
    5218      108386 :       if (facet->flipped && !neighbor->flipped) /* do not merge non-flipped into flipped */
    5219           0 :         continue;
    5220             :       /* merge redundant-flipped facet first */
    5221             :       /* uses early out instead of checking vertex count */
    5222      212947 :       FOREACHvertex_(neighbor->vertices) {
    5223      212947 :         if (vertex->visitid != qh->vertex_visit)
    5224      108386 :           break;
    5225             :       }
    5226      108386 :       if (!vertex) {
    5227           0 :         qh_appendmergeset(qh, neighbor, facet, MRGredundant, 0.0, 1.0);
    5228           0 :         trace2((qh, qh->ferr, 2018, "qh_test_redundant_neighbors: f%d is contained in f%d.  merge\n", neighbor->id, facet->id));
    5229             :       }
    5230             :     }
    5231             :   }
    5232       20048 : } /* test_redundant_neighbors */
    5233             : 
    5234             : /*-<a                             href="qh-merge_r.htm#TOC"
    5235             :   >-------------------------------</a><a name="test_vneighbors">-</a>
    5236             : 
    5237             :   qh_test_vneighbors(qh)
    5238             :     test vertex neighbors for convexity
    5239             :     tests all facets on qh.newfacet_list
    5240             : 
    5241             :   returns:
    5242             :     true if non-convex vneighbors appended to qh.facet_mergeset
    5243             :     initializes vertex neighbors if needed
    5244             : 
    5245             :   notes:
    5246             :     called by qh_all_merges from qh_postmerge if qh.TESTvneighbors ('Qv')
    5247             :     assumes all facet neighbors have been tested
    5248             :     this can be expensive
    5249             :     this does not guarantee that a centrum is below all facets
    5250             :       but it is unlikely
    5251             :     uses qh.visit_id
    5252             : 
    5253             :   design:
    5254             :     build vertex neighbors if necessary
    5255             :     for all new facets
    5256             :       for all vertices
    5257             :         for each unvisited facet neighbor of the vertex
    5258             :           test new facet and neighbor for convexity
    5259             : */
    5260           0 : boolT qh_test_vneighbors(qhT *qh /* qh.newfacet_list */) {
    5261             :   facetT *newfacet, *neighbor, **neighborp;
    5262             :   vertexT *vertex, **vertexp;
    5263           0 :   int nummerges= 0;
    5264             : 
    5265           0 :   trace1((qh, qh->ferr, 1015, "qh_test_vneighbors: testing vertex neighbors for convexity\n"));
    5266           0 :   if (!qh->VERTEXneighbors)
    5267           0 :     qh_vertexneighbors(qh);
    5268           0 :   FORALLnew_facets
    5269           0 :     newfacet->seen= False;
    5270           0 :   FORALLnew_facets {
    5271           0 :     newfacet->seen= True;
    5272           0 :     newfacet->visitid= qh->visit_id++;
    5273           0 :     FOREACHneighbor_(newfacet)
    5274           0 :       newfacet->visitid= qh->visit_id;
    5275           0 :     FOREACHvertex_(newfacet->vertices) {
    5276           0 :       FOREACHneighbor_(vertex) {
    5277           0 :         if (neighbor->seen || neighbor->visitid == qh->visit_id)
    5278           0 :           continue;
    5279           0 :         if (qh_test_appendmerge(qh, newfacet, neighbor, False)) /* ignores optimization for simplicial ridges */
    5280           0 :           nummerges++;
    5281             :       }
    5282             :     }
    5283             :   }
    5284           0 :   zadd_(Ztestvneighbor, nummerges);
    5285           0 :   trace1((qh, qh->ferr, 1016, "qh_test_vneighbors: found %d non-convex, vertex neighbors\n",
    5286             :            nummerges));
    5287           0 :   return (nummerges > 0);
    5288             : } /* test_vneighbors */
    5289             : 
    5290             : /*-<a                             href="qh-merge_r.htm#TOC"
    5291             :   >-------------------------------</a><a name="tracemerge">-</a>
