Final fix for [#31017] Particles not generated on Grid Distribution
[blender.git] / source / blender / blenkernel / intern / particle_system.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 by Janne Karhu.
19  * All rights reserved.
20  *
21  * The Original Code is: all of this file.
22  *
23  * Contributor(s): Raul Fernandez Hernandez (Farsthary), Stephen Swhitehorn.
24  *
25  * Adaptive time step
26  * Copyright 2011 AutoCRC
27  *
28  * ***** END GPL LICENSE BLOCK *****
29  */
30
31 /** \file blender/blenkernel/intern/particle_system.c
32  *  \ingroup bke
33  */
34
35
36 #include <stddef.h>
37
38 #include <stdlib.h>
39 #include <math.h>
40 #include <string.h>
41
42 #ifdef _OPENMP
43 #include <omp.h>
44 #endif
45
46 #include "MEM_guardedalloc.h"
47
48 #include "DNA_anim_types.h"
49 #include "DNA_boid_types.h"
50 #include "DNA_particle_types.h"
51 #include "DNA_mesh_types.h"
52 #include "DNA_meshdata_types.h"
53 #include "DNA_modifier_types.h"
54 #include "DNA_object_force.h"
55 #include "DNA_object_types.h"
56 #include "DNA_material_types.h"
57 #include "DNA_curve_types.h"
58 #include "DNA_group_types.h"
59 #include "DNA_scene_types.h"
60 #include "DNA_texture_types.h"
61 #include "DNA_ipo_types.h" // XXX old animation system stuff... to be removed!
62 #include "DNA_listBase.h"
63
64 #include "BLI_edgehash.h"
65 #include "BLI_rand.h"
66 #include "BLI_jitter.h"
67 #include "BLI_math.h"
68 #include "BLI_blenlib.h"
69 #include "BLI_kdtree.h"
70 #include "BLI_kdopbvh.h"
71 #include "BLI_threads.h"
72 #include "BLI_utildefines.h"
73 #include "BLI_linklist.h"
74
75 #include "BKE_main.h"
76 #include "BKE_animsys.h"
77 #include "BKE_boids.h"
78 #include "BKE_cdderivedmesh.h"
79 #include "BKE_collision.h"
80 #include "BKE_displist.h"
81 #include "BKE_effect.h"
82 #include "BKE_particle.h"
83 #include "BKE_global.h"
84
85 #include "BKE_DerivedMesh.h"
86 #include "BKE_object.h"
87 #include "BKE_material.h"
88 #include "BKE_cloth.h"
89 #include "BKE_depsgraph.h"
90 #include "BKE_lattice.h"
91 #include "BKE_pointcache.h"
92 #include "BKE_mesh.h"
93 #include "BKE_modifier.h"
94 #include "BKE_scene.h"
95 #include "BKE_bvhutils.h"
96
97 #include "PIL_time.h"
98
99 #include "RE_shader_ext.h"
100
101 /* fluid sim particle import */
102 #ifdef WITH_MOD_FLUID
103 #include "DNA_object_fluidsim.h"
104 #include "LBM_fluidsim.h"
105 #include <zlib.h>
106 #include <string.h>
107
108 #endif // WITH_MOD_FLUID
109
110 /************************************************/
111 /*                      Reacting to system events                       */
112 /************************************************/
113
114 static int particles_are_dynamic(ParticleSystem *psys)
115 {
116         if (psys->pointcache->flag & PTCACHE_BAKED)
117                 return 0;
118
119         if (psys->part->type == PART_HAIR)
120                 return psys->flag & PSYS_HAIR_DYNAMICS;
121         else
122                 return ELEM3(psys->part->phystype, PART_PHYS_NEWTON, PART_PHYS_BOIDS, PART_PHYS_FLUID);
123 }
124
125 static int psys_get_current_display_percentage(ParticleSystem *psys)
126 {
127         ParticleSettings *part=psys->part;
128
129         if ((psys->renderdata && !particles_are_dynamic(psys)) ||  /* non-dynamic particles can be rendered fully */
130             (part->child_nbr && part->childtype)  ||    /* display percentage applies to children */
131             (psys->pointcache->flag & PTCACHE_BAKING))  /* baking is always done with full amount */
132         {
133                 return 100;
134         }
135
136         return psys->part->disp;
137 }
138
139 static int tot_particles(ParticleSystem *psys, PTCacheID *pid)
140 {
141         if (pid && psys->pointcache->flag & PTCACHE_EXTERNAL)
142                 return pid->cache->totpoint;
143         else if (psys->part->distr == PART_DISTR_GRID && psys->part->from != PART_FROM_VERT)
144                 return psys->part->grid_res * psys->part->grid_res * psys->part->grid_res - psys->totunexist;
145         else
146                 return psys->part->totpart - psys->totunexist;
147 }
148
149 void psys_reset(ParticleSystem *psys, int mode)
150 {
151         PARTICLE_P;
152
153         if (ELEM(mode, PSYS_RESET_ALL, PSYS_RESET_DEPSGRAPH)) {
154                 if (mode == PSYS_RESET_ALL || !(psys->flag & PSYS_EDITED)) {
155                         /* don't free if not absolutely necessary */
156                         if (psys->totpart != tot_particles(psys, NULL)) {
157                                 psys_free_particles(psys);
158                                 psys->totpart= 0;
159                         }
160
161                         psys->totkeyed= 0;
162                         psys->flag &= ~(PSYS_HAIR_DONE|PSYS_KEYED);
163
164                         if (psys->edit && psys->free_edit) {
165                                 psys->free_edit(psys->edit);
166                                 psys->edit = NULL;
167                                 psys->free_edit = NULL;
168                         }
169                 }
170         }
171         else if (mode == PSYS_RESET_CACHE_MISS) {
172                 /* set all particles to be skipped */
173                 LOOP_PARTICLES
174                         pa->flag |= PARS_NO_DISP;
175         }
176
177         /* reset children */
178         if (psys->child) {
179                 MEM_freeN(psys->child);
180                 psys->child= NULL;
181         }
182
183         psys->totchild= 0;
184
185         /* reset path cache */
186         psys_free_path_cache(psys, psys->edit);
187
188         /* reset point cache */
189         BKE_ptcache_invalidate(psys->pointcache);
190
191         if (psys->fluid_springs) {
192                 MEM_freeN(psys->fluid_springs);
193                 psys->fluid_springs = NULL;
194         }
195
196         psys->tot_fluidsprings = psys->alloc_fluidsprings = 0;
197 }
198
199 static void realloc_particles(ParticleSimulationData *sim, int new_totpart)
200 {
201         ParticleSystem *psys = sim->psys;
202         ParticleSettings *part = psys->part;
203         ParticleData *newpars = NULL;
204         BoidParticle *newboids = NULL;
205         PARTICLE_P;
206         int totpart, totsaved = 0;
207
208         if (new_totpart<0) {
209                 if ((part->distr == PART_DISTR_GRID) && (part->from != PART_FROM_VERT)) {
210                         totpart= part->grid_res;
211                         totpart*=totpart*totpart;
212                 }
213                 else
214                         totpart=part->totpart;
215         }
216         else
217                 totpart=new_totpart;
218
219         if (totpart != psys->totpart) {
220                 if (psys->edit && psys->free_edit) {
221                         psys->free_edit(psys->edit);
222                         psys->edit = NULL;
223                         psys->free_edit = NULL;
224                 }
225
226                 if (totpart) {
227                         newpars= MEM_callocN(totpart*sizeof(ParticleData), "particles");
228                         if (newpars == NULL)
229                                 return;
230
231                         if (psys->part->phystype == PART_PHYS_BOIDS) {
232                                 newboids= MEM_callocN(totpart*sizeof(BoidParticle), "boid particles");
233
234                                 if (newboids == NULL) {
235                                          /* allocation error! */
236                                         if (newpars)
237                                                 MEM_freeN(newpars);
238                                         return;
239                                 }
240                         }
241                 }
242         
243                 if (psys->particles) {
244                         totsaved=MIN2(psys->totpart,totpart);
245                         /*save old pars*/
246                         if (totsaved) {
247                                 memcpy(newpars,psys->particles,totsaved*sizeof(ParticleData));
248
249                                 if (psys->particles->boid)
250                                         memcpy(newboids, psys->particles->boid, totsaved*sizeof(BoidParticle));
251                         }
252
253                         if (psys->particles->keys)
254                                 MEM_freeN(psys->particles->keys);
255
256                         if (psys->particles->boid)
257                                 MEM_freeN(psys->particles->boid);
258
259                         for (p=0, pa=newpars; p<totsaved; p++, pa++) {
260                                 if (pa->keys) {
261                                         pa->keys= NULL;
262                                         pa->totkey= 0;
263                                 }
264                         }
265
266                         for (p=totsaved, pa=psys->particles+totsaved; p<psys->totpart; p++, pa++)
267                                 if (pa->hair) MEM_freeN(pa->hair);
268
269                         MEM_freeN(psys->particles);
270                         psys_free_pdd(psys);
271                 }
272                 
273                 psys->particles=newpars;
274                 psys->totpart=totpart;
275
276                 if (newboids) {
277                         LOOP_PARTICLES
278                                 pa->boid = newboids++;
279                 }
280         }
281
282         if (psys->child) {
283                 MEM_freeN(psys->child);
284                 psys->child=NULL;
285                 psys->totchild=0;
286         }
287 }
288
289 static int get_psys_child_number(struct Scene *scene, ParticleSystem *psys)
290 {
291         int nbr;
292
293         if (!psys->part->childtype)
294                 return 0;
295
296         if (psys->renderdata)
297                 nbr= psys->part->ren_child_nbr;
298         else
299                 nbr= psys->part->child_nbr;
300
301         return get_render_child_particle_number(&scene->r, nbr);
302 }
303
304 static int get_psys_tot_child(struct Scene *scene, ParticleSystem *psys)
305 {
306         return psys->totpart*get_psys_child_number(scene, psys);
307 }
308
309 static void alloc_child_particles(ParticleSystem *psys, int tot)
310 {
311         if (psys->child) {
312                 /* only re-allocate if we have to */
313                 if (psys->part->childtype && psys->totchild == tot) {
314                         memset(psys->child, 0, tot*sizeof(ChildParticle));
315                         return;
316                 }
317
318                 MEM_freeN(psys->child);
319                 psys->child=NULL;
320                 psys->totchild=0;
321         }
322
323         if (psys->part->childtype) {
324                 psys->totchild= tot;
325                 if (psys->totchild)
326                         psys->child= MEM_callocN(psys->totchild*sizeof(ChildParticle), "child_particles");
327         }
328 }
329
330 /************************************************/
331 /*                      Distribution                                            */
332 /************************************************/
333
334 void psys_calc_dmcache(Object *ob, DerivedMesh *dm, ParticleSystem *psys)
335 {
336         /* use for building derived mesh mapping info:
337          *
338          * node: the allocated links - total derived mesh element count 
339          * nodearray: the array of nodes aligned with the base mesh's elements, so
340          *            each original elements can reference its derived elements
341          */
342         Mesh *me= (Mesh*)ob->data;
343         PARTICLE_P;
344         
345         /* CACHE LOCATIONS */
346         if (!dm->deformedOnly) {
347                 /* Will use later to speed up subsurf/derivedmesh */
348                 LinkNode *node, *nodedmelem, **nodearray;
349                 int totdmelem, totelem, i, *origindex;
350
351                 if (psys->part->from == PART_FROM_VERT) {
352                         totdmelem= dm->getNumVerts(dm);
353                         totelem= me->totvert;
354                         origindex= dm->getVertDataArray(dm, CD_ORIGINDEX);
355                 }
356                 else { /* FROM_FACE/FROM_VOLUME */
357                         totdmelem= dm->getNumTessFaces(dm);
358                         totelem= me->totpoly;
359                         origindex= dm->getTessFaceDataArray(dm, CD_ORIGINDEX);
360                 }
361         
362                 nodedmelem= MEM_callocN(sizeof(LinkNode)*totdmelem, "psys node elems");
363                 nodearray= MEM_callocN(sizeof(LinkNode *)*totelem, "psys node array");
364                 
365                 for (i=0, node=nodedmelem; i<totdmelem; i++, origindex++, node++) {
366                         node->link= SET_INT_IN_POINTER(i);
367
368                         if (*origindex != -1) {
369                                 if (nodearray[*origindex]) {
370                                         /* prepend */
371                                         node->next = nodearray[*origindex];
372                                         nodearray[*origindex] = node;
373                                 }
374                                 else
375                                         nodearray[*origindex] = node;
376                         }
377                 }
378                 
379                 /* cache the verts/faces! */
380                 LOOP_PARTICLES {
381                         if (pa->num < 0) {
382                                 pa->num_dmcache = -1;
383                                 continue;
384                         }
385
386                         if (psys->part->from == PART_FROM_VERT) {
387                                 if (nodearray[pa->num])
388                                         pa->num_dmcache= GET_INT_FROM_POINTER(nodearray[pa->num]->link);
389                         }
390                         else { /* FROM_FACE/FROM_VOLUME */
391                                 /* Note that sometimes the pa->num is over the nodearray size, this is bad, maybe there is a better place to fix this,
392                                  * but for now passing NULL is OK. every face will be searched for the particle so its slower - Campbell */
393                                 pa->num_dmcache= psys_particle_dm_face_lookup(ob, dm, pa->num, pa->fuv, pa->num < totelem ? nodearray[pa->num] : NULL);
394                         }
395                 }
396
397                 MEM_freeN(nodearray);
398                 MEM_freeN(nodedmelem);
399         }
400         else {
401                 /* TODO PARTICLE, make the following line unnecessary, each function
402                  * should know to use the num or num_dmcache, set the num_dmcache to
403                  * an invalid value, just in case */
404                 
405                 LOOP_PARTICLES
406                         pa->num_dmcache = -1;
407         }
408 }
409
410 static void distribute_simple_children(Scene *scene, Object *ob, DerivedMesh *finaldm, ParticleSystem *psys)
411 {
412         ChildParticle *cpa = NULL;
413         int i, p;
414         int child_nbr= get_psys_child_number(scene, psys);
415         int totpart= get_psys_tot_child(scene, psys);
416
417         alloc_child_particles(psys, totpart);
418
419         cpa = psys->child;
420         for (i=0; i<child_nbr; i++) {
421                 for (p=0; p<psys->totpart; p++,cpa++) {
422                         float length=2.0;
423                         cpa->parent=p;
424                                         
425                         /* create even spherical distribution inside unit sphere */
426                         while (length>=1.0f) {
427                                 cpa->fuv[0]=2.0f*BLI_frand()-1.0f;
428                                 cpa->fuv[1]=2.0f*BLI_frand()-1.0f;
429                                 cpa->fuv[2]=2.0f*BLI_frand()-1.0f;
430                                 length=len_v3(cpa->fuv);
431                         }
432
433                         cpa->num=-1;
434                 }
435         }
436         /* dmcache must be updated for parent particles if children from faces is used */
437         psys_calc_dmcache(ob, finaldm, psys);
438 }
439 static void distribute_grid(DerivedMesh *dm, ParticleSystem *psys)
440 {
441         ParticleData *pa=NULL;
442         float min[3], max[3], delta[3], d;
443         MVert *mv, *mvert = dm->getVertDataArray(dm,0);
444         int totvert=dm->getNumVerts(dm), from=psys->part->from;
