Blender  V2.59
collision.c
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00001 /*
00002  * $Id: collision.c 36423 2011-05-02 03:44:02Z campbellbarton $
00003  *
00004  * ***** BEGIN GPL LICENSE BLOCK *****
00005  *
00006  * This program is free software; you can redistribute it and/or
00007  * modify it under the terms of the GNU General Public License
00008  * as published by the Free Software Foundation; either version 2
00009  * of the License, or (at your option) any later version.
00010  *
00011  * This program is distributed in the hope that it will be useful,
00012  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00013  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014  * GNU General Public License for more details.
00015  *
00016  * You should have received a copy of the GNU General Public License
00017  * along with this program; if not, write to the Free Software Foundation,
00018  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
00019  *
00020  * The Original Code is Copyright (C) Blender Foundation
00021  * All rights reserved.
00022  *
00023  * The Original Code is: all of this file.
00024  *
00025  * Contributor(s): none yet.
00026  *
00027  * ***** END GPL LICENSE BLOCK *****
00028  */
00029 
00035 #include "MEM_guardedalloc.h"
00036 
00037 #include "BKE_cloth.h"
00038 
00039 #include "DNA_cloth_types.h"
00040 #include "DNA_group_types.h"
00041 #include "DNA_mesh_types.h"
00042 #include "DNA_object_types.h"
00043 #include "DNA_object_force.h"
00044 #include "DNA_scene_types.h"
00045 #include "DNA_meshdata_types.h"
00046 
00047 #include "BLI_blenlib.h"
00048 #include "BLI_math.h"
00049 #include "BLI_edgehash.h"
00050 #include "BLI_utildefines.h"
00051 #include "BLI_ghash.h"
00052 #include "BLI_memarena.h"
00053 #include "BLI_rand.h"
00054 
00055 #include "BKE_DerivedMesh.h"
00056 #include "BKE_global.h"
00057 #include "BKE_scene.h"
00058 #include "BKE_mesh.h"
00059 #include "BKE_object.h"
00060 #include "BKE_modifier.h"
00061 
00062 #include "BKE_DerivedMesh.h"
00063 #ifdef USE_BULLET
00064 #include "Bullet-C-Api.h"
00065 #endif
00066 #include "BLI_kdopbvh.h"
00067 #include "BKE_collision.h"
00068 
00069 #ifdef WITH_ELTOPO
00070 #include "eltopo-capi.h"
00071 #endif
00072 
00073 
00074 /***********************************
00075 Collision modifier code start
00076 ***********************************/
00077 
00078 /* step is limited from 0 (frame start position) to 1 (frame end position) */
00079 void collision_move_object ( CollisionModifierData *collmd, float step, float prevstep )
00080 {
00081         float tv[3] = {0, 0, 0};
00082         unsigned int i = 0;
00083 
00084         for ( i = 0; i < collmd->numverts; i++ )
00085         {
00086                 VECSUB ( tv, collmd->xnew[i].co, collmd->x[i].co );
00087                 VECADDS ( collmd->current_x[i].co, collmd->x[i].co, tv, prevstep );
00088                 VECADDS ( collmd->current_xnew[i].co, collmd->x[i].co, tv, step );
00089                 VECSUB ( collmd->current_v[i].co, collmd->current_xnew[i].co, collmd->current_x[i].co );
00090         }
00091 
00092         bvhtree_update_from_mvert ( collmd->bvhtree, collmd->mfaces, collmd->numfaces, collmd->current_x, collmd->current_xnew, collmd->numverts, 1 );
00093 }
00094 
00095 BVHTree *bvhtree_build_from_mvert ( MFace *mfaces, unsigned int numfaces, MVert *x, unsigned int UNUSED(numverts), float epsilon )
00096 {
00097         BVHTree *tree;
00098         float co[12];
00099         unsigned int i;
00100         MFace *tface = mfaces;
00101 
00102         tree = BLI_bvhtree_new ( numfaces*2, epsilon, 4, 26 );
00103 
00104         // fill tree
00105         for ( i = 0; i < numfaces; i++, tface++ )
00106         {
00107                 VECCOPY ( &co[0*3], x[tface->v1].co );
00108                 VECCOPY ( &co[1*3], x[tface->v2].co );
00109                 VECCOPY ( &co[2*3], x[tface->v3].co );
00110                 if ( tface->v4 )
00111                         VECCOPY ( &co[3*3], x[tface->v4].co );
00112 
00113                 BLI_bvhtree_insert ( tree, i, co, ( mfaces->v4 ? 4 : 3 ) );
00114         }
00115 
00116         // balance tree
00117         BLI_bvhtree_balance ( tree );
00118 
00119         return tree;
00120 }
00121 
00122 void bvhtree_update_from_mvert ( BVHTree * bvhtree, MFace *faces, int numfaces, MVert *x, MVert *xnew, int UNUSED(numverts), int moving )
00123 {
00124         int i;
00125         MFace *mfaces = faces;
00126         float co[12], co_moving[12];
00127         int ret = 0;
00128 
00129         if ( !bvhtree )
00130                 return;
00131 
00132         if ( x )
00133         {
00134                 for ( i = 0; i < numfaces; i++, mfaces++ )
00135                 {
00136                         VECCOPY ( &co[0*3], x[mfaces->v1].co );