    5292             : 
    5293             :   qh_tracemerge(qh, facet1, facet2 )
    5294             :     print trace message after merge
    5295             : */
    5296       20048 : void qh_tracemerge(qhT *qh, facetT *facet1, facetT *facet2, mergeType mergetype) {
    5297       20048 :   boolT waserror= False;
    5298             :   const char *mergename;
    5299             : 
    5300             : #ifndef qh_NOtrace
    5301       20048 :   if(mergetype > 0 && mergetype < sizeof(mergetypes)/sizeof(char *))
    5302       20048 :     mergename= mergetypes[mergetype];
    5303             :   else
    5304           0 :     mergename= mergetypes[MRGnone];
    5305       20048 :   if (qh->IStracing >= 4)
    5306           0 :     qh_errprint(qh, "MERGED", facet2, NULL, NULL, NULL);
    5307       20048 :   if (facet2 == qh->tracefacet || (qh->tracevertex && qh->tracevertex->newfacet)) {
    5308           0 :     qh_fprintf(qh, qh->ferr, 8085, "qh_tracemerge: trace facet and vertex after merge of f%d into f%d type %d (%s), furthest p%d\n",
    5309             :       facet1->id, facet2->id, mergetype, mergename, qh->furthest_id);
    5310           0 :     if (facet2 != qh->tracefacet)
    5311           0 :       qh_errprint(qh, "TRACE", qh->tracefacet,
    5312           0 :         (qh->tracevertex && qh->tracevertex->neighbors) ?
    5313           0 :            SETfirstt_(qh->tracevertex->neighbors, facetT) : NULL,
    5314             :         NULL, qh->tracevertex);
    5315             :   }
    5316       20048 :   if (qh->tracevertex) {
    5317           0 :     if (qh->tracevertex->deleted)
    5318           0 :       qh_fprintf(qh, qh->ferr, 8086, "qh_tracemerge: trace vertex deleted at furthest p%d\n",
    5319             :             qh->furthest_id);
    5320             :     else
    5321           0 :       qh_checkvertex(qh, qh->tracevertex, qh_ALL, &waserror);
    5322             :   }
    5323       20048 :   if (qh->tracefacet && qh->tracefacet->normal && !qh->tracefacet->visible)
    5324           0 :     qh_checkfacet(qh, qh->tracefacet, True /* newmerge */, &waserror);
    5325             : #endif /* !qh_NOtrace */
    5326       20048 :   if (qh->CHECKfrequently || qh->IStracing >= 4) { /* can't check polygon here */
    5327           0 :     if (qh->IStracing >= 4 && qh->num_facets < 500) {
    5328           0 :       qh_printlists(qh);
    5329             :     }
    5330           0 :     qh_checkfacet(qh, facet2, True /* newmerge */, &waserror);
    5331             :   }
    5332       20048 :   if (waserror)
    5333           0 :     qh_errexit(qh, qh_ERRqhull, NULL, NULL); /* erroneous facet logged by qh_checkfacet */
    5334       20048 : } /* tracemerge */
    5335             : 
    5336             : /*-<a                             href="qh-merge_r.htm#TOC"
    5337             :   >-------------------------------</a><a name="tracemerging">-</a>
    5338             : 
    5339             :   qh_tracemerging(qh)
    5340             :     print trace message during POSTmerging
    5341             : 
    5342             :   returns:
    5343             :     updates qh.mergereport
    5344             : 
    5345             :   notes:
    5346             :     called from qh_mergecycle() and qh_mergefacet()
    5347             : 
    5348             :   see:
    5349             :     qh_buildtracing()
    5350             : */
    5351           0 : void qh_tracemerging(qhT *qh) {
    5352             :   realT cpu;
    5353             :   int total;
    5354             :   time_t timedata;
    5355             :   struct tm *tp;
    5356             : 
    5357           0 :   qh->mergereport= zzval_(Ztotmerge);
    5358           0 :   time(&timedata);
    5359           0 :   tp= localtime(&timedata);
    5360           0 :   cpu= qh_CPUclock;
    5361           0 :   cpu /= qh_SECticks;
    5362           0 :   total= zzval_(Ztotmerge) - zzval_(Zcyclehorizon) + zzval_(Zcyclefacettot);
    5363           0 :   qh_fprintf(qh, qh->ferr, 8087, "\n\
    5364             : At %d:%d:%d & %2.5g CPU secs, qhull has merged %d facets with max_outside %2.2g, min_vertex %2.2g.\n\
