text: /*
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
   */
  
  #ifndef __BMESH_ITERATORS_H__
  #define __BMESH_ITERATORS_H__
  
  /** \file
   * \ingroup bmesh
   */
  
  /**
   * \brief BMesh Iterators
   *
   * The functions and structures in this file
   * provide a unified method for iterating over
   * the elements of a mesh and answering simple
   * adjacency queries. Tool authors should use
   * the iterators provided in this file instead
   * of inspecting the structure directly.
   */
  
  #include "BLI_compiler_attrs.h"
  #include "BLI_mempool.h"
  
  /* Defines for passing to BM_iter_new.
   *
   * "OF" can be substituted for "around"
   * so BM_VERTS_OF_FACE means "vertices
   * around a face."
   */
  
  /* these iterator over all elements of a specific
   * type in the mesh.
   *
   * be sure to keep 'bm_iter_itype_htype_map' in sync with any changes
   */
  typedef enum BMIterType {
    BM_VERTS_OF_MESH = 1,
    BM_EDGES_OF_MESH = 2,
    BM_FACES_OF_MESH = 3,
    /* these are topological iterators. */
    BM_EDGES_OF_VERT = 4,
    BM_FACES_OF_VERT = 5,
    BM_LOOPS_OF_VERT = 6,
    BM_VERTS_OF_EDGE = 7, /* just v1, v2: added so py can use generalized sequencer wrapper */
    BM_FACES_OF_EDGE = 8,
    BM_VERTS_OF_FACE = 9,
    BM_EDGES_OF_FACE = 10,
    BM_LOOPS_OF_FACE = 11,
    /* returns elements from all boundaries, and returns
     * the first element at the end to flag that we're entering
     * a different face hole boundary*/
    // BM_ALL_LOOPS_OF_FACE = 12,
    /* iterate through loops around this loop, which are fetched
     * from the other faces in the radial cycle surrounding the
     * input loop's edge.*/
    BM_LOOPS_OF_LOOP = 12,
    BM_LOOPS_OF_EDGE = 13,
  } BMIterType;
  
  #define BM_ITYPE_MAX 14
  
  /* the iterator htype for each iterator */
  extern const char bm_iter_itype_htype_map[BM_ITYPE_MAX];
  
  #define BM_ITER_MESH(ele, iter, bm, itype) \
    for (BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_new(iter, bm, itype, NULL); ele; \
         BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_step(iter))
  
  #define BM_ITER_MESH_INDEX(ele, iter, bm, itype, indexvar) \
    for (BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_new(iter, bm, itype, NULL), indexvar = 0; ele; \
         BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_step(iter), (indexvar)++)
  
  /* a version of BM_ITER_MESH which keeps the next item in storage
   * so we can delete the current item, see bug [#36923] */
  #ifdef DEBUG
  #  define BM_ITER_MESH_MUTABLE(ele, ele_next, iter, bm, itype) \
      for (BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_new(iter, bm, itype, NULL); \
           ele ? ((void)((iter)->count = BM_iter_mesh_count(itype, bm)), \
                  (void)(ele_next = BM_iter_step(iter)), \
                  1) : \
                 0; \
           BM_CHECK_TYPE_ELEM_ASSIGN(ele) = ele_next)
  #else
  #  define BM_ITER_MESH_MUTABLE(ele, ele_next, iter, bm, itype) \
      for (BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_new(iter, bm, itype, NULL); \
           ele ? ((BM_CHECK_TYPE_ELEM_ASSIGN(ele_next) = BM_iter_step(iter)), 1) : 0; \
           ele = ele_next)
  #endif
  
  #define BM_ITER_ELEM(ele, iter, data, itype) \
    for (BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_new(iter, NULL, itype, data); ele; \
         BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_step(iter))
  
  #define BM_ITER_ELEM_INDEX(ele, iter, data, itype, indexvar) \
    for (BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_new(iter, NULL, itype, data), indexvar = 0; ele; \
         BM_CHECK_TYPE_ELEM_ASSIGN(ele) = BM_iter_step(iter), (indexvar)++)
  
  /* iterator type structs */
  struct BMIter__elem_of_mesh {
    BLI_mempool_iter pooliter;
  };
  struct BMIter__edge_of_vert {
    BMVert *vdata;
    BMEdge *e_first, *e_next;
  };
  struct BMIter__face_of_vert {
    BMVert *vdata;
    BMLoop *l_first, *l_next;
    BMEdge *e_first, *e_next;
  };
  struct BMIter__loop_of_vert {
    BMVert *vdata;
    BMLoop *l_first, *l_next;
    BMEdge *e_first, *e_next;
  };
  struct BMIter__loop_of_edge {
    BMEdge *edata;
    BMLoop *l_first, *l_next;
  };
  struct BMIter__loop_of_loop {
    BMLoop *ldata;
    BMLoop *l_first, *l_next;
  };
  struct BMIter__face_of_edge {
    BMEdge *edata;
    BMLoop *l_first, *l_next;
  };
  struct BMIter__vert_of_edge {
    BMEdge *edata;
  };
  struct BMIter__vert_of_face {
    BMFace *pdata;
    BMLoop *l_first, *l_next;
  };
  struct BMIter__edge_of_face {
    BMFace *pdata;
    BMLoop *l_first, *l_next;
  };
  struct BMIter__loop_of_face {
    BMFace *pdata;
    BMLoop *l_first, *l_next;
  };
  
  typedef void (*BMIter__begin_cb)(void *);
  typedef void *(*BMIter__step_cb)(void *);
  