445         int i, j, k, p, res=psys->part->grid_res, size[3], axis;
446
447         mv=mvert;
448
449         /* find bounding box of dm */
450         copy_v3_v3(min, mv->co);
451         copy_v3_v3(max, mv->co);
452         mv++;
453
454         for (i=1; i<totvert; i++, mv++) {
455                 min[0]=MIN2(min[0],mv->co[0]);
456                 min[1]=MIN2(min[1],mv->co[1]);
457                 min[2]=MIN2(min[2],mv->co[2]);
458
459                 max[0]=MAX2(max[0],mv->co[0]);
460                 max[1]=MAX2(max[1],mv->co[1]);
461                 max[2]=MAX2(max[2],mv->co[2]);
462         }
463
464         sub_v3_v3v3(delta, max, min);
465
466         /* determine major axis */
467         axis = (delta[0]>=delta[1]) ? 0 : ((delta[1]>=delta[2]) ? 1 : 2);
468          
469         d = delta[axis]/(float)res;
470
471         size[axis] = res;
472         size[(axis+1)%3] = (int)ceil(delta[(axis+1)%3]/d);
473         size[(axis+2)%3] = (int)ceil(delta[(axis+2)%3]/d);
474
475         /* float errors grrr.. */
476         size[(axis+1)%3] = MIN2(size[(axis+1)%3],res);
477         size[(axis+2)%3] = MIN2(size[(axis+2)%3],res);
478
479         size[0] = MAX2(size[0], 1);
480         size[1] = MAX2(size[1], 1);
481         size[2] = MAX2(size[2], 1);
482
483         /* no full offset for flat/thin objects */
484         min[0]+= d < delta[0] ? d/2.f : delta[0]/2.f;
485         min[1]+= d < delta[1] ? d/2.f : delta[1]/2.f;
486         min[2]+= d < delta[2] ? d/2.f : delta[2]/2.f;
487
488         for (i=0,p=0,pa=psys->particles; i<res; i++) {
489                 for (j=0; j<res; j++) {
490                         for (k=0; k<res; k++,p++,pa++) {
491                                 pa->fuv[0] = min[0] + (float)i*d;
492                                 pa->fuv[1] = min[1] + (float)j*d;
493                                 pa->fuv[2] = min[2] + (float)k*d;
494                                 pa->flag |= PARS_UNEXIST;
495                                 pa->hair_index = 0; /* abused in volume calculation */
496                         }
497                 }
498         }
499
500         /* enable particles near verts/edges/faces/inside surface */
501         if (from==PART_FROM_VERT) {
502                 float vec[3];
503
504                 pa=psys->particles;
505
506                 min[0] -= d/2.0f;
507                 min[1] -= d/2.0f;
508                 min[2] -= d/2.0f;
509
510                 for (i=0,mv=mvert; i<totvert; i++,mv++) {
511                         sub_v3_v3v3(vec,mv->co,min);
512                         vec[0]/=delta[0];
513                         vec[1]/=delta[1];
514                         vec[2]/=delta[2];
515                         (pa     + ((int)(vec[0] * (size[0] - 1)) * res +
516                                (int)(vec[1] * (size[1] - 1))) * res +
517                                 (int)(vec[2] * (size[2] - 1)))->flag &= ~PARS_UNEXIST;
518                 }
519         }
520         else if (ELEM(from,PART_FROM_FACE,PART_FROM_VOLUME)) {
521                 float co1[3], co2[3];
522
523                 MFace *mface= NULL, *mface_array;
524                 float v1[3], v2[3], v3[3], v4[4], lambda;
525                 int a, a1, a2, a0mul, a1mul, a2mul, totface;
526                 int amax= from==PART_FROM_FACE ? 3 : 1;
527
528                 totface=dm->getNumTessFaces(dm);
529                 mface=mface_array=dm->getTessFaceDataArray(dm,CD_MFACE);
530                 
531                 for (a=0; a<amax; a++) {
532                         if (a==0) { a0mul=res*res; a1mul=res; a2mul=1; }
533                         else if (a==1) { a0mul=res; a1mul=1; a2mul=res*res; }
534                         else { a0mul=1; a1mul=res*res; a2mul=res; }
535
536                         for (a1=0; a1<size[(a+1)%3]; a1++) {
537                                 for (a2=0; a2<size[(a+2)%3]; a2++) {
538                                         mface= mface_array;
539
540                                         pa = psys->particles + a1*a1mul + a2*a2mul;
541                                         copy_v3_v3(co1, pa->fuv);
542                                         co1[a] -= d < delta[a] ? d/2.f : delta[a]/2.f;
543                                         copy_v3_v3(co2, co1);
544                                         co2[a] += delta[a] + 0.001f*d;
545                                         co1[a] -= 0.001f*d;
546                                         
547                                         /* lets intersect the faces */
548                                         for (i=0; i<totface; i++,mface++) {
549                                                 copy_v3_v3(v1, mvert[mface->v1].co);
550                                                 copy_v3_v3(v2, mvert[mface->v2].co);
551                                                 copy_v3_v3(v3, mvert[mface->v3].co);
552
553                                                 if (isect_axial_line_tri_v3(a, co1, co2, v2, v3, v1, &lambda)) {
554                                                         if (from==PART_FROM_FACE)
555                                                                 (pa+(int)(lambda*size[a])*a0mul)->flag &= ~PARS_UNEXIST;
556                                                         else /* store number of intersections */
557                                                                 (pa+(int)(lambda*size[a])*a0mul)->hair_index++;
558                                                 }
559                                                 else if (mface->v4) {
560                                                         copy_v3_v3(v4, mvert[mface->v4].co);
561
562                                                         if (isect_axial_line_tri_v3(a, co1, co2, v4, v1, v3, &lambda)) {
563                                                                 if (from==PART_FROM_FACE)
564                                                                         (pa+(int)(lambda*size[a])*a0mul)->flag &= ~PARS_UNEXIST;
565                                                                 else
566                                                                         (pa+(int)(lambda*size[a])*a0mul)->hair_index++;
567                                                         }
568                                                 }
569                                         }
570
571                                         if (from==PART_FROM_VOLUME) {
572                                                 int in=pa->hair_index%2;
573                                                 if (in) pa->hair_index++;
574                                                 for (i=0; i<size[0]; i++) {
575                                                         if (in || (pa+i*a0mul)->hair_index%2)
576                                                                 (pa+i*a0mul)->flag &= ~PARS_UNEXIST;
577                                                         /* odd intersections == in->out / out->in */
578                                                         /* even intersections -> in stays same */
579                                                         in=(in + (pa+i*a0mul)->hair_index) % 2;
580                                                 }
581                                         }
582                                 }
583                         }
584                 }
585         }
586
587         if (psys->part->flag & PART_GRID_HEXAGONAL) {
588                 for (i=0,p=0,pa=psys->particles; i<res; i++) {
589                         for (j=0; j<res; j++) {
590                                 for (k=0; k<res; k++,p++,pa++) {
591                                         if (j%2)
592                                                 pa->fuv[0] += d/2.f;
593
594                                         if (k%2) {
595                                                 pa->fuv[0] += d/2.f;
596                                                 pa->fuv[1] += d/2.f;
597                                         }
598                                 }
599                         }
600                 }
601         }
602
603         if (psys->part->flag & PART_GRID_INVERT) {
604                 for (i=0; i<size[0]; i++) {
605                         for (j=0; j<size[1]; j++) {
606                                 pa=psys->particles + res*(i*res + j);
607                                 for (k=0; k<size[2]; k++, pa++) {
608                                         pa->flag ^= PARS_UNEXIST;
609                                 }
610                         }
611                 }
612         }
613
614         if (psys->part->grid_rand > 0.f) {
615                 float rfac = d * psys->part->grid_rand;
616                 for (p=0,pa=psys->particles; p<psys->totpart; p++,pa++) {
617                         if (pa->flag & PARS_UNEXIST)
618                                 continue;
619
620                         pa->fuv[0] += rfac * (PSYS_FRAND(p + 31) - 0.5f);
621                         pa->fuv[1] += rfac * (PSYS_FRAND(p + 32) - 0.5f);
622                         pa->fuv[2] += rfac * (PSYS_FRAND(p + 33) - 0.5f);
623                 }
624         }
625 }
626
627 /* modified copy from rayshade.c */
628 static void hammersley_create(float *out, int n, int seed, float amount)
629 {
630         RNG *rng;
631         double p, t, offs[2];
632         int k, kk;
633
634         rng = BLI_rng_new(31415926 + n + seed);
635         offs[0] = BLI_rng_get_double(rng) + (double)amount;
636         offs[1] = BLI_rng_get_double(rng) + (double)amount;
637         BLI_rng_free(rng);
638
639         for (k = 0; k < n; k++) {
640                 t = 0;
641                 for (p = 0.5, kk = k; kk; p *= 0.5, kk >>= 1)
642                         if (kk & 1) /* kk mod 2 = 1 */
643                                 t += p;
644
645                 out[2*k + 0] = fmod((double)k/(double)n + offs[0], 1.0);
646                 out[2*k + 1] = fmod(t + offs[1], 1.0);
647         }
648 }
649
650 /* modified copy from effect.c */
651 static void init_mv_jit(float *jit, int num, int seed2, float amount)
652 {
653         RNG *rng;
654         float *jit2, x, rad1, rad2, rad3;
655         int i, num2;
656
657         if (num==0) return;
658
659         rad1= (float)(1.0f/sqrtf((float)num));
660         rad2= (float)(1.0f/((float)num));
661         rad3= (float)sqrt((float)num)/((float)num);
662
663         rng = BLI_rng_new(31415926 + num + seed2);
664         x= 0;
665                 num2 = 2 * num;
666         for (i=0; i<num2; i+=2) {
667         
668                 jit[i] = x + amount*rad1*(0.5f - BLI_rng_get_float(rng));
669                 jit[i+1] = i/(2.0f*num) + amount*rad1*(0.5f - BLI_rng_get_float(rng));
670                 
671                 jit[i]-= (float)floor(jit[i]);
672                 jit[i+1]-= (float)floor(jit[i+1]);
673                 
674                 x+= rad3;
675                 x -= (float)floor(x);
676         }
677
678         jit2= MEM_mallocN(12 + 2*sizeof(float)*num, "initjit");
679
680         for (i=0 ; i<4 ; i++) {
681                 BLI_jitterate1(jit, jit2, num, rad1);
682                 BLI_jitterate1(jit, jit2, num, rad1);
683                 BLI_jitterate2(jit, jit2, num, rad2);
684         }
685         MEM_freeN(jit2);
686         BLI_rng_free(rng);
687 }
688
689 static void psys_uv_to_w(float u, float v, int quad, float *w)
690 {
691         float vert[4][3], co[3];
692
693         if (!quad) {
694                 if (u+v > 1.0f)
695                         v= 1.0f-v;
696                 else
697                         u= 1.0f-u;
698         }
699
700         vert[0][0] = 0.0f; vert[0][1] = 0.0f; vert[0][2] = 0.0f;
701         vert[1][0] = 1.0f; vert[1][1] = 0.0f; vert[1][2] = 0.0f;
702         vert[2][0] = 1.0f; vert[2][1] = 1.0f; vert[2][2] = 0.0f;
703
704         co[0] = u;
705         co[1] = v;
706         co[2] = 0.0f;
707
708         if (quad) {
709                 vert[3][0] = 0.0f; vert[3][1] = 1.0f; vert[3][2] = 0.0f;
710                 interp_weights_poly_v3( w,vert, 4, co);
711         }
712         else {
713                 interp_weights_poly_v3( w,vert, 3, co);
714                 w[3] = 0.0f;
715         }
716 }
717
718 /* Find the index in "sum" array before "value" is crossed. */
719 static int distribute_binary_search(float *sum, int n, float value)
720 {
721         int mid, low=0, high=n;
722
723         if (value == 0.f)
724                 return 0;
725
726         while (low <= high) {
727                 mid= (low + high)/2;
728                 
729                 if (sum[mid] < value && value <= sum[mid+1])
730                         return mid;
731                 
732                 if (sum[mid] >= value)
733                         high= mid - 1;
734                 else if (sum[mid] < value)
735                         low= mid + 1;
736                 else
737                         return mid;
738         }
739
740         return low;
741 }
742
743 /* the max number if calls to rng_* funcs within psys_thread_distribute_particle
744  * be sure to keep up to date if this changes */
745 #define PSYS_RND_DIST_SKIP 2
746
747 /* note: this function must be thread safe, for from == PART_FROM_CHILD */
748 #define ONLY_WORKING_WITH_PA_VERTS 0
749 static void distribute_threads_exec(ParticleThread *thread, ParticleData *pa, ChildParticle *cpa, int p)
750 {
751         ParticleThreadContext *ctx= thread->ctx;
752         Object *ob= ctx->sim.ob;
753         DerivedMesh *dm= ctx->dm;
754         float *v1, *v2, *v3, *v4, nor[3], orco1[3], co1[3], co2[3], nor1[3];
755         float cur_d, min_d, randu, randv;
756         int from= ctx->from;
757         int cfrom= ctx->cfrom;
758         int distr= ctx->distr;
759         int i, intersect, tot;
760         int rng_skip_tot= PSYS_RND_DIST_SKIP; /* count how many rng_* calls wont need skipping */
761
762         if (from == PART_FROM_VERT) {
763                 /* TODO_PARTICLE - use original index */
764                 pa->num= ctx->index[p];
765                 pa->fuv[0] = 1.0f;
766                 pa->fuv[1] = pa->fuv[2] = pa->fuv[3] = 0.0;
767
768 #if ONLY_WORKING_WITH_PA_VERTS
769                 if (ctx->tree) {
770                         KDTreeNearest ptn[3];
771                         int w, maxw;
772
773                         psys_particle_on_dm(ctx->dm,from,pa->num,pa->num_dmcache,pa->fuv,pa->foffset,co1,0,0,0,orco1,0);
774                         BKE_mesh_orco_verts_transform((Mesh*)ob->data, &orco1, 1, 1);
775                         maxw = BLI_kdtree_find_n_nearest(ctx->tree,3,orco1,NULL,ptn);
776
777                         for (w=0; w<maxw; w++) {
778                                 pa->verts[w]=ptn->num;
779                         }
780                 }
781 #endif
782         }
783         else if (from == PART_FROM_FACE || from == PART_FROM_VOLUME) {
784                 MFace *mface;
785
786                 pa->num = i = ctx->index[p];
787                 mface = dm->getTessFaceData(dm,i,CD_MFACE);
788                 
789                 switch (distr) {
790                 case PART_DISTR_JIT:
791                         if (ctx->jitlevel == 1) {
792                                 if (mface->v4)
793                                         psys_uv_to_w(0.5f, 0.5f, mface->v4, pa->fuv);
794                                 else
795                                         psys_uv_to_w(0.33333f, 0.33333f, mface->v4, pa->fuv);
796                         }
797                         else {
798                                 ctx->jitoff[i] = fmod(ctx->jitoff[i],(float)ctx->jitlevel);
799                                 if (!isnan(ctx->jitoff[i])) {
800                                         psys_uv_to_w(ctx->jit[2*(int)ctx->jitoff[i]], ctx->jit[2*(int)ctx->jitoff[i]+1], mface->v4, pa->fuv);
801                                         ctx->jitoff[i]++;
802                                 }
803                         }
804                         break;
805                 case PART_DISTR_RAND:
806                         randu= BLI_rng_get_float(thread->rng);
807                         randv= BLI_rng_get_float(thread->rng);
808                         rng_skip_tot -= 2;
809
810                         psys_uv_to_w(randu, randv, mface->v4, pa->fuv);
811                         break;
812                 }
813                 pa->foffset= 0.0f;
814                 
815                 /* experimental */
816                 if (from==PART_FROM_VOLUME) {
