#include <climits>
#include "MEM_guardedalloc.h"
#include "BLI_alloca.h"
#include "BLI_linklist.h"
#include "BLI_linklist_stack.h"
#include "BLI_math_geom.h"
#include "BLI_math_vector.h"
#include "BLI_utildefines.h"
#include "BLI_utildefines_stack.h"
#include "bmesh.hh"
#include "bmesh_bisect_plane.hh"
#include "BLI_strict_flags.h"

Macros
BMesh Element Accessors
Wrappers to hide internal data-structure abuse, later we may want to move this into some hash lookup to a separate struct, but for now we can store in BMesh data.
#define	BM_VERT_DIR(v) ((short )(&(v)->head.index))[0] / Direction -1/0/1 */

#define	BM_VERT_SKIP(v) ((short )(&(v)->head.index))[1] / Skip Vert 0/1 */

#define	BM_VERT_DIST(v) ((v)->no[0]) /* Distance from the plane. */

#define	BM_VERT_SORTVAL(v) ((v)->no[1]) /* Temp value for sorting. */

#define	BM_VERT_LOOPINDEX(v)

Functions
Math Functions
static short	plane_point_test_v3 (const float plane[4], const float co[3], const float eps, float *r_depth)

BMesh Flag Accessors
Hide flag access (for more readable code since same flag is used differently for vert/edge-face).
BLI_INLINE void	vert_is_center_enable (BMVert *v)

BLI_INLINE void	vert_is_center_disable (BMVert *v)

BLI_INLINE bool	vert_is_center_test (BMVert *v)

BLI_INLINE bool	vert_pair_adjacent_in_orig_face (BMVert v_a, BMVert v_b, const uint f_len_orig)

BLI_INLINE void	edge_is_cut_enable (BMEdge *e)

BLI_INLINE void	edge_is_cut_disable (BMEdge *e)

BLI_INLINE bool	edge_is_cut_test (BMEdge *e)

BLI_INLINE void	face_in_stack_enable (BMFace *f)

BLI_INLINE void	face_in_stack_disable (BMFace *f)

BLI_INLINE bool	face_in_stack_test (BMFace *f)

BMesh Face Bisect
static int	bm_vert_sortval_cb (const void v_a_v, const void v_b_v)

static void	bm_face_bisect_verts (BMesh bm, BMFace f, const float plane[4], const short oflag_center, const short oflag_new)

Public BMesh Bisect Function
void	BM_mesh_bisect_plane (BMesh *bm, const float plane[4], const bool use_snap_center, const bool use_tag, const short oflag_center, const short oflag_new, const float eps)

Detailed Description

Cut the geometry in half using a plane.

Implementation: This simply works by splitting tagged edges who's verts span either side of the plane, then splitting faces along their dividing verts. The only complex case is when a ngon spans the axis multiple times, in this case we need to do some extra checks to correctly bisect the ngon. see: bm_face_bisect_verts

Definition in file bmesh_bisect_plane.cc.

Macro Definition Documentation

◆ BM_VERT_DIR

#define BM_VERT_DIR ( v ) ((short *)(&(v)->head.index))[0] /* Direction -1/0/1 */

Definition at line 66 of file bmesh_bisect_plane.cc.

Referenced by bm_face_bisect_verts(), and BM_mesh_bisect_plane().

◆ BM_VERT_DIST

#define BM_VERT_DIST ( v ) ((v)->no[0]) /* Distance from the plane. */

Definition at line 68 of file bmesh_bisect_plane.cc.

Referenced by BM_mesh_bisect_plane().

◆ BM_VERT_LOOPINDEX

#define BM_VERT_LOOPINDEX ( v )

Value:

/* The verts index within a face (temp var) */ \

(*((uint *)(&(v)->no[2])))

uint

unsigned int uint

Definition BLI_sys_types.h:68

v

ATTR_WARN_UNUSED_RESULT const BMVert * v

Definition bmesh_query_inline.hh:17

Definition at line 70 of file bmesh_bisect_plane.cc.

Referenced by bm_face_bisect_verts(), and vert_pair_adjacent_in_orig_face().

◆ BM_VERT_SKIP

#define BM_VERT_SKIP ( v ) ((short *)(&(v)->head.index))[1] /* Skip Vert 0/1 */

Definition at line 67 of file bmesh_bisect_plane.cc.

Referenced by bm_face_bisect_verts().

◆ BM_VERT_SORTVAL

#define BM_VERT_SORTVAL ( v ) ((v)->no[1]) /* Temp value for sorting. */

Definition at line 69 of file bmesh_bisect_plane.cc.

Referenced by bm_face_bisect_verts(), and bm_vert_sortval_cb().

Function Documentation

◆ bm_face_bisect_verts()

static void bm_face_bisect_verts	(	BMesh *	bm,
		BMFace *	f,
		const float	plane[4],
		const short	oflag_center,
		const short	oflag_new )

static

◆ BM_mesh_bisect_plane()

void BM_mesh_bisect_plane	(	BMesh *	bm,
		const float	plane[4],
		bool	use_snap_center,
		bool	use_tag,
		short	oflag_center,
		short	oflag_new,
		float	eps )

Parameters

use_snap_center	Snap verts onto the plane.
use_tag	Only bisect tagged edges and faces.
oflag_center	Operator flag, enabled for geometry on the axis (existing and created)

Definition at line 388 of file bmesh_bisect_plane.cc.

References BLI_LINKSTACK_DECLARE, BLI_LINKSTACK_FREE, BLI_LINKSTACK_INIT, BLI_LINKSTACK_POP, BLI_LINKSTACK_PUSH, bm, BM_edge_split(), BM_EDGES_OF_MESH, BM_elem_flag_enable, BM_elem_flag_test, BM_ELEM_TAG, bm_face_bisect_verts(), BM_FACES_OF_MESH, BM_ITER_ELEM, BM_ITER_ELEM_INDEX, BM_ITER_MESH, BM_ITER_MESH_INDEX, BM_LOOPS_OF_VERT, BM_mesh_elem_hflag_disable_all(), BM_VERT, BM_VERT_DIR, BM_VERT_DIST, BM_VERTS_OF_EDGE, BM_VERTS_OF_MESH, BMO_edge_flag_enable, BMO_vert_flag_enable, closest_to_plane_v3(), BMVert::co, e, edge_is_cut_enable(), edge_is_cut_test(), BMesh::elem_index_dirty, eps, BMLoop::f, face_in_stack_disable(), face_in_stack_enable(), face_in_stack_test(), MEM_freeN(), MEM_mallocN, plane_point_test_v3(), BMLoop::radial_next, BMesh::totedge, v, vert_is_center_disable(), vert_is_center_enable(), and vert_is_center_test().