/*
 * 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_CLASS_H__
#define __BMESH_CLASS_H__

/** \file
 * \ingroup bmesh
 */

/* bmesh data structures */

/* disable holes for now,
 * these are ifdef'd because they use more memory and cant be saved in DNA currently */
// #define USE_BMESH_HOLES

struct BMEdge;
struct BMFace;
struct BMLoop;
struct BMVert;
struct BMesh;

struct MLoopNorSpaceArray;

struct BLI_mempool;

/* note: it is very important for BMHeader to start with two
 * pointers. this is a requirement of mempool's method of
 * iteration.
 *
 * hrm. it doesn't but still works ok, remove the comment above? - campbell.
 */

// #pragma GCC diagnostic error "-Wpadded"

/**
 * BMHeader
 *
 * All mesh elements begin with a BMHeader. This structure
 * hold several types of data
 *
 * 1: The type of the element (vert, edge, loop or face)
 * 2: Persistent "header" flags/markings (smooth, seam, select, hidden, etc)
 *     note that this is different from the "tool" flags.
 * 3: Unique ID in the bmesh.
 * 4: some elements for internal record keeping.
 */
typedef struct BMHeader {
  /** Customdata layers. */
  void *data;

  /**
   * \note
   * - Use BM_elem_index_get/set macros for index
   * - Uninitialized to -1 so we can easily tell its not set.
   * - Used for edge/vert/face/loop, check BMesh.elem_index_dirty for valid index values,
   *   this is abused by various tools which set it dirty.
   * - For loops this is used for sorting during tessellation.
   */
  int index;

  /** Element geometric type (verts/edges/loops/faces). */
  char htype;
  /** This would be a CD layer, see below. */
  char hflag;

  /**
   * Internal use only!
   * \note We are very picky about not bloating this struct
   * but in this case its padded up to 16 bytes anyway,
   * so adding a flag here gives no increase in size.
   */
  char api_flag;
  // char _pad;
} BMHeader;

BLI_STATIC_ASSERT((sizeof(BMHeader) <= 16), "BMHeader size has grown!");

/* note: need some way to specify custom locations for custom data layers.  so we can
 * make them point directly into structs.  and some way to make it only happen to the
 * active layer, and properly update when switching active layers.*/

typedef struct BMVert {
  BMHeader head;

  float co[3]; /* vertex coordinates */
  float no[3]; /* vertex normal */

  /**
   * Pointer to (any) edge using this vertex (for disk cycles).
   *
   * \note Some higher level functions set this to different edges that use this vertex,
   * which is a bit of an abuse of internal bmesh data but also works OK for now
   * (use with care!).
   */
  struct BMEdge *e;
} BMVert;

typedef struct BMVert_OFlag {
  BMVert base;
  struct BMFlagLayer *oflags;
} BMVert_OFlag;

/* disk link structure, only used by edges */
typedef struct BMDiskLink {
  struct BMEdge *next, *prev;
} BMDiskLink;

typedef struct BMEdge {
  BMHeader head;

  struct BMVert *v1, *v2; /* vertices (unordered) */

  /* the list of loops around the edge (use l->radial_prev/next)
   * to access the other loops using the edge */
  struct BMLoop *l;

  /**
   * Disk Cycle Pointers
   *
   * relative data: d1 indicates indicates the next/prev
   * edge around vertex v1 and d2 does the same for v2.
   */
  BMDiskLink v1_disk_link, v2_disk_link;
} BMEdge;

typedef struct BMEdge_OFlag {
  BMEdge base;
  struct BMFlagLayer *oflags;
} BMEdge_OFlag;

typedef struct BMLoop {
  BMHeader head;
  /* notice no flags layer */

  struct BMVert *v;
  struct BMEdge *e; /* edge, using verts (v, next->v) */
  struct BMFace *f;

  /* circular linked list of loops which all use the same edge as this one '->e',
   * but not necessarily the same vertex (can be either v1 or v2 of our own '->e') */
  struct BMLoop *radial_next, *radial_prev;

  /* these were originally commented as private but are used all over the code */
  /* can't use ListBase API, due to head */
  struct BMLoop *next, *prev; /* next/prev verts around the face */
} BMLoop;

/* can cast BMFace/BMEdge/BMVert, but NOT BMLoop, since these don't have a flag layer */
typedef struct BMElemF {
  BMHeader head;
} BMElemF;

