add linklist stack macros, use where over allocating an array was previously done.
[blender-staging.git] / source / blender / bmesh / operators / bmo_connect_nonplanar.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  * Contributor(s): Campbell Barton
19  *
20  * ***** END GPL LICENSE BLOCK *****
21  */
22
23 /** \file blender/bmesh/operators/bmo_connect_nonplanar.c
24  *  \ingroup bmesh
25  *
26  * Connect verts non-planer faces iteratively (splits faces).
27  */
28
29 #include "MEM_guardedalloc.h"
30
31 #include "BLI_math.h"
32 #include "BLI_utildefines.h"
33 #include "BLI_alloca.h"
34 #include "BLI_linklist_stack.h"
35
36 #include "bmesh.h"
37
38 #include "intern/bmesh_operators_private.h" /* own include */
39
40 #define EDGE_OUT        (1 << 0)
41 #define FACE_OUT        (1 << 1)
42
43 /**
44  * Calculates the face subset normal.
45  */
46 static bool bm_face_subset_calc_normal(BMLoop *l_first, BMLoop *l_last, float r_no[3])
47 {
48         float const *v_prev, *v_curr;
49
50         /* Newell's Method */
51         BMLoop *l_iter = l_first;
52         BMLoop *l_term = l_last->next;
53
54         zero_v3(r_no);
55
56         v_prev = l_last->v->co;
57         do {
58                 v_curr = l_iter->v->co;
59                 add_newell_cross_v3_v3v3(r_no, v_prev, v_curr);
60                 v_prev = v_curr;
61         } while ((l_iter = l_iter->next) != l_term);
62
63         return (normalize_v3(r_no) != 0.0f);
64 }
65
66 /**
67  * Calculates how non-planar the face subset is.
68  */
69 static float bm_face_subset_calc_planar(BMLoop *l_first, BMLoop *l_last, const float no[3])
70 {
71         float axis_mat[3][3];
72         float z_prev, z_curr;
73         float delta_z = 0.0f;
74
75         /* Newell's Method */
76         BMLoop *l_iter = l_first;
77         BMLoop *l_term = l_last->next;
78
79         axis_dominant_v3_to_m3(axis_mat, no);
80
81         z_prev = dot_m3_v3_row_z(axis_mat, l_last->v->co);
82         do {
83                 z_curr = dot_m3_v3_row_z(axis_mat, l_iter->v->co);
84                 delta_z += fabsf(z_curr - z_prev);
85                 z_prev = z_curr;
86         } while ((l_iter = l_iter->next) != l_term);
87
88         return delta_z;
89 }
90
91 static bool bm_face_split_find(BMFace *f, BMVert *v_pair[2], float *r_angle)
92 {
93         BMLoop *l_iter, *l_first;
94         BMLoop **l_arr = BLI_array_alloca(l_arr, f->len);
95         const unsigned int f_len = f->len;
96         unsigned int i_a, i_b;
97         bool found = false;
98
99         /* angle finding */
100         float err_best = FLT_MAX;
101         float angle_best = FLT_MAX;
102
103         l_iter = l_first = BM_FACE_FIRST_LOOP(f);
104         i_a = 0;
105         do {
106                 l_arr[i_a++] = l_iter;
107         } while ((l_iter = l_iter->next) != l_first);
108
109         /* now for the big search, O(N^2), however faces normally aren't so large */
110         for (i_a = 0; i_a < f_len; i_a++) {
111                 BMLoop *l_a = l_arr[i_a];
112                 for (i_b = i_a + 2; i_b < f_len; i_b++) {
113                         BMLoop *l_b = l_arr[i_b];
114                         /* check these are not touching
115                          * (we could be smarter here) */
116                         if ((l_a->next != l_b) &&
117                             (l_a->prev != l_b))
118                         {
119                                 /* first calculate normals */
120                                 float no_a[3], no_b[3];
121
122                                 if (bm_face_subset_calc_normal(l_a, l_b, no_a) &&
123                                     bm_face_subset_calc_normal(l_b, l_a, no_b))
124                                 {
125                                         const float err_a = bm_face_subset_calc_planar(l_a, l_b, no_a);
126                                         const float err_b = bm_face_subset_calc_planar(l_b, l_a, no_b);
127                                         const float err_test = err_a + err_b;
128
129                                         if (err_test < err_best) {
130                                                 /* check we're legal (we could batch this) */
131                                                 BMLoop *l_split[2] = {l_a, l_b};
132                                                 BM_face_legal_splits(f, &l_split, 1);
133                                                 if (l_split[0]) {
134                                                         err_best = err_test;
135                                                         v_pair[0] = l_a->v;
136                                                         v_pair[1] = l_b->v;
137
138                                                         angle_best = angle_normalized_v3v3(no_a, no_b);
139                                                         found = true;
140                                                 }
141                                         }
142                                 }
143                         }
144                 }
145         }
146
147         *r_angle = angle_best;
148
149         return found;
150
151
152 }
153
154 static bool bm_face_split_by_angle(BMesh *bm, BMFace *f, BMFace *r_f_pair[2], const float angle_limit)
155 {
156         BMVert *v_pair[2];
157         float angle;
158
159         if (bm_face_split_find(f, v_pair, &angle) && (angle > angle_limit)) {
160                 BMFace *f_new;
161                 BMLoop *l_new;
162                 f_new = BM_face_split(bm, f, v_pair[0], v_pair[1], &l_new, NULL, false);
163                 if (f_new) {
164                         r_f_pair[0] = f;
165                         r_f_pair[1] = f_new;
166
167                         BMO_elem_flag_enable(bm, f, FACE_OUT);
168                         BMO_elem_flag_enable(bm, f_new, FACE_OUT);
169                         BMO_elem_flag_enable(bm, l_new->e, EDGE_OUT);
170                         return true;
171                 }
172         }
173
174         return false;
175
176 }
177
178 void bmo_connect_verts_nonplanar_exec(BMesh *bm, BMOperator *op)
179 {
180         BMOIter siter;
181         BMFace *f;
182         int totface = 0, totloop = 0;
183         BLI_LINKSTACK_DECLARE(fstack, BMFace *);
184
185         const float angle_limit = BMO_slot_float_get(op->slots_in, "angle_limit");
186
187
188         BMO_ITER (f, &siter, op->slots_in, "faces", BM_FACE) {
189                 if (f->len > 3) {
190                         totface += 1;
191                         totloop += f->len;
192                 }
193         }
194
195         if (totface == 0) {
196                 return;
197         }
198
199         BLI_LINKSTACK_INIT(fstack);
200
201         BMO_ITER (f, &siter, op->slots_in, "faces", BM_FACE) {
202                 if (f->len > 3) {
203                         BLI_LINKSTACK_PUSH(fstack, f);
204                 }
205         }
206
207         while ((f = BLI_LINKSTACK_POP(fstack))) {
208                 BMFace *f_pair[2];
209                 if (bm_face_split_by_angle(bm, f, f_pair, angle_limit)) {
210                         int j;
211                         for (j = 0; j < 2; j++) {
212                                 BM_face_normal_update(f_pair[j]);
213                                 if (f_pair[j]->len > 3) {
214                                         BLI_LINKSTACK_PUSH(fstack, f_pair[j]);
215                                 }
216                         }
217                 }
218         }
219
220         BLI_LINKSTACK_FREE(fstack);
221
222         BMO_slot_buffer_from_enabled_flag(bm, op, op->slots_out, "edges.out", BM_EDGE, EDGE_OUT);
223         BMO_slot_buffer_from_enabled_flag(bm, op, op->slots_out, "faces.out", BM_FACE, FACE_OUT);
224 }