817                         MVert *mvert=dm->getVertDataArray(dm,CD_MVERT);
818
819                         tot=dm->getNumTessFaces(dm);
820
821                         psys_interpolate_face(mvert,mface,0,0,pa->fuv,co1,nor,0,0,0,0);
822
823                         normalize_v3(nor);
824                         mul_v3_fl(nor,-100.0);
825
826                         add_v3_v3v3(co2,co1,nor);
827
828                         min_d=2.0;
829                         intersect=0;
830
831                         for (i=0,mface=dm->getTessFaceDataArray(dm,CD_MFACE); i<tot; i++,mface++) {
832                                 if (i==pa->num) continue;
833
834                                 v1=mvert[mface->v1].co;
835                                 v2=mvert[mface->v2].co;
836                                 v3=mvert[mface->v3].co;
837
838                                 if (isect_line_tri_v3(co1, co2, v2, v3, v1, &cur_d, 0)) {
839                                         if (cur_d<min_d) {
840                                                 min_d=cur_d;
841                                                 pa->foffset=cur_d*50.0f; /* to the middle of volume */
842                                                 intersect=1;
843                                         }
844                                 }
845                                 if (mface->v4) {
846                                         v4=mvert[mface->v4].co;
847
848                                         if (isect_line_tri_v3(co1, co2, v4, v1, v3, &cur_d, 0)) {
849                                                 if (cur_d<min_d) {
850                                                         min_d=cur_d;
851                                                         pa->foffset=cur_d*50.0f; /* to the middle of volume */
852                                                         intersect=1;
853                                                 }
854                                         }
855                                 }
856                         }
857                         if (intersect==0)
858                                 pa->foffset=0.0;
859                         else {
860                                 switch (distr) {
861                                         case PART_DISTR_JIT:
862                                                 pa->foffset *= ctx->jit[p % (2 * ctx->jitlevel)];
863                                                 break;
864                                         case PART_DISTR_RAND:
865                                                 pa->foffset *= BLI_frand();
866                                                 break;
867                                 }
868                         }
869                 }
870         }
871         else if (from == PART_FROM_CHILD) {
872                 MFace *mf;
873
874                 if (ctx->index[p] < 0) {
875                         cpa->num=0;
876                         cpa->fuv[0]=cpa->fuv[1]=cpa->fuv[2]=cpa->fuv[3]=0.0f;
877                         cpa->pa[0]=cpa->pa[1]=cpa->pa[2]=cpa->pa[3]=0;
878                         return;
879                 }
880
881                 mf= dm->getTessFaceData(dm, ctx->index[p], CD_MFACE);
882
883                 randu= BLI_rng_get_float(thread->rng);
884                 randv= BLI_rng_get_float(thread->rng);
885                 rng_skip_tot -= 2;
886
887                 psys_uv_to_w(randu, randv, mf->v4, cpa->fuv);
888
889                 cpa->num = ctx->index[p];
890
891                 if (ctx->tree) {
892                         KDTreeNearest ptn[10];
893                         int w,maxw;//, do_seams;
894                         float maxd /*, mind,dd */, totw= 0.0f;
895                         int parent[10];
896                         float pweight[10];
897
898                         psys_particle_on_dm(dm,cfrom,cpa->num,DMCACHE_ISCHILD,cpa->fuv,cpa->foffset,co1,nor1,NULL,NULL,orco1,NULL);
899                         BKE_mesh_orco_verts_transform((Mesh*)ob->data, &orco1, 1, 1);
900                         maxw = BLI_kdtree_find_n_nearest(ctx->tree,4,orco1,NULL,ptn);
901
902                         maxd=ptn[maxw-1].dist;
903                         /* mind=ptn[0].dist; */ /* UNUSED */
904                         
905                         /* the weights here could be done better */
906                         for (w=0; w<maxw; w++) {
907                                 parent[w]=ptn[w].index;
908                                 pweight[w]=(float)pow(2.0,(double)(-6.0f*ptn[w].dist/maxd));
909                         }
910                         for (;w<10; w++) {
911                                 parent[w]=-1;
912                                 pweight[w]=0.0f;
913                         }
914
915                         for (w=0,i=0; w<maxw && i<4; w++) {
916                                 if (parent[w]>=0) {
917                                         cpa->pa[i]=parent[w];
918                                         cpa->w[i]=pweight[w];
919                                         totw+=pweight[w];
920                                         i++;
921                                 }
922                         }
923                         for (;i<4; i++) {
924                                 cpa->pa[i]=-1;
925                                 cpa->w[i]=0.0f;
926                         }
927
928                         if (totw>0.0f) for (w=0; w<4; w++)
929                                 cpa->w[w]/=totw;
930
931                         cpa->parent=cpa->pa[0];
932                 }
933         }
934
935         if (rng_skip_tot > 0) /* should never be below zero */
936                 BLI_rng_skip(thread->rng, rng_skip_tot);
937 }
938
939 static void *distribute_threads_exec_cb(void *data)
940 {
941         ParticleThread *thread= (ParticleThread*)data;
942         ParticleSystem *psys= thread->ctx->sim.psys;
943         ParticleData *pa;
944         ChildParticle *cpa;
945         int p, totpart;
946
947         if (thread->ctx->from == PART_FROM_CHILD) {
948                 totpart= psys->totchild;
949                 cpa= psys->child;
950
951                 for (p=0; p<totpart; p++, cpa++) {
952                         if (thread->ctx->skip) /* simplification skip */
953                                 BLI_rng_skip(thread->rng, PSYS_RND_DIST_SKIP * thread->ctx->skip[p]);
954
955                         if ((p+thread->num) % thread->tot == 0)
956                                 distribute_threads_exec(thread, NULL, cpa, p);
957                         else /* thread skip */
958                                 BLI_rng_skip(thread->rng, PSYS_RND_DIST_SKIP);
959                 }
960         }
961         else {
962                 totpart= psys->totpart;
963                 pa= psys->particles + thread->num;
964                 for (p=thread->num; p<totpart; p+=thread->tot, pa+=thread->tot)
965                         distribute_threads_exec(thread, pa, NULL, p);
966         }
967
968         return 0;
969 }
970
971 /* not thread safe, but qsort doesn't take userdata argument */
972 static int *COMPARE_ORIG_INDEX = NULL;
973 static int distribute_compare_orig_index(const void *p1, const void *p2)
974 {
975         int index1 = COMPARE_ORIG_INDEX[*(const int *)p1];
976         int index2 = COMPARE_ORIG_INDEX[*(const int *)p2];
977
978         if (index1 < index2)
979                 return -1;
980         else if (index1 == index2) {
981                 /* this pointer comparison appears to make qsort stable for glibc,
982                  * and apparently on solaris too, makes the renders reproducible */
983                 if (p1 < p2)
984                         return -1;
985                 else if (p1 == p2)
986                         return 0;
987                 else
988                         return 1;
989         }
990         else
991                 return 1;
992 }
993
994 static void distribute_invalid(Scene *scene, ParticleSystem *psys, int from)
995 {
996         if (from == PART_FROM_CHILD) {
997                 ChildParticle *cpa;
998                 int p, totchild = get_psys_tot_child(scene, psys);
999
1000                 if (psys->child && totchild) {
1001                         for (p=0,cpa=psys->child; p<totchild; p++,cpa++) {
1002                                 cpa->fuv[0]=cpa->fuv[1]=cpa->fuv[2]=cpa->fuv[3] = 0.0;
1003                                 cpa->foffset= 0.0f;
1004                                 cpa->parent=0;
1005                                 cpa->pa[0]=cpa->pa[1]=cpa->pa[2]=cpa->pa[3]=0;
1006                                 cpa->num= -1;
1007                         }
1008                 }
1009         }
1010         else {
1011                 PARTICLE_P;
1012                 LOOP_PARTICLES {
1013                         pa->fuv[0] = pa->fuv[1] = pa->fuv[2] = pa->fuv[3] = 0.0;
1014                         pa->foffset= 0.0f;
1015                         pa->num= -1;
1016                 }
1017         }
1018 }
1019
1020 /* Creates a distribution of coordinates on a DerivedMesh       */
1021 /* This is to denote functionality that does not yet work with mesh - only derived mesh */
1022 static int distribute_threads_init_data(ParticleThread *threads, Scene *scene, DerivedMesh *finaldm, int from)
1023 {
1024         ParticleThreadContext *ctx= threads[0].ctx;
1025         Object *ob= ctx->sim.ob;
1026         ParticleSystem *psys= ctx->sim.psys;
1027         ParticleData *pa=0, *tpars= 0;
1028         ParticleSettings *part;
1029         ParticleSeam *seams= 0;
1030         KDTree *tree=0;
1031         DerivedMesh *dm= NULL;
1032         float *jit= NULL;
1033         int i, seed, p=0, totthread= threads[0].tot;
1034         int cfrom=0;
1035         int totelem=0, totpart, *particle_element=0, children=0, totseam=0;
1036         int jitlevel= 1, distr;
1037         float *element_weight=NULL,*element_sum=NULL,*jitter_offset=NULL, *vweight=NULL;
1038         float cur, maxweight=0.0, tweight, totweight, inv_totweight, co[3], nor[3], orco[3], ornor[3];
1039         
1040         if (ELEM3(NULL, ob, psys, psys->part))
1041                 return 0;
1042
1043         part=psys->part;
1044         totpart=psys->totpart;
1045         if (totpart==0)
1046                 return 0;
1047
1048         if (!finaldm->deformedOnly && !finaldm->getTessFaceDataArray(finaldm, CD_ORIGINDEX)) {
1049                 printf("Can't create particles with the current modifier stack, disable destructive modifiers\n");
1050 // XXX          error("Can't paint with the current modifier stack, disable destructive modifiers");
1051                 return 0;
1052         }
1053
1054         /* First handle special cases */
1055         if (from == PART_FROM_CHILD) {
1056                 /* Simple children */
1057                 if (part->childtype != PART_CHILD_FACES) {
1058                         BLI_srandom(31415926 + psys->seed + psys->child_seed);
1059                         distribute_simple_children(scene, ob, finaldm, psys);
1060                         return 0;
1061                 }
1062         }
1063         else {
1064                 /* Grid distribution */
1065                 if (part->distr==PART_DISTR_GRID && from != PART_FROM_VERT) {
1066                         BLI_srandom(31415926 + psys->seed);
1067                         dm= CDDM_from_mesh((Mesh*)ob->data, ob);
1068                         DM_ensure_tessface(dm);
1069                         distribute_grid(dm,psys);
1070                         dm->release(dm);
1071                         return 0;
1072                 }
1073         }
1074         
1075         /* Create trees and original coordinates if needed */
1076         if (from == PART_FROM_CHILD) {
1077                 distr=PART_DISTR_RAND;
1078                 BLI_srandom(31415926 + psys->seed + psys->child_seed);
1079                 dm= finaldm;
1080
1081                 /* BMESH ONLY */
1082                 DM_ensure_tessface(dm);
1083
1084                 children=1;
1085
1086                 tree=BLI_kdtree_new(totpart);
1087
1088                 for (p=0,pa=psys->particles; p<totpart; p++,pa++) {
1089                         psys_particle_on_dm(dm,part->from,pa->num,pa->num_dmcache,pa->fuv,pa->foffset,co,nor,0,0,orco,ornor);
1090                         BKE_mesh_orco_verts_transform((Mesh*)ob->data, &orco, 1, 1);
1091                         BLI_kdtree_insert(tree, p, orco, ornor);
1092                 }
1093
1094                 BLI_kdtree_balance(tree);
1095
1096                 totpart = get_psys_tot_child(scene, psys);
1097                 cfrom = from = PART_FROM_FACE;
1098         }
1099         else {
1100                 distr = part->distr;
1101                 BLI_srandom(31415926 + psys->seed);
1102                 
1103                 dm= CDDM_from_mesh((Mesh*)ob->data, ob);
1104
1105                 /* BMESH ONLY, for verts we don't care about tessfaces */
1106                 if (from != PART_FROM_VERT) {
1107                         DM_ensure_tessface(dm);
1108                 }
1109
1110                 /* we need orco for consistent distributions */
1111                 DM_add_vert_layer(dm, CD_ORCO, CD_ASSIGN, BKE_mesh_orco_verts_get(ob));
1112
1113                 if (from == PART_FROM_VERT) {
1114                         MVert *mv= dm->getVertDataArray(dm, CD_MVERT);
1115                         float (*orcodata)[3] = dm->getVertDataArray(dm, CD_ORCO);
1116                         int totvert = dm->getNumVerts(dm);
1117
1118                         tree=BLI_kdtree_new(totvert);
1119
1120                         for (p=0; p<totvert; p++) {
1121                                 if (orcodata) {
1122                                         copy_v3_v3(co,orcodata[p]);
1123                                         BKE_mesh_orco_verts_transform((Mesh*)ob->data, &co, 1, 1);
1124                                 }
1125                                 else
1126                                         copy_v3_v3(co,mv[p].co);
1127                                 BLI_kdtree_insert(tree,p,co,NULL);
1128                         }
1129
1130                         BLI_kdtree_balance(tree);
1131                 }
1132         }
1133
1134         /* Get total number of emission elements and allocate needed arrays */
1135         totelem = (from == PART_FROM_VERT) ? dm->getNumVerts(dm) : dm->getNumTessFaces(dm);
1136
1137         if (totelem == 0) {
1138                 distribute_invalid(scene, psys, children ? PART_FROM_CHILD : 0);
1139
1140                 if (G.debug & G_DEBUG)
1141                         fprintf(stderr,"Particle distribution error: Nothing to emit from!\n");
1142
1143                 if (dm != finaldm) dm->release(dm);
1144
1145                 BLI_kdtree_free(tree);
1146
1147                 return 0;
1148         }
1149
1150         element_weight  = MEM_callocN(sizeof(float)*totelem, "particle_distribution_weights");
1151         particle_element= MEM_callocN(sizeof(int)*totpart, "particle_distribution_indexes");
1152         element_sum             = MEM_callocN(sizeof(float)*(totelem+1), "particle_distribution_sum");
1153         jitter_offset   = MEM_callocN(sizeof(float)*totelem, "particle_distribution_jitoff");
1154
1155         /* Calculate weights from face areas */
1156         if ((part->flag&PART_EDISTR || children) && from != PART_FROM_VERT) {
1157                 MVert *v1, *v2, *v3, *v4;
1158                 float totarea=0.f, co1[3], co2[3], co3[3], co4[3];
1159                 float (*orcodata)[3];
1160                 
1161                 orcodata= dm->getVertDataArray(dm, CD_ORCO);
1162
1163                 for (i=0; i<totelem; i++) {
1164                         MFace *mf=dm->getTessFaceData(dm,i,CD_MFACE);
1165
1166                         if (orcodata) {
1167                                 copy_v3_v3(co1, orcodata[mf->v1]);
1168                                 copy_v3_v3(co2, orcodata[mf->v2]);
1169                                 copy_v3_v3(co3, orcodata[mf->v3]);
1170                                 BKE_mesh_orco_verts_transform((Mesh*)ob->data, &co1, 1, 1);
1171                                 BKE_mesh_orco_verts_transform((Mesh*)ob->data, &co2, 1, 1);
1172                                 BKE_mesh_orco_verts_transform((Mesh*)ob->data, &co3, 1, 1);
1173                                 if (mf->v4) {
1174                                         copy_v3_v3(co4, orcodata[mf->v4]);
1175                                         BKE_mesh_orco_verts_transform((Mesh*)ob->data, &co4, 1, 1);