00137                         VECCOPY ( &co[1*3], x[mfaces->v2].co );
00138                         VECCOPY ( &co[2*3], x[mfaces->v3].co );
00139                         if ( mfaces->v4 )
00140                                 VECCOPY ( &co[3*3], x[mfaces->v4].co );
00141 
00142                         // copy new locations into array
00143                         if ( moving && xnew )
00144                         {
00145                                 // update moving positions
00146                                 VECCOPY ( &co_moving[0*3], xnew[mfaces->v1].co );
00147                                 VECCOPY ( &co_moving[1*3], xnew[mfaces->v2].co );
00148                                 VECCOPY ( &co_moving[2*3], xnew[mfaces->v3].co );
00149                                 if ( mfaces->v4 )
00150                                         VECCOPY ( &co_moving[3*3], xnew[mfaces->v4].co );
00151 
00152                                 ret = BLI_bvhtree_update_node ( bvhtree, i, co, co_moving, ( mfaces->v4 ? 4 : 3 ) );
00153                         }
00154                         else
00155                         {
00156                                 ret = BLI_bvhtree_update_node ( bvhtree, i, co, NULL, ( mfaces->v4 ? 4 : 3 ) );
00157                         }
00158 
00159                         // check if tree is already full
00160                         if ( !ret )
00161                                 break;
00162                 }
00163 
00164                 BLI_bvhtree_update_tree ( bvhtree );
00165         }
00166 }
00167 
00168 /***********************************
00169 Collision modifier code end
00170 ***********************************/
00171 
00178 #define mySWAP(a,b) do { double tmp = b ; b = a ; a = tmp ; } while(0)
00179 #if 0 /* UNUSED */
00180 static int 
00181 gsl_poly_solve_cubic (double a, double b, double c, 
00182                                           double *x0, double *x1, double *x2)
00183 {
00184         double q = (a * a - 3 * b);
00185         double r = (2 * a * a * a - 9 * a * b + 27 * c);
00186 
00187         double Q = q / 9;
00188         double R = r / 54;
00189 
00190         double Q3 = Q * Q * Q;
00191         double R2 = R * R;
00192 
00193         double CR2 = 729 * r * r;
00194         double CQ3 = 2916 * q * q * q;
00195 
00196         if (R == 0 && Q == 0)
00197         {
00198                 *x0 = - a / 3 ;
00199                 *x1 = - a / 3 ;
00200                 *x2 = - a / 3 ;
00201                 return 3 ;
00202         }
00203         else if (CR2 == CQ3) 
00204         {
00205                 /* this test is actually R2 == Q3, written in a form suitable
00206                 for exact computation with integers */
00207 
00208                 /* Due to finite precision some double roots may be missed, and
00209                 considered to be a pair of complex roots z = x +/- epsilon i
00210                 close to the real axis. */
00211 
00212                 double sqrtQ = sqrt (Q);
00213 
00214                 if (R > 0)
00215                 {
00216                         *x0 = -2 * sqrtQ  - a / 3;
00217                         *x1 = sqrtQ - a / 3;
00218                         *x2 = sqrtQ - a / 3;
00219                 }
00220                 else
00221                 {
00222                         *x0 = - sqrtQ  - a / 3;
00223                         *x1 = - sqrtQ - a / 3;
00224                         *x2 = 2 * sqrtQ - a / 3;
00225                 }
00226                 return 3 ;
00227         }
00228         else if (CR2 < CQ3) /* equivalent to R2 < Q3 */
00229         {
00230                 double sqrtQ = sqrt (Q);
00231                 double sqrtQ3 = sqrtQ * sqrtQ * sqrtQ;
00232                 double theta = acos (R / sqrtQ3);
00233                 double norm = -2 * sqrtQ;
00234                 *x0 = norm * cos (theta / 3) - a / 3;
00235                 *x1 = norm * cos ((theta + 2.0 * M_PI) / 3) - a / 3;
00236                 *x2 = norm * cos ((theta - 2.0 * M_PI) / 3) - a / 3;
00237 
00238                 /* Sort *x0, *x1, *x2 into increasing order */
00239 
00240                 if (*x0 > *x1)
00241                         mySWAP(*x0, *x1) ;
00242 
00243                 if (*x1 > *x2)
00244                 {
00245                         mySWAP(*x1, *x2) ;
00246 
00247                         if (*x0 > *x1)
00248                                 mySWAP(*x0, *x1) ;
00249                 }
00250 
00251                 return 3;
00252         }
00253         else
00254         {
00255                 double sgnR = (R >= 0 ? 1 : -1);
00256                 double A = -sgnR * pow (fabs (R) + sqrt (R2 - Q3), 1.0/3.0);
00257                 double B = Q / A ;
00258                 *x0 = A + B - a / 3;
00259                 return 1;
00260         }
00261 }
00262 
00263 
00264 
