490603ac0a71f17e9c6e409959d0a8781010d6c9
[blender-staging.git] / source / blender / editors / mesh / editmesh_knife.c
1 /*
2  * ***** BEGIN GPL LICENSE BLOCK *****
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public License
6  * as published by the Free Software Foundation; either version 2
7  * of the License, or (at your option) any later version.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software Foundation,
16  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
17  *
18  * The Original Code is Copyright (C) 2007 Blender Foundation.
19  * All rights reserved.
20  *
21  * 
22  * Contributor(s): Joseph Eagar, Joshua Leung, Howard Trickey,
23  *                 Campbell Barton
24  *
25  * ***** END GPL LICENSE BLOCK *****
26  */
27
28 /** \file blender/editors/mesh/editmesh_knife.c
29  *  \ingroup edmesh
30  */
31
32 #ifdef _MSC_VER
33 #  define _USE_MATH_DEFINES
34 #endif
35
36 #include "MEM_guardedalloc.h"
37
38 #include "BLI_listbase.h"
39 #include "BLI_string.h"
40 #include "BLI_array.h"
41 #include "BLI_alloca.h"
42 #include "BLI_linklist.h"
43 #include "BLI_math.h"
44 #include "BLI_smallhash.h"
45 #include "BLI_memarena.h"
46
47 #include "BLF_translation.h"
48
49 #include "BKE_DerivedMesh.h"
50 #include "BKE_context.h"
51 #include "BKE_editmesh.h"
52 #include "BKE_editmesh_bvh.h"
53 #include "BKE_report.h"
54
55 #include "BIF_gl.h"
56 #include "BIF_glutil.h" /* for paint cursor */
57
58 #include "ED_screen.h"
59 #include "ED_space_api.h"
60 #include "ED_view3d.h"
61 #include "ED_mesh.h"
62
63 #include "WM_api.h"
64 #include "WM_types.h"
65
66 #include "DNA_object_types.h"
67 #include "UI_resources.h"
68
69 #include "RNA_access.h"
70 #include "RNA_define.h"
71
72 #include "mesh_intern.h"  /* own include */
73
74 /* this code here is kindof messy. . .I might need to eventually rework it - joeedh */
75
76 #define KMAXDIST    10  /* max mouse distance from edge before not detecting it */
77
78 #define KNIFE_FLT_EPS          0.00001f
79 #define KNIFE_FLT_EPS_SQUARED  (KNIFE_FLT_EPS * KNIFE_FLT_EPS)
80 #define KNIFE_FLT_EPSBIG       0.0005f
81
82 typedef struct KnifeColors {
83         unsigned char line[3];
84         unsigned char edge[3];
85         unsigned char curpoint[3];
86         unsigned char curpoint_a[4];
87         unsigned char point[3];
88         unsigned char point_a[4];
89 } KnifeColors;
90
91 /* knifetool operator */
92 typedef struct KnifeVert {
93         BMVert *v; /* non-NULL if this is an original vert */
94         ListBase edges;
95         ListBase faces;
96
97         float co[3], cageco[3], sco[2]; /* sco is screen coordinates for cageco */
98         bool is_face, in_space;
99         bool draw;
100 } KnifeVert;
101
102 typedef struct Ref {
103         struct Ref *next, *prev;
104         void *ref;
105 } Ref;
106
107 typedef struct KnifeEdge {
108         KnifeVert *v1, *v2;
109         BMFace *basef; /* face to restrict face fill to */
110         ListBase faces;
111
112         BMEdge *e /* , *e_old */; /* non-NULL if this is an original edge */
113         bool draw;
114 } KnifeEdge;
115
116 typedef struct KnifeLineHit {
117         float hit[3], cagehit[3];
118         float schit[2];
119         float l; /* lambda along cut line */
120         float perc; /* lambda along hit line */
121         float m; /* depth front-to-back */
122
123         /* Exactly one of kfe, v, or f should be non-NULL,
124          * saying whether cut line crosses and edge,
125          * is snapped to a vert, or is in the middle of some face. */
126         KnifeEdge *kfe;
127         KnifeVert *v;
128         BMFace *f;
129 } KnifeLineHit;
130
131 typedef struct KnifePosData {
132         float co[3];
133         float cage[3];
134
135         /* At most one of vert, edge, or bmface should be non-NULL,
136          * saying whether the point is snapped to a vertex, edge, or in a face.
137          * If none are set, this point is in space and is_space should be true. */
138         KnifeVert *vert;
139         KnifeEdge *edge;
140         BMFace *bmface;
141         bool is_space;
142
143         float mval[2]; /* mouse screen position (may be non-integral if snapped to something) */
144 } KnifePosData;
145
146 /* struct for properties used while drawing */
147 typedef struct KnifeTool_OpData {
148         ARegion *ar;        /* region that knifetool was activated in */
149         void *draw_handle;  /* for drawing preview loop */
150         ViewContext vc;     /* note: _don't_ use 'mval', instead use the one we define below */
151         float mval[2];      /* mouse value with snapping applied */
152         //bContext *C;
153
154         Object *ob;
155         BMEditMesh *em;
156
157         MemArena *arena;
158
159         GHash *origvertmap;
160         GHash *origedgemap;
161         GHash *kedgefacemap;
162         GHash *facetrimap;
163
164         BMBVHTree *bmbvh;
165
166         BLI_mempool *kverts;
167         BLI_mempool *kedges;
168
169         float vthresh;
170         float ethresh;
171
172         /* used for drag-cutting */
173         KnifeLineHit *linehits;
174         int totlinehit;
175
176         /* Data for mouse-position-derived data (cur) and previous click (prev) */
177         KnifePosData curr, prev;
178
179         int totkedge, totkvert;
180
181         BLI_mempool *refs;
182
183         float projmat[4][4];
184
185         KnifeColors colors;
186
187         /* run by the UI or not */
188         bool is_interactive;
189
190         /* operatpr options */
191         bool cut_through;    /* preference, can be modified at runtime (that feature may go) */
192         bool only_select;    /* set on initialization */
193         bool select_result;  /* set on initialization */
194
195         bool is_ortho;
196         float ortho_extent;
197         float clipsta, clipend;
198
199         enum {
200                 MODE_IDLE,
201                 MODE_DRAGGING,
202                 MODE_CONNECT,
203                 MODE_PANNING
204         } mode;
205
206         int prevmode;
207         bool snap_midpoints;
208         bool ignore_edge_snapping;
209         bool ignore_vert_snapping;
210
211         enum {
212                 ANGLE_FREE,
213                 ANGLE_0,
214                 ANGLE_45,
215                 ANGLE_90,
216                 ANGLE_135
217         } angle_snapping;
218
219         const float (*cagecos)[3];
220 } KnifeTool_OpData;
221
222 static ListBase *knife_get_face_kedges(KnifeTool_OpData *kcd, BMFace *f);
223
224 static void knife_input_ray_segment(KnifeTool_OpData *kcd, const float mval[2], const float ofs,
225                                     float r_origin[3], float r_dest[3]);
226
227 static bool knife_verts_edge_in_face(KnifeVert *v1, KnifeVert *v2, BMFace *f);
228
229 static void knife_update_header(bContext *C, KnifeTool_OpData *kcd)
230 {
231 #define HEADER_LENGTH 256
232         char header[HEADER_LENGTH];
233
234         BLI_snprintf(header, HEADER_LENGTH, IFACE_("LMB: define cut lines, Return/Spacebar: confirm, Esc or RMB: cancel, "
235                                                    "E: new cut, Ctrl: midpoint snap (%s), Shift: ignore snap (%s), "
236                                                    "C: angle constrain (%s), Z: cut through (%s)"),
237                      WM_bool_as_string(kcd->snap_midpoints),
238                      WM_bool_as_string(kcd->ignore_edge_snapping),
239                      WM_bool_as_string(kcd->angle_snapping),
240                      WM_bool_as_string(kcd->cut_through));
241         ED_area_headerprint(CTX_wm_area(C), header);
242 #undef HEADER_LENGTH
243 }
244
245 static void knife_project_v2(const KnifeTool_OpData *kcd, const float co[3], float sco[2])
246 {
247         ED_view3d_project_float_v2_m4(kcd->ar, co, sco, (float (*)[4])kcd->projmat);
248 }
249
250 static void knife_pos_data_clear(KnifePosData *kpd)
251 {
252         zero_v3(kpd->co);
253         zero_v3(kpd->cage);
254         kpd->vert = NULL;
255         kpd->edge = NULL;
256         kpd->bmface = NULL;
257         zero_v2(kpd->mval);
258 }
259
260 static ListBase *knife_empty_list(KnifeTool_OpData *kcd)
261 {
262         ListBase *lst;
263
264         lst = BLI_memarena_alloc(kcd->arena, sizeof(ListBase));
265         BLI_listbase_clear(lst);
266         return lst;
267 }
268
269 static void knife_append_list(KnifeTool_OpData *kcd, ListBase *lst, void *elem)
270 {
271         Ref *ref;
272
273         ref = BLI_mempool_calloc(kcd->refs);
274         ref->ref = elem;
275         BLI_addtail(lst, ref);
276 }
277
278 static Ref *find_ref(ListBase *lb, void *ref)
279 {
280         Ref *ref1;
281
282         for (ref1 = lb->first; ref1; ref1 = ref1->next) {
283                 if (ref1->ref == ref)
284                         return ref1;
285         }
286
287         return NULL;
288 }
289
290 static void knife_append_list_no_dup(KnifeTool_OpData *kcd, ListBase *lst, void *elem)
291 {
292         if (!find_ref(lst, elem))
293                 knife_append_list(kcd, lst, elem);
294 }
295
296 static KnifeEdge *new_knife_edge(KnifeTool_OpData *kcd)
297 {
298         kcd->totkedge++;
299         return BLI_mempool_calloc(kcd->kedges);
300 }
301
302 static void knife_add_to_vert_edges(KnifeTool_OpData *kcd, KnifeEdge *kfe)
303 {
304         knife_append_list(kcd, &kfe->v1->edges, kfe);
305         knife_append_list(kcd, &kfe->v2->edges, kfe);
306 }
307
308 /* Add faces of an edge to a KnifeVert's faces list.  No checks for dups. */
309 static void knife_add_edge_faces_to_vert(KnifeTool_OpData *kcd, KnifeVert *kfv, BMEdge *e)
310 {
311         BMIter bmiter;
312         BMFace *f;
313
314         BM_ITER_ELEM (f, &bmiter, e, BM_FACES_OF_EDGE) {
315                 knife_append_list(kcd, &kfv->faces, f);
316         }
317 }
318
319 /* Find a face in common in the two faces lists.
320  * If more than one, return the first; if none, return NULL */
321 static BMFace *knife_find_common_face(ListBase *faces1, ListBase *faces2)
322 {
323         Ref *ref1, *ref2;
324
325         for (ref1 = faces1->first; ref1; ref1 = ref1->next) {
326                 for (ref2 = faces2->first; ref2; ref2 = ref2->next) {
327                         if (ref1->ref == ref2->ref)
328                                 return (BMFace *)(ref1->ref);
329                 }
330         }
331         return NULL;
332 }
333
334 static KnifeVert *new_knife_vert(KnifeTool_OpData *kcd, const float co[3], const float cageco[3])
335 {
336         KnifeVert *kfv = BLI_mempool_calloc(kcd->kverts);
337
338         kcd->totkvert++;
339
340         copy_v3_v3(kfv->co, co);
341         copy_v3_v3(kfv->cageco, cageco);
342
343         knife_project_v2(kcd, kfv->co, kfv->sco);
344
345         return kfv;
346 }
347
348 /* get a KnifeVert wrapper for an existing BMVert */
349 static KnifeVert *get_bm_knife_vert(KnifeTool_OpData *kcd, BMVert *v)
350 {
351         KnifeVert *kfv = BLI_ghash_lookup(kcd->origvertmap, v);
352         const float *cageco;
353
354         if (!kfv) {
355                 BMIter bmiter;
356                 BMFace *f;
357
358                 if (BM_elem_index_get(v) >= 0)
359                         cageco = kcd->cagecos[BM_elem_index_get(v)];
360                 else
361                         cageco = v->co;
362                 kfv = new_knife_vert(kcd, v->co, cageco);
363                 kfv->v = v;
364                 BLI_ghash_insert(kcd->origvertmap, v, kfv);
365                 BM_ITER_ELEM (f, &bmiter, v, BM_FACES_OF_VERT) {
366                         knife_append_list(kcd, &kfv->faces, f);
367                 }
368         }
369
370         return kfv;
371 }
372
373 /* get a KnifeEdge wrapper for an existing BMEdge */
374 static KnifeEdge *get_bm_knife_edge(KnifeTool_OpData *kcd, BMEdge *e)
375 {
376         KnifeEdge *kfe = BLI_ghash_lookup(kcd->origedgemap, e);
377         if (!kfe) {
378                 BMIter bmiter;
379                 BMFace *f;
380
381                 kfe = new_knife_edge(kcd);
382                 kfe->e = e;
383                 kfe->v1 = get_bm_knife_vert(kcd, e->v1);
384                 kfe->v2 = get_bm_knife_vert(kcd, e->v2);
385
386                 knife_add_to_vert_edges(kcd, kfe);
387
388                 BLI_ghash_insert(kcd->origedgemap, e, kfe);
389
390                 BM_ITER_ELEM (f, &bmiter, e, BM_FACES_OF_EDGE) {
391                         knife_append_list(kcd, &kfe->faces, f);
392                 }
393         }
394
395         return kfe;
396 }
397
398 /* Record the index in kcd->em->looptris of first looptri triple for a given face,
399  * given an index for some triple in that array.
400  * This assumes that all of the triangles for a given face are contiguous
401  * in that array (as they are by the current tesselation routines).
402  * Actually store index + 1 in the hash, because 0 looks like "no entry"
403  * to hash lookup routine; will reverse this in the get routine.
404  * Doing this lazily rather than all at once for all faces.
405  */
406 static void set_lowest_face_tri(KnifeTool_OpData *kcd, BMFace *f, int index)
407 {
408         int i;
409
410         if (BLI_ghash_lookup(kcd->facetrimap, f))
411                 return;
412
413         BLI_assert(index >= 0 && index < kcd->em->tottri);
414         BLI_assert(kcd->em->looptris[index][0]->f == f);
415         for (i = index - 1; i >= 0; i--) {
416                 if (kcd->em->looptris[i][0]->f != f) {
417                         i++;
418                         break;
419                 }
420         }
421         if (i == -1)
422                 i++;
423
424         BLI_ghash_insert(kcd->facetrimap, f, SET_INT_IN_POINTER(i + 1));
425 }
426
427 /* This should only be called for faces that have had a lowest face tri set by previous function */
428 static int get_lowest_face_tri(KnifeTool_OpData *kcd, BMFace *f)
429 {
430         int ans;
431
432         ans = GET_INT_FROM_POINTER(BLI_ghash_lookup(kcd->facetrimap, f));
433         BLI_assert(ans != 0);
434         return ans - 1;
435 }
436
437 /* User has just clicked for first time or first time after a restart (E key).