/* can cast anything to this, including BMLoop */
typedef struct BMElem {
  BMHeader head;
} BMElem;

#ifdef USE_BMESH_HOLES
/* eventually, this structure will be used for supporting holes in faces */
typedef struct BMLoopList {
  struct BMLoopList *next, *prev;
  struct BMLoop *first, *last;
} BMLoopList;
#endif

typedef struct BMFace {
  BMHeader head;

#ifdef USE_BMESH_HOLES
  int totbounds; /*total boundaries, is one plus the number of holes in the face*/
  ListBase loops;
#else
  BMLoop *l_first;
#endif
  int len;      /* number of vertices in the face */
  float no[3];  /* face normal */
  short mat_nr; /* material index */
  //  short _pad[3];
} BMFace;

typedef struct BMFace_OFlag {
  BMFace base;
  struct BMFlagLayer *oflags;
} BMFace_OFlag;

typedef struct BMFlagLayer {
  short f; /* flags */
} BMFlagLayer;

// #pragma GCC diagnostic ignored "-Wpadded"

typedef struct BMesh {
  int totvert, totedge, totloop, totface;
  int totvertsel, totedgesel, totfacesel;

  /* flag index arrays as being dirty so we can check if they are clean and
   * avoid looping over the entire vert/edge/face/loop array in those cases.
   * valid flags are - BM_VERT | BM_EDGE | BM_FACE | BM_LOOP. */
  char elem_index_dirty;

  /* flag array table as being dirty so we know when its safe to use it,
   * or when it needs to be re-created */
  char elem_table_dirty;

  /* element pools */
  struct BLI_mempool *vpool, *epool, *lpool, *fpool;

  /* mempool lookup tables (optional)
   * index tables, to map indices to elements via
   * BM_mesh_elem_table_ensure and associated functions.  don't
   * touch this or read it directly.\
   * Use BM_mesh_elem_table_ensure(), BM_vert/edge/face_at_index() */
  BMVert **vtable;
  BMEdge **etable;
  BMFace **ftable;

  /* size of allocated tables */
  int vtable_tot;
  int etable_tot;
  int ftable_tot;

  /* operator api stuff (must be all NULL or all alloc'd) */
  struct BLI_mempool *vtoolflagpool, *etoolflagpool, *ftoolflagpool;

  uint use_toolflags : 1;

  int toolflag_index;
  struct BMOperator *currentop;

  CustomData vdata, edata, ldata, pdata;

#ifdef USE_BMESH_HOLES
  struct BLI_mempool *looplistpool;
#endif

  struct MLoopNorSpaceArray *lnor_spacearr;
  char spacearr_dirty;

  /* should be copy of scene select mode */
  /* stored in BMEditMesh too, this is a bit confusing,
   * make sure they're in sync!
   * Only use when the edit mesh cant be accessed - campbell */
  short selectmode;

  /* ID of the shape key this bmesh came from */
  int shapenr;

  int totflags;
  ListBase selected;

  BMFace *act_face;

  ListBase errorstack;

  void *py_handle;
} BMesh;

/* BMHeader->htype (char) */
enum {
  BM_VERT = 1,
  BM_EDGE = 2,
  BM_LOOP = 4,
  BM_FACE = 8,
};

typedef struct BMLoopNorEditData {
  int loop_index;
  BMLoop *loop;
  float niloc[3];
  float nloc[3];
  float *loc;
  short *clnors_data;
} BMLoopNorEditData;

typedef struct BMLoopNorEditDataArray {
  BMLoopNorEditData *lnor_editdata;
  /**
   * This one has full amount of loops,
   * used to map loop index to actual BMLoopNorEditData struct.
   */
  BMLoopNorEditData **lidx_to_lnor_editdata;

  int cd_custom_normal_offset;
  int totloop;
} BMLoopNorEditDataArray;

#define BM_ALL (BM_VERT | BM_EDGE | BM_LOOP | BM_FACE)
#define BM_ALL_NOLOOP (BM_VERT | BM_EDGE | BM_FACE)

enum {
  BM_SPACEARR_DIRTY = 1 << 0,
  BM_SPACEARR_DIRTY_ALL = 1 << 1,
  BM_SPACEARR_BMO_SET = 1 << 2,
};