00270 static int 
00271 gsl_poly_solve_quadratic (double a, double b, double c, 
00272                                                   double *x0, double *x1)
00273 {
00274         double disc = b * b - 4 * a * c;
00275 
00276         if (a == 0) /* Handle linear case */
00277         {
00278                 if (b == 0)
00279                 {
00280                         return 0;
00281                 }
00282                 else
00283                 {
00284                         *x0 = -c / b;
00285                         return 1;
00286                 };
00287         }
00288 
00289         if (disc > 0)
00290         {
00291                 if (b == 0)
00292                 {
00293                         double r = fabs (0.5 * sqrt (disc) / a);
00294                         *x0 = -r;
00295                         *x1 =  r;
00296                 }
00297                 else
00298                 {
00299                         double sgnb = (b > 0 ? 1 : -1);
00300                         double temp = -0.5 * (b + sgnb * sqrt (disc));
00301                         double r1 = temp / a ;
00302                         double r2 = c / temp ;
00303 
00304                         if (r1 < r2) 
00305                         {
00306                                 *x0 = r1 ;
00307                                 *x1 = r2 ;
00308                         } 
00309                         else 
00310                         {
00311                                 *x0 = r2 ;
00312                                 *x1 = r1 ;
00313                         }
00314                 }
00315                 return 2;
00316         }
00317         else if (disc == 0) 
00318         {
00319                 *x0 = -0.5 * b / a ;
00320                 *x1 = -0.5 * b / a ;
00321                 return 2 ;
00322         }
00323         else
00324         {
00325                 return 0;
00326         }
00327 }
00328 #endif /* UNUSED */
00329 
00330 
00331 
00332 /*
00333 * See Bridson et al. "Robust Treatment of Collision, Contact and Friction for Cloth Animation"
00334 *     page 4, left column
00335 */
00336 #if 0
00337 static int cloth_get_collision_time ( double a[3], double b[3], double c[3], double d[3], double e[3], double f[3], double solution[3] )
00338 {
00339         int num_sols = 0;
00340 
00341         // x^0 - checked 
00342         double g =      a[0] * c[1] * e[2] - a[0] * c[2] * e[1] +
00343                 a[1] * c[2] * e[0] - a[1] * c[0] * e[2] + 
00344                 a[2] * c[0] * e[1] - a[2] * c[1] * e[0];
00345 
00346         // x^1
00347         double h = -b[2] * c[1] * e[0] + b[1] * c[2] * e[0] - a[2] * d[1] * e[0] +
00348                 a[1] * d[2] * e[0] + b[2] * c[0] * e[1] - b[0] * c[2] * e[1] +
00349                 a[2] * d[0] * e[1] - a[0] * d[2] * e[1] - b[1] * c[0] * e[2] +
00350                 b[0] * c[1] * e[2] - a[1] * d[0] * e[2] + a[0] * d[1] * e[2] -
00351                 a[2] * c[1] * f[0] + a[1] * c[2] * f[0] + a[2] * c[0] * f[1] -
00352                 a[0] * c[2] * f[1] - a[1] * c[0] * f[2] + a[0] * c[1] * f[2];
00353 
00354         // x^2
00355         double i = -b[2] * d[1] * e[0] + b[1] * d[2] * e[0] +
00356                 b[2] * d[0] * e[1] - b[0] * d[2] * e[1] -
00357                 b[1] * d[0] * e[2] + b[0] * d[1] * e[2] -
00358                 b[2] * c[1] * f[0] + b[1] * c[2] * f[0] -
00359                 a[2] * d[1] * f[0] + a[1] * d[2] * f[0] +
00360                 b[2] * c[0] * f[1] - b[0] * c[2] * f[1] + 
00361                 a[2] * d[0] * f[1] - a[0] * d[2] * f[1] -
00362                 b[1] * c[0] * f[2] + b[0] * c[1] * f[2] -
00363                 a[1] * d[0] * f[2] + a[0] * d[1] * f[2];
00364 
00365         // x^3 - checked
00366         double j = -b[2] * d[1] * f[0] + b[1] * d[2] * f[0] +
00367                 b[2] * d[0] * f[1] - b[0] * d[2] * f[1] -
00368                 b[1] * d[0] * f[2] + b[0] * d[1] * f[2];
00369 
00370         /*
00371         printf("r1: %lf\n", a[0] * c[1] * e[2] - a[0] * c[2] * e[1]);
00372         printf("r2: %lf\n", a[1] * c[2] * e[0] - a[1] * c[0] * e[2]);
00373         printf("r3: %lf\n", a[2] * c[0] * e[1] - a[2] * c[1] * e[0]);
00374 
00375         printf("x1 x: %f, y: %f, z: %f\n", a[0], a[1], a[2]);
00376         printf("x2 x: %f, y: %f, z: %f\n", c[0], c[1], c[2]);
00377         printf("x3 x: %f, y: %f, z: %f\n", e[0], e[1], e[2]);
00378 
00379         printf("v1 x: %f, y: %f, z: %f\n", b[0], b[1], b[2]);
00380         printf("v2 x: %f, y: %f, z: %f\n", d[0], d[1], d[2]);
00381         printf("v3 x: %f, y: %f, z: %f\n", f[0], f[1], f[2]);
00382 
00383         printf("t^3: %lf, t^2: %lf, t^1: %lf, t^0: %lf\n", j, i, h, g);
00384         
00385 */
00386         // Solve cubic equation to determine times t1, t2, t3, when the collision will occur.