438  * Copy the current position data into prev. */
439 static void knife_start_cut(KnifeTool_OpData *kcd)
440 {
441         kcd->prev = kcd->curr;
442         kcd->curr.is_space = 0; /*TODO: why do we do this? */
443
444         if (kcd->prev.vert == NULL && kcd->prev.edge == NULL && is_zero_v3(kcd->prev.cage)) {
445                 /* Make prevcage a point on the view ray to mouse closest to a point on model: choose vertex 0 */
446                 float origin[3], origin_ofs[3];
447                 BMVert *v0;
448
449                 knife_input_ray_segment(kcd, kcd->curr.mval, 1.0f, origin, origin_ofs);
450                 v0 = BM_vert_at_index_find(kcd->em->bm, 0);
451                 if (v0) {
452                         closest_to_line_v3(kcd->prev.cage, v0->co, origin_ofs, origin);
453                         copy_v3_v3(kcd->prev.co, kcd->prev.cage); /*TODO: do we need this? */
454                         copy_v3_v3(kcd->curr.cage, kcd->prev.cage);
455                         copy_v3_v3(kcd->curr.co, kcd->prev.co);
456                 }
457         }
458 }
459
460 static ListBase *knife_get_face_kedges(KnifeTool_OpData *kcd, BMFace *f)
461 {
462         ListBase *lst = BLI_ghash_lookup(kcd->kedgefacemap, f);
463
464         if (!lst) {
465                 BMIter bmiter;
466                 BMEdge *e;
467
468                 lst = knife_empty_list(kcd);
469
470                 BM_ITER_ELEM (e, &bmiter, f, BM_EDGES_OF_FACE) {
471                         knife_append_list(kcd, lst, get_bm_knife_edge(kcd, e));
472                 }
473
474                 BLI_ghash_insert(kcd->kedgefacemap, f, lst);
475         }
476
477         return lst;
478 }
479
480 static void knife_edge_append_face(KnifeTool_OpData *kcd, KnifeEdge *kfe, BMFace *f)
481 {
482         knife_append_list(kcd, knife_get_face_kedges(kcd, f), kfe);
483         knife_append_list(kcd, &kfe->faces, f);
484 }
485
486 static KnifeVert *knife_split_edge(KnifeTool_OpData *kcd, KnifeEdge *kfe, float co[3], KnifeEdge **newkfe_out)
487 {
488         KnifeEdge *newkfe = new_knife_edge(kcd);
489         Ref *ref;
490         BMFace *f;
491         float perc, cageco[3], l12;
492
493         l12 = len_v3v3(kfe->v1->co, kfe->v2->co);
494         if (l12 < KNIFE_FLT_EPS) {
495                 copy_v3_v3(cageco, kfe->v1->cageco);
496         }
497         else {
498                 perc = len_v3v3(co, kfe->v1->co) / l12;
499                 interp_v3_v3v3(cageco, kfe->v1->cageco, kfe->v2->cageco, perc);
500         }
501
502         newkfe->v1 = kfe->v1;
503         newkfe->v2 = new_knife_vert(kcd, co, cageco);
504         newkfe->v2->draw = 1;
505         if (kfe->e) {
506                 knife_add_edge_faces_to_vert(kcd, newkfe->v2, kfe->e);
507         }
508         else {
509                 /* kfe cuts across an existing face.
510                  * If v1 and v2 are in multiple faces together (e.g., if they
511                  * are in doubled polys) then this arbitrarily chooses one of them */
512                 f = knife_find_common_face(&kfe->v1->faces, &kfe->v2->faces);
513                 if (f)
514                         knife_append_list(kcd, &newkfe->v2->faces, f);
515         }
516         newkfe->basef = kfe->basef;
517
518         ref = find_ref(&kfe->v1->edges, kfe);
519         BLI_remlink(&kfe->v1->edges, ref);
520
521         kfe->v1 = newkfe->v2;
522         BLI_addtail(&kfe->v1->edges, ref);
523
524         for (ref = kfe->faces.first; ref; ref = ref->next)
525                 knife_edge_append_face(kcd, newkfe, ref->ref);
526
527         knife_add_to_vert_edges(kcd, newkfe);
528
529         newkfe->draw = kfe->draw;
530         newkfe->e = kfe->e;
531
532         *newkfe_out = newkfe;
533
534         return newkfe->v2;
535 }
536
537 /* primary key: lambda along cut
538  * secondary key: lambda along depth
539  * tertiary key: pointer comparisons of verts if both snapped to verts
540  */
541 static int linehit_compare(const void *vlh1, const void *vlh2)
542 {
543         const KnifeLineHit *lh1 = vlh1;
544         const KnifeLineHit *lh2 = vlh2;
545
546         if      (lh1->l < lh2->l) return -1;
547         else if (lh1->l > lh2->l) return  1;
548         else {
549                 if      (lh1->m < lh2->m) return -1;
550                 else if (lh1->m > lh2->m) return  1;
551                 else {
552                         if      (lh1->v < lh2->v) return -1;
553                         else if (lh1->v > lh2->v) return  1;
554                         else return 0;
555                 }
556         }
557 }
558
559 /*
560  * Sort linehits by distance along cut line, and secondarily from
561  * front to back (from eye), and tertiarily by snap vertex,
562  * and remove any duplicates.
563  */
564 static void prepare_linehits_for_cut(KnifeTool_OpData *kcd)
565 {
566         KnifeLineHit *linehits, *lhi, *lhj;
567         int i, j, n;
568
569         n = kcd->totlinehit;
570         linehits = kcd->linehits;
571         if (n == 0)
572                 return;
573
574         qsort(linehits, n, sizeof(KnifeLineHit), linehit_compare);
575
576         /* Remove any edge hits that are preceded or followed
577          * by a vertex hit that is very near. Mark such edge hits using
578          * l == -1 and then do another pass to actually remove.
579          * Also remove all but one of a series of vertex hits for the same vertex. */
580         for (i = 0; i < n; i++) {
581                 lhi = &linehits[i];
582                 if (lhi->v) {
583                         for (j = i - 1; j >= 0; j--) {
584                                 lhj = &linehits[j];
585                                 if (!lhj->kfe ||
586                                     fabsf(lhi->l - lhj->l) > KNIFE_FLT_EPSBIG ||
587                                     fabsf(lhi->m - lhj->m) > KNIFE_FLT_EPSBIG)
588                                 {
589                                         break;
590                                 }
591                                 lhj->l = -1.0f;
592                         }
593                         for (j = i + 1; j < n; j++) {
594                                 lhj = &linehits[j];
595                                 if (fabsf(lhi->l - lhj->l) > KNIFE_FLT_EPSBIG ||
596                                     fabsf(lhi->m - lhj->m) > KNIFE_FLT_EPSBIG)
597                                 {
598                                         break;
599                                 }
600                                 if (lhj->kfe || lhi->v == lhj->v) {
601                                         lhj->l = -1.0f;
602                                 }
603                         }
604                 }
605         }
606
607         /* delete-in-place loop: copying from pos j to pos i+1 */
608         i = 0;
609         j = 1;
610         while (j < n) {
611                 lhi = &linehits[i];
612                 lhj = &linehits[j];
613                 if (lhj->l == -1.0f) {
614                         j++; /* skip copying this one */
615                 }
616                 else {
617                         /* copy unless a no-op */
618                         if (lhi->l == -1.0f) {
619                                 /* could happen if linehits[0] is being deleted */
620                                 memcpy(&linehits[i], &linehits[j], sizeof(KnifeLineHit));
621                         }
622                         else {
623                                 if (i + 1 != j)
624                                         memcpy(&linehits[i + 1], &linehits[j], sizeof(KnifeLineHit));
625                                 i++;
626                         }
627                         j++;
628                 }
629         }
630         kcd->totlinehit = i + 1;
631 }
632
633 /* Add hit to list of hits in facehits[f], where facehits is a map, if not already there */
634 static void add_hit_to_facehits(KnifeTool_OpData *kcd, GHash *facehits, BMFace *f, KnifeLineHit *hit)
635 {
636         ListBase *lst = BLI_ghash_lookup(facehits, f);
637
638         if (!lst) {
639                 lst = knife_empty_list(kcd);
640                 BLI_ghash_insert(facehits, f, lst);
641         }
642         knife_append_list_no_dup(kcd, lst, hit);
643 }
644
645 static void knife_add_single_cut(KnifeTool_OpData *kcd, KnifeLineHit *lh1, KnifeLineHit *lh2, BMFace *f)
646 {
647         KnifeEdge *kfe, *kfe2;
648
649         if ((lh1->v && lh1->v == lh2->v) ||
650             (lh1->kfe && lh1->kfe == lh2->kfe))
651         {
652                 return;
653         }
654
655         /* Check if edge actually lies within face (might not, if this face is concave) */
656         if ((lh1->v && !lh1->kfe) && (lh2->v && !lh2->kfe)) {
657                 if (!knife_verts_edge_in_face(lh1->v, lh2->v, f)) {
658                         return;
659                 }
660         }
661
662         kfe = new_knife_edge(kcd);
663         kfe->draw = true;
664         kfe->basef = f;
665
666         if (lh1->v) {
667                 kfe->v1 = lh1->v;
668         }
669         else if (lh1->kfe) {
670                 kfe->v1 = knife_split_edge(kcd, lh1->kfe, lh1->cagehit, &kfe2);
671                 lh1->v = kfe->v1;  /* record the KnifeVert for this hit  */
672         }
673         else {
674                 BLI_assert(lh1->f);
675                 kfe->v1 = new_knife_vert(kcd, lh1->hit, lh1->cagehit);
676                 kfe->v1->draw = true;
677                 kfe->v1->is_face = true;
678                 knife_append_list(kcd, &kfe->v1->faces, lh1->f);
679                 lh1->v = kfe->v1;  /* record the KnifeVert for this hit */
680         }
681
682         if (lh2->v) {
683                 kfe->v2 = lh2->v;
684         }
685         else if (lh2->kfe) {
686                 kfe->v2 = knife_split_edge(kcd, lh2->kfe, lh2->cagehit, &kfe2);
687                 lh2->v = kfe->v2;  /* future uses of lh2 won't split again */
688         }
689         else {
690                 BLI_assert(lh2->f);
691                 kfe->v2 = new_knife_vert(kcd, lh2->hit, lh2->cagehit);
692                 kfe->v2->draw = true;
693                 kfe->v2->is_face = true;
694                 knife_append_list(kcd, &kfe->v2->faces, lh2->f);
695                 lh2->v = kfe->v2;  /* record the KnifeVert for this hit */
696         }
697
698         knife_add_to_vert_edges(kcd, kfe);
699
700         /* TODO: check if this is ever needed */
701         if (kfe->basef && !find_ref(&kfe->faces, kfe->basef))
702                 knife_edge_append_face(kcd, kfe, kfe->basef);
703
704 }
705
706 /* Given a list of KnifeLineHits for one face, sorted by l
707  * and then by m, make the required KnifeVerts and
708  * KnifeEdges.
709  */
710 static void knife_cut_face(KnifeTool_OpData *kcd, BMFace *f, ListBase *hits)
711 {
712         Ref *r;
713         KnifeLineHit *lh, *prevlh;
714         int n;
715
716         (void) kcd;
717
718         n = BLI_countlist(hits);
719         if (n < 2)
720                 return;
721
722         prevlh = NULL;
723         for (r = hits->first; r; r = r->next) {
724                 lh = (KnifeLineHit *)r->ref;
725                 if (prevlh)
726                         knife_add_single_cut(kcd, prevlh, lh, f);
727                 prevlh = lh;
728         }
729
730 }
731
732 /* User has just left-clicked after the first time.
733  * Add all knife cuts implied by line from prev to curr.
734  * If that line crossed edges then kcd->linehits will be non-NULL.
735  * Make all of the KnifeVerts and KnifeEdges implied by this cut.
736  */
737 static void knife_add_cut(KnifeTool_OpData *kcd)
738 {
739         int i;
740         KnifeLineHit *lh;
741         GHash *facehits;
742         BMFace *f;
743         Ref *r;
744         GHashIterator giter;
745         ListBase *lst;
746
747         prepare_linehits_for_cut(kcd);
748         if (kcd->totlinehit == 0) {
749                 kcd->prev = kcd->curr;
750                 return;
751         }
752
753         /* make facehits: map face -> list of linehits touching it */
754         facehits = BLI_ghash_ptr_new("knife facehits");
755         for (i = 0; i < kcd->totlinehit; i++) {
756                 lh = &kcd->linehits[i];
757                 if (lh->f) {
758                         add_hit_to_facehits(kcd, facehits, lh->f, lh);
759                 }
760                 if (lh->v) {
761                         for (r = lh->v->faces.first; r; r = r->next) {
762                                 add_hit_to_facehits(kcd, facehits, r->ref, lh);
763                         }
764                 }
765                 if (lh->kfe) {
766                         for (r = lh->kfe->faces.first; r; r = r->next) {
767                                 add_hit_to_facehits(kcd, facehits, r->ref, lh);
768                         }
769                 }
770         }
771
772         /* Note: as following loop progresses, the 'v' fields of
773          * the linehits will be filled in (as edges are split or
774          * in-face verts are made), so it may be true that both
775          * the v and the kfe or f fields will be non-NULL. */
776         GHASH_ITER (giter, facehits) {
777                 f = (BMFace *)BLI_ghashIterator_getKey(&giter);
778                 lst = (ListBase *)BLI_ghashIterator_getValue(&giter);
779                 knife_cut_face(kcd, f, lst);
780         }
781
782         /* set up for next cut */
783         kcd->prev = kcd->curr;
784         if (kcd->prev.bmface) {
785                 /* was "in face" but now we have a KnifeVert it is snapped to */
786                 kcd->prev.bmface = NULL;
787                 kcd->prev.vert = kcd->linehits[kcd->totlinehit - 1].v;
788         }
789
790         BLI_ghash_free(facehits, NULL, NULL);
791         MEM_freeN(kcd->linehits);
792         kcd->linehits = NULL;
793         kcd->totlinehit = 0;
794 }
795
796 static void knife_finish_cut(KnifeTool_OpData *kcd)
797 {
798         if (kcd->linehits) {
799                 MEM_freeN(kcd->linehits);
800                 kcd->linehits = NULL;
801                 kcd->totlinehit = 0;
802         }
803 }
804
805 static void knifetool_draw_angle_snapping(const KnifeTool_OpData *kcd)
806 {
807         bglMats mats;
808         double u[3], u1[2], u2[2], v1[3], v2[3], dx, dy;
809         double wminx, wminy, wmaxx, wmaxy;
810
811         /* make u the window coords of prevcage */
812         view3d_get_transformation(kcd->ar, kcd->vc.rv3d, kcd->ob, &mats);
813         gluProject(kcd->prev.cage[0], kcd->prev.cage[1], kcd->prev.cage[2],
814                    mats.modelview, mats.projection, mats.viewport,
815                    &u[0], &u[1], &u[2]);
816
817         /* make u1, u2 the points on window going through u at snap angle */
818         wminx = kcd->ar->winrct.xmin;
819         wmaxx = kcd->ar->winrct.xmin + kcd->ar->winx;
820         wminy = kcd->ar->winrct.ymin;
821         wmaxy = kcd->ar->winrct.ymin + kcd->ar->winy;
822
823         switch (kcd->angle_snapping) {
824                 case ANGLE_0:
825                         u1[0] = wminx;
826                         u2[0] = wmaxx;
827                         u1[1] = u2[1] = u[1];
828                         break;
829                 case ANGLE_90:
830                         u1[0] = u2[0] = u[0];
831                         u1[1] = wminy;
832                         u2[1] = wmaxy;
833                         break;
834                 case ANGLE_45:
835                         /* clip against left or bottom */
836                         dx = u[0] - wminx;
837                         dy = u[1] - wminy;
838                         if (dy > dx) {
839                                 u1[0] = wminx;
840                                 u1[1] = u[1] - dx;
841                         }
842                         else {
843                                 u1[0] = u[0] - dy;
844                                 u1[1] = wminy;
845                         }
846                         /* clip against right or top */
847                         dx = wmaxx - u[0];
848                         dy = wmaxy - u[1];
849                         if (dy > dx) {
850                                 u2[0] = wmaxx;
851                                 u2[1] = u[1] + dx;
852                         }
853                         else {
854                                 u2[0] = u[0] + dy;
855                                 u2[1] = wmaxy;
856                         }
857                         break;
858                 case ANGLE_135:
859                         /* clip against right or bottom */
860                         dx = wmaxx - u[0];
861                         dy = u[1] - wminy;
862                         if (dy > dx) {
863                                 u1[0] = wmaxx;
864                                 u1[1] = u[1] - dx;
865                         }
866                         else {
867                                 u1[0] = u[0] + dy;
868                                 u1[1] = wminy;
869                         }
870                         /* clip against left or top */
871                         dx = u[0] - wminx;
872                         dy = wmaxy - u[1];