1176                                 }
1177                         }
1178                         else {
1179                                 v1= (MVert*)dm->getVertData(dm,mf->v1,CD_MVERT);
1180                                 v2= (MVert*)dm->getVertData(dm,mf->v2,CD_MVERT);
1181                                 v3= (MVert*)dm->getVertData(dm,mf->v3,CD_MVERT);
1182                                 copy_v3_v3(co1, v1->co);
1183                                 copy_v3_v3(co2, v2->co);
1184                                 copy_v3_v3(co3, v3->co);
1185                                 if (mf->v4) {
1186                                         v4= (MVert*)dm->getVertData(dm,mf->v4,CD_MVERT);
1187                                         copy_v3_v3(co4, v4->co);
1188                                 }
1189                         }
1190
1191                         cur = mf->v4 ? area_quad_v3(co1, co2, co3, co4) : area_tri_v3(co1, co2, co3);
1192                         
1193                         if (cur > maxweight)
1194                                 maxweight = cur;
1195
1196                         element_weight[i] = cur;
1197                         totarea += cur;
1198                 }
1199
1200                 for (i=0; i<totelem; i++)
1201                         element_weight[i] /= totarea;
1202
1203                 maxweight /= totarea;
1204         }
1205         else {
1206                 float min=1.0f/(float)(MIN2(totelem,totpart));
1207                 for (i=0; i<totelem; i++)
1208                         element_weight[i]=min;
1209                 maxweight=min;
1210         }
1211
1212         /* Calculate weights from vgroup */
1213         vweight = psys_cache_vgroup(dm,psys,PSYS_VG_DENSITY);
1214
1215         if (vweight) {
1216                 if (from==PART_FROM_VERT) {
1217                         for (i=0;i<totelem; i++)
1218                                 element_weight[i]*=vweight[i];
1219                 }
1220                 else { /* PART_FROM_FACE / PART_FROM_VOLUME */
1221                         for (i=0;i<totelem; i++) {
1222                                 MFace *mf=dm->getTessFaceData(dm,i,CD_MFACE);
1223                                 tweight = vweight[mf->v1] + vweight[mf->v2] + vweight[mf->v3];
1224                                 
1225                                 if (mf->v4) {
1226                                         tweight += vweight[mf->v4];
1227                                         tweight /= 4.0f;
1228                                 }
1229                                 else {
1230                                         tweight /= 3.0f;
1231                                 }
1232
1233                                 element_weight[i]*=tweight;
1234                         }
1235                 }
1236                 MEM_freeN(vweight);
1237         }
1238
1239         /* Calculate total weight of all elements */
1240         totweight= 0.0f;
1241         for (i=0;i<totelem; i++)
1242                 totweight += element_weight[i];
1243
1244         inv_totweight = (totweight > 0.f ? 1.f/totweight : 0.f);
1245
1246         /* Calculate cumulative weights */
1247         element_sum[0] = 0.0f;
1248         for (i=0; i<totelem; i++)
1249                 element_sum[i+1] = element_sum[i] + element_weight[i] * inv_totweight;
1250         
1251         /* Finally assign elements to particles */
1252         if ((part->flag&PART_TRAND) || (part->simplify_flag&PART_SIMPLIFY_ENABLE)) {
1253                 float pos;
1254
1255                 for (p=0; p<totpart; p++) {
1256                         /* In theory element_sum[totelem] should be 1.0, but due to float errors this is not necessarily always true, so scale pos accordingly. */
1257                         pos= BLI_frand() * element_sum[totelem];
1258                         particle_element[p] = distribute_binary_search(element_sum, totelem, pos);
1259                         particle_element[p] = MIN2(totelem-1, particle_element[p]);
1260                         jitter_offset[particle_element[p]] = pos;
1261                 }
1262         }
1263         else {
1264                 double step, pos;
1265                 
1266                 step= (totpart < 2) ? 0.5 : 1.0/(double)totpart;
1267                 pos= 1e-6; /* tiny offset to avoid zero weight face */
1268                 i= 0;
1269
1270                 for (p=0; p<totpart; p++, pos+=step) {
1271                         while ((i < totelem) && (pos > element_sum[i+1]))
1272                                 i++;
1273
1274                         particle_element[p] = MIN2(totelem-1, i);
1275
1276                         /* avoid zero weight face */
1277                         if (p == totpart-1 && element_weight[particle_element[p]] == 0.0f)
1278                                 particle_element[p] = particle_element[p-1];
1279
1280                         jitter_offset[particle_element[p]] = pos;
1281                 }
1282         }
1283
1284         MEM_freeN(element_sum);
1285
1286         /* For hair, sort by origindex (allows optimization's in rendering), */
1287         /* however with virtual parents the children need to be in random order. */
1288         if (part->type == PART_HAIR && !(part->childtype==PART_CHILD_FACES && part->parents!=0.0f)) {
1289                 COMPARE_ORIG_INDEX = NULL;
1290
1291                 if (from == PART_FROM_VERT) {
1292                         if (dm->numVertData)
1293                                 COMPARE_ORIG_INDEX= dm->getVertDataArray(dm, CD_ORIGINDEX);
1294                 }
1295                 else {
1296                         if (dm->numTessFaceData)
1297                                 COMPARE_ORIG_INDEX= dm->getTessFaceDataArray(dm, CD_ORIGINDEX);
1298                 }
1299
1300                 if (COMPARE_ORIG_INDEX) {
1301                         qsort(particle_element, totpart, sizeof(int), distribute_compare_orig_index);
1302                         COMPARE_ORIG_INDEX = NULL;
1303                 }
1304         }
1305
1306         /* Create jittering if needed */
1307         if (distr==PART_DISTR_JIT && ELEM(from,PART_FROM_FACE,PART_FROM_VOLUME)) {
1308                 jitlevel= part->userjit;
1309                 
1310                 if (jitlevel == 0) {
1311                         jitlevel= totpart/totelem;
1312                         if (part->flag & PART_EDISTR) jitlevel*= 2;     /* looks better in general, not very scietific */
1313                         if (jitlevel<3) jitlevel= 3;
1314                 }
1315                 
1316                 jit= MEM_callocN((2+ jitlevel*2)*sizeof(float), "jit");
1317
1318                 /* for small amounts of particles we use regular jitter since it looks
1319                  * a bit better, for larger amounts we switch to hammersley sequence 
1320                  * because it is much faster */
1321                 if (jitlevel < 25)
1322                         init_mv_jit(jit, jitlevel, psys->seed, part->jitfac);
1323                 else
1324                         hammersley_create(jit, jitlevel+1, psys->seed, part->jitfac);
1325                 BLI_array_randomize(jit, 2*sizeof(float), jitlevel, psys->seed); /* for custom jit or even distribution */
1326         }
1327
1328         /* Setup things for threaded distribution */
1329         ctx->tree= tree;
1330         ctx->seams= seams;
1331         ctx->totseam= totseam;
1332         ctx->sim.psys= psys;
1333         ctx->index= particle_element;
1334         ctx->jit= jit;
1335         ctx->jitlevel= jitlevel;
1336         ctx->jitoff= jitter_offset;
1337         ctx->weight= element_weight;
1338         ctx->maxweight= maxweight;
1339         ctx->from= (children)? PART_FROM_CHILD: from;
1340         ctx->cfrom= cfrom;
1341         ctx->distr= distr;
1342         ctx->dm= dm;
1343         ctx->tpars= tpars;
1344
1345         if (children) {
1346                 totpart= psys_render_simplify_distribution(ctx, totpart);
1347                 alloc_child_particles(psys, totpart);
1348         }
1349
1350         if (!children || psys->totchild < 10000)
1351                 totthread= 1;
1352         
1353         seed= 31415926 + ctx->sim.psys->seed;
1354         for (i=0; i<totthread; i++) {
1355                 threads[i].rng= BLI_rng_new(seed);
1356                 threads[i].tot= totthread;
1357         }
1358
1359         return 1;
1360 }
1361
1362 static void distribute_particles_on_dm(ParticleSimulationData *sim, int from)
1363 {
1364         DerivedMesh *finaldm = sim->psmd->dm;
1365         ListBase threads;
1366         ParticleThread *pthreads;
1367         ParticleThreadContext *ctx;
1368         int i, totthread;
1369
1370         pthreads= psys_threads_create(sim);
1371
1372         if (!distribute_threads_init_data(pthreads, sim->scene, finaldm, from)) {
1373                 psys_threads_free(pthreads);
1374                 return;
1375         }
1376
1377         totthread= pthreads[0].tot;
1378         if (totthread > 1) {
1379                 BLI_init_threads(&threads, distribute_threads_exec_cb, totthread);
1380
1381                 for (i=0; i<totthread; i++)
1382                         BLI_insert_thread(&threads, &pthreads[i]);
1383
1384                 BLI_end_threads(&threads);
1385         }
1386         else
1387                 distribute_threads_exec_cb(&pthreads[0]);
1388
1389         psys_calc_dmcache(sim->ob, finaldm, sim->psys);
1390
1391         ctx= pthreads[0].ctx;
1392         if (ctx->dm != finaldm)
1393                 ctx->dm->release(ctx->dm);
1394
1395         psys_threads_free(pthreads);
1396 }
1397
1398 /* ready for future use, to emit particles without geometry */
1399 static void distribute_particles_on_shape(ParticleSimulationData *sim, int UNUSED(from))
1400 {
1401         distribute_invalid(sim->scene, sim->psys, 0);
1402
1403         fprintf(stderr,"Shape emission not yet possible!\n");
1404 }
1405
1406 static void distribute_particles(ParticleSimulationData *sim, int from)
1407 {
1408         PARTICLE_PSMD;
1409         int distr_error=0;
1410
1411         if (psmd) {
1412                 if (psmd->dm)
1413                         distribute_particles_on_dm(sim, from);
1414                 else
1415                         distr_error=1;
1416         }
1417         else
1418                 distribute_particles_on_shape(sim, from);
1419
1420         if (distr_error) {
1421                 distribute_invalid(sim->scene, sim->psys, from);
1422
1423                 fprintf(stderr,"Particle distribution error!\n");
1424         }
1425 }
1426
1427 /* threaded child particle distribution and path caching */
1428 ParticleThread *psys_threads_create(ParticleSimulationData *sim)
1429 {
1430         ParticleThread *threads;
1431         ParticleThreadContext *ctx;
1432         int i, totthread;
1433
1434         if (sim->scene->r.mode & R_FIXED_THREADS)
1435                 totthread= sim->scene->r.threads;
1436         else
1437                 totthread= BLI_system_thread_count();
1438         
1439         threads= MEM_callocN(sizeof(ParticleThread)*totthread, "ParticleThread");
1440         ctx= MEM_callocN(sizeof(ParticleThreadContext), "ParticleThreadContext");
1441
1442         ctx->sim = *sim;
1443         ctx->dm= ctx->sim.psmd->dm;
1444         ctx->ma= give_current_material(sim->ob, sim->psys->part->omat);
1445
1446         memset(threads, 0, sizeof(ParticleThread)*totthread);
1447
1448         for (i=0; i<totthread; i++) {
1449                 threads[i].ctx= ctx;
1450                 threads[i].num= i;
1451                 threads[i].tot= totthread;
1452         }
1453
1454         return threads;
1455 }
1456
1457 void psys_threads_free(ParticleThread *threads)
1458 {
1459         ParticleThreadContext *ctx= threads[0].ctx;
1460         int i, totthread= threads[0].tot;
1461
1462         /* path caching */
1463         if (ctx->vg_length)
1464                 MEM_freeN(ctx->vg_length);
1465         if (ctx->vg_clump)
1466                 MEM_freeN(ctx->vg_clump);
1467         if (ctx->vg_kink)
1468                 MEM_freeN(ctx->vg_kink);
1469         if (ctx->vg_rough1)
1470                 MEM_freeN(ctx->vg_rough1);
1471         if (ctx->vg_rough2)
1472                 MEM_freeN(ctx->vg_rough2);
1473         if (ctx->vg_roughe)
1474                 MEM_freeN(ctx->vg_roughe);
1475
1476         if (ctx->sim.psys->lattice) {
1477                 end_latt_deform(ctx->sim.psys->lattice);
1478                 ctx->sim.psys->lattice= NULL;
1479         }
1480
1481         /* distribution */
1482         if (ctx->jit) MEM_freeN(ctx->jit);
1483         if (ctx->jitoff) MEM_freeN(ctx->jitoff);
1484         if (ctx->weight) MEM_freeN(ctx->weight);
1485         if (ctx->index) MEM_freeN(ctx->index);
1486         if (ctx->skip) MEM_freeN(ctx->skip);
1487         if (ctx->seams) MEM_freeN(ctx->seams);
1488         //if (ctx->vertpart) MEM_freeN(ctx->vertpart);
1489         BLI_kdtree_free(ctx->tree);
1490
1491         /* threads */
1492         for (i=0; i<totthread; i++) {
1493                 if (threads[i].rng)
1494                         BLI_rng_free(threads[i].rng);
1495                 if (threads[i].rng_path)
1496                         BLI_rng_free(threads[i].rng_path);
1497         }
1498
1499         MEM_freeN(ctx);
1500         MEM_freeN(threads);
1501 }
1502
1503 /* set particle parameters that don't change during particle's life */
1504 void initialize_particle(ParticleSimulationData *sim, ParticleData *pa, int p)
1505 {
1506         ParticleSystem *psys = sim->psys;
1507         ParticleSettings *part = psys->part;
1508         ParticleTexture ptex;
1509
1510         pa->flag &= ~PARS_UNEXIST;
1511
1512         if (part->type != PART_FLUID) {
1513                 psys_get_texture(sim, pa, &ptex, PAMAP_INIT, 0.f);
1514                 
1515                 if (ptex.exist < PSYS_FRAND(p+125))
1516                         pa->flag |= PARS_UNEXIST;
1517
1518                 pa->time = (part->type == PART_HAIR) ? 0.f : part->sta + (part->end - part->sta)*ptex.time;
1519         }
1520
1521         pa->hair_index = 0;
1522         /* we can't reset to -1 anymore since we've figured out correct index in distribute_particles */
1523         /* usage other than straight after distribute has to handle this index by itself - jahka*/
1524         //pa->num_dmcache = DMCACHE_NOTFOUND; /* assume we don't have a derived mesh face */
1525 }
1526 static void initialize_all_particles(ParticleSimulationData *sim)
1527 {
1528         ParticleSystem *psys = sim->psys;
1529         PARTICLE_P;
1530
1531         psys->totunexist = 0;
1532
1533         LOOP_PARTICLES {
1534                 if ((pa->flag & PARS_UNEXIST)==0)
1535                         initialize_particle(sim, pa, p);
1536
1537                 if (pa->flag & PARS_UNEXIST)
1538                         psys->totunexist++;
1539         }
1540
1541         /* Free unexisting particles. */
1542         if (psys->totpart && psys->totunexist == psys->totpart) {
1543                 if (psys->particles->boid)
1544                         MEM_freeN(psys->particles->boid);
1545
1546                 MEM_freeN(psys->particles);
1547                 psys->particles = NULL;
1548                 psys->totpart = psys->totunexist = 0;
1549         }
1550
1551         if (psys->totunexist) {
1552                 int newtotpart = psys->totpart - psys->totunexist;
1553                 ParticleData *npa, *newpars;
1554                 
1555                 npa = newpars = MEM_callocN(newtotpart * sizeof(ParticleData), "particles");
1556
1557                 for (p=0, pa=psys->particles; p<newtotpart; p++, pa++, npa++) {
1558                         while (pa->flag & PARS_UNEXIST)
1559                                 pa++;
1560
1561                         memcpy(npa, pa, sizeof(ParticleData));
1562                 }
1563
1564                 if (psys->particles->boid)
1565                         MEM_freeN(psys->particles->boid);
1566                 MEM_freeN(psys->particles);
1567                 psys->particles = newpars;
1568                 psys->totpart -= psys->totunexist;
1569
1570                 if (psys->particles->boid) {
1571                         BoidParticle *newboids = MEM_callocN(psys->totpart * sizeof(BoidParticle), "boid particles");
1572
1573                         LOOP_PARTICLES
1574                                 pa->boid = newboids++;
1575
1576                 }