00387         if ( ABS ( j ) > DBL_EPSILON )
00388         {
00389                 i /= j;
00390                 h /= j;
00391                 g /= j;
00392                 num_sols = gsl_poly_solve_cubic ( i, h, g, &solution[0], &solution[1], &solution[2] );
00393         }
00394         else
00395         {
00396                 num_sols = gsl_poly_solve_quadratic ( i, h, g, &solution[0], &solution[1] );
00397                 solution[2] = -1.0;
00398         }
00399 
00400         // printf("num_sols: %d, sol1: %lf, sol2: %lf, sol3: %lf\n", num_sols, solution[0],  solution[1],  solution[2]);
00401 
00402         // Discard negative solutions
00403         if ( ( num_sols >= 1 ) && ( solution[0] < DBL_EPSILON ) )
00404         {
00405                 --num_sols;
00406                 solution[0] = solution[num_sols];
00407         }
00408         if ( ( num_sols >= 2 ) && ( solution[1] < DBL_EPSILON ) )
00409         {
00410                 --num_sols;
00411                 solution[1] = solution[num_sols];
00412         }
00413         if ( ( num_sols == 3 ) && ( solution[2] < DBL_EPSILON ) )
00414         {
00415                 --num_sols;
00416         }
00417 
00418         // Sort
00419         if ( num_sols == 2 )
00420         {
00421                 if ( solution[0] > solution[1] )
00422                 {
00423                         double tmp = solution[0];
00424                         solution[0] = solution[1];
00425                         solution[1] = tmp;
00426                 }
00427         }
00428         else if ( num_sols == 3 )
00429         {
00430 
00431                 // Bubblesort
00432                 if ( solution[0] > solution[1] )
00433                 {
00434                         double tmp = solution[0]; solution[0] = solution[1]; solution[1] = tmp;
00435                 }
00436                 if ( solution[1] > solution[2] )
00437                 {
00438                         double tmp = solution[1]; solution[1] = solution[2]; solution[2] = tmp;
00439                 }
00440                 if ( solution[0] > solution[1] )
00441                 {
00442                         double tmp = solution[0]; solution[0] = solution[1]; solution[1] = tmp;
00443                 }
00444         }
00445 
00446         return num_sols;
00447 }
00448 #endif
00449 
00450 
00451 // w3 is not perfect
00452 static void collision_compute_barycentric ( float pv[3], float p1[3], float p2[3], float p3[3], float *w1, float *w2, float *w3 )
00453 {
00454         double  tempV1[3], tempV2[3], tempV4[3];
00455         double  a,b,c,d,e,f;
00456 
00457         VECSUB ( tempV1, p1, p3 );
00458         VECSUB ( tempV2, p2, p3 );
00459         VECSUB ( tempV4, pv, p3 );
00460 
00461         a = INPR ( tempV1, tempV1 );
00462         b = INPR ( tempV1, tempV2 );
00463         c = INPR ( tempV2, tempV2 );
00464         e = INPR ( tempV1, tempV4 );
00465         f = INPR ( tempV2, tempV4 );
00466 
00467         d = ( a * c - b * b );
00468 
00469         if ( ABS ( d ) < ALMOST_ZERO )
00470         {
00471                 *w1 = *w2 = *w3 = 1.0 / 3.0;
00472                 return;
00473         }
00474 
00475         w1[0] = ( float ) ( ( e * c - b * f ) / d );
00476 
00477         if ( w1[0] < 0 )
00478                 w1[0] = 0;
00479 
00480         w2[0] = ( float ) ( ( f - b * ( double ) w1[0] ) / c );
00481 
00482         if ( w2[0] < 0 )
00483                 w2[0] = 0;
00484 
00485         w3[0] = 1.0f - w1[0] - w2[0];
00486 }
00487 
00488 DO_INLINE void collision_interpolateOnTriangle ( float to[3], float v1[3], float v2[3], float v3[3], double w1, double w2, double w3 )
00489 {
00490         to[0] = to[1] = to[2] = 0;
00491         VECADDMUL ( to, v1, w1 );
00492         VECADDMUL ( to, v2, w2 );
00493         VECADDMUL ( to, v3, w3 );
00494 }
00495 
00496 #ifndef WITH_ELTOPO
00497 static int cloth_collision_response_static ( ClothModifierData *clmd, CollisionModifierData *collmd, CollPair *collpair, CollPair *collision_end )
00498 {
00499         int result = 0;
00500         Cloth *cloth1;
00501         float w1, w2, w3, u1, u2, u3;
00502         float v1[3], v2[3], relativeVelocity[3];
00503         float magrelVel;
00504         float epsilon2 = BLI_bvhtree_getepsilon ( collmd->bvhtree );
00505 
00506         cloth1 = clmd->clothObject;
00507 
00508         for ( ; collpair != collision_end; collpair++ )
00509         {
00510                 // only handle static collisions here
00511                 if ( collpair->flag & COLLISION_IN_FUTURE )
00512                         continue;
00513 
00514                 // compute barycentric coordinates for both collision points
00515                 collision_compute_barycentric ( collpair->pa,
00516                         cloth1->verts[collpair->ap1].txold,
00517                         cloth1->verts[collpair->ap2].txold,
00518                         cloth1->verts[collpair->ap3].txold,
00519                         &w1, &w2, &w3 );
00520 
00521                 // was: txold
00522                 collision_compute_barycentric ( collpair->pb,
00523                         collmd->current_x[collpair->bp1].co,
00524                         collmd->current_x[collpair->bp2].co,
00525                         collmd->current_x[collpair->bp3].co,
00526                         &u1, &u2, &u3 );
00527 
00528                 // Calculate relative "velocity".