873                         if (dy > dx) {
874                                 u2[0] = wminx;
875                                 u2[1] = u[1] + dx;
876                         }
877                         else {
878                                 u2[0] = u[0] - dy;
879                                 u2[1] = wmaxy;
880                         }
881                         break;
882                 default:
883                         return;
884         }
885
886         /* unproject u1 and u2 back into object space */
887         gluUnProject(u1[0], u1[1], 0.0,
888                      mats.modelview, mats.projection, mats.viewport,
889                      &v1[0], &v1[1], &v1[2]);
890         gluUnProject(u2[0], u2[1], 0.0,
891                      mats.modelview, mats.projection, mats.viewport,
892                      &v2[0], &v2[1], &v2[2]);
893
894         UI_ThemeColor(TH_TRANSFORM);
895         glLineWidth(2.0);
896         glBegin(GL_LINES);
897         glVertex3dv(v1);
898         glVertex3dv(v2);
899         glEnd();
900 }
901
902 static void knife_init_colors(KnifeColors *colors)
903 {
904         /* possible BMESH_TODO: add explicit themes or calculate these by
905          * figuring out contrasting colors with grid / edges / verts
906          * a la UI_make_axis_color */
907         UI_GetThemeColor3ubv(TH_NURB_VLINE, colors->line);
908         UI_GetThemeColor3ubv(TH_NURB_ULINE, colors->edge);
909         UI_GetThemeColor3ubv(TH_HANDLE_SEL_VECT, colors->curpoint);
910         UI_GetThemeColor3ubv(TH_HANDLE_SEL_VECT, colors->curpoint_a);
911         colors->curpoint_a[3] = 102;
912         UI_GetThemeColor3ubv(TH_ACTIVE_SPLINE, colors->point);
913         UI_GetThemeColor3ubv(TH_ACTIVE_SPLINE, colors->point_a);
914         colors->point_a[3] = 102;
915 }
916
917 /* modal loop selection drawing callback */
918 static void knifetool_draw(const bContext *C, ARegion *UNUSED(ar), void *arg)
919 {
920         View3D *v3d = CTX_wm_view3d(C);
921         const KnifeTool_OpData *kcd = arg;
922
923         if (v3d->zbuf) glDisable(GL_DEPTH_TEST);
924
925         glPolygonOffset(1.0f, 1.0f);
926
927         glPushMatrix();
928         glMultMatrixf(kcd->ob->obmat);
929
930         if (kcd->mode == MODE_DRAGGING) {
931                 if (kcd->angle_snapping != ANGLE_FREE)
932                         knifetool_draw_angle_snapping(kcd);
933
934                 glColor3ubv(kcd->colors.line);
935                 
936                 glLineWidth(2.0);
937
938                 glBegin(GL_LINES);
939                 glVertex3fv(kcd->prev.cage);
940                 glVertex3fv(kcd->curr.cage);
941                 glEnd();
942
943                 glLineWidth(1.0);
944         }
945
946         if (kcd->prev.vert) {
947                 glColor3ubv(kcd->colors.point);
948                 glPointSize(11);
949
950                 glBegin(GL_POINTS);
951                 glVertex3fv(kcd->prev.cage);
952                 glEnd();
953         }
954
955         if (kcd->prev.bmface) {
956                 glColor3ubv(kcd->colors.curpoint);
957                 glPointSize(9);
958
959                 glBegin(GL_POINTS);
960                 glVertex3fv(kcd->prev.cage);
961                 glEnd();
962         }
963
964         if (kcd->curr.edge) {
965                 glColor3ubv(kcd->colors.edge);
966                 glLineWidth(2.0);
967
968                 glBegin(GL_LINES);
969                 glVertex3fv(kcd->curr.edge->v1->cageco);
970                 glVertex3fv(kcd->curr.edge->v2->cageco);
971                 glEnd();
972
973                 glLineWidth(1.0);
974         }
975         else if (kcd->curr.vert) {
976                 glColor3ubv(kcd->colors.point);
977                 glPointSize(11);
978
979                 glBegin(GL_POINTS);
980                 glVertex3fv(kcd->curr.cage);
981                 glEnd();
982         }
983
984         if (kcd->curr.bmface) {
985                 glColor3ubv(kcd->colors.curpoint);
986                 glPointSize(9);
987
988                 glBegin(GL_POINTS);
989                 glVertex3fv(kcd->curr.cage);
990                 glEnd();
991         }
992
993         if (kcd->totlinehit > 0) {
994                 KnifeLineHit *lh;
995                 int i;
996
997                 glEnable(GL_BLEND);
998                 glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
999
1000                 /* draw any snapped verts first */
1001                 glColor4ubv(kcd->colors.point_a);
1002                 glPointSize(11);
1003                 glBegin(GL_POINTS);
1004                 lh = kcd->linehits;
1005                 for (i = 0; i < kcd->totlinehit; i++, lh++) {
1006                         if (lh->v)
1007                                 glVertex3fv(lh->cagehit);
1008                 }
1009                 glEnd();
1010
1011                 /* now draw the rest */
1012                 glColor4ubv(kcd->colors.curpoint_a);
1013                 glPointSize(7);
1014                 glBegin(GL_POINTS);
1015                 lh = kcd->linehits;
1016                 for (i = 0; i < kcd->totlinehit; i++, lh++) {
1017                         if (!lh->v)
1018                                 glVertex3fv(lh->cagehit);
1019                 }
1020                 glEnd();
1021                 glDisable(GL_BLEND);
1022         }
1023
1024         if (kcd->totkedge > 0) {
1025                 BLI_mempool_iter iter;
1026                 KnifeEdge *kfe;
1027
1028                 glLineWidth(1.0);
1029                 glBegin(GL_LINES);
1030
1031                 BLI_mempool_iternew(kcd->kedges, &iter);
1032                 for (kfe = BLI_mempool_iterstep(&iter); kfe; kfe = BLI_mempool_iterstep(&iter)) {
1033                         if (!kfe->draw)
1034                                 continue;
1035
1036                         glColor3ubv(kcd->colors.line);
1037
1038                         glVertex3fv(kfe->v1->cageco);
1039                         glVertex3fv(kfe->v2->cageco);
1040                 }
1041
1042                 glEnd();
1043                 glLineWidth(1.0);
1044         }
1045
1046         if (kcd->totkvert > 0) {
1047                 BLI_mempool_iter iter;
1048                 KnifeVert *kfv;
1049
1050                 glPointSize(5.0);
1051
1052                 glBegin(GL_POINTS);
1053                 BLI_mempool_iternew(kcd->kverts, &iter);
1054                 for (kfv = BLI_mempool_iterstep(&iter); kfv; kfv = BLI_mempool_iterstep(&iter)) {
1055                         if (!kfv->draw)
1056                                 continue;
1057
1058                         glColor3ubv(kcd->colors.point);
1059
1060                         glVertex3fv(kfv->cageco);
1061                 }
1062
1063                 glEnd();
1064         }
1065
1066         glPopMatrix();
1067
1068         if (v3d->zbuf) glEnable(GL_DEPTH_TEST);
1069 }
1070
1071 /* Find intersection of v1-v2 with face f.
1072  * Only take intersections that are at least face_tol (in screen space) away
1073  * from other intersection elements.
1074  * If v1-v2 is coplanar with f, call that "no intersection though
1075  * it really means "infinite number of intersections".
1076  * In such a case we should have gotten hits on edges or verts of the face. */
1077 static bool knife_ray_intersect_face(KnifeTool_OpData *kcd,
1078                                      const float s[2],
1079                                      const float v1[3], const float v2[3],
1080                                      BMFace *f,
1081                                      const float face_tol,
1082                                      float intersectp[3])
1083 {
1084         int tottri, tri_i;
1085         float lv1[3], lv2[3], lv3[3], raydir[3];
1086         float tri_norm[3], tri_plane[4];
1087         float se1[2], se2[2];
1088         float d, lambda;
1089         BMLoop **tri;
1090         ListBase *lst;
1091         Ref *ref;
1092         KnifeEdge *kfe;
1093
1094         sub_v3_v3v3(raydir, v2, v1);
1095         normalize_v3(raydir);
1096         tri_i = get_lowest_face_tri(kcd, f);
1097         tottri = kcd->em->tottri;
1098         BLI_assert(tri_i >= 0 && tri_i < tottri);
1099
1100         for (; tri_i < tottri; tri_i++) {
1101                 tri = kcd->em->looptris[tri_i];
1102                 if (tri[0]->f != f)
1103                         break;
1104                 copy_v3_v3(lv1, kcd->cagecos[BM_elem_index_get(tri[0]->v)]);
1105                 copy_v3_v3(lv2, kcd->cagecos[BM_elem_index_get(tri[1]->v)]);
1106                 copy_v3_v3(lv3, kcd->cagecos[BM_elem_index_get(tri[2]->v)]);
1107                 /* using epsilon test in case ray is directly through an internal
1108                  * tesselation edge and might not hit either tesselation tri with
1109                  * an exact test;
1110                  * we will exclude hits near real edges by a later test */
1111                 if (isect_ray_tri_epsilon_v3(v1, raydir, lv1, lv2, lv3, &lambda, NULL, KNIFE_FLT_EPS)) {
1112                         /* check if line coplanar with tri */
1113                         normal_tri_v3(tri_norm, lv1, lv2, lv3);
1114                         plane_from_point_normal_v3(tri_plane, lv1, tri_norm);
1115                         if ((fabsf(dist_squared_to_plane_v3(v1, tri_plane)) < KNIFE_FLT_EPS) &&
1116                             (fabsf(dist_squared_to_plane_v3(v2, tri_plane)) < KNIFE_FLT_EPS))
1117                         {
1118                                 return false;
1119                         }
1120                         copy_v3_v3(intersectp, v1);
1121                         madd_v3_v3fl(intersectp, raydir, lambda);
1122                         /* Now check that far enough away from verts and edges */
1123                         lst = knife_get_face_kedges(kcd, f);
1124                         for (ref = lst->first; ref; ref = ref->next) {
1125                                 kfe = ref->ref;
1126                                 knife_project_v2(kcd, kfe->v1->cageco, se1);
1127                                 knife_project_v2(kcd, kfe->v2->cageco, se2);
1128                                 d = dist_to_line_segment_v2(s, se1, se2);
1129                                 if (d < face_tol) {
1130                                         return false;
1131                                 }
1132                         }
1133                         return true;
1134                 }
1135         }
1136         return false;
1137 }
1138
1139 /* Calculate maximum excursion from (0,0,0) of mesh */
1140 static void calc_ortho_extent(KnifeTool_OpData *kcd)
1141 {
1142         BMIter iter;
1143         BMVert *v;
1144         BMesh *bm = kcd->em->bm;
1145         float max_xyz = 0.0f;
1146         int i;
1147
1148         BM_ITER_MESH (v, &iter, bm, BM_VERTS_OF_MESH) {
1149                 for (i = 0; i < 3; i++)
1150                         max_xyz = max_ff(max_xyz, fabsf(v->co[i]));
1151         }
1152         kcd->ortho_extent = max_xyz;
1153 }
1154
1155 /* Check if p is visible (not clipped, not occluded by another face).
1156  * s in screen projection of p. */
1157 static bool point_is_visible(KnifeTool_OpData *kcd, const float p[3], const float s[2], bglMats *mats)
1158 {
1159         float p1[3];
1160         BMFace *f_hit;
1161
1162         /* If not cutting through, make sure no face is in front of p */
1163         if (!kcd->cut_through) {
1164                 float dist;
1165                 float view[3];
1166
1167                 /* TODO: I think there's a simpler way to get the required raycast ray */
1168                 ED_view3d_unproject(mats, view, s[0], s[1], 0.0f);
1169
1170                 /* avoid projecting behind the viewpoint */
1171                 if (kcd->is_ortho) {
1172                         dist = FLT_MAX;
1173                 }
1174                 else {
1175                         float p_world[3];
1176                         mul_v3_m4v3(p_world, kcd->ob->obmat, p);
1177                         dist = len_v3v3(view, p_world);
1178                 }
1179
1180                 mul_m4_v3(kcd->ob->imat, view);
1181
1182                 /* make p1 a little towards view, so ray doesn't hit p's face. */
1183                 copy_v3_v3(p1, p);
1184                 sub_v3_v3(view, p1);
1185                 normalize_v3(view);
1186                 madd_v3_v3fl(p1, view, 3.0f * KNIFE_FLT_EPSBIG);
1187
1188                 /* see if there's a face hit between p1 and the view */
1189                 f_hit = BKE_bmbvh_ray_cast(kcd->bmbvh, p1, view, KNIFE_FLT_EPS, &dist, NULL, NULL);
1190                 if (f_hit)
1191                         return false;
1192         }
1193
1194         /* If box clipping on, make sure p is not clipped */
1195         if (kcd->vc.rv3d->rflag & RV3D_CLIPPING &&
1196             ED_view3d_clipping_test(kcd->vc.rv3d, p, true))
1197         {
1198                 return false;
1199         }
1200
1201         return true;
1202 }
1203
1204 /* Clip the line (v1, v2) to planes perpendicular to it and distances d from
1205  * the closest point on the line to the origin */
1206 static void clip_to_ortho_planes(float v1[3], float v2[3], float d)
1207 {
1208         float closest[3];
1209         const float origin[3] = {0.0f, 0.0f, 0.0f};
1210
1211         closest_to_line_v3(closest, origin, v1, v2);
1212         dist_ensure_v3_v3fl(v1, closest, d);
1213         dist_ensure_v3_v3fl(v2, closest, d);
1214 }
1215
1216 static void set_linehit_depth(KnifeTool_OpData *kcd, KnifeLineHit *lh)
1217 {
1218         float vnear[3], vfar[3];
1219
1220         ED_view3d_win_to_segment(kcd->ar, kcd->vc.v3d, lh->schit, vnear, vfar, true);
1221         mul_m4_v3(kcd->ob->imat, vnear);
1222         if (kcd->is_ortho) {
1223                 if (kcd->ortho_extent == 0.0f)
1224                         calc_ortho_extent(kcd);
1225                 clip_to_ortho_planes(vnear, vfar, kcd->ortho_extent + 10.0f);
1226         }
1227         lh->m = len_v3v3(vnear, lh->cagehit);
1228 }
1229
1230 /* Finds visible (or all, if cutting through) edges that intersects the current screen drag line */
1231 static void knife_find_line_hits(KnifeTool_OpData *kcd)
1232 {
1233         bglMats mats;
1234         SmallHash faces, kfes, kfvs;
1235         float v1[3], v2[3], v3[3], v4[3], s1[2], s2[2];
1236         BVHTree *planetree, *tree;
1237         BVHTreeOverlap *results, *result;
1238         BMLoop **ls;
1239         BMFace *f;
1240         KnifeEdge *kfe;
1241         KnifeVert *v;
1242         ListBase *lst;
1243         Ref *ref;
1244         KnifeLineHit *linehits = NULL;
1245         BLI_array_declare(linehits);
1246         SmallHashIter hiter;
1247         KnifeLineHit hit;
1248         void *val;
1249         float plane_cos[12];
1250         float s[2], se1[2], se2[2], sint[2];
1251         float p[3], p2[3], r1[3], r2[3];
1252         float d, d1, d2, lambda;
1253         float vert_tol, vert_tol_sq, line_tol, face_tol;
1254         int isect_kind;
1255         unsigned int tot;
1256         int i;
1257
1258         bgl_get_mats(&mats);
1259
1260         if (kcd->linehits) {
1261                 MEM_freeN(kcd->linehits);
1262                 kcd->linehits = NULL;
1263                 kcd->totlinehit = 0;
1264         }
1265
1266         copy_v3_v3(v1, kcd->prev.cage);
1267         copy_v3_v3(v2, kcd->curr.cage);
1268
1269         /* project screen line's 3d coordinates back into 2d */
1270         knife_project_v2(kcd, v1, s1);
1271         knife_project_v2(kcd, v2, s2);
1272
1273         if (kcd->is_interactive) {
1274                 if (len_squared_v2v2(s1, s2) < 1.0f) {
1275                         return;
1276                 }
1277         }
1278         else {
1279                 if (len_squared_v2v2(s1, s2) < KNIFE_FLT_EPS_SQUARED) {
1280                         return;
1281                 }
1282         }
1283
1284         /* unproject screen line */
1285         ED_view3d_win_to_segment(kcd->ar, kcd->vc.v3d, s1, v1, v3, true);
1286         ED_view3d_win_to_segment(kcd->ar, kcd->vc.v3d, s2, v2, v4, true);
1287
1288         mul_m4_v3(kcd->ob->imat, v1);
1289         mul_m4_v3(kcd->ob->imat, v2);
1290         mul_m4_v3(kcd->ob->imat, v3);
1291         mul_m4_v3(kcd->ob->imat, v4);
1292
1293         /* numeric error, 'v1' -> 'v2', 'v2' -> 'v4' can end up being ~2000 units apart in otho mode
1294          * (from ED_view3d_win_to_segment_clip() above)
1295          * this gives precision error; rather then solving properly
1296          * (which may involve using doubles everywhere!),
1297          * limit the distance between these points */
1298         if (kcd->is_ortho) {
1299                 if (kcd->ortho_extent == 0.0f)
1300                         calc_ortho_extent(kcd);
1301                 clip_to_ortho_planes(v1, v3, kcd->ortho_extent + 10.0f);
1302                 clip_to_ortho_planes(v2, v4, kcd->ortho_extent + 10.0f);
1303         }
1304
1305         /* First use bvh tree to find faces, knife edges, and knife verts that might
1306          * intersect the cut plane with rays v1-v3 and v2-v4.
