text: /*<html><pre>  -<a                             href="qh-merge_r.htm"
    >-------------------------------</a><a name="TOP">-</a>
  
     merge_r.h
     header file for merge_r.c
  
     see qh-merge_r.htm and merge_r.c
  
     Copyright (c) 1993-2020 C.B. Barber.
     $Id: //main/2019/qhull/src/libqhull_r/merge_r.h#2 $$Change: 2953 $
     $DateTime: 2020/05/21 22:05:32 $$Author: bbarber $
  */
  
  #ifndef qhDEFmerge
  #define qhDEFmerge 1
  
  #include "libqhull_r.h"
  
  
  /*============ -constants- ==============*/
  
  /*-<a                             href="qh-merge_r.htm#TOC"
    >--------------------------------</a><a name="qh_ANGLEnone">-</a>
  
    qh_ANGLEnone
      indicates missing angle for mergeT->angle
  */
  #define qh_ANGLEnone 2.0
  
  /*-<a                             href="qh-merge_r.htm#TOC"
    >--------------------------------</a><a name="MRG">-</a>
  
    MRG... (mergeType)
      indicates the type of a merge (mergeT->type)
      MRGcoplanar...MRGtwisted set by qh_test_centrum_merge, qh_test_nonsimplicial_merge
  */
  typedef enum {  /* must match mergetypes[] */
    MRGnone= 0,
                    /* MRGcoplanar..MRGtwisted go into qh.facet_mergeset for qh_all_merges 
                       qh_compare_facetmerge selects lower mergetypes for merging first */
    MRGcoplanar,          /* (1) centrum coplanar if centrum ('Cn') or vertex not clearly above or below neighbor */
    MRGanglecoplanar,     /* (2) angle coplanar if angle ('An') is coplanar */
    MRGconcave,           /* (3) concave ridge */
    MRGconcavecoplanar,   /* (4) concave and coplanar ridge, one side concave, other side coplanar */
    MRGtwisted,           /* (5) twisted ridge, both concave and convex, facet1 is wider */
                    /* MRGflip go into qh.facet_mergeset for qh_flipped_merges */
    MRGflip,              /* (6) flipped facet if qh.interior_point is above facet, w/ facet1 == facet2 */
                    /* MRGdupridge go into qh.facet_mergeset for qh_forcedmerges */
    MRGdupridge,          /* (7) dupridge if more than two neighbors.  Set by qh_mark_dupridges for qh_MERGEridge */
                    /* MRGsubridge and MRGvertices go into vertex_mergeset */
    MRGsubridge,          /* (8) merge pinched vertex to remove the subridge of a MRGdupridge */
    MRGvertices,          /* (9) merge pinched vertex to remove a facet's ridges with the same vertices */
                    /* MRGdegen, MRGredundant, and MRGmirror go into qh.degen_mergeset */
    MRGdegen,             /* (10) degenerate facet (!enough neighbors) facet1 == facet2 */
    MRGredundant,         /* (11) redundant facet (vertex subset) */
                          /* merge_degenredundant assumes degen < redundant */
    MRGmirror,            /* (12) mirror facets: same vertices due to null facets in qh_triangulate 
                             f.redundant for both facets*/
                    /* MRGcoplanarhorizon for qh_mergecycle_all only */
    MRGcoplanarhorizon,   /* (13) new facet coplanar with the horizon (qh_mergecycle_all) */
    ENDmrg
  } mergeType;
  
  /*-<a                             href="qh-merge_r.htm#TOC"
    >--------------------------------</a><a name="qh_MERGEapex">-</a>
  
    qh_MERGEapex
      flag for qh_mergefacet() to indicate an apex merge
  */
  #define qh_MERGEapex     true
  
  /*============ -structures- ====================*/
  
  /*-<a                             href="qh-merge_r.htm#TOC"
    >--------------------------------</a><a name="mergeT">-</a>
  
    mergeT
      structure used to merge facets
  */
  
  typedef struct mergeT mergeT;
  struct mergeT {         /* initialize in qh_appendmergeset */
    realT   angle;        /* cosine of angle between normals of facet1 and facet2, 
                             null value and right angle is 0.0, coplanar is 1.0, narrow is -1.0 */
    realT   distance;     /* absolute value of distance between vertices, centrum and facet, or vertex and facet */
    facetT *facet1;       /* will merge facet1 into facet2 */
    facetT *facet2;
    vertexT *vertex1;     /* will merge vertext1 into vertex2 for MRGsubridge or MRGvertices */
    vertexT *vertex2;
    ridgeT  *ridge1;      /* the duplicate ridges resolved by MRGvertices */
    ridgeT  *ridge2;      /* merge is deleted if either ridge is deleted (qh_delridge) */
    mergeType mergetype;
  };
  
  
  /*=========== -macros- =========================*/
  
  /*-<a                             href="qh-merge_r.htm#TOC"
    >--------------------------------</a><a name="FOREACHmerge_">-</a>
  