00529                 collision_interpolateOnTriangle ( v1, cloth1->verts[collpair->ap1].tv, cloth1->verts[collpair->ap2].tv, cloth1->verts[collpair->ap3].tv, w1, w2, w3 );
00530 
00531                 collision_interpolateOnTriangle ( v2, collmd->current_v[collpair->bp1].co, collmd->current_v[collpair->bp2].co, collmd->current_v[collpair->bp3].co, u1, u2, u3 );
00532 
00533                 VECSUB ( relativeVelocity, v2, v1 );
00534 
00535                 // Calculate the normal component of the relative velocity (actually only the magnitude - the direction is stored in 'normal').
00536                 magrelVel = INPR ( relativeVelocity, collpair->normal );
00537 
00538                 // printf("magrelVel: %f\n", magrelVel);
00539 
00540                 // Calculate masses of points.
00541                 // TODO
00542 
00543                 // If v_n_mag < 0 the edges are approaching each other.
00544                 if ( magrelVel > ALMOST_ZERO )
00545                 {
00546                         // Calculate Impulse magnitude to stop all motion in normal direction.
00547                         float magtangent = 0, repulse = 0, d = 0;
00548                         double impulse = 0.0;
00549                         float vrel_t_pre[3];
00550                         float temp[3], spf;
00551 
00552                         // calculate tangential velocity
00553                         VECCOPY ( temp, collpair->normal );
00554                         mul_v3_fl( temp, magrelVel );
00555                         VECSUB ( vrel_t_pre, relativeVelocity, temp );
00556 
00557                         // Decrease in magnitude of relative tangential velocity due to coulomb friction
00558                         // in original formula "magrelVel" should be the "change of relative velocity in normal direction"
00559                         magtangent = MIN2 ( clmd->coll_parms->friction * 0.01 * magrelVel,sqrt ( INPR ( vrel_t_pre,vrel_t_pre ) ) );
00560 
00561                         // Apply friction impulse.
00562                         if ( magtangent > ALMOST_ZERO )
00563                         {
00564                                 normalize_v3( vrel_t_pre );
00565 
00566                                 impulse = magtangent / ( 1.0 + w1*w1 + w2*w2 + w3*w3 ); // 2.0 * 
00567                                 VECADDMUL ( cloth1->verts[collpair->ap1].impulse, vrel_t_pre, w1 * impulse );
00568                                 VECADDMUL ( cloth1->verts[collpair->ap2].impulse, vrel_t_pre, w2 * impulse );
00569                                 VECADDMUL ( cloth1->verts[collpair->ap3].impulse, vrel_t_pre, w3 * impulse );
00570                         }
00571 
00572                         // Apply velocity stopping impulse
00573                         // I_c = m * v_N / 2.0
00574                         // no 2.0 * magrelVel normally, but looks nicer DG
00575                         impulse =  magrelVel / ( 1.0 + w1*w1 + w2*w2 + w3*w3 );
00576 
00577                         VECADDMUL ( cloth1->verts[collpair->ap1].impulse, collpair->normal, w1 * impulse );
00578                         cloth1->verts[collpair->ap1].impulse_count++;
00579 
00580                         VECADDMUL ( cloth1->verts[collpair->ap2].impulse, collpair->normal, w2 * impulse );
00581                         cloth1->verts[collpair->ap2].impulse_count++;
00582 
00583                         VECADDMUL ( cloth1->verts[collpair->ap3].impulse, collpair->normal, w3 * impulse );
00584                         cloth1->verts[collpair->ap3].impulse_count++;
00585 
00586                         // Apply repulse impulse if distance too short
00587                         // I_r = -min(dt*kd, m(0,1d/dt - v_n))
00588                         spf = (float)clmd->sim_parms->stepsPerFrame / clmd->sim_parms->timescale;
00589 
00590                         d = clmd->coll_parms->epsilon*8.0/9.0 + epsilon2*8.0/9.0 - collpair->distance;
00591                         if ( ( magrelVel < 0.1*d*spf ) && ( d > ALMOST_ZERO ) )
00592                         {
00593                                 repulse = MIN2 ( d*1.0/spf, 0.1*d*spf - magrelVel );
00594 
00595                                 // stay on the safe side and clamp repulse
00596                                 if ( impulse > ALMOST_ZERO )
00597                                         repulse = MIN2 ( repulse, 5.0*impulse );
00598                                 repulse = MAX2 ( impulse, repulse );
00599 
00600                                 impulse = repulse / ( 1.0 + w1*w1 + w2*w2 + w3*w3 ); // original 2.0 / 0.25
00601                                 VECADDMUL ( cloth1->verts[collpair->ap1].impulse, collpair->normal,  impulse );
00602                                 VECADDMUL ( cloth1->verts[collpair->ap2].impulse, collpair->normal,  impulse );
00603                                 VECADDMUL ( cloth1->verts[collpair->ap3].impulse, collpair->normal,  impulse );
00604                         }
00605 
00606                         result = 1;
00607                 }
00608         }
00609         return result;
00610 }
00611 #endif /* !WITH_ELTOPO */
00612 
00613 #ifdef WITH_ELTOPO
00614 typedef struct edgepairkey {
00615         int a1, a2, b1, b2;
00616 } edgepairkey;
00617 
00618 unsigned int edgepair_hash(void *vkey)
00619 {
00620         edgepairkey *key = vkey;
00621         int keys[4] = {key->a1, key->a2, key->b1, key->b2};
00622         int i, j;
00623         
00624         for (i=0; i<4; i++) {
00625                 for (j=0; j<3; j++) {
00626                         if (keys[j] >= keys[j+1]) {
00627                                 SWAP(int, keys[j], keys[j+1]);
00628                         }
00629                 }
00630         }
00631         
00632         return keys[0]*101 + keys[1]*72 + keys[2]*53 + keys[3]*34;
00633 }
00634 