1307          * This deduplicates the candidates before doing more expensive intersection tests. */
1308
1309         tree = BKE_bmbvh_tree_get(kcd->bmbvh);
1310         planetree = BLI_bvhtree_new(4, FLT_EPSILON * 4, 8, 8);
1311         copy_v3_v3(plane_cos + 0, v1);
1312         copy_v3_v3(plane_cos + 3, v2);
1313         copy_v3_v3(plane_cos + 6, v3);
1314         copy_v3_v3(plane_cos + 9, v4);
1315         BLI_bvhtree_insert(planetree, 0, plane_cos, 4);
1316         BLI_bvhtree_balance(planetree);
1317
1318         results = BLI_bvhtree_overlap(tree, planetree, &tot);
1319         if (!results) {
1320                 BLI_bvhtree_free(planetree);
1321                 return;
1322         }
1323
1324         BLI_smallhash_init(&faces);
1325         BLI_smallhash_init(&kfes);
1326         BLI_smallhash_init(&kfvs);
1327
1328         for (i = 0, result = results; i < tot; i++, result++) {
1329                 ls = (BMLoop **)kcd->em->looptris[result->indexA];
1330                 f = ls[0]->f;
1331                 set_lowest_face_tri(kcd, f, result->indexA);
1332                 /* for faces, store index of lowest hit looptri in hash */
1333                 if (BLI_smallhash_haskey(&faces, (uintptr_t)f)) {
1334                         continue;
1335                 }
1336                 /* don't care what the value is except that it is non-NULL, for iterator */
1337                 BLI_smallhash_insert(&faces, (uintptr_t)f, f);
1338
1339                 lst = knife_get_face_kedges(kcd, f);
1340                 for (ref = lst->first; ref; ref = ref->next) {
1341                         kfe = ref->ref;
1342                         if (BLI_smallhash_haskey(&kfes, (uintptr_t)kfe))
1343                                 continue;
1344                         BLI_smallhash_insert(&kfes, (uintptr_t)kfe, kfe);
1345                         v = kfe->v1;
1346                         if (!BLI_smallhash_haskey(&kfvs, (uintptr_t)v))
1347                                 BLI_smallhash_insert(&kfvs, (uintptr_t)v, v);
1348                         v = kfe->v2;
1349                         if (!BLI_smallhash_haskey(&kfvs, (uintptr_t)v))
1350                                 BLI_smallhash_insert(&kfvs, (uintptr_t)v, v);
1351                 }
1352         }
1353
1354         /* Now go through the candidates and find intersections */
1355         /* These tolerances, in screen space, are for intermediate hits, as ends are already snapped to screen */
1356         vert_tol = KNIFE_FLT_EPS * 2000.0f;
1357         line_tol = KNIFE_FLT_EPS * 2000.0f;
1358         vert_tol_sq = vert_tol * vert_tol;
1359         face_tol = max_ff(vert_tol, line_tol);
1360         /* Assume these tolerances swamp floating point rounding errors in calculations below */
1361
1362         /* first look for vertex hits */
1363         for (val = BLI_smallhash_iternew(&kfvs, &hiter, (uintptr_t *)&v); val;
1364              val = BLI_smallhash_iternext(&hiter, (uintptr_t *)&v))
1365         {
1366                 knife_project_v2(kcd, v->cageco, s);
1367                 d = dist_squared_to_line_segment_v2(s, s1, s2);
1368                 if (d <= vert_tol_sq) {
1369                         if (point_is_visible(kcd, v->cageco, s, &mats)) {
1370                                 memset(&hit, 0, sizeof(hit));
1371                                 hit.v = v;
1372                                 copy_v3_v3(hit.hit, v->cageco);
1373                                 copy_v3_v3(hit.cagehit, v->cageco);
1374                                 copy_v2_v2(hit.schit, s);
1375                                 set_linehit_depth(kcd, &hit);
1376                                 BLI_array_append(linehits, hit);
1377                         }
1378                 }
1379         }
1380         /* now edge hits; don't add if a vertex at end of edge should have hit */
1381         for (val = BLI_smallhash_iternew(&kfes, &hiter, (uintptr_t *)&kfe); val;
1382              val = BLI_smallhash_iternext(&hiter, (uintptr_t *)&kfe))
1383         {
1384                 knife_project_v2(kcd, kfe->v1->cageco, se1);
1385                 knife_project_v2(kcd, kfe->v2->cageco, se2);
1386                 isect_kind = isect_seg_seg_v2_point(s1, s2, se1, se2, sint);
1387                 if (isect_kind == -1) {
1388                         /* isect_seg_seg_v2 doesn't do tolerance test around ends of s1-s2 */
1389                         closest_to_line_segment_v2(sint, s1, se1, se2);
1390                         if (len_squared_v2v2(sint, s1) <= vert_tol_sq)
1391                                 isect_kind = 1;
1392                         else {
1393                                 closest_to_line_segment_v2(sint, s2, se1, se2);
1394                                 if (len_squared_v2v2(sint, s2) <= vert_tol_sq)
1395                                         isect_kind = 1;
1396                         }
1397                 }
1398                 if (isect_kind == 1) {
1399                         d1 = len_v2v2(sint, se1);
1400                         d2 = len_v2v2(se2, se1);
1401                         if (!(d1 <= vert_tol || d2 <= vert_tol || fabsf(d1 - d2) <= vert_tol)) {
1402                                 lambda = d1 / d2;
1403                                 /* Can't just interpolate between ends of kfe because
1404                                  * that doesn't work with perspective transformation.
1405                                  * Need to find 3d intersection of ray through sint */
1406                                 knife_input_ray_segment(kcd, sint, 1.0f, r1, r2);
1407                                 isect_kind = isect_line_line_v3(kfe->v1->cageco, kfe->v2->cageco, r1, r2, p, p2);
1408                                 if (isect_kind >= 1 && point_is_visible(kcd, p, sint, &mats)) {
1409                                         memset(&hit, 0, sizeof(hit));
1410                                         if (kcd->snap_midpoints) {
1411                                                 /* choose intermediate point snap too */
1412                                                 mid_v3_v3v3(p, kfe->v1->cageco, kfe->v2->cageco);
1413                                                 mid_v2_v2v2(sint, se1, se2);
1414                                                 lambda = 0.5f;
1415                                         }
1416                                         hit.kfe = kfe;
1417                                         copy_v3_v3(hit.hit, p);
1418                                         copy_v3_v3(hit.cagehit, p);
1419                                         copy_v2_v2(hit.schit, sint);
1420                                         hit.perc = lambda;
1421                                         set_linehit_depth(kcd, &hit);
1422                                         BLI_array_append(linehits, hit);
1423                                 }
1424                         }
1425                 }
1426         }
1427         /* now face hits; don't add if a vertex or edge in face should have hit */
1428         for (val = BLI_smallhash_iternew(&faces, &hiter, (uintptr_t *)&f); val;
1429              val = BLI_smallhash_iternext(&hiter, (uintptr_t *)&f))
1430         {
1431                 if (knife_ray_intersect_face(kcd, s1, v1, v3, f, face_tol, p)) {
1432                         if (point_is_visible(kcd, p, s1, &mats)) {
1433                                 memset(&hit, 0, sizeof(hit));
1434                                 hit.f = f;
1435                                 copy_v3_v3(hit.hit, p);
1436                                 copy_v3_v3(hit.cagehit, p);
1437                                 copy_v2_v2(hit.schit, s1);
1438                                 set_linehit_depth(kcd, &hit);
1439                                 BLI_array_append(linehits, hit);
1440                         }
1441                 }
1442                 if (knife_ray_intersect_face(kcd, s2, v2, v4, f, face_tol, p)) {
1443                         if (point_is_visible(kcd, p, s2, &mats)) {
1444                                 memset(&hit, 0, sizeof(hit));
1445                                 hit.f = f;
1446                                 copy_v3_v3(hit.hit, p);
1447                                 copy_v3_v3(hit.cagehit, p);
1448                                 copy_v2_v2(hit.schit, s2);
1449                                 set_linehit_depth(kcd, &hit);
1450                                 BLI_array_append(linehits, hit);
1451                         }
1452                 }
1453         }
1454
1455         kcd->linehits = linehits;
1456         kcd->totlinehit = BLI_array_count(linehits);
1457
1458         /* find position along screen line, used for sorting */
1459         for (i = 0; i < kcd->totlinehit; i++) {
1460                 KnifeLineHit *lh = kcd->linehits + i;
1461
1462                 lh->l = len_v2v2(lh->schit, s1) / len_v2v2(s2, s1);
1463         }
1464
1465         BLI_smallhash_release(&faces);
1466         BLI_smallhash_release(&kfes);
1467         BLI_smallhash_release(&kfvs);
1468         BLI_bvhtree_free(planetree);
1469         if (results)
1470                 MEM_freeN(results);
1471 }
1472
1473 static void knife_input_ray_segment(KnifeTool_OpData *kcd, const float mval[2], const float ofs,
1474                                     float r_origin[3], float r_origin_ofs[3])
1475 {
1476         bglMats mats;
1477
1478         bgl_get_mats(&mats);
1479
1480         /* unproject to find view ray */
1481         ED_view3d_unproject(&mats, r_origin,     mval[0], mval[1], 0.0f);
1482         ED_view3d_unproject(&mats, r_origin_ofs, mval[0], mval[1], ofs);
1483
1484         /* transform into object space */
1485         invert_m4_m4(kcd->ob->imat, kcd->ob->obmat); 
1486
1487         mul_m4_v3(kcd->ob->imat, r_origin);
1488         mul_m4_v3(kcd->ob->imat, r_origin_ofs);
1489 }
1490
1491 static BMFace *knife_find_closest_face(KnifeTool_OpData *kcd, float co[3], float cageco[3], bool *is_space)
1492 {
1493         BMFace *f;
1494         float dist = KMAXDIST;
1495         float origin[3];
1496         float origin_ofs[3];
1497         float ray[3];
1498
1499         /* unproject to find view ray */
1500         knife_input_ray_segment(kcd, kcd->curr.mval, 1.0f, origin, origin_ofs);
1501         sub_v3_v3v3(ray, origin_ofs, origin);
1502
1503         f = BKE_bmbvh_ray_cast(kcd->bmbvh, origin, ray, 0.0f, NULL, co, cageco);
1504
1505         if (is_space)
1506                 *is_space = !f;
1507
1508         if (!f) {
1509                 if (kcd->is_interactive) {
1510                         /* try to use backbuffer selection method if ray casting failed */
1511                         f = EDBM_face_find_nearest(&kcd->vc, &dist);
1512
1513                         /* cheat for now; just put in the origin instead
1514                          * of a true coordinate on the face.