1577         }
1578 }
1579
1580 static void get_angular_velocity_vector(short avemode, ParticleKey *state, float vec[3])
1581 {
1582         switch (avemode) {
1583                 case PART_AVE_VELOCITY:
1584                         copy_v3_v3(vec, state->vel);
1585                         break;
1586                 case PART_AVE_HORIZONTAL:
1587                 {
1588                         float zvec[3];
1589                         zvec[0] = zvec[1] = 0;
1590                         zvec[2] = 1.f;
1591                         cross_v3_v3v3(vec, state->vel, zvec);
1592                         break;
1593                 }
1594                 case PART_AVE_VERTICAL:
1595                 {
1596                         float zvec[3], temp[3];
1597                         zvec[0] = zvec[1] = 0;
1598                         zvec[2] = 1.f;
1599                         cross_v3_v3v3(temp, state->vel, zvec);
1600                         cross_v3_v3v3(vec, temp, state->vel);
1601                         break;
1602                 }
1603                 case PART_AVE_GLOBAL_X:
1604                         vec[0] = 1.f;
1605                         vec[1] = vec[2] = 0;
1606                         break;
1607                 case PART_AVE_GLOBAL_Y:
1608                         vec[1] = 1.f;
1609                         vec[0] = vec[2] = 0;
1610                         break;
1611                 case PART_AVE_GLOBAL_Z:
1612                         vec[2] = 1.f;
1613                         vec[0] = vec[1] = 0;
1614                         break;
1615         }
1616 }
1617
1618 void psys_get_birth_coordinates(ParticleSimulationData *sim, ParticleData *pa, ParticleKey *state, float dtime, float cfra)
1619 {
1620         Object *ob = sim->ob;
1621         ParticleSystem *psys = sim->psys;
1622         ParticleSettings *part;
1623         ParticleTexture ptex;
1624         float fac, phasefac, nor[3] = {0,0,0},loc[3],vel[3] = {0.0,0.0,0.0},rot[4],q2[4];
1625         float r_vel[3],r_ave[3],r_rot[4],vec[3],p_vel[3] = {0.0,0.0,0.0};
1626         float x_vec[3] = {1.0,0.0,0.0}, utan[3] = {0.0,1.0,0.0}, vtan[3] = {0.0,0.0,1.0}, rot_vec[3] = {0.0,0.0,0.0};
1627         float q_phase[4];
1628         int p = pa - psys->particles;
1629         part=psys->part;
1630
1631         /* get birth location from object               */
1632         if (part->tanfac != 0.f)
1633                 psys_particle_on_emitter(sim->psmd, part->from,pa->num, pa->num_dmcache, pa->fuv,pa->foffset,loc,nor,utan,vtan,0,0);
1634         else
1635                 psys_particle_on_emitter(sim->psmd, part->from,pa->num, pa->num_dmcache, pa->fuv,pa->foffset,loc,nor,0,0,0,0);
1636                 
1637         /* get possible textural influence */
1638         psys_get_texture(sim, pa, &ptex, PAMAP_IVEL, cfra);
1639
1640         /* particles live in global space so    */
1641         /* let's convert:                                               */
1642         /* -location                                                    */
1643         mul_m4_v3(ob->obmat, loc);
1644                 
1645         /* -normal                                                              */
1646         mul_mat3_m4_v3(ob->obmat, nor);
1647         normalize_v3(nor);
1648
1649         /* -tangent                                                             */
1650         if (part->tanfac!=0.0f) {
1651                 //float phase=vg_rot?2.0f*(psys_particle_value_from_verts(sim->psmd->dm,part->from,pa,vg_rot)-0.5f):0.0f;
1652                 float phase=0.0f;
1653                 mul_v3_fl(vtan,-cosf((float)M_PI*(part->tanphase+phase)));
1654                 fac= -sinf((float)M_PI*(part->tanphase+phase));
1655                 madd_v3_v3fl(vtan, utan, fac);
1656
1657                 mul_mat3_m4_v3(ob->obmat,vtan);
1658
1659                 copy_v3_v3(utan, nor);
1660                 mul_v3_fl(utan,dot_v3v3(vtan,nor));
1661                 sub_v3_v3(vtan, utan);
1662                         
1663                 normalize_v3(vtan);
1664         }
1665                 
1666
1667         /* -velocity (boids need this even if there's no random velocity) */
1668         if (part->randfac != 0.0f || (part->phystype==PART_PHYS_BOIDS && pa->boid)) {
1669                 r_vel[0] = 2.0f * (PSYS_FRAND(p + 10) - 0.5f);
1670                 r_vel[1] = 2.0f * (PSYS_FRAND(p + 11) - 0.5f);
1671                 r_vel[2] = 2.0f * (PSYS_FRAND(p + 12) - 0.5f);
1672
1673                 mul_mat3_m4_v3(ob->obmat, r_vel);
1674                 normalize_v3(r_vel);
1675         }
1676
1677         /* -angular velocity                                    */
1678         if (part->avemode==PART_AVE_RAND) {
1679                 r_ave[0] = 2.0f * (PSYS_FRAND(p + 13) - 0.5f);
1680                 r_ave[1] = 2.0f * (PSYS_FRAND(p + 14) - 0.5f);
1681                 r_ave[2] = 2.0f * (PSYS_FRAND(p + 15) - 0.5f);
1682
1683                 mul_mat3_m4_v3(ob->obmat,r_ave);
1684                 normalize_v3(r_ave);
1685         }
1686                 
1687         /* -rotation                                                    */
1688         if (part->randrotfac != 0.0f) {
1689                 r_rot[0] = 2.0f * (PSYS_FRAND(p + 16) - 0.5f);
1690                 r_rot[1] = 2.0f * (PSYS_FRAND(p + 17) - 0.5f);
1691                 r_rot[2] = 2.0f * (PSYS_FRAND(p + 18) - 0.5f);
1692                 r_rot[3] = 2.0f * (PSYS_FRAND(p + 19) - 0.5f);
1693                 normalize_qt(r_rot);
1694
1695                 mat4_to_quat(rot,ob->obmat);
1696                 mul_qt_qtqt(r_rot,r_rot,rot);
1697         }
1698
1699         if (part->phystype==PART_PHYS_BOIDS && pa->boid) {
1700                 float dvec[3], q[4], mat[3][3];
1701
1702                 copy_v3_v3(state->co,loc);
1703
1704                 /* boids don't get any initial velocity  */
1705                 zero_v3(state->vel);
1706
1707                 /* boids store direction in ave */
1708                 if (fabsf(nor[2])==1.0f) {
1709                         sub_v3_v3v3(state->ave, loc, ob->obmat[3]);
1710                         normalize_v3(state->ave);
1711                 }
1712                 else {
1713                         copy_v3_v3(state->ave, nor);
1714                 }
1715
1716                 /* calculate rotation matrix */
1717                 project_v3_v3v3(dvec, r_vel, state->ave);
1718                 sub_v3_v3v3(mat[0], state->ave, dvec);
1719                 normalize_v3(mat[0]);
1720                 negate_v3_v3(mat[2], r_vel);
1721                 normalize_v3(mat[2]);
1722                 cross_v3_v3v3(mat[1], mat[2], mat[0]);
1723                 
1724                 /* apply rotation */
1725                 mat3_to_quat_is_ok( q,mat);
1726                 copy_qt_qt(state->rot, q);
1727         }
1728         else {
1729                 /* conversion done so now we apply new: */
1730                 /* -velocity from:                                              */
1731
1732                 /*              *reactions                                              */
1733                 if (dtime > 0.f) {
1734                         sub_v3_v3v3(vel, pa->state.vel, pa->prev_state.vel);
1735                 }
1736
1737                 /*              *emitter velocity                               */
1738                 if (dtime != 0.f && part->obfac != 0.f) {
1739                         sub_v3_v3v3(vel, loc, state->co);
1740                         mul_v3_fl(vel, part->obfac/dtime);
1741                 }
1742                 
1743                 /*              *emitter normal                                 */
1744                 if (part->normfac != 0.f)
1745                         madd_v3_v3fl(vel, nor, part->normfac);
1746                 
1747                 /*              *emitter tangent                                */
1748                 if (sim->psmd && part->tanfac != 0.f)
1749                         madd_v3_v3fl(vel, vtan, part->tanfac);
1750
1751                 /*              *emitter object orientation             */
1752                 if (part->ob_vel[0] != 0.f) {
1753                         normalize_v3_v3(vec, ob->obmat[0]);
1754                         madd_v3_v3fl(vel, vec, part->ob_vel[0]);
1755                 }
1756                 if (part->ob_vel[1] != 0.f) {
1757                         normalize_v3_v3(vec, ob->obmat[1]);
1758                         madd_v3_v3fl(vel, vec, part->ob_vel[1]);
1759                 }
1760                 if (part->ob_vel[2] != 0.f) {
1761                         normalize_v3_v3(vec, ob->obmat[2]);
1762                         madd_v3_v3fl(vel, vec, part->ob_vel[2]);
1763                 }
1764
1765                 /*              *texture                                                */
1766                 /* TODO */
1767
1768                 /*              *random                                                 */
1769                 if (part->randfac != 0.f)
1770                         madd_v3_v3fl(vel, r_vel, part->randfac);
1771
1772                 /*              *particle                                               */
1773                 if (part->partfac != 0.f)
1774                         madd_v3_v3fl(vel, p_vel, part->partfac);
1775                 
1776                 mul_v3_v3fl(state->vel, vel, ptex.ivel);
1777
1778                 /* -location from emitter                               */
1779                 copy_v3_v3(state->co,loc);
1780
1781                 /* -rotation                                                    */
1782                 unit_qt(state->rot);
1783
1784                 if (part->rotmode) {
1785                         /* create vector into which rotation is aligned */
1786                         switch (part->rotmode) {
1787                                 case PART_ROT_NOR:
1788                                         copy_v3_v3(rot_vec, nor);
1789                                         break;
1790                                 case PART_ROT_VEL:
1791                                         copy_v3_v3(rot_vec, vel);
1792                                         break;
1793                                 case PART_ROT_GLOB_X:
1794                                 case PART_ROT_GLOB_Y:
1795                                 case PART_ROT_GLOB_Z:
1796                                         rot_vec[part->rotmode - PART_ROT_GLOB_X] = 1.0f;
1797                                         break;
1798                                 case PART_ROT_OB_X:
1799                                 case PART_ROT_OB_Y:
1800                                 case PART_ROT_OB_Z:
1801                                         copy_v3_v3(rot_vec, ob->obmat[part->rotmode - PART_ROT_OB_X]);
1802                                         break;
1803                         }
1804                         
1805                         /* create rotation quat */
1806                         negate_v3(rot_vec);
1807                         vec_to_quat( q2,rot_vec, OB_POSX, OB_POSZ);
1808
1809                         /* randomize rotation quat */
1810                         if (part->randrotfac!=0.0f)
1811                                 interp_qt_qtqt(rot, q2, r_rot, part->randrotfac);
1812                         else
1813                                 copy_qt_qt(rot,q2);
1814
1815                         /* rotation phase */
1816                         phasefac = part->phasefac;
1817                         if (part->randphasefac != 0.0f)
1818                                 phasefac += part->randphasefac * PSYS_FRAND(p + 20);
1819                         axis_angle_to_quat( q_phase,x_vec, phasefac*(float)M_PI);
1820
1821                         /* combine base rotation & phase */
1822                         mul_qt_qtqt(state->rot, rot, q_phase);
1823                 }
1824
1825                 /* -angular velocity                                    */
1826
1827                 zero_v3(state->ave);
1828
1829                 if (part->avemode) {
1830                         if (part->avemode == PART_AVE_RAND)
1831                                 copy_v3_v3(state->ave, r_ave);
1832                         else
1833                                 get_angular_velocity_vector(part->avemode, state, state->ave);
1834
1835                         normalize_v3(state->ave);
1836                         mul_v3_fl(state->ave, part->avefac);
1837                 }
1838         }
1839 }
1840 /* sets particle to the emitter surface with initial velocity & rotation */
1841 void reset_particle(ParticleSimulationData *sim, ParticleData *pa, float dtime, float cfra)
1842 {
1843         Object *ob = sim->ob;
1844         ParticleSystem *psys = sim->psys;
1845         ParticleSettings *part;
1846         ParticleTexture ptex;
1847         int p = pa - psys->particles;
1848         part=psys->part;
1849         
1850         /* get precise emitter matrix if particle is born */
1851         if (part->type!=PART_HAIR && dtime > 0.f && pa->time < cfra && pa->time >= sim->psys->cfra) {
1852                 /* we have to force RECALC_ANIM here since where_is_objec_time only does drivers */
1853                 while (ob) {
1854                         BKE_animsys_evaluate_animdata(sim->scene, &ob->id, ob->adt, pa->time, ADT_RECALC_ANIM);
1855                         ob = ob->parent;
1856                 }
1857                 ob = sim->ob;
1858                 BKE_object_where_is_calc_time(sim->scene, ob, pa->time);
1859
1860                 psys->flag |= PSYS_OB_ANIM_RESTORE;
1861         }
1862
1863         psys_get_birth_coordinates(sim, pa, &pa->state, dtime, cfra);
1864
1865         if (part->phystype==PART_PHYS_BOIDS && pa->boid) {
1866                 BoidParticle *bpa = pa->boid;
1867
1868                 /* and gravity in r_ve */
1869                 bpa->gravity[0] = bpa->gravity[1] = 0.0f;
1870                 bpa->gravity[2] = -1.0f;
1871                 if ((sim->scene->physics_settings.flag & PHYS_GLOBAL_GRAVITY) &&
1872                     (sim->scene->physics_settings.gravity[2] != 0.0f))
1873                 {
1874                         bpa->gravity[2] = sim->scene->physics_settings.gravity[2];
1875                 }
1876
1877                 bpa->data.health = part->boids->health;
1878                 bpa->data.mode = eBoidMode_InAir;
1879                 bpa->data.state_id = ((BoidState*)part->boids->states.first)->id;
1880                 bpa->data.acc[0]=bpa->data.acc[1]=bpa->data.acc[2]=0.0f;
1881         }
1882
1883
1884         if (part->type == PART_HAIR) {
1885                 pa->lifetime = 100.0f;
1886         }
1887         else {
1888                 /* get possible textural influence */
1889                 psys_get_texture(sim, pa, &ptex, PAMAP_LIFE, cfra);
1890
1891                 pa->lifetime = part->lifetime * ptex.life;
1892
1893                 if (part->randlife != 0.0f)
1894                         pa->lifetime *= 1.0f - part->randlife * PSYS_FRAND(p + 21);
1895         }
1896
1897         pa->dietime = pa->time + pa->lifetime;
1898
1899         if (sim->psys->pointcache && sim->psys->pointcache->flag & PTCACHE_BAKED &&
1900                 sim->psys->pointcache->mem_cache.first) {
1901                 float dietime = psys_get_dietime_from_cache(sim->psys->pointcache, p);
1902                 pa->dietime = MIN2(pa->dietime, dietime);
1903         }
1904
1905         if (pa->time > cfra)
1906                 pa->alive = PARS_UNBORN;
1907         else if (pa->dietime <= cfra)
1908                 pa->alive = PARS_DEAD;
1909         else
1910                 pa->alive = PARS_ALIVE;
1911
1912         pa->state.time = cfra;
1913 }
1914 static void reset_all_particles(ParticleSimulationData *sim, float dtime, float cfra, int from)
1915 {
1916         ParticleData *pa;
1917         int p, totpart=sim->psys->totpart;
1918         
1919         for (p=from, pa=sim->psys->particles+from; p<totpart; p++, pa++)
1920                 reset_particle(sim, pa, dtime, cfra);
1921 }
1922 /************************************************/
1923 /*                      Particle targets                                        */
1924 /************************************************/
1925 ParticleSystem *psys_get_target_system(Object *ob, ParticleTarget *pt)
1926 {
1927         ParticleSystem *psys = NULL;
1928
1929         if (pt->ob == NULL || pt->ob == ob)
1930                 psys = BLI_findlink(&ob->particlesystem, pt->psys-1);
1931         else