/* args for _Generic */
#define _BM_GENERIC_TYPE_ELEM_NONCONST \
  void *, BMVert *, BMEdge *, BMLoop *, BMFace *, BMVert_OFlag *, BMEdge_OFlag *, BMFace_OFlag *, \
      BMElem *, BMElemF *, BMHeader *

#define _BM_GENERIC_TYPE_ELEM_CONST \
  const void *, const BMVert *, const BMEdge *, const BMLoop *, const BMFace *, \
      const BMVert_OFlag *, const BMEdge_OFlag *, const BMFace_OFlag *, const BMElem *, \
      const BMElemF *, const BMHeader *, void *const, BMVert *const, BMEdge *const, \
      BMLoop *const, BMFace *const, BMElem *const, BMElemF *const, BMHeader *const

#define BM_CHECK_TYPE_ELEM_CONST(ele) CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPES_CONST)

#define BM_CHECK_TYPE_ELEM_NONCONST(ele) CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_ELEM_NONCONST)

#define BM_CHECK_TYPE_ELEM(ele) \
  CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_ELEM_NONCONST, _BM_GENERIC_TYPE_ELEM_CONST)

/* vert */
#define _BM_GENERIC_TYPE_VERT_NONCONST BMVert *, BMVert_OFlag *
#define _BM_GENERIC_TYPE_VERT_CONST const BMVert *, const BMVert_OFlag *
#define BM_CHECK_TYPE_VERT_CONST(ele) CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_VERT_CONST)
#define BM_CHECK_TYPE_VERT_NONCONST(ele) CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_ELEM_NONCONST)
#define BM_CHECK_TYPE_VERT(ele) \
  CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_VERT_NONCONST, _BM_GENERIC_TYPE_VERT_CONST)
/* edge */
#define _BM_GENERIC_TYPE_EDGE_NONCONST BMEdge *, BMEdge_OFlag *
#define _BM_GENERIC_TYPE_EDGE_CONST const BMEdge *, const BMEdge_OFlag *
#define BM_CHECK_TYPE_EDGE_CONST(ele) CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_EDGE_CONST)
#define BM_CHECK_TYPE_EDGE_NONCONST(ele) CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_ELEM_NONCONST)
#define BM_CHECK_TYPE_EDGE(ele) \
  CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_EDGE_NONCONST, _BM_GENERIC_TYPE_EDGE_CONST)
/* face */
#define _BM_GENERIC_TYPE_FACE_NONCONST BMFace *, BMFace_OFlag *
#define _BM_GENERIC_TYPE_FACE_CONST const BMFace *, const BMFace_OFlag *
#define BM_CHECK_TYPE_FACE_CONST(ele) CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_FACE_CONST)
#define BM_CHECK_TYPE_FACE_NONCONST(ele) CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_ELEM_NONCONST)
#define BM_CHECK_TYPE_FACE(ele) \
  CHECK_TYPE_ANY(ele, _BM_GENERIC_TYPE_FACE_NONCONST, _BM_GENERIC_TYPE_FACE_CONST)

/* Assignment from a void* to a typed pointer is not allowed in C++,
 * casting the LHS to void works fine though.
 */
#ifdef __cplusplus
#  define BM_CHECK_TYPE_ELEM_ASSIGN(ele) (BM_CHECK_TYPE_ELEM(ele)), *((void **)&ele)
#else
#  define BM_CHECK_TYPE_ELEM_ASSIGN(ele) (BM_CHECK_TYPE_ELEM(ele)), ele
#endif

/* BMHeader->hflag (char) */
enum {
  BM_ELEM_SELECT = (1 << 0),
  BM_ELEM_HIDDEN = (1 << 1),
  BM_ELEM_SEAM = (1 << 2),
  /**
   * used for faces and edges, note from the user POV,
   * this is a sharp edge when disabled */
  BM_ELEM_SMOOTH = (1 << 3),
  /**
   * internal flag, used for ensuring correct normals
   * during multires interpolation, and any other time
   * when temp tagging is handy.
   * always assume dirty & clear before use. */
  BM_ELEM_TAG = (1 << 4),