00635 int edgepair_cmp(const void *va, const void *vb)
00636 {
00637         edgepairkey *a = va, *b = vb;
00638         int keysa[4] = {a->a1, a->a2, a->b1, a->b2};
00639         int keysb[4] = {b->a1, b->a2, b->b1, b->b2};
00640         int i;
00641         
00642         for (i=0; i<4; i++) {
00643                 int j, ok=0;
00644                 for (j=0; j<4; j++) {
00645                         if (keysa[i] == keysa[j]) {
00646                                 ok = 1;
00647                                 break;
00648                         }
00649                 }
00650                 if (!ok)
00651                         return -1;
00652         }
00653         
00654         return 0;
00655 }
00656 
00657 static void get_edgepairkey(edgepairkey *key, int a1, int a2, int b1, int b2)
00658 {
00659         key->a1 = a1;
00660         key->a2 = a2;
00661         key->b1 = b1;
00662         key->b2 = b2;
00663 }
00664 
00665 /*an immense amount of duplication goes on here. . .a major performance hit, I'm sure*/
00666 static CollPair* cloth_edge_collision ( ModifierData *md1, ModifierData *md2, 
00667                                                                                 BVHTreeOverlap *overlap, CollPair *collpair,
00668                                                                                 GHash *visithash, MemArena *arena)
00669 {
00670         ClothModifierData *clmd = ( ClothModifierData * ) md1;
00671         CollisionModifierData *collmd = ( CollisionModifierData * ) md2;
00672         MFace *face1=NULL, *face2 = NULL;
00673         ClothVertex *verts1 = clmd->clothObject->verts;
00674         double distance = 0;
00675         edgepairkey *key, tstkey;
00676         float epsilon1 = clmd->coll_parms->epsilon;
00677         float epsilon2 = BLI_bvhtree_getepsilon ( collmd->bvhtree );
00678         float no[3], uv[3], t, relnor;
00679         int i, i1, i2, i3, i4, i5, i6;
00680         Cloth *cloth = clmd->clothObject;
00681         float n1[3], n2[3], off[3], v1[2][3], v2[2][3], v3[2][3], v4[2][3], v5[2][3], v6[2][3];
00682         void **verts[] = {v1, v2, v3, v4, v5, v6};
00683         int j, ret, bp1, bp2, bp3, ap1, ap2, ap3, table[6];
00684         
00685         face1 = & ( clmd->clothObject->mfaces[overlap->indexA] );
00686         face2 = & ( collmd->mfaces[overlap->indexB] );
00687 
00688         // check all 4 possible collisions
00689         for ( i = 0; i < 4; i++ )
00690         {
00691                 if ( i == 0 )
00692                 {
00693                         // fill faceA
00694                         ap1 = face1->v1;
00695                         ap2 = face1->v2;
00696                         ap3 = face1->v3;
00697 
00698                         // fill faceB
00699                         bp1 = face2->v1;
00700                         bp2 = face2->v2;
00701                         bp3 = face2->v3;
00702                 }
00703                 else if ( i == 1 )
00704                 {
00705                         if ( face1->v4 )
00706                         {
00707                                 // fill faceA
00708                                 ap1 = face1->v1;
00709                                 ap2 = face1->v3;
00710                                 ap3 = face1->v4;
00711 
00712                                 // fill faceB
00713                                 bp1 = face2->v1;
00714                                 bp2 = face2->v2;
00715                                 bp3 = face2->v3;
00716                         }
00717                         else {
00718                                 continue;
00719                         }
00720                 }
00721                 if ( i == 2 )
00722                 {
00723                         if ( face2->v4 )
00724                         {
00725                                 // fill faceA
00726                                 ap1 = face1->v1;
00727                                 ap2 = face1->v2;
00728                                 ap3 = face1->v3;
00729 
00730                                 // fill faceB
00731                                 bp1 = face2->v1;
00732                                 bp2 = face2->v3;
00733                                 bp3 = face2->v4;
00734                         }
00735                         else {
00736                                 continue;
00737                         }
00738                 }
00739                 else if ( i == 3 )
00740                 {
00741                         if ( face1->v4 && face2->v4 )
00742                         {
00743                                 // fill faceA
00744                                 ap1 = face1->v1;
00745                                 ap2 = face1->v3;
00746                                 ap3 = face1->v4;
00747 
00748                                 // fill faceB
00749                                 bp1 = face2->v1;
00750                                 bp2 = face2->v3;
00751                                 bp3 = face2->v4;
00752                         }
00753                         else {
00754                                 continue;
00755                         }
00756                 }
00757                 
00758                 copy_v3_v3(v1[0], cloth->verts[ap1].txold); 
00759                 copy_v3_v3(v1[1], cloth->verts[ap1].tx);
00760                 copy_v3_v3(v2[0], cloth->verts[ap2].txold);
00761                 copy_v3_v3(v2[1], cloth->verts[ap2].tx);
00762                 copy_v3_v3(v3[0], cloth->verts[ap3].txold);
00763                 copy_v3_v3(v3[1], cloth->verts[ap3].tx);
00764                 
00765                 copy_v3_v3(v4[0], collmd->current_x[bp1].co);
00766                 copy_v3_v3(v4[1], collmd->current_xnew[bp1].co);
00767                 copy_v3_v3(v5[0], collmd->current_x[bp2].co);