1932                 psys = BLI_findlink(&pt->ob->particlesystem, pt->psys-1);
1933
1934         if (psys)
1935                 pt->flag |= PTARGET_VALID;
1936         else
1937                 pt->flag &= ~PTARGET_VALID;
1938
1939         return psys;
1940 }
1941 /************************************************/
1942 /*                      Keyed particles                                         */
1943 /************************************************/
1944 /* Counts valid keyed targets */
1945 void psys_count_keyed_targets(ParticleSimulationData *sim)
1946 {
1947         ParticleSystem *psys = sim->psys, *kpsys;
1948         ParticleTarget *pt = psys->targets.first;
1949         int keys_valid = 1;
1950         psys->totkeyed = 0;
1951
1952         for (; pt; pt=pt->next) {
1953                 kpsys = psys_get_target_system(sim->ob, pt);
1954
1955                 if (kpsys && kpsys->totpart) {
1956                         psys->totkeyed += keys_valid;
1957                         if (psys->flag & PSYS_KEYED_TIMING && pt->duration != 0.0f)
1958                                 psys->totkeyed += 1;
1959                 }
1960                 else {
1961                         keys_valid = 0;
1962                 }
1963         }
1964
1965         psys->totkeyed *= psys->flag & PSYS_KEYED_TIMING ? 1 : psys->part->keyed_loops;
1966 }
1967
1968 static void set_keyed_keys(ParticleSimulationData *sim)
1969 {
1970         ParticleSystem *psys = sim->psys;
1971         ParticleSimulationData ksim= {0};
1972         ParticleTarget *pt;
1973         PARTICLE_P;
1974         ParticleKey *key;
1975         int totpart = psys->totpart, k, totkeys = psys->totkeyed;
1976         int keyed_flag = 0;
1977
1978         ksim.scene= sim->scene;
1979         
1980         /* no proper targets so let's clear and bail out */
1981         if (psys->totkeyed==0) {
1982                 free_keyed_keys(psys);
1983                 psys->flag &= ~PSYS_KEYED;
1984                 return;
1985         }
1986
1987         if (totpart && psys->particles->totkey != totkeys) {
1988                 free_keyed_keys(psys);
1989                 
1990                 key = MEM_callocN(totpart*totkeys*sizeof(ParticleKey), "Keyed keys");
1991                 
1992                 LOOP_PARTICLES {
1993                         pa->keys = key;
1994                         pa->totkey = totkeys;
1995                         key += totkeys;
1996                 }
1997         }
1998         
1999         psys->flag &= ~PSYS_KEYED;
2000
2001
2002         pt = psys->targets.first;
2003         for (k=0; k<totkeys; k++) {
2004                 ksim.ob = pt->ob ? pt->ob : sim->ob;
2005                 ksim.psys = BLI_findlink(&ksim.ob->particlesystem, pt->psys - 1);
2006                 keyed_flag = (ksim.psys->flag & PSYS_KEYED);
2007                 ksim.psys->flag &= ~PSYS_KEYED;
2008
2009                 LOOP_PARTICLES {
2010                         key = pa->keys + k;
2011                         key->time = -1.0; /* use current time */
2012
2013                         psys_get_particle_state(&ksim, p%ksim.psys->totpart, key, 1);
2014
2015                         if (psys->flag & PSYS_KEYED_TIMING) {
2016                                 key->time = pa->time + pt->time;
2017                                 if (pt->duration != 0.0f && k+1 < totkeys) {
2018                                         copy_particle_key(key+1, key, 1);
2019                                         (key+1)->time = pa->time + pt->time + pt->duration;
2020                                 }
2021                         }
2022                         else if (totkeys > 1)
2023                                 key->time = pa->time + (float)k / (float)(totkeys - 1) * pa->lifetime;
2024                         else
2025                                 key->time = pa->time;
2026                 }
2027
2028                 if (psys->flag & PSYS_KEYED_TIMING && pt->duration!=0.0f)
2029                         k++;
2030
2031                 ksim.psys->flag |= keyed_flag;
2032
2033                 pt = (pt->next && pt->next->flag & PTARGET_VALID)? pt->next : psys->targets.first;
2034         }
2035
2036         psys->flag |= PSYS_KEYED;
2037 }
2038
2039 /************************************************/
2040 /*                      Point Cache                                                     */
2041 /************************************************/
2042 void psys_make_temp_pointcache(Object *ob, ParticleSystem *psys)
2043 {
2044         PointCache *cache = psys->pointcache;
2045
2046         if (cache->flag & PTCACHE_DISK_CACHE && cache->mem_cache.first == NULL) {
2047                 PTCacheID pid;
2048                 BKE_ptcache_id_from_particles(&pid, ob, psys);
2049                 cache->flag &= ~PTCACHE_DISK_CACHE;
2050                 BKE_ptcache_disk_to_mem(&pid);
2051                 cache->flag |= PTCACHE_DISK_CACHE;
2052         }
2053 }
2054 static void psys_clear_temp_pointcache(ParticleSystem *psys)
2055 {
2056         if (psys->pointcache->flag & PTCACHE_DISK_CACHE)
2057                 BKE_ptcache_free_mem(&psys->pointcache->mem_cache);
2058 }
2059 void psys_get_pointcache_start_end(Scene *scene, ParticleSystem *psys, int *sfra, int *efra)
2060 {
2061         ParticleSettings *part = psys->part;
2062
2063         *sfra = MAX2(1, (int)part->sta);
2064         *efra = MIN2((int)(part->end + part->lifetime + 1.0f), scene->r.efra);
2065 }
2066
2067 /************************************************/
2068 /*                      Effectors                                                       */
2069 /************************************************/
2070 static void psys_update_particle_bvhtree(ParticleSystem *psys, float cfra)
2071 {
2072         if (psys) {
2073                 PARTICLE_P;
2074                 int totpart = 0;
2075
2076                 if (!psys->bvhtree || psys->bvhtree_frame != cfra) {
2077                         LOOP_SHOWN_PARTICLES {
2078                                 totpart++;
2079                         }
2080                         
2081                         BLI_bvhtree_free(psys->bvhtree);
2082                         psys->bvhtree = BLI_bvhtree_new(totpart, 0.0, 4, 6);
2083
2084                         LOOP_SHOWN_PARTICLES {
2085                                 if (pa->alive == PARS_ALIVE) {
2086                                         if (pa->state.time == cfra)
2087                                                 BLI_bvhtree_insert(psys->bvhtree, p, pa->prev_state.co, 1);
2088                                         else
2089                                                 BLI_bvhtree_insert(psys->bvhtree, p, pa->state.co, 1);
2090                                 }
2091                         }
2092                         BLI_bvhtree_balance(psys->bvhtree);
2093
2094                         psys->bvhtree_frame = cfra;
2095                 }
2096         }
2097 }
2098 void psys_update_particle_tree(ParticleSystem *psys, float cfra)
2099 {
2100         if (psys) {
2101                 PARTICLE_P;
2102                 int totpart = 0;
2103
2104                 if (!psys->tree || psys->tree_frame != cfra) {
2105                         LOOP_SHOWN_PARTICLES {
2106                                 totpart++;
2107                         }
2108
2109                         BLI_kdtree_free(psys->tree);
2110                         psys->tree = BLI_kdtree_new(psys->totpart);
2111
2112                         LOOP_SHOWN_PARTICLES {
2113                                 if (pa->alive == PARS_ALIVE) {
2114                                         if (pa->state.time == cfra)
2115                                                 BLI_kdtree_insert(psys->tree, p, pa->prev_state.co, NULL);
2116                                         else
2117                                                 BLI_kdtree_insert(psys->tree, p, pa->state.co, NULL);
2118                                 }
2119                         }
2120                         BLI_kdtree_balance(psys->tree);
2121
2122                         psys->tree_frame = cfra;
2123                 }
2124         }
2125 }
2126
2127 static void psys_update_effectors(ParticleSimulationData *sim)
2128 {
2129         pdEndEffectors(&sim->psys->effectors);
2130         sim->psys->effectors = pdInitEffectors(sim->scene, sim->ob, sim->psys, sim->psys->part->effector_weights);
2131         precalc_guides(sim, sim->psys->effectors);
2132 }
2133
2134 static void integrate_particle(ParticleSettings *part, ParticleData *pa, float dtime, float *external_acceleration, void (*force_func)(void *forcedata, ParticleKey *state, float *force, float *impulse), void *forcedata)
2135 {
2136         ParticleKey states[5];
2137         float force[3],acceleration[3],impulse[3],dx[4][3],dv[4][3],oldpos[3];
2138         float pa_mass= (part->flag & PART_SIZEMASS ? part->mass * pa->size : part->mass);
2139         int i, steps=1;
2140         int integrator = part->integrator;
2141
2142         copy_v3_v3(oldpos, pa->state.co);
2143         
2144         /* Verlet integration behaves strangely with moving emitters, so do first step with euler. */
2145         if (pa->prev_state.time < 0.f && integrator == PART_INT_VERLET)
2146                 integrator = PART_INT_EULER;
2147
2148         switch (integrator) {
2149                 case PART_INT_EULER:
2150                         steps=1;
2151                         break;
2152                 case PART_INT_MIDPOINT:
2153                         steps=2;
2154                         break;
2155                 case PART_INT_RK4:
2156                         steps=4;
2157                         break;
2158                 case PART_INT_VERLET:
2159                         steps=1;
2160                         break;
2161         }
2162
2163         for (i=0; i<steps; i++) {
2164                 copy_particle_key(states + i, &pa->state, 1);
2165         }
2166
2167         states->time = 0.f;
2168
2169         for (i=0; i<steps; i++) {
2170                 zero_v3(force);
2171                 zero_v3(impulse);
2172
2173                 force_func(forcedata, states+i, force, impulse);
2174
2175                 /* force to acceleration*/
2176                 mul_v3_v3fl(acceleration, force, 1.0f/pa_mass);
2177
2178                 if (external_acceleration)
2179                         add_v3_v3(acceleration, external_acceleration);
2180                 
2181                 /* calculate next state */
2182                 add_v3_v3(states[i].vel, impulse);
2183
2184                 switch (integrator) {
2185                         case PART_INT_EULER:
2186                                 madd_v3_v3v3fl(pa->state.co, states->co, states->vel, dtime);
2187                                 madd_v3_v3v3fl(pa->state.vel, states->vel, acceleration, dtime);
2188                                 break;
2189                         case PART_INT_MIDPOINT:
2190                                 if (i==0) {
2191                                         madd_v3_v3v3fl(states[1].co, states->co, states->vel, dtime*0.5f);
2192                                         madd_v3_v3v3fl(states[1].vel, states->vel, acceleration, dtime*0.5f);
2193                                         states[1].time = dtime*0.5f;
2194                                         /*fra=sim->psys->cfra+0.5f*dfra;*/
2195                                 }
2196                                 else {
2197                                         madd_v3_v3v3fl(pa->state.co, states->co, states[1].vel, dtime);
2198                                         madd_v3_v3v3fl(pa->state.vel, states->vel, acceleration, dtime);
2199                                 }
2200                                 break;
2201                         case PART_INT_RK4:
2202                                 switch (i) {
2203                                         case 0:
2204                                                 copy_v3_v3(dx[0], states->vel);
2205                                                 mul_v3_fl(dx[0], dtime);
2206                                                 copy_v3_v3(dv[0], acceleration);
2207                                                 mul_v3_fl(dv[0], dtime);
2208
2209                                                 madd_v3_v3v3fl(states[1].co, states->co, dx[0], 0.5f);
2210                                                 madd_v3_v3v3fl(states[1].vel, states->vel, dv[0], 0.5f);
2211                                                 states[1].time = dtime*0.5f;
2212                                                 /*fra=sim->psys->cfra+0.5f*dfra;*/
2213                                                 break;
2214                                         case 1:
2215                                                 madd_v3_v3v3fl(dx[1], states->vel, dv[0], 0.5f);
2216                                                 mul_v3_fl(dx[1], dtime);
2217                                                 copy_v3_v3(dv[1], acceleration);
2218                                                 mul_v3_fl(dv[1], dtime);
2219
2220                                                 madd_v3_v3v3fl(states[2].co, states->co, dx[1], 0.5f);
2221                                                 madd_v3_v3v3fl(states[2].vel, states->vel, dv[1], 0.5f);
2222                                                 states[2].time = dtime*0.5f;
2223                                                 break;
2224                                         case 2:
2225                                                 madd_v3_v3v3fl(dx[2], states->vel, dv[1], 0.5f);
2226                                                 mul_v3_fl(dx[2], dtime);
2227                                                 copy_v3_v3(dv[2], acceleration);
2228                                                 mul_v3_fl(dv[2], dtime);
2229
2230                                                 add_v3_v3v3(states[3].co, states->co, dx[2]);
2231                                                 add_v3_v3v3(states[3].vel, states->vel, dv[2]);
2232                                                 states[3].time = dtime;
2233                                                 /*fra=cfra;*/
2234                                                 break;
2235                                         case 3:
2236                                                 add_v3_v3v3(dx[3], states->vel, dv[2]);
2237                                                 mul_v3_fl(dx[3], dtime);
2238                                                 copy_v3_v3(dv[3], acceleration);
2239                                                 mul_v3_fl(dv[3], dtime);
2240
2241                                                 madd_v3_v3v3fl(pa->state.co, states->co, dx[0], 1.0f/6.0f);
2242                                                 madd_v3_v3fl(pa->state.co, dx[1], 1.0f/3.0f);
2243                                                 madd_v3_v3fl(pa->state.co, dx[2], 1.0f/3.0f);
2244                                                 madd_v3_v3fl(pa->state.co, dx[3], 1.0f/6.0f);
2245
2246                                                 madd_v3_v3v3fl(pa->state.vel, states->vel, dv[0], 1.0f/6.0f);
2247                                                 madd_v3_v3fl(pa->state.vel, dv[1], 1.0f/3.0f);
2248                                                 madd_v3_v3fl(pa->state.vel, dv[2], 1.0f/3.0f);
2249                                                 madd_v3_v3fl(pa->state.vel, dv[3], 1.0f/6.0f);
2250                                 }
2251                                 break;
2252                         case PART_INT_VERLET:   /* Verlet integration */
2253                                 madd_v3_v3v3fl(pa->state.vel, pa->prev_state.vel, acceleration, dtime);
2254                                 madd_v3_v3v3fl(pa->state.co, pa->prev_state.co, pa->state.vel, dtime);
2255
2256                                 sub_v3_v3v3(pa->state.vel, pa->state.co, oldpos);
2257                                 mul_v3_fl(pa->state.vel, 1.0f/dtime);
2258                                 break;
2259                 }
2260         }
2261 }
2262
2263 /*********************************************************************************************************
2264  *                    SPH fluid physics 
2265  *
2266  * In theory, there could be unlimited implementation of SPH simulators
2267  *
2268  * This code uses in some parts adapted algorithms from the pseudo code as outlined in the Research paper:
2269  *
2270  * Titled: Particle-based Viscoelastic Fluid Simulation.
