/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * 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.
 *
 * Contributor(s): Geoffrey Bantle, Levi Schooley, Joseph Eagar.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#ifndef __BMESH_CLASS_H__
#define __BMESH_CLASS_H__

/** \file blender/bmesh/bmesh_class.h
 *  \ingroup bmesh
 */

/* bmesh data structures */

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

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

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 {
	void *data; /* customdata layers */
	int index; /* notes:
	            * - 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. */

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

	/* 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;
	struct BMFlagLayer *oflags; /* keep after header, an array of flags, mostly used by the operator stack */

	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;

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

typedef struct BMEdge {
	BMHeader head;
	struct BMFlagLayer *oflags; /* keep after header, an array of flags, mostly used by the operator stack */

	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 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;

	/* keep directly after header,
	 * optional array of flags, only used by the operator stack */
	struct BMFlagLayer *oflags;
} 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;
	struct BMFlagLayer *oflags; /* an array of flags, mostly used by the operator stack */

#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 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;

	int stackdepth;
	struct BMOperator *currentop;
	
	CustomData vdata, edata, ldata, pdata;

#ifdef USE_BMESH_HOLES
	struct BLI_mempool *looplistpool;
#endif

	/* 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 walkers, 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
};

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

/* BMHeader->hflag (char) */
enum {
	BM_ELEM_SELECT  = (1 << 0),
	BM_ELEM_HIDDEN  = (1 << 1),
	BM_ELEM_SEAM    = (1 << 2),
	BM_ELEM_SMOOTH  = (1 << 3), /* used for faces and edges, note from the user POV,
                                 * this is a sharp edge when disabled */

	BM_ELEM_TAG     = (1 << 4), /* 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_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

	BM_ELEM_INTERNAL_TAG = (1 << 7) /* for low level internal API tagging,
                                     * since tools may want to tag verts and
                                     * not have functions clobber them */
};

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

typedef bool (*BMElemFilterFunc)(BMElem *, void *user_data);

/* defines */
#define BM_ELEM_CD_SET_INT(ele, offset, f) \
	{ 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))))

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

#define BM_ELEM_CD_SET_FLOAT(ele, offset, f) \
	{ 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), (unsigned char)(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

/**
 * 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__ */