00768                 copy_v3_v3(v5[1], collmd->current_xnew[bp2].co);
00769                 copy_v3_v3(v6[0], collmd->current_x[bp3].co);
00770                 copy_v3_v3(v6[1], collmd->current_xnew[bp3].co);
00771                 
00772                 normal_tri_v3(n2, v4[1], v5[1], v6[1]);
00773 
00774                 /*offset new positions a bit, to account for margins*/
00775                 i1 = ap1; i2 = ap2; i3 = ap3;
00776                 i4 = bp1; i5 = bp2; i6 = bp3;
00777 
00778                 for (j=0; j<3; j++) {
00779                         int collp1, collp2, k, j2 = (j+1)%3;
00780                         
00781                         table[0] = ap1; table[1] = ap2; table[2] = ap3;
00782                         table[3] = bp1; table[4] = bp2; table[5] = bp3;
00783                         for (k=0; k<3; k++) {
00784                                 float p1[3], p2[3];
00785                                 int k2 = (k+1)%3;
00786                                 
00787                                 get_edgepairkey(&tstkey, table[j], table[j2], table[k+3], table[k2+3]);
00788                                 //if (BLI_ghash_haskey(visithash, &tstkey))
00789                                 //      continue;
00790                                 
00791                                 key = BLI_memarena_alloc(arena, sizeof(edgepairkey));
00792                                 *key = tstkey;
00793                                 BLI_ghash_insert(visithash, key, NULL);
00794 
00795                                 sub_v3_v3v3(p1, verts[j], verts[j2]);
00796                                 sub_v3_v3v3(p2, verts[k+3], verts[k2+3]);
00797                                 
00798                                 cross_v3_v3v3(off, p1, p2);
00799                                 normalize_v3(off);
00800 
00801                                 if (dot_v3v3(n2, off) < 0.0)
00802                                         negate_v3(off);
00803                                 
00804                                 mul_v3_fl(off,  epsilon1 + epsilon2 + ALMOST_ZERO);
00805                                 copy_v3_v3(p1, verts[k+3]);
00806                                 copy_v3_v3(p2, verts[k2+3]);
00807                                 add_v3_v3(p1, off);
00808                                 add_v3_v3(p2, off);
00809                                 
00810                                 ret = eltopo_line_line_moving_isect_v3v3_f(verts[j], table[j], verts[j2], table[j2], 
00811                                                                                                                    p1, table[k+3], p2, table[k2+3], 
00812                                                                                                                    no, uv, &t, &relnor);
00813                                 /*cloth vert versus coll face*/
00814                                 if (ret) {
00815                                         collpair->ap1 = table[j]; collpair->ap2 = table[j2]; 
00816                                         collpair->bp1 = table[k+3]; collpair->bp2 = table[k2+3];
00817                                         
00818                                         /*I'm not sure if this is correct, but hopefully it's 
00819                                           better then simply ignoring back edges*/
00820                                         if (dot_v3v3(n2, no) < 0.0) {
00821                                                 negate_v3(no);
00822                                         }
00823                                         
00824                                         copy_v3_v3(collpair->normal, no);
00825                                         mul_v3_v3fl(collpair->vector, collpair->normal, relnor);
00826                                         collpair->distance = relnor;
00827                                         collpair->time = t;
00828                                         
00829                                         copy_v2_v2(collpair->bary, uv);
00830                                         
00831                                         collpair->flag = COLLISION_IS_EDGES;
00832                                         collpair++;
00833                                 }
00834                         }
00835                 }
00836         }
00837         
00838         return collpair;
00839 }
00840 
00841 static int cloth_edge_collision_response_moving ( ClothModifierData *clmd, CollisionModifierData *collmd, CollPair *collpair, CollPair *collision_end )
00842 {
00843         int result = 0;
00844         Cloth *cloth1;
00845         float w1, w2;
00846         float v1[3], v2[3], relativeVelocity[3];
00847         float magrelVel, pimpulse[3];
00848 
00849         cloth1 = clmd->clothObject;
00850 
00851         for ( ; collpair != collision_end; collpair++ )
00852         {
00853                 if (!(collpair->flag & COLLISION_IS_EDGES))
00854                         continue;
00855                 
00856                 // was: txold
00857                 w1 = collpair->bary[0]; w2 = collpair->bary[1];                 
00858                 
00859                 // Calculate relative "velocity".
00860                 VECADDFAC(v1, cloth1->verts[collpair->ap1].tv, cloth1->verts[collpair->ap2].tv, w1);
00861                 VECADDFAC(v2, collmd->current_v[collpair->bp1].co, collmd->current_v[collpair->bp2].co, w2);
00862                 
00863                 VECSUB ( relativeVelocity, v2, v1);
00864                 
00865                 // Calculate the normal component of the relative velocity (actually only the magnitude - the direction is stored in 'normal').
00866                 magrelVel = INPR ( relativeVelocity, collpair->normal );
00867 
00868                 // If v_n_mag < 0 the edges are approaching each other.