2271  * Authors: Simon Clavet, Philippe Beaudoin and Pierre Poulin
2272  * Website: http://www.iro.umontreal.ca/labs/infographie/papers/Clavet-2005-PVFS/
2273  *
2274  * Presented at Siggraph, (2005)
2275  *
2276  * ********************************************************************************************************/
2277 #define PSYS_FLUID_SPRINGS_INITIAL_SIZE 256
2278 static ParticleSpring *sph_spring_add(ParticleSystem *psys, ParticleSpring *spring)
2279 {
2280         /* Are more refs required? */
2281         if (psys->alloc_fluidsprings == 0 || psys->fluid_springs == NULL) {
2282                 psys->alloc_fluidsprings = PSYS_FLUID_SPRINGS_INITIAL_SIZE;
2283                 psys->fluid_springs = (ParticleSpring*)MEM_callocN(psys->alloc_fluidsprings * sizeof(ParticleSpring), "Particle Fluid Springs");
2284         }
2285         else if (psys->tot_fluidsprings == psys->alloc_fluidsprings) {
2286                 /* Double the number of refs allocated */
2287                 psys->alloc_fluidsprings *= 2;
2288                 psys->fluid_springs = (ParticleSpring*)MEM_reallocN(psys->fluid_springs, psys->alloc_fluidsprings * sizeof(ParticleSpring));
2289         }
2290
2291         memcpy(psys->fluid_springs + psys->tot_fluidsprings, spring, sizeof(ParticleSpring));
2292         psys->tot_fluidsprings++;
2293
2294         return psys->fluid_springs + psys->tot_fluidsprings - 1;
2295 }
2296 static void sph_spring_delete(ParticleSystem *psys, int j)
2297 {
2298         if (j != psys->tot_fluidsprings - 1)
2299                 psys->fluid_springs[j] = psys->fluid_springs[psys->tot_fluidsprings - 1];
2300
2301         psys->tot_fluidsprings--;
2302
2303         if (psys->tot_fluidsprings < psys->alloc_fluidsprings/2 && psys->alloc_fluidsprings > PSYS_FLUID_SPRINGS_INITIAL_SIZE) {
2304                 psys->alloc_fluidsprings /= 2;
2305                 psys->fluid_springs = (ParticleSpring*)MEM_reallocN(psys->fluid_springs,  psys->alloc_fluidsprings * sizeof(ParticleSpring));
2306         }
2307 }
2308 static void sph_springs_modify(ParticleSystem *psys, float dtime)
2309 {
2310         SPHFluidSettings *fluid = psys->part->fluid;
2311         ParticleData *pa1, *pa2;
2312         ParticleSpring *spring = psys->fluid_springs;
2313         
2314         float h, d, Rij[3], rij, Lij;
2315         int i;
2316
2317         float yield_ratio = fluid->yield_ratio;
2318         float plasticity = fluid->plasticity_constant;
2319         /* scale things according to dtime */
2320         float timefix = 25.f * dtime;
2321
2322         if ((fluid->flag & SPH_VISCOELASTIC_SPRINGS)==0 || fluid->spring_k == 0.f)
2323                 return;
2324
2325         /* Loop through the springs */
2326         for (i=0; i<psys->tot_fluidsprings; i++, spring++) {
2327                 pa1 = psys->particles + spring->particle_index[0];
2328                 pa2 = psys->particles + spring->particle_index[1];
2329
2330                 sub_v3_v3v3(Rij, pa2->prev_state.co, pa1->prev_state.co);
2331                 rij = normalize_v3(Rij);
2332
2333                 /* adjust rest length */
2334                 Lij = spring->rest_length;
2335                 d = yield_ratio * timefix * Lij;
2336
2337                 if (rij > Lij + d) // Stretch
2338                         spring->rest_length += plasticity * (rij - Lij - d) * timefix;
2339                 else if (rij < Lij - d) // Compress
2340                         spring->rest_length -= plasticity * (Lij - d - rij) * timefix;
2341
2342                 h = 4.f*pa1->size;
2343
2344                 if (spring->rest_length > h)
2345                         spring->delete_flag = 1;
2346         }
2347
2348         /* Loop through springs backwaqrds - for efficient delete function */
2349         for (i=psys->tot_fluidsprings-1; i >= 0; i--) {
2350                 if (psys->fluid_springs[i].delete_flag)
2351                         sph_spring_delete(psys, i);
2352         }
2353 }
2354 static EdgeHash *sph_springhash_build(ParticleSystem *psys)
2355 {
2356         EdgeHash *springhash = NULL;
2357         ParticleSpring *spring;
2358         int i = 0;
2359
2360         springhash = BLI_edgehash_new();
2361
2362         for (i=0, spring=psys->fluid_springs; i<psys->tot_fluidsprings; i++, spring++)
2363                 BLI_edgehash_insert(springhash, spring->particle_index[0], spring->particle_index[1], SET_INT_IN_POINTER(i+1));
2364
2365         return springhash;
2366 }
2367
2368 #define SPH_NEIGHBORS 512
2369 typedef struct SPHNeighbor {
2370         ParticleSystem *psys;
2371         int index;
2372 } SPHNeighbor;
2373
2374 typedef struct SPHRangeData {
2375         SPHNeighbor neighbors[SPH_NEIGHBORS];
2376         int tot_neighbors;
2377
2378         float density, near_density;
2379         float h;
2380
2381         ParticleSystem *npsys;
2382         ParticleData *pa;
2383
2384         float massfac;
2385         int use_size;
2386 } SPHRangeData;
2387
2388 typedef struct SPHData {
2389         ParticleSystem *psys[10];
2390         ParticleData *pa;
2391         float mass;
2392         EdgeHash *eh;
2393         float *gravity;
2394         /* Average distance to neighbors (other particles in the support domain),
2395          * for calculating the Courant number (adaptive time step). */
2396         int pass;
2397         float element_size;
2398         float flow[3];
2399
2400         /* Integrator callbacks. This allows different SPH implementations. */
2401         void (*force_cb) (void *sphdata_v, ParticleKey *state, float *force, float *impulse);
2402         void (*density_cb) (void *rangedata_v, int index, float squared_dist);
2403 } SPHData;
2404
2405 static void sph_density_accum_cb(void *userdata, int index, float squared_dist)
2406 {
2407         SPHRangeData *pfr = (SPHRangeData *)userdata;
2408         ParticleData *npa = pfr->npsys->particles + index;
2409         float q;
2410         float dist;
2411
2412         if (npa == pfr->pa || squared_dist < FLT_EPSILON)
2413                 return;
2414
2415         /* Ugh! One particle has too many neighbors! If some aren't taken into
2416          * account, the forces will be biased by the tree search order. This
2417          * effectively adds enery to the system, and results in a churning motion.
2418          * But, we have to stop somewhere, and it's not the end of the world.
2419          *  - jahka and z0r
2420          */
2421         if (pfr->tot_neighbors >= SPH_NEIGHBORS)
2422                 return;
2423
2424         pfr->neighbors[pfr->tot_neighbors].index = index;
2425         pfr->neighbors[pfr->tot_neighbors].psys = pfr->npsys;
2426         pfr->tot_neighbors++;
2427
2428         dist = sqrtf(squared_dist);
2429         q = (1.f - dist/pfr->h) * pfr->massfac;
2430
2431         if (pfr->use_size)
2432                 q *= npa->size;
2433
2434         pfr->density += q*q;
2435         pfr->near_density += q*q*q;
2436 }
2437
2438 /*
2439  * Find the Courant number for an SPH particle (used for adaptive time step).
2440  */
2441 static void sph_particle_courant(SPHData *sphdata, SPHRangeData *pfr)
2442 {
2443         ParticleData *pa, *npa;
2444         int i;
2445         float flow[3], offset[3], dist;
2446
2447         zero_v3(flow);
2448
2449         dist = 0.0f;
2450         if (pfr->tot_neighbors > 0) {
2451                 pa = pfr->pa;
2452                 for (i=0; i < pfr->tot_neighbors; i++) {
2453                         npa = pfr->neighbors[i].psys->particles + pfr->neighbors[i].index;
2454                         sub_v3_v3v3(offset, pa->prev_state.co, npa->prev_state.co);
2455                         dist += len_v3(offset);
2456                         add_v3_v3(flow, npa->prev_state.vel);
2457                 }
2458                 dist += sphdata->psys[0]->part->fluid->radius; // TODO: remove this? - z0r
2459                 sphdata->element_size = dist / pfr->tot_neighbors;
2460                 mul_v3_v3fl(sphdata->flow, flow, 1.0f / pfr->tot_neighbors);
2461         }
2462         else {
2463                 sphdata->element_size = MAXFLOAT;
2464                 copy_v3_v3(sphdata->flow, flow);
2465         }
2466 }
2467 static void sph_force_cb(void *sphdata_v, ParticleKey *state, float *force, float *UNUSED(impulse))
2468 {
2469         SPHData *sphdata = (SPHData *)sphdata_v;
2470         ParticleSystem **psys = sphdata->psys;
2471         ParticleData *pa = sphdata->pa;
2472         SPHFluidSettings *fluid = psys[0]->part->fluid;
2473         ParticleSpring *spring = NULL;
2474         SPHRangeData pfr;
2475         SPHNeighbor *pfn;
2476         float mass = sphdata->mass;
2477         float *gravity = sphdata->gravity;
2478         EdgeHash *springhash = sphdata->eh;
2479
2480         float q, u, rij, dv[3];
2481         float pressure, near_pressure;
2482
2483         float visc = fluid->viscosity_omega;
2484         float stiff_visc = fluid->viscosity_beta * (fluid->flag & SPH_FAC_VISCOSITY ? fluid->viscosity_omega : 1.f);
2485
2486         float inv_mass = 1.0f/mass;
2487         float spring_constant = fluid->spring_k;
2488         
2489         float h = fluid->radius * (fluid->flag & SPH_FAC_RADIUS ? 4.f*pa->size : 1.f); /* 4.0 seems to be a pretty good value */
2490         float rest_density = fluid->rest_density * (fluid->flag & SPH_FAC_DENSITY ? 4.77f : 1.f); /* 4.77 is an experimentally determined density factor */
2491         float rest_length = fluid->rest_length * (fluid->flag & SPH_FAC_REST_LENGTH ? 2.588f * pa->size : 1.f);
2492
2493         float stiffness = fluid->stiffness_k;
2494         float stiffness_near_fac = fluid->stiffness_knear * (fluid->flag & SPH_FAC_REPULSION ? fluid->stiffness_k : 1.f);
2495
2496         ParticleData *npa;
2497         float vec[3];
2498         float vel[3];
2499         float co[3];
2500
2501         int i, spring_index, index = pa - psys[0]->particles;
2502
2503         pfr.tot_neighbors = 0;
2504         pfr.density = pfr.near_density = 0.f;
2505         pfr.h = h;
2506         pfr.pa = pa;
2507
2508         for (i=0; i<10 && psys[i]; i++) {
2509                 pfr.npsys = psys[i];
2510                 pfr.massfac = psys[i]->part->mass*inv_mass;
2511                 pfr.use_size = psys[i]->part->flag & PART_SIZEMASS;
2512
2513                 BLI_bvhtree_range_query(psys[i]->bvhtree, state->co, h, sphdata->density_cb, &pfr);
2514         }
2515
2516         pressure =  stiffness * (pfr.density - rest_density);
2517         near_pressure = stiffness_near_fac * pfr.near_density;
2518
2519         pfn = pfr.neighbors;
2520         for (i=0; i<pfr.tot_neighbors; i++, pfn++) {
2521                 npa = pfn->psys->particles + pfn->index;
2522
2523                 madd_v3_v3v3fl(co, npa->prev_state.co, npa->prev_state.vel, state->time);
2524
2525                 sub_v3_v3v3(vec, co, state->co);
2526                 rij = normalize_v3(vec);
2527
2528                 q = (1.f - rij/h) * pfn->psys->part->mass * inv_mass;
2529
2530                 if (pfn->psys->part->flag & PART_SIZEMASS)
2531                         q *= npa->size;
2532
2533                 copy_v3_v3(vel, npa->prev_state.vel);
2534
2535                 /* Double Density Relaxation */
2536                 madd_v3_v3fl(force, vec, -(pressure + near_pressure*q)*q);
2537
2538                 /* Viscosity */
2539                 if (visc > 0.f  || stiff_visc > 0.f) {
2540                         sub_v3_v3v3(dv, vel, state->vel);
2541                         u = dot_v3v3(vec, dv);
2542
2543                         if (u < 0.f && visc > 0.f)
2544                                 madd_v3_v3fl(force, vec, 0.5f * q * visc * u );
2545
2546                         if (u > 0.f && stiff_visc > 0.f)
2547                                 madd_v3_v3fl(force, vec, 0.5f * q * stiff_visc * u );
2548                 }
2549
2550                 if (spring_constant > 0.f) {
2551                         /* Viscoelastic spring force */
2552                         if (pfn->psys == psys[0] && fluid->flag & SPH_VISCOELASTIC_SPRINGS && springhash) {
2553                                 /* BLI_edgehash_lookup appears to be thread-safe. - z0r */
2554                                 spring_index = GET_INT_FROM_POINTER(BLI_edgehash_lookup(springhash, index, pfn->index));
2555
2556                                 if (spring_index) {
2557                                         spring = psys[0]->fluid_springs + spring_index - 1;
2558
2559                                         madd_v3_v3fl(force, vec, -10.f * spring_constant * (1.f - rij/h) * (spring->rest_length - rij));
2560                                 }
2561                                 else if (fluid->spring_frames == 0 || (pa->prev_state.time-pa->time) <= fluid->spring_frames) {
2562                                         ParticleSpring temp_spring;
2563                                         temp_spring.particle_index[0] = index;
2564                                         temp_spring.particle_index[1] = pfn->index;
2565                                         temp_spring.rest_length = (fluid->flag & SPH_CURRENT_REST_LENGTH) ? rij : rest_length;
2566                                         temp_spring.delete_flag = 0;
2567
2568                                         /* sph_spring_add is not thread-safe. - z0r */
2569                                         #pragma omp critical
2570                                         sph_spring_add(psys[0], &temp_spring);
2571                                 }
2572                         }
2573                         else {/* PART_SPRING_HOOKES - Hooke's spring force */
2574                                 madd_v3_v3fl(force, vec, -10.f * spring_constant * (1.f - rij/h) * (rest_length - rij));
2575                         }
2576                 }
2577         }
2578         
2579         /* Artificial buoyancy force in negative gravity direction  */
2580         if (fluid->buoyancy > 0.f && gravity)
2581                 madd_v3_v3fl(force, gravity, fluid->buoyancy * (pfr.density-rest_density));
2582
2583         if (sphdata->pass == 0 && psys[0]->part->time_flag & PART_TIME_AUTOSF)
2584                 sph_particle_courant(sphdata, &pfr);
2585         sphdata->pass++;
2586 }
2587
2588 static void sph_solver_init(ParticleSimulationData *sim, SPHData *sphdata)
2589 {
2590         ParticleTarget *pt;
2591         int i;
2592
2593         // Add other coupled particle systems.
2594         sphdata->psys[0] = sim->psys;
2595         for (i=1, pt=sim->psys->targets.first; i<10; i++, pt=(pt?pt->next:NULL))
2596                 sphdata->psys[i] = pt ? psys_get_target_system(sim->ob, pt) : NULL;
2597
2598         if (psys_uses_gravity(sim))
2599                 sphdata->gravity = sim->scene->physics_settings.gravity;
2600         else
2601                 sphdata->gravity = NULL;
2602         sphdata->eh = sph_springhash_build(sim->psys);
2603
2604         // These per-particle values should be overridden later, but just for
2605         // completeness we give them default values now.
2606         sphdata->pa = NULL;
2607         sphdata->mass = 1.0f;
2608
2609         sphdata->force_cb = sph_force_cb;
2610         sphdata->density_cb = sph_density_accum_cb;
2611 }
2612
2613 static void sph_solver_finalise(SPHData *sphdata)
2614 {
2615         if (sphdata->eh) {
2616                 BLI_edgehash_free(sphdata->eh, NULL);
2617                 sphdata->eh = NULL;
2618         }
2619 }
2620
2621 static void sph_integrate(ParticleSimulationData *sim, ParticleData *pa, float dfra, SPHData *sphdata)
2622 {
2623         ParticleSettings *part = sim->psys->part;
2624         // float timestep = psys_get_timestep(sim); // UNUSED
2625         float pa_mass = part->mass * (part->flag & PART_SIZEMASS ? pa->size : 1.f);
2626         float dtime = dfra*psys_get_timestep(sim);
2627         // int steps = 1; // UNUSED
2628         float effector_acceleration[3];
2629
2630         sphdata->pa = pa;
2631         sphdata->mass = pa_mass;
2632         sphdata->pass = 0;
2633         //sphdata.element_size and sphdata.flow are set in the callback.