    FOREACHmerge_( merges ) {...}
      assign 'merge' to each merge in merges
  
    notes:
      uses 'mergeT *merge, **mergep;'
      if qh_mergefacet(),
        restart or use qh_setdellast() since qh.facet_mergeset may change
      see <a href="qset_r.h#FOREACHsetelement_">FOREACHsetelement_</a>
  */
  #define FOREACHmerge_(merges) FOREACHsetelement_(mergeT, merges, merge)
  
  /*-<a                             href="qh-poly_r.htm#TOC"
    >--------------------------------</a><a name="FOREACHmergeA_">-</a>
  
    FOREACHmergeA_( vertices ) { ... }
      assign 'mergeA' to each merge in merges
  
    notes:
      uses 'mergeT *mergeA, *mergeAp;'
      see <a href="qset_r.h#FOREACHsetelement_">FOREACHsetelement_</a>
  */
  #define FOREACHmergeA_(merges) FOREACHsetelement_(mergeT, merges, mergeA)
  
  /*-<a                             href="qh-poly_r.htm#TOC"
    >--------------------------------</a><a name="FOREACHmerge_i_">-</a>
  
    FOREACHmerge_i_(qh, vertices ) { ... }
      assign 'merge' and 'merge_i' for each merge in mergeset
  
    declare:
      mergeT *merge;
      int     merge_n, merge_i;
  
    see:
      <a href="qset_r.h#FOREACHsetelement_i_">FOREACHsetelement_i_</a>
  */
  #define FOREACHmerge_i_(qh, mergeset) FOREACHsetelement_i_(qh, mergeT, mergeset, merge)
  