  BM_ELEM_DRAW = (1 << 5), /* edge display */

  /* spare tag, assumed dirty, use define in each function to name based on use */
  // _BM_ELEM_TAG_ALT = (1 << 6),  // UNUSED
  /**
   * For low level internal API tagging,
   * since tools may want to tag verts and not have functions clobber them.
   * Leave cleared! */
  BM_ELEM_INTERNAL_TAG = (1 << 7),
};

struct BPy_BMGeneric;
extern void bpy_bm_generic_invalidate(struct BPy_BMGeneric *self);

typedef bool (*BMElemFilterFunc)(const BMElem *, void *user_data);
typedef bool (*BMVertFilterFunc)(const BMVert *, void *user_data);
typedef bool (*BMEdgeFilterFunc)(const BMEdge *, void *user_data);
typedef bool (*BMFaceFilterFunc)(const BMFace *, void *user_data);
typedef bool (*BMLoopFilterFunc)(const BMLoop *, void *user_data);

/* defines */
#define BM_ELEM_CD_SET_INT(ele, offset, f) \
  { \
    CHECK_TYPE_NONCONST(ele); \
    assert(offset != -1); \
    *((int *)((char *)(ele)->head.data + (offset))) = (f); \
  } \
  (void)0

#define BM_ELEM_CD_GET_INT(ele, offset) \
  (assert(offset != -1), *((int *)((char *)(ele)->head.data + (offset))))

#if defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
#  define BM_ELEM_CD_GET_VOID_P(ele, offset) \
    (assert(offset != -1), \
     _Generic(ele, \
              GENERIC_TYPE_ANY(POINTER_OFFSET((ele)->head.data, offset), \
                               _BM_GENERIC_TYPE_ELEM_NONCONST), \
              GENERIC_TYPE_ANY((const void *)POINTER_OFFSET((ele)->head.data, offset), \
                               _BM_GENERIC_TYPE_ELEM_CONST)))
#else
#  define BM_ELEM_CD_GET_VOID_P(ele, offset) \
    (assert(offset != -1), (void *)((char *)(ele)->head.data + (offset)))
#endif

#define BM_ELEM_CD_SET_FLOAT(ele, offset, f) \
  { \
    CHECK_TYPE_NONCONST(ele); \
    assert(offset != -1); \
    *((float *)((char *)(ele)->head.data + (offset))) = (f); \
  } \
  (void)0

#define BM_ELEM_CD_GET_FLOAT(ele, offset) \
  (assert(offset != -1), *((float *)((char *)(ele)->head.data + (offset))))

#define BM_ELEM_CD_GET_FLOAT_AS_UCHAR(ele, offset) \
  (assert(offset != -1), (uchar)(BM_ELEM_CD_GET_FLOAT(ele, offset) * 255.0f))

/*forward declarations*/

#ifdef USE_BMESH_HOLES
#  define BM_FACE_FIRST_LOOP(p) (((BMLoopList *)((p)->loops.first))->first)
#else
#  define BM_FACE_FIRST_LOOP(p) ((p)->l_first)
#endif

#define BM_DISK_EDGE_NEXT(e, v) \
  (CHECK_TYPE_INLINE(e, BMEdge *), \
   CHECK_TYPE_INLINE(v, BMVert *), \
   BLI_assert(BM_vert_in_edge(e, v)), \
   (((&e->v1_disk_link)[v == e->v2]).next))
#define BM_DISK_EDGE_PREV(e, v) \
  (CHECK_TYPE_INLINE(e, BMEdge *), \
   CHECK_TYPE_INLINE(v, BMVert *), \
   BLI_assert(BM_vert_in_edge(e, v)), \
   (((&e->v1_disk_link)[v == e->v2]).prev))

/**
 * size to use for stack arrays when dealing with NGons,
 * alloc after this limit is reached.
 * this value is rather arbitrary */
#define BM_DEFAULT_NGON_STACK_SIZE 32
/**
 * size to use for stack arrays dealing with connected mesh data
 * verts of faces, edges of vert - etc.
 * often used with #BM_iter_as_arrayN() */
#define BM_DEFAULT_ITER_STACK_SIZE 16

/* avoid inf loop, this value is arbitrary
 * but should not error on valid cases */
#define BM_LOOP_RADIAL_MAX 10000
#define BM_NGON_MAX 100000

/* setting zero so we can catch bugs in OpenMP/BMesh */
#ifdef DEBUG
#  define BM_OMP_LIMIT 0
#else
#  define BM_OMP_LIMIT 10000
#endif

#endif /* __BMESH_CLASS_H__ */