2634
2635         /* restore previous state and treat gravity & effectors as external acceleration*/
2636         sub_v3_v3v3(effector_acceleration, pa->state.vel, pa->prev_state.vel);
2637         mul_v3_fl(effector_acceleration, 1.f/dtime);
2638
2639         copy_particle_key(&pa->state, &pa->prev_state, 0);
2640
2641         integrate_particle(part, pa, dtime, effector_acceleration, sphdata->force_cb, sphdata);
2642 }
2643
2644 /************************************************/
2645 /*                      Basic physics                                           */
2646 /************************************************/
2647 typedef struct EfData {
2648         ParticleTexture ptex;
2649         ParticleSimulationData *sim;
2650         ParticleData *pa;
2651 } EfData;
2652 static void basic_force_cb(void *efdata_v, ParticleKey *state, float *force, float *impulse)
2653 {
2654         EfData *efdata = (EfData *)efdata_v;
2655         ParticleSimulationData *sim = efdata->sim;
2656         ParticleSettings *part = sim->psys->part;
2657         ParticleData *pa = efdata->pa;
2658         EffectedPoint epoint;
2659
2660         /* add effectors */
2661         pd_point_from_particle(efdata->sim, efdata->pa, state, &epoint);
2662         if (part->type != PART_HAIR || part->effector_weights->flag & EFF_WEIGHT_DO_HAIR)
2663                 pdDoEffectors(sim->psys->effectors, sim->colliders, part->effector_weights, &epoint, force, impulse);
2664
2665         mul_v3_fl(force, efdata->ptex.field);
2666         mul_v3_fl(impulse, efdata->ptex.field);
2667
2668         /* calculate air-particle interaction */
2669         if (part->dragfac != 0.0f)
2670                 madd_v3_v3fl(force, state->vel, -part->dragfac * pa->size * pa->size * len_v3(state->vel));
2671
2672         /* brownian force */
2673         if (part->brownfac != 0.0f) {
2674                 force[0] += (BLI_frand()-0.5f) * part->brownfac;
2675                 force[1] += (BLI_frand()-0.5f) * part->brownfac;
2676                 force[2] += (BLI_frand()-0.5f) * part->brownfac;
2677         }
2678
2679         if (part->flag & PART_ROT_DYN && epoint.ave)
2680                 copy_v3_v3(pa->state.ave, epoint.ave);
2681 }
2682 /* gathers all forces that effect particles and calculates a new state for the particle */
2683 static void basic_integrate(ParticleSimulationData *sim, int p, float dfra, float cfra)
2684 {
2685         ParticleSettings *part = sim->psys->part;
2686         ParticleData *pa = sim->psys->particles + p;
2687         ParticleKey tkey;
2688         float dtime=dfra*psys_get_timestep(sim), time;
2689         float *gravity = NULL, gr[3];
2690         EfData efdata;
2691
2692         psys_get_texture(sim, pa, &efdata.ptex, PAMAP_PHYSICS, cfra);
2693
2694         efdata.pa = pa;
2695         efdata.sim = sim;
2696
2697         /* add global acceleration (gravitation) */
2698         if (psys_uses_gravity(sim) &&
2699                 /* normal gravity is too strong for hair so it's disabled by default */
2700                 (part->type != PART_HAIR || part->effector_weights->flag & EFF_WEIGHT_DO_HAIR))
2701         {
2702                 zero_v3(gr);
2703                 madd_v3_v3fl(gr, sim->scene->physics_settings.gravity, part->effector_weights->global_gravity * efdata.ptex.gravity);
2704                 gravity = gr;
2705         }
2706
2707         /* maintain angular velocity */
2708         copy_v3_v3(pa->state.ave, pa->prev_state.ave);
2709
2710         integrate_particle(part, pa, dtime, gravity, basic_force_cb, &efdata);
2711
2712         /* damp affects final velocity */
2713         if (part->dampfac != 0.f)
2714                 mul_v3_fl(pa->state.vel, 1.f - part->dampfac * efdata.ptex.damp * 25.f * dtime);
2715
2716         //copy_v3_v3(pa->state.ave, states->ave);
2717
2718         /* finally we do guides */
2719         time=(cfra-pa->time)/pa->lifetime;
2720         CLAMP(time, 0.0f, 1.0f);
2721
2722         copy_v3_v3(tkey.co,pa->state.co);
2723         copy_v3_v3(tkey.vel,pa->state.vel);
2724         tkey.time=pa->state.time;
2725
2726         if (part->type != PART_HAIR) {
2727                 if (do_guides(sim->psys->effectors, &tkey, p, time)) {
2728                         copy_v3_v3(pa->state.co,tkey.co);
2729                         /* guides don't produce valid velocity */
2730                         sub_v3_v3v3(pa->state.vel, tkey.co, pa->prev_state.co);
2731                         mul_v3_fl(pa->state.vel,1.0f/dtime);
2732                         pa->state.time=tkey.time;
2733                 }
2734         }
2735 }
2736 static void basic_rotate(ParticleSettings *part, ParticleData *pa, float dfra, float timestep)
2737 {
2738         float rotfac, rot1[4], rot2[4] = {1.0,0.0,0.0,0.0}, dtime=dfra*timestep, extrotfac;
2739
2740         if ((part->flag & PART_ROTATIONS) == 0) {
2741                 unit_qt(pa->state.rot);
2742                 return;
2743         }
2744
2745         if (part->flag & PART_ROT_DYN) {
2746                 extrotfac = len_v3(pa->state.ave);
2747         }
2748         else {
2749                 extrotfac = 0.0f;
2750         }
2751
2752         if ((part->flag & PART_ROT_DYN) && ELEM3(part->avemode, PART_AVE_VELOCITY, PART_AVE_HORIZONTAL, PART_AVE_VERTICAL)) {
2753                 float angle;
2754                 float len1 = len_v3(pa->prev_state.vel);
2755                 float len2 = len_v3(pa->state.vel);
2756                 float vec[3];
2757
2758                 if (len1 == 0.0f || len2 == 0.0f) {
2759                         zero_v3(pa->state.ave);
2760                 }
2761                 else {
2762                         cross_v3_v3v3(pa->state.ave, pa->prev_state.vel, pa->state.vel);
2763                         normalize_v3(pa->state.ave);
2764                         angle = dot_v3v3(pa->prev_state.vel, pa->state.vel) / (len1 * len2);
2765                         mul_v3_fl(pa->state.ave, saacos(angle) / dtime);
2766                 }
2767
2768                 get_angular_velocity_vector(part->avemode, &pa->state, vec);
2769                 axis_angle_to_quat(rot2, vec, dtime*part->avefac);
2770         }
2771
2772         rotfac = len_v3(pa->state.ave);
2773         if (rotfac == 0.0f || (part->flag & PART_ROT_DYN)==0 || extrotfac == 0.0f) {
2774                 unit_qt(rot1);
2775         }
2776         else {
2777                 axis_angle_to_quat(rot1,pa->state.ave,rotfac*dtime);
2778         }
2779         mul_qt_qtqt(pa->state.rot,rot1,pa->prev_state.rot);
2780         mul_qt_qtqt(pa->state.rot,rot2,pa->state.rot);
2781
2782         /* keep rotation quat in good health */
2783         normalize_qt(pa->state.rot);
2784 }
2785
2786 /************************************************/
2787 /*                      Collisions                                                      */
2788 /************************************************/
2789 #define COLLISION_MAX_COLLISIONS        10
2790 #define COLLISION_MIN_RADIUS 0.001f
2791 #define COLLISION_MIN_DISTANCE 0.0001f
2792 #define COLLISION_ZERO 0.00001f
2793 typedef float (*NRDistanceFunc)(float *p, float radius, ParticleCollisionElement *pce, float *nor);
2794 static float nr_signed_distance_to_plane(float *p, float radius, ParticleCollisionElement *pce, float *nor)
2795 {
2796         float p0[3], e1[3], e2[3], d;
2797
2798         sub_v3_v3v3(e1, pce->x1, pce->x0);
2799         sub_v3_v3v3(e2, pce->x2, pce->x0);
2800         sub_v3_v3v3(p0, p, pce->x0);
2801
2802         cross_v3_v3v3(nor, e1, e2);
2803         normalize_v3(nor);
2804
2805         d = dot_v3v3(p0, nor);
2806
2807         if (pce->inv_nor == -1) {
2808                 if (d < 0.f)
2809                         pce->inv_nor = 1;
2810                 else
2811                         pce->inv_nor = 0;
2812         }
2813
2814         if (pce->inv_nor == 1) {
2815                 negate_v3(nor);
2816                 d = -d;
2817         }
2818
2819         return d - radius;
2820 }
2821 static float nr_distance_to_edge(float *p, float radius, ParticleCollisionElement *pce, float *UNUSED(nor))
2822 {
2823         float v0[3], v1[3], v2[3], c[3];
2824
2825         sub_v3_v3v3(v0, pce->x1, pce->x0);
2826         sub_v3_v3v3(v1, p, pce->x0);
2827         sub_v3_v3v3(v2, p, pce->x1);
2828
2829         cross_v3_v3v3(c, v1, v2);
2830
2831         return fabsf(len_v3(c)/len_v3(v0)) - radius;
2832 }
2833 static float nr_distance_to_vert(float *p, float radius, ParticleCollisionElement *pce, float *UNUSED(nor))
2834 {
2835         return len_v3v3(p, pce->x0) - radius;
2836 }
2837 static void collision_interpolate_element(ParticleCollisionElement *pce, float t, float fac, ParticleCollision *col)
2838 {
2839         /* t is the current time for newton rhapson */
2840         /* fac is the starting factor for current collision iteration */
2841         /* the col->fac's are factors for the particle subframe step start and end during collision modifier step */
2842         float f = fac + t*(1.f-fac);
2843         float mul = col->fac1 + f * (col->fac2-col->fac1);
2844         if (pce->tot > 0) {
2845                 madd_v3_v3v3fl(pce->x0, pce->x[0], pce->v[0], mul);
2846
2847                 if (pce->tot > 1) {
2848                         madd_v3_v3v3fl(pce->x1, pce->x[1], pce->v[1], mul);
2849
2850                         if (pce->tot > 2)
2851                                 madd_v3_v3v3fl(pce->x2, pce->x[2], pce->v[2], mul);
2852                 }
2853         }
2854 }
2855 static void collision_point_velocity(ParticleCollisionElement *pce)
2856 {
2857         float v[3];
2858
2859         copy_v3_v3(pce->vel, pce->v[0]);
2860
2861         if (pce->tot > 1) {
2862                 sub_v3_v3v3(v, pce->v[1], pce->v[0]);
2863                 madd_v3_v3fl(pce->vel, v, pce->uv[0]);
2864
2865                 if (pce->tot > 2) {
2866                         sub_v3_v3v3(v, pce->v[2], pce->v[0]);
2867                         madd_v3_v3fl(pce->vel, v, pce->uv[1]);
2868                 }
2869         }
2870 }
2871 static float collision_point_distance_with_normal(float p[3], ParticleCollisionElement *pce, float fac, ParticleCollision *col, float *nor)
2872 {
2873         if (fac >= 0.f)
2874                 collision_interpolate_element(pce, 0.f, fac, col);
2875
2876         switch (pce->tot) {
2877                 case 1:
2878                 {
2879                         sub_v3_v3v3(nor, p, pce->x0);
2880                         return normalize_v3(nor);
2881                 }
2882                 case 2:
2883                 {
2884                         float u, e[3], vec[3];
2885                         sub_v3_v3v3(e, pce->x1, pce->x0);
2886                         sub_v3_v3v3(vec, p, pce->x0);
2887                         u = dot_v3v3(vec, e) / dot_v3v3(e, e);
2888
2889                         madd_v3_v3v3fl(nor, vec, e, -u);
2890                         return normalize_v3(nor);
2891                 }
2892                 case 3:
2893                         return nr_signed_distance_to_plane(p, 0.f, pce, nor);
2894         }
2895         return 0;
2896 }
2897 static void collision_point_on_surface(float p[3], ParticleCollisionElement *pce, float fac, ParticleCollision *col, float *co)
2898 {
2899         collision_interpolate_element(pce, 0.f, fac, col);
2900
2901         switch (pce->tot) {
2902                 case 1:
2903                 {
2904                         sub_v3_v3v3(co, p, pce->x0);
2905                         normalize_v3(co);
2906                         madd_v3_v3v3fl(co, pce->x0, co, col->radius);
2907                         break;
2908                 }
2909                 case 2:
2910                 {
2911                         float u, e[3], vec[3], nor[3];
2912                         sub_v3_v3v3(e, pce->x1, pce->x0);
2913                         sub_v3_v3v3(vec, p, pce->x0);
2914                         u = dot_v3v3(vec, e) / dot_v3v3(e, e);
2915
2916                         madd_v3_v3v3fl(nor, vec, e, -u);
2917                         normalize_v3(nor);
2918
2919                         madd_v3_v3v3fl(co, pce->x0, e, pce->uv[0]);
2920                         madd_v3_v3fl(co, nor, col->radius);
2921                         break;
2922                 }
2923                 case 3:
2924                 {
2925                                 float p0[3], e1[3], e2[3], nor[3];
2926
2927                                 sub_v3_v3v3(e1, pce->x1, pce->x0);
2928                                 sub_v3_v3v3(e2, pce->x2, pce->x0);
2929                                 sub_v3_v3v3(p0, p, pce->x0);
2930
2931                                 cross_v3_v3v3(nor, e1, e2);
2932                                 normalize_v3(nor);
2933
2934                                 if (pce->inv_nor == 1)
2935                                         negate_v3(nor);
2936
2937                                 madd_v3_v3v3fl(co, pce->x0, nor, col->radius);
2938                                 madd_v3_v3fl(co, e1, pce->uv[0]);
2939                                 madd_v3_v3fl(co, e2, pce->uv[1]);
2940                         break;
2941                 }
2942         }
2943 }
2944 /* find first root in range [0-1] starting from 0 */
2945 static float collision_newton_rhapson(ParticleCollision *col, float radius, ParticleCollisionElement *pce, NRDistanceFunc distance_func)
2946 {
2947         float t0, t1, d0, d1, dd, n[3];
2948         int iter;
2949
2950         pce->inv_nor = -1;
2951
2952         /* start from the beginning */
2953         t0 = 0.f;
2954         collision_interpolate_element(pce, t0, col->f, col);
2955         d0 = distance_func(col->co1, radius, pce, n);
2956         t1 = 0.001f;
2957         d1 = 0.f;
2958
2959         for (iter=0; iter<10; iter++) {//, itersum++) {
2960                 /* get current location */
2961                 collision_interpolate_element(pce, t1, col->f, col);
2962                 interp_v3_v3v3(pce->p, col->co1, col->co2, t1);
2963
2964                 d1 = distance_func(pce->p, radius, pce, n);
2965
2966                 /* no movement, so no collision */
2967                 if (d1 == d0) {
2968                         return -1.f;
2969                 }
2970
2971                 /* particle already inside face, so report collision */
2972                 if (iter == 0 && d0 < 0.f && d0 > -radius) {
2973                         copy_v3_v3(pce->p, col->co1);
2974                         copy_v3_v3(pce->nor, n);
2975                         pce->inside = 1;
2976                         return 0.f;
2977                 }
2978                 
2979                 dd = (t1-t0)/(d1-d0);
2980
2981                 t0 = t1;
2982                 d0 = d1;
2983
2984                 t1 -= d1*dd;
2985
2986                 /* particle movin away from plane could also mean a strangely rotating face, so check from end */
2987                 if (iter == 0 && t1 < 0.f) {
2988                         t0 = 1.f;
2989                         collision_interpolate_element(pce, t0, col->f, col);
2990                         d0 = distance_func(col->co2, radius, pce, n);
2991                         t1 = 0.999f;
2992                         d1 = 0.f;
2993
2994                         continue;
2995                 }
2996                 else if (iter == 1 && (t1 < -COLLISION_ZERO || t1 > 1.f))
2997                         return -1.f;
2998
2999                 if (d1 <= COLLISION_ZERO && d1 >= -COLLISION_ZERO) {
3000                         if (t1 >= -COLLISION_ZERO && t1 <= 1.f) {
3001                                 if (distance_func == nr_signed_distance_to_plane)
3002                                         copy_v3_v3(pce->nor, n);
3003
3004                                 CLAMP(t1, 0.f, 1.f);
3005
3006                                 return t1;
3007                         }
3008                         else
3009                                 return -1.f;
3010                 }
3011         }
3012         return -1.0;
3013 }
3014 static int collision_sphere_to_tri(ParticleCollision *col, float radius, ParticleCollisionElement *pce, float *t)
3015 {
3016         ParticleCollisionElement *result = &col->pce;
3017         float ct, u, v;
3018