1515                          * This just puts a point 1.0f infront of the view. */
1516                         add_v3_v3v3(co, origin, ray);
1517                 }
1518         }
1519
1520         return f;
1521 }
1522
1523 /* find the 2d screen space density of vertices within a radius.  used to scale snapping
1524  * distance for picking edges/verts.*/
1525 static int knife_sample_screen_density(KnifeTool_OpData *kcd, const float radius)
1526 {
1527         BMFace *f;
1528         bool is_space;
1529         float co[3], cageco[3], sco[2];
1530
1531         BLI_assert(kcd->is_interactive == true);
1532
1533         f = knife_find_closest_face(kcd, co, cageco, &is_space);
1534
1535         if (f && !is_space) {
1536                 const float radius_sq = radius * radius;
1537                 ListBase *lst;
1538                 Ref *ref;
1539                 float dis_sq;
1540                 int c = 0;
1541
1542                 knife_project_v2(kcd, cageco, sco);
1543
1544                 lst = knife_get_face_kedges(kcd, f);
1545                 for (ref = lst->first; ref; ref = ref->next) {
1546                         KnifeEdge *kfe = ref->ref;
1547                         int i;
1548
1549                         for (i = 0; i < 2; i++) {
1550                                 KnifeVert *kfv = i ? kfe->v2 : kfe->v1;
1551
1552                                 knife_project_v2(kcd, kfv->cageco, kfv->sco);
1553
1554                                 dis_sq = len_squared_v2v2(kfv->sco, sco);
1555                                 if (dis_sq < radius_sq) {
1556                                         if (kcd->vc.rv3d->rflag & RV3D_CLIPPING) {
1557                                                 if (ED_view3d_clipping_test(kcd->vc.rv3d, kfv->cageco, true) == 0) {
1558                                                         c++;
1559                                                 }
1560                                         }
1561                                         else {
1562                                                 c++;
1563                                         }
1564                                 }
1565                         }
1566                 }
1567
1568                 return c;
1569         }
1570
1571         return 0;
1572 }
1573
1574 /* returns snapping distance for edges/verts, scaled by the density of the
1575  * surrounding mesh (in screen space)*/
1576 static float knife_snap_size(KnifeTool_OpData *kcd, float maxsize)
1577 {
1578         float density;
1579
1580         if (kcd->is_interactive) {
1581                 density = (float)knife_sample_screen_density(kcd, maxsize * 2.0f);
1582         }
1583         else {
1584                 density = 1.0f;
1585         }
1586
1587         if (density < 1.0f)
1588                 density = 1.0f;
1589
1590         return min_ff(maxsize / (density * 0.5f), maxsize);
1591 }
1592
1593 /* p is closest point on edge to the mouse cursor */
1594 static KnifeEdge *knife_find_closest_edge(KnifeTool_OpData *kcd, float p[3], float cagep[3],
1595                                           BMFace **fptr, bool *is_space)
1596 {
1597         BMFace *f;
1598         float co[3], cageco[3], sco[2];
1599         float maxdist = knife_snap_size(kcd, kcd->ethresh);
1600
1601         if (kcd->ignore_vert_snapping)
1602                 maxdist *= 0.5f;
1603
1604         f = knife_find_closest_face(kcd, co, cageco, NULL);
1605         *is_space = !f;
1606
1607         /* set p to co, in case we don't find anything, means a face cut */
1608         copy_v3_v3(p, co);
1609         copy_v3_v3(cagep, cageco);
1610
1611         kcd->curr.bmface = f;
1612
1613         if (f) {
1614                 const float maxdist_sq = maxdist * maxdist;
1615                 KnifeEdge *cure = NULL;
1616                 ListBase *lst;
1617                 Ref *ref;
1618                 float dis_sq, curdis_sq = FLT_MAX;
1619
1620                 knife_project_v2(kcd, cageco, sco);
1621
1622                 /* look through all edges associated with this face */
1623                 lst = knife_get_face_kedges(kcd, f);
1624                 for (ref = lst->first; ref; ref = ref->next) {
1625                         KnifeEdge *kfe = ref->ref;
1626
1627                         /* project edge vertices into screen space */
1628                         knife_project_v2(kcd, kfe->v1->cageco, kfe->v1->sco);
1629                         knife_project_v2(kcd, kfe->v2->cageco, kfe->v2->sco);
1630
1631                         dis_sq = dist_squared_to_line_segment_v2(sco, kfe->v1->sco, kfe->v2->sco);
1632                         if (dis_sq < curdis_sq && dis_sq < maxdist_sq) {
1633                                 if (kcd->vc.rv3d->rflag & RV3D_CLIPPING) {
1634                                         float lambda = line_point_factor_v2(sco, kfe->v1->sco, kfe->v2->sco);
1635                                         float vec[3];
1636
1637                                         interp_v3_v3v3(vec, kfe->v1->cageco, kfe->v2->cageco, lambda);
1638
1639                                         if (ED_view3d_clipping_test(kcd->vc.rv3d, vec, true) == 0) {
1640                                                 cure = kfe;
1641                                                 curdis_sq = dis_sq;
1642                                         }
1643                                 }
1644                                 else {
1645                                         cure = kfe;
1646                                         curdis_sq = dis_sq;
1647                                 }
1648                         }
1649                 }
1650
1651                 if (fptr)
1652                         *fptr = f;
1653
1654                 if (cure) {
1655                         if (!kcd->ignore_edge_snapping || !(cure->e)) {
1656                                 KnifeVert *edgesnap = NULL;
1657
1658                                 if (kcd->snap_midpoints) {
1659                                         mid_v3_v3v3(p, cure->v1->co, cure->v2->co);
1660                                         mid_v3_v3v3(cagep, cure->v1->cageco, cure->v2->cageco);
1661                                 }
1662                                 else {
1663                                         float d;
1664
1665                                         closest_to_line_segment_v3(cagep, cageco, cure->v1->cageco, cure->v2->cageco);
1666                                         d = len_v3v3(cagep, cure->v1->cageco) / len_v3v3(cure->v1->cageco, cure->v2->cageco);
1667                                         interp_v3_v3v3(p, cure->v1->co, cure->v2->co, d);
1668                                 }
1669
1670                                 /* update mouse coordinates to the snapped-to edge's screen coordinates
1671                                  * this is important for angle snap, which uses the previous mouse position */
1672                                 edgesnap = new_knife_vert(kcd, p, cagep);
1673                                 kcd->curr.mval[0] = edgesnap->sco[0];
1674                                 kcd->curr.mval[1] = edgesnap->sco[1];
1675
1676                         }
1677                         else {
1678                                 return NULL;
1679                         }
1680                 }
1681
1682                 return cure;
1683         }
1684
1685         if (fptr)
1686                 *fptr = NULL;
1687
1688         return NULL;
1689 }
1690
1691 /* find a vertex near the mouse cursor, if it exists */
1692 static KnifeVert *knife_find_closest_vert(KnifeTool_OpData *kcd, float p[3], float cagep[3], BMFace **fptr,
1693                                           bool *is_space)
1694 {
1695         BMFace *f;
1696         float co[3], cageco[3], sco[2], maxdist = knife_snap_size(kcd, kcd->vthresh);
1697
1698         if (kcd->ignore_vert_snapping)
1699                 maxdist *= 0.5f;
1700
1701         f = knife_find_closest_face(kcd, co, cageco, is_space);
1702
1703         /* set p to co, in case we don't find anything, means a face cut */
1704         copy_v3_v3(p, co);
1705         copy_v3_v3(cagep, cageco);
1706         kcd->curr.bmface = f;
1707
1708         if (f) {
1709                 const float maxdist_sq = maxdist * maxdist;
1710                 ListBase *lst;
1711                 Ref *ref;
1712                 KnifeVert *curv = NULL;
1713                 float dis_sq, curdis_sq = FLT_MAX;
1714
1715                 knife_project_v2(kcd, cageco, sco);
1716
1717                 lst = knife_get_face_kedges(kcd, f);
1718                 for (ref = lst->first; ref; ref = ref->next) {
1719                         KnifeEdge *kfe = ref->ref;
1720                         int i;
1721
1722                         for (i = 0; i < 2; i++) {
1723                                 KnifeVert *kfv = i ? kfe->v2 : kfe->v1;
1724
1725                                 knife_project_v2(kcd, kfv->cageco, kfv->sco);
1726
1727                                 dis_sq = len_squared_v2v2(kfv->sco, sco);
1728                                 if (dis_sq < curdis_sq && dis_sq < maxdist_sq) {
1729                                         if (kcd->vc.rv3d->rflag & RV3D_CLIPPING) {
1730                                                 if (ED_view3d_clipping_test(kcd->vc.rv3d, kfv->cageco, true) == 0) {
1731                                                         curv = kfv;
1732                                                         curdis_sq = dis_sq;
1733                                                 }
1734                                         }
1735                                         else {
1736                                                 curv = kfv;
1737                                                 curdis_sq = dis_sq;
1738                                         }
1739                                 }
1740                         }
1741                 }
1742
1743                 if (!kcd->ignore_vert_snapping || !(curv && curv->v)) {
1744                         if (fptr)
1745                                 *fptr = f;
1746
1747                         if (curv) {
1748                                 copy_v3_v3(p, curv->co);
1749                                 copy_v3_v3(cagep, curv->cageco);
1750
1751                                 /* update mouse coordinates to the snapped-to vertex's screen coordinates
1752                                  * this is important for angle snap, which uses the previous mouse position */
1753                                 kcd->curr.mval[0] = curv->sco[0];
1754                                 kcd->curr.mval[1] = curv->sco[1];
1755                         }
1756
1757                         return curv;
1758                 }
1759                 else {
1760                         if (fptr)
1761                                 *fptr = f;
1762
1763                         return NULL;
1764                 }
1765         }
1766
1767         if (fptr)
1768                 *fptr = NULL;
1769
1770         return NULL;
1771 }
1772
1773 /* update both kcd->curr.mval and kcd->mval to snap to required angle */
1774 static void knife_snap_angle(KnifeTool_OpData *kcd)
1775 {
1776         float dx, dy;
1777         float w, abs_tan;
1778
1779         dx = kcd->curr.mval[0] - kcd->prev.mval[0];
1780         dy = kcd->curr.mval[1] - kcd->prev.mval[1];
1781         if (dx == 0.0f && dy == 0.0f)
1782                 return;
1783
1784         if (dx == 0.0f) {
1785                 kcd->angle_snapping = ANGLE_90;
1786                 kcd->curr.mval[0] = kcd->prev.mval[0];
1787         }
1788
1789         w = dy / dx;
1790         abs_tan = fabsf(w);
1791         if (abs_tan <= 0.4142f) { /* tan(22.5 degrees) = 0.4142 */
1792                 kcd->angle_snapping = ANGLE_0;
1793                 kcd->curr.mval[1] = kcd->prev.mval[1];
1794         }
1795         else if (abs_tan < 2.4142f) { /* tan(67.5 degrees) = 2.4142 */
1796                 if (w > 0) {
1797                         kcd->angle_snapping = ANGLE_45;
1798                         kcd->curr.mval[1] = kcd->prev.mval[1] + dx;
1799                 }
1800                 else {
1801                         kcd->angle_snapping = ANGLE_135;
1802                         kcd->curr.mval[1] = kcd->prev.mval[1] - dx;
1803                 }
1804         }
1805         else {
1806                 kcd->angle_snapping = ANGLE_90;
1807                 kcd->curr.mval[0] = kcd->prev.mval[0];
1808         }
1809
1810         copy_v2_v2(kcd->mval, kcd->curr.mval);
1811 }
1812
1813 /* update active knife edge/vert pointers */
1814 static int knife_update_active(KnifeTool_OpData *kcd)
1815 {
1816         knife_pos_data_clear(&kcd->curr);
1817         copy_v2_v2(kcd->curr.mval, kcd->mval);
1818
1819         /* view matrix may have changed, reproject */
1820         knife_project_v2(kcd, kcd->prev.co, kcd->prev.mval);
1821
1822         if (kcd->angle_snapping != ANGLE_FREE && kcd->mode == MODE_DRAGGING)
1823                 knife_snap_angle(kcd);
1824
1825         /* XXX knife_snap_angle updates the view coordinate mouse values to constrained angles,
1826          * which current mouse values are set to current mouse values are then used
1827          * for vertex and edge snap detection, without regard to the exact angle constraint */
1828         kcd->curr.vert = knife_find_closest_vert(kcd, kcd->curr.co, kcd->curr.cage, &kcd->curr.bmface, &kcd->curr.is_space);
1829
1830         if (!kcd->curr.vert) {
1831                 kcd->curr.edge = knife_find_closest_edge(kcd, kcd->curr.co, kcd->curr.cage,
1832                                                          &kcd->curr.bmface, &kcd->curr.is_space);
1833         }
1834
1835         /* if no hits are found this would normally default to (0, 0, 0) so instead
1836          * get a point at the mouse ray closest to the previous point.
1837          * Note that drawing lines in `free-space` isn't properly supported
1838          * but theres no guarantee (0, 0, 0) has any geometry either - campbell */
1839         if (kcd->curr.vert == NULL && kcd->curr.edge == NULL && kcd->curr.bmface == NULL) {
1840                 float origin[3];
1841                 float origin_ofs[3];
1842
1843                 knife_input_ray_segment(kcd, kcd->curr.mval, 1.0f, origin, origin_ofs);
1844
1845                 closest_to_line_v3(kcd->curr.cage, kcd->prev.cage, origin_ofs, origin);
1846                 copy_v3_v3(kcd->curr.co, kcd->curr.cage);
1847         }
1848
1849         if (kcd->mode == MODE_DRAGGING) {
1850                 knife_find_line_hits(kcd);
1851         }
1852         return 1;
1853 }
1854
1855 /* sort list of kverts by fraction along edge e */
1856 static void sort_by_frac_along(ListBase *lst, BMEdge *e)
1857 {
1858         /* note, since we know the point is along the edge, sort from distance to v1co */
1859         const float *v1co = e->v1->co;
1860         Ref *cur = NULL, *prev = NULL, *next = NULL;
1861
1862         if (lst->first == lst->last)
1863                 return;
1864
1865         for (cur = ((Ref *)lst->first)->next; cur; cur = next) {
1866                 KnifeVert *vcur = cur->ref;
1867                 const float vcur_fac_sq = len_squared_v3v3(v1co, vcur->co);
1868
1869                 next = cur->next;
1870                 prev = cur->prev;
1871
1872                 BLI_remlink(lst, cur);
1873
1874                 while (prev) {
1875                         KnifeVert *vprev = prev->ref;
1876                         if (len_squared_v3v3(v1co, vprev->co) <= vcur_fac_sq)
1877                                 break;
1878                         prev = prev->prev;
1879                 }
1880
1881                 BLI_insertlinkafter(lst, prev, cur);
1882         }
1883 }
1884
1885 /* The chain so far goes from an instantiated vertex to kfv (some may be reversed).
1886  * If possible, complete the chain to another instantiated vertex and return 1, else return 0.
1887  * The visited hash says which KnifeVert's have already been tried, not including kfv. */
1888 static bool find_chain_search(KnifeTool_OpData *kcd, KnifeVert *kfv, ListBase *fedges, SmallHash *visited,
1889                               ListBase *chain)
1890 {
1891         Ref *r;
1892         KnifeEdge *kfe;
1893         KnifeVert *kfv_other;
1894
1895         if (kfv->v)
1896                 return true;
1897
1898         BLI_smallhash_insert(visited, (uintptr_t)kfv, NULL);
1899         /* Try all possible next edges. Could either go through fedges
1900          * (all the KnifeEdges for the face being cut) or could go through
1901          * kve->edges and restrict to cutting face and uninstantiated edges.
1902          * Not clear which is better. Let's do the first. */
1903         for (r = fedges->first; r; r = r->next) {
1904                 kfe = r->ref;
1905                 kfv_other = NULL;
1906                 if (kfe->v1 == kfv)
1907                         kfv_other = kfe->v2;
1908                 else if (kfe->v2 == kfv)
1909                         kfv_other = kfe->v1;
1910                 if (kfv_other && !BLI_smallhash_haskey(visited, (uintptr_t)kfv_other)) {
1911                         knife_append_list(kcd, chain, kfe);
1912                         if (find_chain_search(kcd, kfv_other, fedges, visited, chain))
1913                                 return true;
1914                         BLI_remlink(chain, chain->last);
1915                 }
1916         }
1917         return false;
1918 }
1919
1920 static ListBase *find_chain_from_vertex(KnifeTool_OpData *kcd, KnifeEdge *kfe, BMVert *v, ListBase *fedges)
1921 {
1922         SmallHash visited_, *visited = &visited_;
1923         ListBase *ans;
1924         bool found;
1925
1926         ans = knife_empty_list(kcd);
1927         knife_append_list(kcd, ans, kfe);
1928         found = false;
1929         BLI_smallhash_init(visited);
1930         if (kfe->v1->v == v) {
1931                 BLI_smallhash_insert(visited, (uintptr_t)(kfe->v1), NULL);
1932                 found = find_chain_search(kcd, kfe->v2, fedges, visited, ans);
1933         }
1934         else {
1935                 BLI_assert(kfe->v2->v == v);
1936                 BLI_smallhash_insert(visited, (uintptr_t)(kfe->v2), NULL);
1937                 found = find_chain_search(kcd, kfe->v1, fedges, visited, ans);
1938         }
1939
1940         BLI_smallhash_release(visited);
1941
1942         if (found)
1943                 return ans;
1944         else
1945                 return NULL;
1946 }
1947
1948 /* Find a chain in fedges from one instantiated vertex to another.
1949  * Remove the edges in the chain from fedges and return a separate list of the chain. */
1950 static ListBase *find_chain(KnifeTool_OpData *kcd, ListBase *fedges)
1951 {
1952         Ref *r, *ref;
1953         KnifeEdge *kfe;
1954         BMVert *v1, *v2;
1955         ListBase *ans;
1956
1957         ans = NULL;
1958
1959         for (r = fedges->first; r; r = r->next) {
1960                 kfe = r->ref;
1961                 v1 = kfe->v1->v;
1962                 v2 = kfe->v2->v;
1963                 if (v1 && v2) {
1964                         ans = knife_empty_list(kcd);
1965                         knife_append_list(kcd, ans, kfe);
1966                         break;
1967                 }
1968                 if (v1)
1969                         ans = find_chain_from_vertex(kcd, kfe, v1, fedges);
1970                 else if (v2)
1971                         ans = find_chain_from_vertex(kcd, kfe, v2, fedges);
1972                 if (ans)
1973                         break;
1974         }
1975         if (ans) {
1976                 BLI_assert(BLI_countlist(ans) > 0);
1977                 for (r = ans->first; r; r = r->next) {
1978                         ref = find_ref(fedges, r->ref);
1979                         BLI_assert(ref != NULL);
1980                         BLI_remlink(fedges, ref);
1981                 }
1982         }
1983         return ans;
1984 }
1985
1986 /* The hole so far goes from kfvfirst to kfv (some may be reversed).
1987  * If possible, complete the hole back to kfvfirst and return 1, else return 0.
1988  * The visited hash says which KnifeVert's have already been tried, not including kfv or kfvfirst. */
1989 static bool find_hole_search(KnifeTool_OpData *kcd, KnifeVert *kfvfirst, KnifeVert *kfv, ListBase *fedges,
1990                              SmallHash *visited, ListBase *hole)
1991 {
1992         Ref *r;
1993         KnifeEdge *kfe, *kfelast;
1994         KnifeVert *kfv_other;
1995
1996         if (kfv == kfvfirst)
1997                 return true;
1998
1999         BLI_smallhash_insert(visited, (uintptr_t)kfv, NULL);
2000         kfelast = ((Ref *)hole->last)->ref;
2001         for (r = fedges->first; r; r = r->next) {
2002                 kfe = r->ref;
2003                 if (kfe == kfelast)
2004                         continue;
2005                 if (kfe->v1->v || kfe->v2->v)
2006                         continue;
2007                 kfv_other = NULL;
2008                 if (kfe->v1 == kfv)
2009                         kfv_other = kfe->v2;
2010                 else if (kfe->v2 == kfv)
2011                         kfv_other = kfe->v1;
2012                 if (kfv_other && !BLI_smallhash_haskey(visited, (uintptr_t)kfv_other)) {
2013                         knife_append_list(kcd, hole, kfe);
2014                         if (find_hole_search(kcd, kfvfirst, kfv_other, fedges, visited, hole))
2015                                 return true;
2016                         BLI_remlink(hole, hole->last);
2017                 }
2018         }
2019         return false;
2020 }
2021
2022 /* Find a hole (simple cycle with no instantiated vertices).