  /* Iterator Structure */
  /* note: some of these vars are not used,
   * so they have been commented to save stack space since this struct is used all over */
  typedef struct BMIter {
    /* keep union first */
    union {
      struct BMIter__elem_of_mesh elem_of_mesh;
  
      struct BMIter__edge_of_vert edge_of_vert;
      struct BMIter__face_of_vert face_of_vert;
      struct BMIter__loop_of_vert loop_of_vert;
      struct BMIter__loop_of_edge loop_of_edge;
      struct BMIter__loop_of_loop loop_of_loop;
      struct BMIter__face_of_edge face_of_edge;
      struct BMIter__vert_of_edge vert_of_edge;
      struct BMIter__vert_of_face vert_of_face;
      struct BMIter__edge_of_face edge_of_face;
      struct BMIter__loop_of_face loop_of_face;
    } data;
  
    BMIter__begin_cb begin;
    BMIter__step_cb step;
  
    int count; /* note, only some iterators set this, don't rely on it */
    char itype;
  } BMIter;
  
  void *BM_iter_at_index(BMesh *bm, const char itype, void *data, int index) ATTR_WARN_UNUSED_RESULT;
  int BM_iter_as_array(BMesh *bm, const char itype, void *data, void **array, const int len);
  void *BM_iter_as_arrayN(BMesh *bm,
                          const char itype,
                          void *data,
                          int *r_len,
                          void **stack_array,
                          int stack_array_size) ATTR_WARN_UNUSED_RESULT;
  int BMO_iter_as_array(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
                        const char *slot_name,
                        const char restrictmask,
                        void **array,
                        const int len);
  void *BMO_iter_as_arrayN(BMOpSlot slot_args[BMO_OP_MAX_SLOTS],
                           const char *slot_name,
                           const char restrictmask,
                           int *r_len,
                           /* optional args to avoid an alloc (normally stack array) */
                           void **stack_array,
                           int stack_array_size);
  
  int BM_iter_mesh_bitmap_from_filter(const char itype,
                                      BMesh *bm,
                                      uint *bitmap,
                                      bool (*test_fn)(BMElem *, void *user_data),
                                      void *user_data);
  int BM_iter_mesh_bitmap_from_filter_tessface(BMesh *bm,
                                               uint *bitmap,
                                               bool (*test_fn)(BMFace *, void *user_data),
                                               void *user_data);
  
  int BM_iter_elem_count_flag(const char itype, void *data, const char hflag, const bool value);
  int BMO_iter_elem_count_flag(
      BMesh *bm, const char itype, void *data, const short oflag, const bool value);
  int BM_iter_mesh_count(const char itype, BMesh *bm);
  int BM_iter_mesh_count_flag(const char itype, BMesh *bm, const char hflag, const bool value);
  
  /* private for bmesh_iterators_inline.c */
  
  #define BMITER_CB_DEF(name) \
    struct BMIter__##name; \
    void bmiter__##name##_begin(struct BMIter__##name *iter); \
    void *bmiter__##name##_step(struct BMIter__##name *iter)
  
  BMITER_CB_DEF(elem_of_mesh);
  BMITER_CB_DEF(edge_of_vert);
  BMITER_CB_DEF(face_of_vert);
  BMITER_CB_DEF(loop_of_vert);
  BMITER_CB_DEF(loop_of_edge);
  BMITER_CB_DEF(loop_of_loop);
  BMITER_CB_DEF(face_of_edge);
  BMITER_CB_DEF(vert_of_edge);
  BMITER_CB_DEF(vert_of_face);
  BMITER_CB_DEF(edge_of_face);
  BMITER_CB_DEF(loop_of_face);
  
  #undef BMITER_CB_DEF
  
  #include "intern/bmesh_iterators_inline.h"
  
  #define BM_ITER_CHECK_TYPE_DATA(data) \
    CHECK_TYPE_ANY(data, void *, BMFace *, BMEdge *, BMVert *, BMLoop *, BMElem *)
  
  #define BM_iter_new(iter, bm, itype, data) \
    (BM_ITER_CHECK_TYPE_DATA(data), BM_iter_new(iter, bm, itype, data))
  #define BM_iter_init(iter, bm, itype, data) \
    (BM_ITER_CHECK_TYPE_DATA(data), BM_iter_init(iter, bm, itype, data))
  
  #endif /* __BMESH_ITERATORS_H__ */
  