    5365             :   The hull contains %d facets and %d vertices.\n",
    5366             :       tp->tm_hour, tp->tm_min, tp->tm_sec, cpu, total, qh->max_outside, qh->min_vertex,
    5367           0 :       qh->num_facets - qh->num_visible,
    5368           0 :       qh->num_vertices-qh_setsize(qh, qh->del_vertices));
    5369           0 : } /* tracemerging */
    5370             : 
    5371             : /*-<a                             href="qh-merge_r.htm#TOC"
    5372             :   >-------------------------------</a><a name="updatetested">-</a>
    5373             : 
    5374             :   qh_updatetested(qh, facet1, facet2 )
    5375             :     clear facet2->tested and facet1->ridge->tested for merge
    5376             : 
    5377             :   returns:
    5378             :     deletes facet2->center unless it's already large
    5379             :       if so, clears facet2->ridge->tested
    5380             : 
    5381             :   notes:
    5382             :     only called by qh_mergefacet
    5383             : 
    5384             :   design:
    5385             :     clear facet2->tested
    5386             :     clear ridge->tested for facet1's ridges
    5387             :     if facet2 has a centrum
    5388             :       if facet2 is large
    5389             :         set facet2->keepcentrum
    5390             :       else if facet2 has 3 vertices due to many merges, or not large and post merging
    5391             :         clear facet2->keepcentrum
    5392             :       unless facet2->keepcentrum
    5393             :         clear facet2->center to recompute centrum later
    5394             :         clear ridge->tested for facet2's ridges
    5395             : */
    5396       20048 : void qh_updatetested(qhT *qh, facetT *facet1, facetT *facet2) {
    5397             :   ridgeT *ridge, **ridgep;
    5398             :   int size;
    5399             : 
    5400       20048 :   facet2->tested= False;
    5401       80192 :   FOREACHridge_(facet1->ridges)
    5402       60144 :     ridge->tested= False;
    5403       20048 :   if (!facet2->center)
    5404         836 :     return;
    5405       19212 :   size= qh_setsize(qh, facet2->vertices);
    5406       19212 :   if (!facet2->keepcentrum) {
    5407       18768 :     if (size > qh->hull_dim + qh_MAXnewcentrum) {
    5408           4 :       facet2->keepcentrum= True;
    5409           4 :       zinc_(Zwidevertices);
    5410             :     }
    5411         444 :   }else if (size <= qh->hull_dim + qh_MAXnewcentrum) {
    5412             :     /* center and keepcentrum was set */
    5413           0 :     if (size == qh->hull_dim || qh->POSTmerging)
    5414           0 :       facet2->keepcentrum= False; /* if many merges need to recompute centrum */
    5415             :   }
    5416       19212 :   if (!facet2->keepcentrum) {
    5417       18764 :     qh_memfree(qh, facet2->center, qh->normal_size);
    5418       18764 :     facet2->center= NULL;
    5419       75698 :     FOREACHridge_(facet2->ridges)
    5420       56934 :       ridge->tested= False;
    5421             :   }
    5422             : } /* updatetested */
    5423             : 
    5424             : /*-<a                             href="qh-merge_r.htm#TOC"
    5425             :   >-------------------------------</a><a name="vertexridges">-</a>
    5426             : 
    5427             :   qh_vertexridges(qh, vertex, allneighbors )
    5428             :     return temporary set of ridges adjacent to a vertex
    5429             :     vertex->neighbors defined (qh_vertexneighbors)
    5430             : 
    5431             :   notes:
    5432             :     uses qh.visit_id
    5433             :     does not include implicit ridges for simplicial facets
    5434             :     skips last neighbor, unless allneighbors.  For new facets, the last neighbor shares ridges with adjacent neighbors
    5435             :     if the last neighbor is not simplicial, it will have ridges for its simplicial neighbors
    5436             :     Use allneighbors when a new cone is attached to an existing convex hull
    5437             :     similar to qh_neighbor_vertices