2023  * Remove the edges in the cycle from fedges and return a separate list of the cycle */
2024 static ListBase *find_hole(KnifeTool_OpData *kcd, ListBase *fedges)
2025 {
2026         ListBase *ans;
2027         Ref *r, *ref;
2028         KnifeEdge *kfe;
2029         SmallHash visited_, *visited = &visited_;
2030         bool found;
2031
2032         ans = NULL;
2033         found = false;
2034
2035         for (r = fedges->first; r && !found; r = r->next) {
2036                 kfe = r->ref;
2037                 if (kfe->v1->v || kfe->v2->v || kfe->v1 == kfe->v2)
2038                         continue;
2039
2040                 BLI_smallhash_init(visited);
2041                 ans = knife_empty_list(kcd);
2042                 knife_append_list(kcd, ans, kfe);
2043
2044                 found = find_hole_search(kcd, kfe->v1, kfe->v2, fedges, visited, ans);
2045
2046                 BLI_smallhash_release(visited);
2047         }
2048
2049         if (found) {
2050                 for (r = ans->first; r; r = r->next) {
2051                         kfe = r->ref;
2052                         ref = find_ref(fedges, r->ref);
2053                         if (ref)
2054                                 BLI_remlink(fedges, ref);
2055                 }
2056                 return ans;
2057         }
2058         else {
2059                 return NULL;
2060         }
2061 }
2062
2063 /* Try to find "nice" diagonals - short, and far apart from each other.
2064  * If found, return true and make a 'main chain' going across f which uses
2065  * the two diagonals and one part of the hole, and a 'side chain' that
2066  * completes the hole. */
2067 static bool find_hole_chains(KnifeTool_OpData *kcd, ListBase *hole, BMFace *f, ListBase **mainchain,
2068                              ListBase **sidechain)
2069 {
2070         float **fco, **hco;
2071         BMVert **fv;
2072         KnifeVert **hv;
2073         KnifeEdge **he;
2074         Ref *r;
2075         KnifeVert *kfv, *kfvother;
2076         KnifeEdge *kfe;
2077         ListBase *chain;
2078         BMVert *v;
2079         BMIter iter;
2080         int nh, nf, i, j, k, m, ax, ay, sep = 0 /* Quite warnings */, bestsep;
2081         int besti[2], bestj[2];
2082         float dist_sq, dist_best_sq;
2083
2084         nh = BLI_countlist(hole);
2085         nf = f->len;
2086         if (nh < 2 || nf < 3)
2087                 return false;
2088
2089         /* Gather 2d projections of hole and face vertex coordinates.
2090          * Use best-axis projection - not completely accurate, maybe revisit */
2091         axis_dominant_v3(&ax, &ay, f->no);
2092         hco = BLI_memarena_alloc(kcd->arena, nh * sizeof(float *));
2093         fco = BLI_memarena_alloc(kcd->arena, nf * sizeof(float *));
2094         hv = BLI_memarena_alloc(kcd->arena, nh * sizeof(KnifeVert *));
2095         fv = BLI_memarena_alloc(kcd->arena, nf * sizeof(BMVert *));
2096         he = BLI_memarena_alloc(kcd->arena, nh * sizeof(KnifeEdge *));
2097
2098         i = 0;
2099         kfv = NULL;
2100         kfvother = NULL;
2101         for (r = hole->first; r; r = r->next) {
2102                 kfe = r->ref;
2103                 he[i] = kfe;
2104                 if (kfvother == NULL) {
2105                         kfv = kfe->v1;
2106                 }
2107                 else {
2108                         kfv = kfvother;
2109                         BLI_assert(kfv == kfe->v1 || kfv == kfe->v2);
2110                 }
2111                 hco[i] = BLI_memarena_alloc(kcd->arena, 2 * sizeof(float));
2112                 hco[i][0] = kfv->co[ax];
2113                 hco[i][1] = kfv->co[ay];
2114                 hv[i] = kfv;
2115                 kfvother = (kfe->v1 == kfv) ? kfe->v2 : kfe->v1;
2116                 i++;
2117         }
2118
2119         j = 0;
2120         BM_ITER_ELEM (v, &iter, f, BM_VERTS_OF_FACE) {
2121                 fco[j] = BLI_memarena_alloc(kcd->arena, 2 * sizeof(float));
2122                 fco[j][0] = v->co[ax];
2123                 fco[j][1] = v->co[ay];
2124                 fv[j] = v;
2125                 j++;
2126         }
2127
2128         /* For first diagonal  (m == 0), want shortest length.
2129          * For second diagonal (m == 1), want max separation of index of hole
2130          * vertex from the hole vertex used in the first diagonal, and from there
2131          * want the one with shortest length not to the same vertex as the first diagonal. */
2132         for (m = 0; m < 2; m++) {
2133                 besti[m] = -1;
2134                 bestj[m] = -1;
2135                 dist_best_sq = FLT_MAX;
2136                 bestsep = 0;
2137                 for (i = 0; i < nh; i++) {
2138                         if (m == 1) {
2139                                 if (i == besti[0])
2140                                         continue;
2141                                 sep = (i + nh - besti[0]) % nh;
2142                                 sep = MIN2(sep, nh - sep);
2143                                 if (sep < bestsep)
2144                                         continue;
2145                                 dist_best_sq = FLT_MAX;
2146                         }
2147                         for (j = 0; j < nf; j++) {
2148                                 bool ok;
2149
2150                                 if (m == 1 && j == bestj[0])
2151                                         continue;
2152                                 dist_sq = len_squared_v2v2(hco[i], fco[j]);
2153                                 if (dist_sq > dist_best_sq)
2154                                         continue;
2155
2156                                 ok = true;
2157                                 for (k = 0; k < nh && ok; k++) {
2158                                         if (k == i || (k + 1) % nh == i)
2159                                                 continue;
2160                                         if (isect_line_line_v2(hco[i], fco[j], hco[k], hco[(k + 1) % nh]))
2161                                                 ok = false;
2162                                 }
2163                                 if (!ok)
2164                                         continue;
2165                                 for (k = 0; k < nf && ok; k++) {
2166                                         if (k == j || (k + 1) % nf == j)
2167                                                 continue;
2168                                         if (isect_line_line_v2(hco[i], fco[j], fco[k], fco[(k + 1) % nf]))
2169                                                 ok = false;
2170                                 }
2171                                 if (ok) {
2172                                         besti[m] = i;
2173                                         bestj[m] = j;
2174                                         if (m == 1)
2175                                                 bestsep = sep;
2176                                         dist_best_sq = dist_sq;
2177                                 }
2178                         }
2179                 }
2180         }
2181
2182         if (besti[0] != -1 && besti[1] != -1) {
2183                 BLI_assert(besti[0] != besti[1] && bestj[0] != bestj[1]);
2184                 kfe = new_knife_edge(kcd);
2185                 kfe->v1 = get_bm_knife_vert(kcd, fv[bestj[0]]);
2186                 kfe->v2 = hv[besti[0]];
2187                 chain = knife_empty_list(kcd);
2188                 knife_append_list(kcd, chain, kfe);
2189                 for (i = besti[0]; i != besti[1]; i = (i + 1) % nh) {
2190                         knife_append_list(kcd, chain, he[i]);
2191                 }
2192                 kfe = new_knife_edge(kcd);
2193                 kfe->v1 = hv[besti[1]];
2194                 kfe->v2 = get_bm_knife_vert(kcd, fv[bestj[1]]);
2195                 knife_append_list(kcd, chain, kfe);
2196                 *mainchain = chain;
2197
2198                 chain = knife_empty_list(kcd);
2199                 for (i = besti[1]; i != besti[0]; i = (i + 1) % nh) {
2200                         knife_append_list(kcd, chain, he[i]);
2201                 }
2202                 *sidechain = chain;
2203
2204                 return true;
2205         }
2206         else {
2207                 return false;
2208         }
2209 }
2210
2211 static bool knife_verts_edge_in_face(KnifeVert *v1, KnifeVert *v2, BMFace *f)
2212 {
2213         BMLoop *l1, *l2, *l;
2214         float mid[3];
2215         BMIter iter;
2216         int v1inside, v2inside;
2217
2218         if (!f || !v1 || !v2)
2219                 return false;
2220
2221         l1 = NULL;
2222         l2 = NULL;
2223
2224         /* find out if v1 and v2, if set, are part of the face */
2225         BM_ITER_ELEM (l, &iter, f, BM_LOOPS_OF_FACE) {
2226                 if (v1->v && l->v == v1->v)
2227                         l1 = l;
2228                 if (v2->v && l->v == v2->v)
2229                         l2 = l;
2230         }
2231
2232         /* BM_face_point_inside_test uses best-axis projection so this isn't most accurate test... */
2233         v1inside = l1 ? 0 : BM_face_point_inside_test(f, v1->co);
2234         v2inside = l2 ? 0 : BM_face_point_inside_test(f, v2->co);
2235         if ((l1 && v2inside) || (l2 && v1inside) || (v1inside && v2inside))
2236                 return true;
2237         if (l1 && l2) {
2238                 /* Can have case where v1 and v2 are on shared chain between two faces.
2239                  * BM_face_legal_splits does visibility and self-intersection tests,
2240                  * but it is expensive and maybe a bit buggy, so use a simple
2241                  * "is the midpoint in the face" test */
2242                 mid_v3_v3v3(mid, v1->co, v2->co);
2243                 return BM_face_point_inside_test(f, mid);
2244         }
2245         return false;
2246 }
2247
2248 static bool knife_edge_in_face(KnifeEdge *kfe, BMFace *f)
2249 {
2250         return knife_verts_edge_in_face(kfe->v1, kfe->v2, f);
2251 }
2252
2253 /* Split face f with KnifeEdges on chain.  f remains as one side, the face formed is put in *newface.
2254  * The new face will be on the left side of the chain as viewed from the normal-out side of f. */
2255 static void knife_make_chain_cut(KnifeTool_OpData *kcd, BMFace *f, ListBase *chain, BMFace **r_f_new)
2256 {
2257         BMesh *bm = kcd->em->bm;
2258         KnifeEdge *kfe, *kfelast;
2259         BMVert *v1, *v2;
2260         BMLoop *l_v1, *l_v2;
2261         BMFace *f_new;
2262         Ref *ref;
2263         KnifeVert *kfv, *kfvprev;
2264         BMLoop *l_new, *l_iter;
2265         int i;
2266         int nco = BLI_countlist(chain) - 1;
2267         float (*cos)[3] = BLI_array_alloca(cos, nco);
2268         KnifeVert **kverts = BLI_array_alloca(kverts, nco);
2269
2270         kfe = ((Ref *)chain->first)->ref;
2271         v1 = kfe->v1->v ? kfe->v1->v : kfe->v2->v;
2272         kfelast = ((Ref *)chain->last)->ref;
2273         v2 = kfelast->v2->v ? kfelast->v2->v : kfelast->v1->v;
2274         BLI_assert(v1 != NULL && v2 != NULL);
2275         kfvprev = kfe->v1->v == v1 ? kfe->v1 : kfe->v2;
2276         for (ref = chain->first, i = 0; i < nco && ref != chain->last; ref = ref->next, i++) {
2277                 kfe = ref->ref;
2278                 BLI_assert(kfvprev == kfe->v1 || kfvprev == kfe->v2);
2279                 kfv = kfe->v1 == kfvprev ? kfe->v2 : kfe->v1;
2280                 copy_v3_v3(cos[i], kfv->co);
2281                 kverts[i] = kfv;
2282                 kfvprev = kfv;
2283         }
2284         BLI_assert(i == nco);
2285         l_new = NULL;
2286
2287         if ((l_v1 = BM_face_vert_share_loop(f, v1)) &&
2288             (l_v2 = BM_face_vert_share_loop(f, v2)))
2289         {
2290                 if (nco == 0) {
2291                         /* Want to prevent creating two-sided polygons */
2292                         if (v1 == v2 || BM_edge_exists(v1, v2)) {
2293                                 f_new = NULL;
2294                         }
2295                         else {
2296                                 f_new = BM_face_split(bm, f, l_v1, l_v2, &l_new, NULL, true);
2297                         }
2298                 }
2299                 else {
2300                         f_new = BM_face_split_n(bm, f, l_v1, l_v2, cos, nco, &l_new, NULL);
2301                         if (f_new) {
2302                                 /* Now go through lnew chain matching up chain kv's and assign real v's to them */
2303                                 for (l_iter = l_new->next, i = 0; i < nco; l_iter = l_iter->next, i++) {
2304                                         BLI_assert(equals_v3v3(cos[i], l_iter->v->co));
2305                                         if (kcd->select_result) {
2306                                                 BM_edge_select_set(bm, l_iter->e, true);
2307                                         }
2308                                         kverts[i]->v = l_iter->v;
2309                                 }
2310                         }
2311                 }
2312         }
2313         else {
2314                 f_new = NULL;
2315         }
2316
2317         /* the select chain above doesnt account for the first loop */
2318         if (kcd->select_result) {
2319                 if (l_new) {
2320                         BM_edge_select_set(bm, l_new->e, true);
2321                 }
2322         }
2323         else if (f_new) {
2324                 BM_elem_select_copy(bm, bm, f_new, f);
2325         }
2326
2327         *r_f_new = f_new;
2328 }
2329
2330 static void knife_make_face_cuts(KnifeTool_OpData *kcd, BMFace *f, ListBase *kfedges)
2331 {
2332         BMesh *bm = kcd->em->bm;
2333         KnifeEdge *kfe;
2334         BMFace *fnew, *fnew2, *fhole;
2335         ListBase *chain, *hole, *sidechain;
2336         ListBase *fnew_kfedges, *fnew2_kfedges;
2337         Ref *ref, *refnext;
2338         int count, oldcount;
2339
2340         oldcount = BLI_countlist(kfedges);
2341         while ((chain = find_chain(kcd, kfedges)) != NULL) {
2342                 knife_make_chain_cut(kcd, f, chain, &fnew);
2343                 if (!fnew) {
2344                         return;
2345                 }
2346
2347                 /* Move kfedges to fnew_kfedges if they are now in fnew.
2348                  * The chain edges were removed already */
2349                 fnew_kfedges = knife_empty_list(kcd);
2350                 for (ref = kfedges->first; ref; ref = refnext) {
2351                         kfe = ref->ref;
2352                         refnext = ref->next;
2353                         if (knife_edge_in_face(kfe, fnew)) {
2354                                 BLI_remlink(kfedges, ref);
2355                                 kfe->basef = fnew;
2356                                 knife_append_list(kcd, fnew_kfedges, kfe);
2357                         }
2358                 }
2359                 if (fnew_kfedges->first)
2360                         knife_make_face_cuts(kcd, fnew, fnew_kfedges);
2361
2362                 /* find_chain should always remove edges if it returns true,
2363                  * but guard against infinite loop anyway */
2364                 count = BLI_countlist(kfedges);
2365                 if (count >= oldcount) {
2366                         BLI_assert(!"knife find_chain infinite loop");
2367                         return;
2368                 }
2369                 oldcount = count;
2370         }
2371
2372         while ((hole = find_hole(kcd, kfedges)) != NULL) {
2373                 if (find_hole_chains(kcd, hole, f, &chain, &sidechain)) {
2374                         /* chain goes across f and sidechain comes back
2375                          * from the second last vertex to the second vertex.