  /*============ prototypes in alphabetical order after pre/postmerge =======*/
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  void    qh_premerge(qhT *qh, int apexpointid, realT maxcentrum, realT maxangle);
  void    qh_postmerge(qhT *qh, const char *reason, realT maxcentrum, realT maxangle,
               bool vneighbors);
  void    qh_all_merges(qhT *qh, bool othermerge, bool vneighbors);
  void    qh_all_vertexmerges(qhT *qh, int apexpointid, facetT *facet, facetT **retryfacet);
  void    qh_appendmergeset(qhT *qh, facetT *facet, facetT *neighbor, mergeType mergetype, coordT dist, realT angle);
  void    qh_appendvertexmerge(qhT *qh, vertexT *vertex, vertexT *destination, mergeType mergetype, realT distance, ridgeT *ridge1, ridgeT *ridge2);
  setT   *qh_basevertices(qhT *qh, facetT *samecycle);
  void    qh_check_dupridge(qhT *qh, facetT *facet1, realT dist1, facetT *facet2, realT dist2);
  void    qh_checkconnect(qhT *qh /* qh.new_facets */);
  void    qh_checkdelfacet(qhT *qh, facetT *facet, setT *mergeset);
  void    qh_checkdelridge(qhT *qh /* qh.visible_facets, vertex_mergeset */);
  bool   qh_checkzero(qhT *qh, bool testall);
  int     qh_compare_anglemerge(const void *p1, const void *p2);
  int     qh_compare_facetmerge(const void *p1, const void *p2);
  int     qh_comparevisit(const void *p1, const void *p2);
  void    qh_copynonconvex(qhT *qh, ridgeT *atridge);
  void    qh_degen_redundant_facet(qhT *qh, facetT *facet);
  void    qh_drop_mergevertex(qhT *qh, mergeT *merge);
  void    qh_delridge_merge(qhT *qh, ridgeT *ridge);
  vertexT *qh_find_newvertex(qhT *qh, vertexT *oldvertex, setT *vertices, setT *ridges);
  vertexT *qh_findbest_pinchedvertex(qhT *qh, mergeT *merge, vertexT *apex, vertexT **pinchedp, realT *distp /* qh.newfacet_list */);
  vertexT *qh_findbest_ridgevertex(qhT *qh, ridgeT *ridge, vertexT **pinchedp, coordT *distp);
  void    qh_findbest_test(qhT *qh, bool testcentrum, facetT *facet, facetT *neighbor,
             facetT **bestfacet, realT *distp, realT *mindistp, realT *maxdistp);
  facetT *qh_findbestneighbor(qhT *qh, facetT *facet, realT *distp, realT *mindistp, realT *maxdistp);
  void    qh_flippedmerges(qhT *qh, facetT *facetlist, bool *wasmerge);
  void    qh_forcedmerges(qhT *qh, bool *wasmerge);
  void    qh_freemergesets(qhT *qh);
  void    qh_getmergeset(qhT *qh, facetT *facetlist);
  void    qh_getmergeset_initial(qhT *qh, facetT *facetlist);
  bool   qh_getpinchedmerges(qhT *qh, vertexT *apex, coordT maxdupdist, bool *iscoplanar /* qh.newfacet_list, vertex_mergeset */);
  bool   qh_hasmerge(setT *mergeset, mergeType type, facetT *facetA, facetT *facetB);
  void    qh_hashridge(qhT *qh, setT *hashtable, int hashsize, ridgeT *ridge, vertexT *oldvertex);
  ridgeT *qh_hashridge_find(qhT *qh, setT *hashtable, int hashsize, ridgeT *ridge,
                vertexT *vertex, vertexT *oldvertex, int *hashslot);
  void    qh_initmergesets(qhT *qh);
  void    qh_makeridges(qhT *qh, facetT *facet);
  void    qh_mark_dupridges(qhT *qh, facetT *facetlist, bool allmerges);
  void    qh_maybe_duplicateridge(qhT *qh, ridgeT *ridge);
  void    qh_maybe_duplicateridges(qhT *qh, facetT *facet);
  void    qh_maydropneighbor(qhT *qh, facetT *facet);
  int     qh_merge_degenredundant(qhT *qh);
  void    qh_merge_nonconvex(qhT *qh, facetT *facet1, facetT *facet2, mergeType mergetype);
  void    qh_merge_pinchedvertices(qhT *qh, int apexpointid /* qh.newfacet_list */);
  void    qh_merge_twisted(qhT *qh, facetT *facet1, facetT *facet2);
  void    qh_mergecycle(qhT *qh, facetT *samecycle, facetT *newfacet);
  void    qh_mergecycle_all(qhT *qh, facetT *facetlist, bool *wasmerge);
  void    qh_mergecycle_facets(qhT *qh, facetT *samecycle, facetT *newfacet);
  void    qh_mergecycle_neighbors(qhT *qh, facetT *samecycle, facetT *newfacet);
  void    qh_mergecycle_ridges(qhT *qh, facetT *samecycle, facetT *newfacet);
  void    qh_mergecycle_vneighbors(qhT *qh, facetT *samecycle, facetT *newfacet);
  void    qh_mergefacet(qhT *qh, facetT *facet1, facetT *facet2, mergeType mergetype, realT *mindist, realT *maxdist, bool mergeapex);
  void    qh_mergefacet2d(qhT *qh, facetT *facet1, facetT *facet2);
  void    qh_mergeneighbors(qhT *qh, facetT *facet1, facetT *facet2);
  void    qh_mergeridges(qhT *qh, facetT *facet1, facetT *facet2);
  void    qh_mergesimplex(qhT *qh, facetT *facet1, facetT *facet2, bool mergeapex);
  void    qh_mergevertex_del(qhT *qh, vertexT *vertex, facetT *facet1, facetT *facet2);
  void    qh_mergevertex_neighbors(qhT *qh, facetT *facet1, facetT *facet2);
  void    qh_mergevertices(qhT *qh, setT *vertices1, setT **vertices);
  setT   *qh_neighbor_intersections(qhT *qh, vertexT *vertex);
  setT   *qh_neighbor_vertices(qhT *qh, vertexT *vertex, setT *subridge);
  void    qh_neighbor_vertices_facet(qhT *qh, vertexT *vertexA, facetT *facet, setT **vertices);
  void    qh_newvertices(qhT *qh, setT *vertices);
  mergeT *qh_next_vertexmerge(qhT *qh);
  facetT *qh_opposite_horizonfacet(qhT *qh, mergeT *merge, vertexT **vertex);
  bool   qh_reducevertices(qhT *qh);
  vertexT *qh_redundant_vertex(qhT *qh, vertexT *vertex);
  bool   qh_remove_extravertices(qhT *qh, facetT *facet);
  void    qh_remove_mergetype(qhT *qh, setT *mergeset, mergeType type);
  void    qh_rename_adjacentvertex(qhT *qh, vertexT *oldvertex, vertexT *newvertex, realT dist);
  vertexT *qh_rename_sharedvertex(qhT *qh, vertexT *vertex, facetT *facet);
  bool   qh_renameridgevertex(qhT *qh, ridgeT *ridge, vertexT *oldvertex, vertexT *newvertex);
  void    qh_renamevertex(qhT *qh, vertexT *oldvertex, vertexT *newvertex, setT *ridges,
                          facetT *oldfacet, facetT *neighborA);
  bool   qh_test_appendmerge(qhT *qh, facetT *facet, facetT *neighbor, bool simplicial);
  void    qh_test_degen_neighbors(qhT *qh, facetT *facet);
  bool   qh_test_centrum_merge(qhT *qh, facetT *facet, facetT *neighbor, realT angle, bool okangle);
  bool   qh_test_nonsimplicial_merge(qhT *qh, facetT *facet, facetT *neighbor, realT angle, bool okangle);
  void    qh_test_redundant_neighbors(qhT *qh, facetT *facet);
  bool   qh_test_vneighbors(qhT *qh /* qh.newfacet_list */);
  void    qh_tracemerge(qhT *qh, facetT *facet1, facetT *facet2, mergeType mergetype);
  void    qh_tracemerging(qhT *qh);
  void    qh_undo_newfacets(qhT *qh);
  void    qh_updatetested(qhT *qh, facetT *facet1, facetT *facet2);
  setT   *qh_vertexridges(qhT *qh, vertexT *vertex, bool allneighbors);
  void    qh_vertexridges_facet(qhT *qh, vertexT *vertex, facetT *facet, setT **ridges);
  void    qh_willdelete(qhT *qh, facetT *facet, facetT *replace);
  
  #ifdef __cplusplus
  } /* extern "C" */
  #endif
  
  #endif /* qhDEFmerge */
  