    5438             : 
    5439             :   design:
    5440             :     for each neighbor of vertex
    5441             :       add ridges that include the vertex to ridges
    5442             : */
    5443           0 : setT *qh_vertexridges(qhT *qh, vertexT *vertex, boolT allneighbors) {
    5444             :   facetT *neighbor, **neighborp;
    5445           0 :   setT *ridges= qh_settemp(qh, qh->TEMPsize);
    5446             :   int size;
    5447             : 
    5448           0 :   qh->visit_id += 2;  /* visit_id for vertex neighbors, visit_id-1 for facets of visited ridges */
    5449           0 :   FOREACHneighbor_(vertex)
    5450           0 :     neighbor->visitid= qh->visit_id;
    5451           0 :   FOREACHneighbor_(vertex) {
    5452           0 :     if (*neighborp || allneighbors)   /* no new ridges in last neighbor */
    5453           0 :       qh_vertexridges_facet(qh, vertex, neighbor, &ridges);
    5454             :   }
    5455           0 :   if (qh->PRINTstatistics || qh->IStracing) {
    5456           0 :     size= qh_setsize(qh, ridges);
    5457           0 :     zinc_(Zvertexridge);
    5458           0 :     zadd_(Zvertexridgetot, size);
    5459           0 :     zmax_(Zvertexridgemax, size);
    5460           0 :     trace3((qh, qh->ferr, 3011, "qh_vertexridges: found %d ridges for v%d\n",
    5461             :              size, vertex->id));
    5462             :   }
    5463           0 :   return ridges;
    5464             : } /* vertexridges */
    5465             : 
    5466             : /*-<a                             href="qh-merge_r.htm#TOC"
    5467             :   >-------------------------------</a><a name="vertexridges_facet">-</a>
    5468             : 
    5469             :   qh_vertexridges_facet(qh, vertex, facet, ridges )
    5470             :     add adjacent ridges for vertex in facet
    5471             :     neighbor->visitid==qh.visit_id if it hasn't been visited
    5472             : 
    5473             :   returns:
    5474             :     ridges updated
    5475             :     sets facet->visitid to qh.visit_id-1
    5476             : 
    5477             :   design:
    5478             :     for each ridge of facet
    5479             :       if ridge of visited neighbor (i.e., unprocessed)
    5480             :         if vertex in ridge
    5481             :           append ridge
    5482             :     mark facet processed
    5483             : */
    5484           0 : void qh_vertexridges_facet(qhT *qh, vertexT *vertex, facetT *facet, setT **ridges) {
    5485             :   ridgeT *ridge, **ridgep;
    5486             :   facetT *neighbor;
    5487           0 :   int last_i= qh->hull_dim-2;
    5488             :   vertexT *second, *last;
    5489             : 
    5490           0 :   FOREACHridge_(facet->ridges) {
    5491           0 :     neighbor= otherfacet_(ridge, facet);
    5492           0 :     if (neighbor->visitid == qh->visit_id) {
    5493           0 :       if (SETfirst_(ridge->vertices) == vertex) {
    5494           0 :         qh_setappend(qh, ridges, ridge);
    5495           0 :       }else if (last_i > 2) {
    5496           0 :         second= SETsecondt_(ridge->vertices, vertexT);
    5497           0 :         last= SETelemt_(ridge->vertices, last_i, vertexT);
    5498           0 :         if (second->id >= vertex->id && last->id <= vertex->id) { /* vertices inverse sorted by id */
    5499           0 :           if (second == vertex || last == vertex)
    5500           0 :             qh_setappend(qh, ridges, ridge);
    5501           0 :           else if (qh_setin(ridge->vertices, vertex))
    5502           0 :             qh_setappend(qh, ridges, ridge);
    5503             :         }
    5504           0 :       }else if (SETelem_(ridge->vertices, last_i) == vertex
    5505           0 :           || (last_i > 1 && SETsecond_(ridge->vertices) == vertex)) {
    5506           0 :         qh_setappend(qh, ridges, ridge);
    5507             :       }
    5508             :     }
    5509             :   }
    5510           0 :   facet->visitid= qh->visit_id-1;
    5511           0 : } /* vertexridges_facet */