2376                          */
2377                         knife_make_chain_cut(kcd, f, chain, &fnew);
2378                         if (!fnew) {
2379                                 BLI_assert(!"knife failed hole cut");
2380                                 return;
2381                         }
2382                         kfe = ((Ref *)sidechain->first)->ref;
2383                         if (knife_edge_in_face(kfe, f)) {
2384                                 knife_make_chain_cut(kcd, f, sidechain, &fnew2);
2385                                 if (fnew2 == NULL) {
2386                                         return;
2387                                 }
2388                                 fhole = f;
2389                         }
2390                         else if (knife_edge_in_face(kfe, fnew)) {
2391                                 knife_make_chain_cut(kcd, fnew, sidechain, &fnew2);
2392                                 if (fnew2 == NULL) {
2393                                         return;
2394                                 }
2395                                 fhole = fnew2;
2396                         }
2397                         else {
2398                                 /* shouldn't happen except in funny edge cases */
2399                                 return;
2400                         }
2401                         BM_face_kill(bm, fhole);
2402                         /* Move kfedges to either fnew or fnew2 if appropriate.
2403                          * The hole edges were removed already */
2404                         fnew_kfedges = knife_empty_list(kcd);
2405                         fnew2_kfedges = knife_empty_list(kcd);
2406                         for (ref = kfedges->first; ref; ref = refnext) {
2407                                 kfe = ref->ref;
2408                                 refnext = ref->next;
2409                                 if (knife_edge_in_face(kfe, fnew)) {
2410                                         BLI_remlink(kfedges, ref);
2411                                         kfe->basef = fnew;
2412                                         knife_append_list(kcd, fnew_kfedges, kfe);
2413                                 }
2414                                 else if (knife_edge_in_face(kfe, fnew2)) {
2415                                         BLI_remlink(kfedges, ref);
2416                                         kfe->basef = fnew2;
2417                                         knife_append_list(kcd, fnew2_kfedges, kfe);
2418                                 }
2419                         }
2420                         /* We'll skip knife edges that are in the newly formed hole.
2421                          * (Maybe we shouldn't have made a hole in the first place?) */
2422                         if (fnew != fhole && fnew_kfedges->first)
2423                                 knife_make_face_cuts(kcd, fnew, fnew_kfedges);
2424                         if (fnew2 != fhole && fnew2_kfedges->first)
2425                                 knife_make_face_cuts(kcd, fnew2, fnew2_kfedges);
2426                         if (f == fhole)
2427                                 break;
2428                         /* find_hole should always remove edges if it returns true,
2429                          * but guard against infinite loop anyway */
2430                         count = BLI_countlist(kfedges);
2431                         if (count >= oldcount) {
2432                                 BLI_assert(!"knife find_hole infinite loop");
2433                                 return;
2434                         }
2435                         oldcount = count;
2436                 }
2437         }
2438 }
2439
2440 /* Use the network of KnifeEdges and KnifeVerts accumulated to make real BMVerts and BMEdedges */
2441 static void knife_make_cuts(KnifeTool_OpData *kcd)
2442 {
2443         BMesh *bm = kcd->em->bm;
2444         KnifeEdge *kfe;
2445         KnifeVert *kfv;
2446         BMFace *f;
2447         BMEdge *e, *enew;
2448         ListBase *lst;
2449         Ref *ref;
2450         float pct;
2451         SmallHashIter hiter;
2452         BLI_mempool_iter iter;
2453         SmallHash fhash_, *fhash = &fhash_;
2454         SmallHash ehash_, *ehash = &ehash_;
2455
2456         BLI_smallhash_init(fhash);
2457         BLI_smallhash_init(ehash);
2458
2459         /* put list of cutting edges for a face into fhash, keyed by face */
2460         BLI_mempool_iternew(kcd->kedges, &iter);
2461         for (kfe = BLI_mempool_iterstep(&iter); kfe; kfe = BLI_mempool_iterstep(&iter)) {
2462                 f = kfe->basef;
2463                 if (!f || kfe->e)
2464                         continue;
2465                 lst = BLI_smallhash_lookup(fhash, (uintptr_t)f);
2466                 if (!lst) {
2467                         lst = knife_empty_list(kcd);
2468                         BLI_smallhash_insert(fhash, (uintptr_t)f, lst);
2469                 }
2470                 knife_append_list(kcd, lst, kfe);
2471         }
2472
2473         /* put list of splitting vertices for an edge into ehash, keyed by edge */
2474         BLI_mempool_iternew(kcd->kverts, &iter);
2475         for (kfv = BLI_mempool_iterstep(&iter); kfv; kfv = BLI_mempool_iterstep(&iter)) {
2476                 if (kfv->v)
2477                         continue;  /* already have a BMVert */
2478                 for (ref = kfv->edges.first; ref; ref = ref->next) {
2479                         kfe = ref->ref;
2480                         e = kfe->e;
2481                         if (!e)
2482                                 continue;
2483                         lst = BLI_smallhash_lookup(ehash, (uintptr_t)e);
2484                         if (!lst) {
2485                                 lst = knife_empty_list(kcd);
2486                                 BLI_smallhash_insert(ehash, (uintptr_t)e, lst);
2487                         }
2488                         /* there can be more than one kfe in kfv's list with same e */
2489                         if (!find_ref(lst, kfv))
2490                                 knife_append_list(kcd, lst, kfv);
2491                 }
2492         }
2493
2494         /* split bmesh edges where needed */
2495         for (lst = BLI_smallhash_iternew(ehash, &hiter, (uintptr_t *)&e); lst;
2496              lst = BLI_smallhash_iternext(&hiter, (uintptr_t *)&e))
2497         {
2498                 sort_by_frac_along(lst, e);
2499                 for (ref = lst->first; ref; ref = ref->next) {
2500                         kfv = ref->ref;
2501                         pct = line_point_factor_v3(kfv->co, e->v1->co, e->v2->co);
2502                         kfv->v = BM_edge_split(bm, e, e->v1, &enew, pct);
2503                 }
2504         }
2505
2506         if (kcd->only_select) {
2507                 EDBM_flag_disable_all(kcd->em, BM_ELEM_SELECT);
2508         }
2509
2510         /* do cuts for each face */
2511         for (lst = BLI_smallhash_iternew(fhash, &hiter, (uintptr_t *)&f); lst;
2512              lst = BLI_smallhash_iternext(&hiter, (uintptr_t *)&f))
2513         {
2514                 knife_make_face_cuts(kcd, f, lst);
2515         }
2516
2517         BLI_smallhash_release(fhash);
2518         BLI_smallhash_release(ehash);
2519 }
2520
2521 /* called on tool confirmation */
2522 static void knifetool_finish_ex(KnifeTool_OpData *kcd)
2523 {
2524         knife_make_cuts(kcd);
2525
2526         EDBM_selectmode_flush(kcd->em);
2527         EDBM_mesh_normals_update(kcd->em);
2528         EDBM_update_generic(kcd->em, true, true);
2529 }
2530 static void knifetool_finish(wmOperator *op)
2531 {
2532         KnifeTool_OpData *kcd = op->customdata;
2533         knifetool_finish_ex(kcd);
2534 }
2535
2536 static void knife_recalc_projmat(KnifeTool_OpData *kcd)
2537 {
2538         invert_m4_m4(kcd->ob->imat, kcd->ob->obmat);
2539         ED_view3d_ob_project_mat_get(kcd->ar->regiondata, kcd->ob, kcd->projmat);
2540         //mul_m4_m4m4(kcd->projmat, kcd->vc.rv3d->winmat, kcd->vc.rv3d->viewmat);
2541
2542         kcd->is_ortho = ED_view3d_clip_range_get(kcd->vc.v3d, kcd->vc.rv3d,
2543                                                  &kcd->clipsta, &kcd->clipend, true);
2544 }
2545
2546 /* called when modal loop selection is done... */
2547 static void knifetool_exit_ex(bContext *C, KnifeTool_OpData *kcd)
2548 {
2549         if (!kcd)
2550                 return;
2551
2552         if (kcd->is_interactive) {
2553                 WM_cursor_modal_restore(CTX_wm_window(C));
2554
2555                 /* deactivate the extra drawing stuff in 3D-View */
2556                 ED_region_draw_cb_exit(kcd->ar->type, kcd->draw_handle);
2557         }
2558
2559         /* free the custom data */
2560         BLI_mempool_destroy(kcd->refs);
2561         BLI_mempool_destroy(kcd->kverts);
2562         BLI_mempool_destroy(kcd->kedges);
2563
2564         BLI_ghash_free(kcd->origedgemap, NULL, NULL);
2565         BLI_ghash_free(kcd->origvertmap, NULL, NULL);
2566         BLI_ghash_free(kcd->kedgefacemap, NULL, NULL);
2567         BLI_ghash_free(kcd->facetrimap, NULL, NULL);
2568
2569         BKE_bmbvh_free(kcd->bmbvh);
2570         BLI_memarena_free(kcd->arena);
2571
2572         /* tag for redraw */
2573         ED_region_tag_redraw(kcd->ar);
2574
2575         if (kcd->cagecos)
2576                 MEM_freeN((void *)kcd->cagecos);
2577
2578         if (kcd->linehits)
2579                 MEM_freeN(kcd->linehits);
2580
2581         /* destroy kcd itself */
2582         MEM_freeN(kcd);
2583 }
2584 static void knifetool_exit(bContext *C, wmOperator *op)
2585 {
2586         KnifeTool_OpData *kcd = op->customdata;
2587         knifetool_exit_ex(C, kcd);
2588         op->customdata = NULL;
2589 }
2590
2591 static void knifetool_update_mval(KnifeTool_OpData *kcd, const float mval[2])
2592 {
2593         knife_recalc_projmat(kcd);
2594         copy_v2_v2(kcd->mval, mval);
2595
2596         if (knife_update_active(kcd)) {
2597                 ED_region_tag_redraw(kcd->ar);
2598         }
2599 }
2600
2601 static void knifetool_update_mval_i(KnifeTool_OpData *kcd, const int mval_i[2])
2602 {
2603         float mval[2] = {UNPACK2(mval_i)};
2604         knifetool_update_mval(kcd, mval);
2605 }
2606
2607 /* called when modal loop selection gets set up... */
2608 static void knifetool_init(bContext *C, KnifeTool_OpData *kcd,
2609                            const bool only_select, const bool cut_through, const bool is_interactive)
2610 {
2611         Scene *scene = CTX_data_scene(C);
2612         Object *obedit = CTX_data_edit_object(C);
2613
2614         /* assign the drawing handle for drawing preview line... */
2615         kcd->ob = obedit;
2616         kcd->ar = CTX_wm_region(C);
2617
2618         em_setup_viewcontext(C, &kcd->vc);
2619
2620         kcd->em = BKE_editmesh_from_object(kcd->ob);
2621
2622         BM_mesh_elem_index_ensure(kcd->em->bm, BM_VERT);
2623
2624         kcd->cagecos = (const float (*)[3])BKE_editmesh_vertexCos_get(kcd->em, scene, NULL);
2625
2626         kcd->bmbvh = BKE_bmbvh_new_from_editmesh(kcd->em,
2627                                                  BMBVH_RETURN_ORIG |
2628                                                  (only_select ? BMBVH_RESPECT_SELECT : BMBVH_RESPECT_HIDDEN),
2629                                                  kcd->cagecos, false);
2630
2631         kcd->arena = BLI_memarena_new(MEM_SIZE_OPTIMAL(1 << 15), "knife");
2632         kcd->vthresh = KMAXDIST - 1;
2633         kcd->ethresh = KMAXDIST;
2634
2635         knife_recalc_projmat(kcd);
2636
2637         ED_region_tag_redraw(kcd->ar);
2638
2639         kcd->refs = BLI_mempool_create(sizeof(Ref), 0, 2048, 0);
2640         kcd->kverts = BLI_mempool_create(sizeof(KnifeVert), 0, 512, BLI_MEMPOOL_ALLOW_ITER);
2641         kcd->kedges = BLI_mempool_create(sizeof(KnifeEdge), 0, 512, BLI_MEMPOOL_ALLOW_ITER);
2642
2643         kcd->origedgemap = BLI_ghash_ptr_new("knife origedgemap");
2644         kcd->origvertmap = BLI_ghash_ptr_new("knife origvertmap");
2645         kcd->kedgefacemap = BLI_ghash_ptr_new("knife kedgefacemap");
2646         kcd->facetrimap = BLI_ghash_ptr_new("knife facetrimap");
2647
2648         /* cut all the way through the mesh if use_occlude_geometry button not pushed */
2649         kcd->is_interactive = is_interactive;
2650         kcd->cut_through = cut_through;
2651         kcd->only_select = only_select;
2652
2653         /* can't usefully select resulting edges in face mode */
2654         kcd->select_result = (kcd->em->selectmode != SCE_SELECT_FACE);
2655
2656         knife_pos_data_clear(&kcd->curr);
2657         knife_pos_data_clear(&kcd->prev);
2658
2659         if (is_interactive) {
2660                 kcd->draw_handle = ED_region_draw_cb_activate(kcd->ar->type, knifetool_draw, kcd, REGION_DRAW_POST_VIEW);
2661
2662                 knife_init_colors(&kcd->colors);
2663         }
2664 }
2665
2666 static void knifetool_cancel(bContext *C, wmOperator *op)
2667 {
2668         /* this is just a wrapper around exit() */
2669         knifetool_exit(C, op);
2670 }
2671
2672 static int knifetool_invoke(bContext *C, wmOperator *op, const wmEvent *event)
2673 {
2674         const bool only_select = RNA_boolean_get(op->ptr, "only_selected");
2675         const bool cut_through = !RNA_boolean_get(op->ptr, "use_occlude_geometry");
2676
2677         KnifeTool_OpData *kcd;
2678
2679         if (only_select) {
2680                 Object *obedit = CTX_data_edit_object(C);
2681                 BMEditMesh *em = BKE_editmesh_from_object(obedit);
2682                 if (em->bm->totfacesel == 0) {
2683                         BKE_report(op->reports, RPT_ERROR, "Selected faces required");
2684                         return OPERATOR_CANCELLED;
2685                 }
2686         }
2687
2688         view3d_operator_needs_opengl(C);
2689
2690         /* alloc new customdata */
2691         kcd = op->customdata = MEM_callocN(sizeof(KnifeTool_OpData), __func__);
2692
2693         knifetool_init(C, kcd, only_select, cut_through, true);
2694
2695         /* add a modal handler for this operator - handles loop selection */
2696         WM_cursor_modal_set(CTX_wm_window(C), BC_KNIFECURSOR);
2697         WM_event_add_modal_handler(C, op);
2698
2699         knifetool_update_mval_i(kcd, event->mval);
2700
2701         knife_update_header(C, kcd);
2702
2703         return OPERATOR_RUNNING_MODAL;
2704 }
2705
2706 enum {
2707         KNF_MODAL_CANCEL = 1,
2708         KNF_MODAL_CONFIRM,
2709         KNF_MODAL_MIDPOINT_ON,
2710         KNF_MODAL_MIDPOINT_OFF,
2711         KNF_MODAL_NEW_CUT,
2712         KNF_MODEL_IGNORE_SNAP_ON,
2713         KNF_MODEL_IGNORE_SNAP_OFF,
2714         KNF_MODAL_ADD_CUT,
2715         KNF_MODAL_ANGLE_SNAP_TOGGLE,
2716         KNF_MODAL_CUT_THROUGH_TOGGLE,
2717         KNF_MODAL_PANNING
2718 };
2719
2720 wmKeyMap *knifetool_modal_keymap(wmKeyConfig *keyconf)
2721 {
2722         static EnumPropertyItem modal_items[] = {
2723                 {KNF_MODAL_CANCEL, "CANCEL", 0, "Cancel", ""},
2724                 {KNF_MODAL_CONFIRM, "CONFIRM", 0, "Confirm", ""},
2725                 {KNF_MODAL_MIDPOINT_ON, "SNAP_MIDPOINTS_ON", 0, "Snap To Midpoints On", ""},
2726                 {KNF_MODAL_MIDPOINT_OFF, "SNAP_MIDPOINTS_OFF", 0, "Snap To Midpoints Off", ""},
2727                 {KNF_MODEL_IGNORE_SNAP_ON, "IGNORE_SNAP_ON", 0, "Ignore Snapping On", ""},
2728                 {KNF_MODEL_IGNORE_SNAP_OFF, "IGNORE_SNAP_OFF", 0, "Ignore Snapping Off", ""},
2729                 {KNF_MODAL_ANGLE_SNAP_TOGGLE, "ANGLE_SNAP_TOGGLE", 0, "Toggle Angle Snapping", ""},