    5512             : 
    5513             : /*-<a                             href="qh-merge_r.htm#TOC"
    5514             :   >-------------------------------</a><a name="willdelete">-</a>
    5515             : 
    5516             :   qh_willdelete(qh, facet, replace )
    5517             :     moves facet to visible list for qh_deletevisible
    5518             :     sets facet->f.replace to replace (may be NULL)
    5519             :     clears f.ridges and f.neighbors -- no longer valid
    5520             : 
    5521             :   returns:
    5522             :     bumps qh.num_visible
    5523             : */
    5524       63263 : void qh_willdelete(qhT *qh, facetT *facet, facetT *replace) {
    5525             : 
    5526       63263 :   trace4((qh, qh->ferr, 4081, "qh_willdelete: move f%d to visible list, set its replacement as f%d, and clear f.neighbors and f.ridges\n", facet->id, getid_(replace)));
    5527       63263 :   if (!qh->visible_list && qh->newfacet_list) {
    5528           0 :     qh_fprintf(qh, qh->ferr, 6378, "qhull internal error (qh_willdelete): expecting qh.visible_list at before qh.newfacet_list f%d.   Got NULL\n",
    5529           0 :         qh->newfacet_list->id);
    5530           0 :     qh_errexit2(qh, qh_ERRqhull, NULL, NULL);
    5531             :   }
    5532       63263 :   qh_removefacet(qh, facet);
    5533       63263 :   qh_prependfacet(qh, facet, &qh->visible_list);
    5534       63263 :   qh->num_visible++;
    5535       63263 :   facet->visible= True;
    5536       63263 :   facet->f.replace= replace;
    5537       63263 :   if (facet->ridges)
    5538       34453 :     SETfirst_(facet->ridges)= NULL;
    5539       63263 :   if (facet->neighbors)
    5540       63263 :     SETfirst_(facet->neighbors)= NULL;
    5541       63263 : } /* willdelete */
    5542             : 
    5543             : #else /* qh_NOmerge */
    5544             : 
    5545             : void qh_all_vertexmerges(qhT *qh, int apexpointid, facetT *facet, facetT **retryfacet) {
    5546             :   QHULL_UNUSED(qh)
    5547             :   QHULL_UNUSED(apexpointid)
    5548             :   QHULL_UNUSED(facet)
    5549             :   QHULL_UNUSED(retryfacet)
    5550             : }
    5551             : void qh_premerge(qhT *qh, int apexpointid, realT maxcentrum, realT maxangle) {
    5552             :   QHULL_UNUSED(qh)
    5553             :   QHULL_UNUSED(apexpointid)
    5554             :   QHULL_UNUSED(maxcentrum)
    5555             :   QHULL_UNUSED(maxangle)
    5556             : }
    5557             : void qh_postmerge(qhT *qh, const char *reason, realT maxcentrum, realT maxangle,
    5558             :                       boolT vneighbors) {
    5559             :   QHULL_UNUSED(qh)
    5560             :   QHULL_UNUSED(reason)
    5561             :   QHULL_UNUSED(maxcentrum)
    5562             :   QHULL_UNUSED(maxangle)
    5563             :   QHULL_UNUSED(vneighbors)
    5564             : }
    5565             : void qh_checkdelfacet(qhT *qh, facetT *facet, setT *mergeset) {
    5566             :   QHULL_UNUSED(qh)
    5567             :   QHULL_UNUSED(facet)
    5568             :   QHULL_UNUSED(mergeset)
    5569             : }
    5570             : void qh_checkdelridge(qhT *qh /* qh.visible_facets, vertex_mergeset */) {
    5571             :   QHULL_UNUSED(qh)
    5572             : }
    5573             : boolT qh_checkzero(qhT *qh, boolT testall) {
    5574             :   QHULL_UNUSED(qh)
    5575             :   QHULL_UNUSED(testall)
    5576             :     
    5577             :   return True;
    5578             : }
    5579             : void qh_freemergesets(qhT *qh) {
    5580             :   QHULL_UNUSED(qh)
    5581             : }
    5582             : void qh_initmergesets(qhT *qh) {
    5583             :   QHULL_UNUSED(qh)
    5584             : }
    5585             : void qh_merge_pinchedvertices(qhT *qh, int apexpointid /* qh.newfacet_list */) {
    5586             :   QHULL_UNUSED(qh)
    5587             :   QHULL_UNUSED(apexpointid)
    5588             : }
    5589             : #endif /* qh_NOmerge */
    5590             : 

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