2730                 {KNF_MODAL_CUT_THROUGH_TOGGLE, "CUT_THROUGH_TOGGLE", 0, "Toggle Cut Through", ""},
2731                 {KNF_MODAL_NEW_CUT, "NEW_CUT", 0, "End Current Cut", ""},
2732                 {KNF_MODAL_ADD_CUT, "ADD_CUT", 0, "Add Cut", ""},
2733                 {KNF_MODAL_PANNING, "PANNING", 0, "Panning", ""},
2734                 {0, NULL, 0, NULL, NULL}
2735         };
2736
2737         wmKeyMap *keymap = WM_modalkeymap_get(keyconf, "Knife Tool Modal Map");
2738
2739         /* this function is called for each spacetype, only needs to add map once */
2740         if (keymap && keymap->modal_items)
2741                 return NULL;
2742
2743         keymap = WM_modalkeymap_add(keyconf, "Knife Tool Modal Map", modal_items);
2744
2745         /* items for modal map */
2746         WM_modalkeymap_add_item(keymap, ESCKEY, KM_PRESS, KM_ANY, 0, KNF_MODAL_CANCEL);
2747         WM_modalkeymap_add_item(keymap, MIDDLEMOUSE, KM_ANY, KM_ANY, 0, KNF_MODAL_PANNING);
2748         WM_modalkeymap_add_item(keymap, LEFTMOUSE, KM_PRESS, KM_ANY, 0, KNF_MODAL_ADD_CUT);
2749         WM_modalkeymap_add_item(keymap, RIGHTMOUSE, KM_PRESS, KM_ANY, 0, KNF_MODAL_CANCEL);
2750         WM_modalkeymap_add_item(keymap, RETKEY, KM_PRESS, KM_ANY, 0, KNF_MODAL_CONFIRM);
2751         WM_modalkeymap_add_item(keymap, PADENTER, KM_PRESS, KM_ANY, 0, KNF_MODAL_CONFIRM);
2752         WM_modalkeymap_add_item(keymap, SPACEKEY, KM_PRESS, KM_ANY, 0, KNF_MODAL_CONFIRM);
2753         WM_modalkeymap_add_item(keymap, EKEY, KM_PRESS, 0, 0, KNF_MODAL_NEW_CUT);
2754
2755         WM_modalkeymap_add_item(keymap, LEFTCTRLKEY, KM_PRESS, KM_ANY, 0, KNF_MODAL_MIDPOINT_ON);
2756         WM_modalkeymap_add_item(keymap, LEFTCTRLKEY, KM_RELEASE, KM_ANY, 0, KNF_MODAL_MIDPOINT_OFF);
2757         WM_modalkeymap_add_item(keymap, RIGHTCTRLKEY, KM_PRESS, KM_ANY, 0, KNF_MODAL_MIDPOINT_ON);
2758         WM_modalkeymap_add_item(keymap, RIGHTCTRLKEY, KM_RELEASE, KM_ANY, 0, KNF_MODAL_MIDPOINT_OFF);
2759
2760         WM_modalkeymap_add_item(keymap, LEFTSHIFTKEY, KM_PRESS, KM_ANY, 0, KNF_MODEL_IGNORE_SNAP_ON);
2761         WM_modalkeymap_add_item(keymap, LEFTSHIFTKEY, KM_RELEASE, KM_ANY, 0, KNF_MODEL_IGNORE_SNAP_OFF);
2762         WM_modalkeymap_add_item(keymap, RIGHTSHIFTKEY, KM_PRESS, KM_ANY, 0, KNF_MODEL_IGNORE_SNAP_ON);
2763         WM_modalkeymap_add_item(keymap, RIGHTSHIFTKEY, KM_RELEASE, KM_ANY, 0, KNF_MODEL_IGNORE_SNAP_OFF);
2764
2765         WM_modalkeymap_add_item(keymap, CKEY, KM_PRESS, 0, 0, KNF_MODAL_ANGLE_SNAP_TOGGLE);
2766         WM_modalkeymap_add_item(keymap, ZKEY, KM_PRESS, 0, 0, KNF_MODAL_CUT_THROUGH_TOGGLE);
2767
2768         WM_modalkeymap_assign(keymap, "MESH_OT_knife_tool");
2769
2770         return keymap;
2771 }
2772
2773 static int knifetool_modal(bContext *C, wmOperator *op, const wmEvent *event)
2774 {
2775         Object *obedit = CTX_data_edit_object(C);
2776         KnifeTool_OpData *kcd = op->customdata;
2777         bool do_refresh = false;
2778
2779         if (!obedit || obedit->type != OB_MESH || BKE_editmesh_from_object(obedit) != kcd->em) {
2780                 knifetool_exit(C, op);
2781                 ED_area_headerprint(CTX_wm_area(C), NULL);
2782                 return OPERATOR_FINISHED;
2783         }
2784
2785         view3d_operator_needs_opengl(C);
2786         ED_view3d_init_mats_rv3d(obedit, kcd->vc.rv3d);  /* needed to initialize clipping */
2787
2788         if (kcd->mode == MODE_PANNING)
2789                 kcd->mode = kcd->prevmode;
2790
2791         /* handle modal keymap */
2792         if (event->type == EVT_MODAL_MAP) {
2793                 switch (event->val) {
2794                         case KNF_MODAL_CANCEL:
2795                                 /* finish */
2796                                 ED_region_tag_redraw(kcd->ar);
2797
2798                                 knifetool_exit(C, op);
2799                                 ED_area_headerprint(CTX_wm_area(C), NULL);
2800
2801                                 return OPERATOR_CANCELLED;
2802                         case KNF_MODAL_CONFIRM:
2803                                 /* finish */
2804                                 ED_region_tag_redraw(kcd->ar);
2805
2806                                 knifetool_finish(op);
2807                                 knifetool_exit(C, op);
2808                                 ED_area_headerprint(CTX_wm_area(C), NULL);
2809
2810                                 return OPERATOR_FINISHED;
2811                         case KNF_MODAL_MIDPOINT_ON:
2812                                 kcd->snap_midpoints = true;
2813
2814                                 knife_recalc_projmat(kcd);
2815                                 knife_update_active(kcd);
2816                                 knife_update_header(C, kcd);
2817                                 ED_region_tag_redraw(kcd->ar);
2818                                 do_refresh = true;
2819                                 break;
2820                         case KNF_MODAL_MIDPOINT_OFF:
2821                                 kcd->snap_midpoints = false;
2822
2823                                 knife_recalc_projmat(kcd);
2824                                 knife_update_active(kcd);
2825                                 knife_update_header(C, kcd);
2826                                 ED_region_tag_redraw(kcd->ar);
2827                                 do_refresh = true;
2828                                 break;
2829                         case KNF_MODEL_IGNORE_SNAP_ON:
2830                                 ED_region_tag_redraw(kcd->ar);
2831                                 kcd->ignore_vert_snapping = kcd->ignore_edge_snapping = true;
2832                                 knife_update_header(C, kcd);
2833                                 do_refresh = true;
2834                                 break;
2835                         case KNF_MODEL_IGNORE_SNAP_OFF:
2836                                 ED_region_tag_redraw(kcd->ar);
2837                                 kcd->ignore_vert_snapping = kcd->ignore_edge_snapping = false;
2838                                 knife_update_header(C, kcd);
2839                                 do_refresh = true;
2840                                 break;
2841                         case KNF_MODAL_ANGLE_SNAP_TOGGLE:
2842                                 kcd->angle_snapping = !kcd->angle_snapping;
2843                                 knife_update_header(C, kcd);
2844                                 do_refresh = true;
2845                                 break;
2846                         case KNF_MODAL_CUT_THROUGH_TOGGLE:
2847                                 kcd->cut_through = !kcd->cut_through;
2848                                 knife_update_header(C, kcd);
2849                                 do_refresh = true;
2850                                 break;
2851                         case KNF_MODAL_NEW_CUT:
2852                                 ED_region_tag_redraw(kcd->ar);
2853                                 knife_finish_cut(kcd);
2854                                 kcd->mode = MODE_IDLE;
2855                                 break;
2856                         case KNF_MODAL_ADD_CUT:
2857                                 knife_recalc_projmat(kcd);
2858
2859                                 if (kcd->mode == MODE_DRAGGING) {
2860                                         knife_add_cut(kcd);
2861                                 }
2862                                 else if (kcd->mode != MODE_PANNING) {
2863                                         knife_start_cut(kcd);
2864                                         kcd->mode = MODE_DRAGGING;
2865                                 }
2866
2867                                 ED_region_tag_redraw(kcd->ar);
2868                                 break;
2869                         case KNF_MODAL_PANNING:
2870                                 if (event->val != KM_RELEASE) {
2871                                         if (kcd->mode != MODE_PANNING) {
2872                                                 kcd->prevmode = kcd->mode;
2873                                                 kcd->mode = MODE_PANNING;
2874                                         }
2875                                 }
2876                                 else {
2877                                         kcd->mode = kcd->prevmode;
2878                                 }
2879
2880                                 ED_region_tag_redraw(kcd->ar);
2881                                 return OPERATOR_PASS_THROUGH;
2882                 }
2883         }
2884         else { /* non-modal-mapped events */
2885                 switch (event->type) {
2886                         case MOUSEPAN:
2887                         case MOUSEZOOM:
2888                         case MOUSEROTATE:
2889                         case WHEELUPMOUSE:
2890                         case WHEELDOWNMOUSE:
2891                                 return OPERATOR_PASS_THROUGH;
2892                         case MOUSEMOVE: /* mouse moved somewhere to select another loop */
2893                                 if (kcd->mode != MODE_PANNING) {
2894                                         knifetool_update_mval_i(kcd, event->mval);
2895                                 }
2896
2897                                 break;
2898                 }
2899         }
2900
2901         if (do_refresh) {
2902                 /* we don't really need to update mval,
2903                  * but this happens to be the best way to refresh at the moment */
2904                 knifetool_update_mval_i(kcd, event->mval);
2905         }
2906
2907         /* keep going until the user confirms */
2908         return OPERATOR_RUNNING_MODAL;
2909 }
2910
2911 void MESH_OT_knife_tool(wmOperatorType *ot)
2912 {
2913         /* description */
2914         ot->name = "Knife Topology Tool";
2915         ot->idname = "MESH_OT_knife_tool";
2916         ot->description = "Cut new topology";
2917
2918         /* callbacks */
2919         ot->invoke = knifetool_invoke;
2920         ot->modal = knifetool_modal;
2921         ot->cancel = knifetool_cancel;
2922         ot->poll = ED_operator_editmesh_view3d;
2923
2924         /* flags */
2925         ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_BLOCKING;
2926
2927         RNA_def_boolean(ot->srna, "use_occlude_geometry", true, "Occlude Geometry", "Only cut the front most geometry");
2928         RNA_def_boolean(ot->srna, "only_selected", false, "Only Selected", "Only cut selected geometry");
2929 }
2930
2931
2932 /* -------------------------------------------------------------------- */
2933 /* Knife tool as a utility function
2934  * that can be used for internal slicing operations */
2935
2936 /**
2937  * Return a point inside the face.
2938  *
2939  * tessellation here seems way overkill,
2940  * but without this its very hard to know of a point is inside the face
2941  */
2942 static void edvm_mesh_knife_face_point(BMFace *f, float r_cent[3])
2943 {
2944         const int tottri = f->len - 2;
2945         BMLoop **loops = BLI_array_alloca(loops, f->len);
2946         unsigned int  (*index)[3] = BLI_array_alloca(index, tottri);
2947         int j;
2948
2949         const float *best_co[3] = {NULL};
2950         float best_area  = -1.0f;
2951         bool ok = false;
2952
2953         BM_face_calc_tessellation(f, loops, index);
2954
2955         for (j = 0; j < tottri; j++) {
2956                 const float *p1 = loops[index[j][0]]->v->co;
2957                 const float *p2 = loops[index[j][1]]->v->co;
2958                 const float *p3 = loops[index[j][2]]->v->co;
2959                 float area;
2960
2961                 float cross[3];
2962                 cross_v3_v3v3(cross, p2, p3);
2963                 area = fabsf(dot_v3v3(p1, cross));
2964                 if (area > best_area) {
2965                         best_co[0] = p1;
2966                         best_co[1] = p2;
2967                         best_co[2] = p3;
2968                         best_area = area;
2969                         ok = true;
2970                 }
2971         }
2972
2973         if (ok) {
2974                 mid_v3_v3v3v3(r_cent, best_co[0], best_co[1], best_co[2]);
2975         }
2976         else {
2977                 mid_v3_v3v3v3(r_cent, loops[0]->v->co, loops[1]->v->co, loops[2]->v->co);
2978         }
2979 }
2980
2981 static bool edbm_mesh_knife_face_isect(ARegion *ar, LinkNode *polys, BMFace *f, float projmat[4][4])
2982 {
2983         float cent_ss[2];
2984         float cent[3];
2985
2986         edvm_mesh_knife_face_point(f, cent);
2987
2988         ED_view3d_project_float_v2_m4(ar, cent, cent_ss, projmat);
2989
2990         /* check */
2991         {
2992                 LinkNode *p = polys;
2993                 int isect = 0;
2994
2995                 while (p) {
2996                         const float (*mval_fl)[2] = p->link;
2997                         const int mval_tot = MEM_allocN_len(mval_fl) / sizeof(*mval_fl);
2998                         isect += (int)isect_point_poly_v2(cent_ss, mval_fl, mval_tot - 1, false);
2999                         p = p->next;
3000                 }
3001
3002                 if (isect % 2) {
3003                         return true;
3004                 }
3005         }
3006
3007         return false;
3008 }
3009
3010 /**
3011  * \param use_tag  When set, tag all faces inside the polylines.
3012  */
3013 void EDBM_mesh_knife(bContext *C, LinkNode *polys, bool use_tag, bool cut_through)
3014 {
3015         KnifeTool_OpData *kcd;
3016
3017         view3d_operator_needs_opengl(C);
3018
3019         /* init */
3020         {
3021                 const bool only_select = false;
3022                 const bool is_interactive = false;  /* can enable for testing */
3023
3024                 kcd = MEM_callocN(sizeof(KnifeTool_OpData), __func__);
3025
3026                 knifetool_init(C, kcd, only_select, cut_through, is_interactive);
3027
3028                 kcd->ignore_edge_snapping = true;
3029                 kcd->ignore_vert_snapping = true;
3030
3031                 if (use_tag) {
3032                         BM_mesh_elem_hflag_enable_all(kcd->em->bm, BM_EDGE, BM_ELEM_TAG, false);
3033                 }
3034         }
3035
3036         /* execute */
3037         {
3038                 LinkNode *p = polys;
3039
3040                 knife_recalc_projmat(kcd);
3041
3042                 while (p) {
3043                         const float (*mval_fl)[2] = p->link;
3044                         const int mval_tot = MEM_allocN_len(mval_fl) / sizeof(*mval_fl);
3045                         int i;
3046
3047                         for (i = 0; i < mval_tot; i++) {
3048                                 knifetool_update_mval(kcd, mval_fl[i]);
3049                                 if (i == 0) {
3050                                         knife_start_cut(kcd);
3051                                         kcd->mode = MODE_DRAGGING;
3052                                 }
3053                                 else {
3054                                         knife_add_cut(kcd);
3055                                 }
3056                         }
3057                         knife_finish_cut(kcd);
3058                         kcd->mode = MODE_IDLE;
3059                         p = p->next;
3060                 }
3061         }
3062
3063         /* finish */
3064         {
3065                 knifetool_finish_ex(kcd);
3066
3067                 /* tag faces inside! */
3068                 if (use_tag) {
3069                         BMesh *bm = kcd->em->bm;
3070                         float projmat[4][4];
3071