00869                 if ( magrelVel > ALMOST_ZERO )
00870                 {
00871                         // Calculate Impulse magnitude to stop all motion in normal direction.
00872                         float magtangent = 0, repulse = 0, d = 0;
00873                         double impulse = 0.0;
00874                         float vrel_t_pre[3];
00875                         float temp[3], spf;
00876                         
00877                         zero_v3(pimpulse);
00878                         
00879                         // calculate tangential velocity
00880                         VECCOPY ( temp, collpair->normal );
00881                         mul_v3_fl( temp, magrelVel );
00882                         VECSUB ( vrel_t_pre, relativeVelocity, temp );
00883 
00884                         // Decrease in magnitude of relative tangential velocity due to coulomb friction
00885                         // in original formula "magrelVel" should be the "change of relative velocity in normal direction"
00886                         magtangent = MIN2 ( clmd->coll_parms->friction * 0.01 * magrelVel,sqrt ( INPR ( vrel_t_pre,vrel_t_pre ) ) );
00887 
00888                         // Apply friction impulse.
00889                         if ( magtangent > ALMOST_ZERO )
00890                         {
00891                                 normalize_v3( vrel_t_pre );
00892 
00893                                 impulse = magtangent; 
00894                                 VECADDMUL ( pimpulse, vrel_t_pre, impulse);
00895                         }
00896 
00897                         // Apply velocity stopping impulse
00898                         // I_c = m * v_N / 2.0
00899                         // no 2.0 * magrelVel normally, but looks nicer DG
00900                         impulse =  magrelVel;
00901                         
00902                         mul_v3_fl(collpair->normal, 0.5);
00903                         VECADDMUL ( pimpulse, collpair->normal, impulse);
00904 
00905                         // Apply repulse impulse if distance too short
00906                         // I_r = -min(dt*kd, m(0,1d/dt - v_n))
00907                         spf = (float)clmd->sim_parms->stepsPerFrame / clmd->sim_parms->timescale;
00908 
00909                         d = collpair->distance;
00910                         if ( ( magrelVel < 0.1*d*spf && ( d > ALMOST_ZERO ) ) )
00911                         {
00912                                 repulse = MIN2 ( d*1.0/spf, 0.1*d*spf - magrelVel );
00913 
00914                                 // stay on the safe side and clamp repulse
00915                                 if ( impulse > ALMOST_ZERO )
00916                                         repulse = MIN2 ( repulse, 5.0*impulse );
00917                                 repulse = MAX2 ( impulse, repulse );
00918 
00919                                 impulse = repulse / ( 5.0 ); // original 2.0 / 0.25
00920                                 VECADDMUL ( pimpulse, collpair->normal, impulse);
00921                         }
00922                         
00923                         w2 = 1.0f-w1;
00924                         if (w1 < 0.5)
00925                                 w1 *= 2.0;
00926                         else
00927                                 w2 *= 2.0;
00928                         
00929                         VECADDFAC(cloth1->verts[collpair->ap1].impulse, cloth1->verts[collpair->ap1].impulse, pimpulse, w1*2.0);
00930                         VECADDFAC(cloth1->verts[collpair->ap2].impulse, cloth1->verts[collpair->ap2].impulse, pimpulse, w2*2.0);
00931                         
00932                         cloth1->verts[collpair->ap1].impulse_count++;
00933                         cloth1->verts[collpair->ap2].impulse_count++;
00934                         
00935                         result = 1;
00936                 }
00937         } 
00938         
00939         return result;
00940 }
00941 
00942 static int cloth_collision_response_moving ( ClothModifierData *clmd, CollisionModifierData *collmd, CollPair *collpair, CollPair *collision_end )
00943 {
00944         int result = 0;
00945         Cloth *cloth1;
00946         float w1, w2, w3, u1, u2, u3;
00947         float v1[3], v2[3], relativeVelocity[3];
00948         float magrelVel;
00949         float epsilon2 = BLI_bvhtree_getepsilon ( collmd->bvhtree );
00950         
00951         cloth1 = clmd->clothObject;
00952 
00953         for ( ; collpair != collision_end; collpair++ )
00954         {
00955                 if (collpair->flag & COLLISION_IS_EDGES)
00956                         continue;
00957                 
00958                 if ( collpair->flag & COLLISION_USE_COLLFACE ) {
00959                         // was: txold
00960                         w1 = collpair->bary[0]; w2 = collpair->bary[1]; w3 = collpair->bary[2];                 
00961 
00962                         // Calculate relative "velocity".
00963                         collision_interpolateOnTriangle ( v1, collmd->current_v[collpair->bp1].co, collmd->current_v[collpair->bp2].co, collmd->current_v[collpair->bp3].co, w1, w2, w3);
00964                         
00965                         VECSUB ( relativeVelocity, v1, cloth1->verts[collpair->collp].tv);
00966                         
00967                         // Calculate the normal component of the relative velocity (actually only the magnitude - the direction is stored in 'normal').
00968                         magrelVel = INPR ( relativeVelocity, collpair->normal );
00969         
00970                         // If v_n_mag < 0 the edges are approaching each other.
00971                         if ( magrelVel > ALMOST_ZERO )
00972                         {
00973                                 // Calculate Impulse magnitude to stop all motion in normal direction.
00974                                 float magtangent = 0, repulse = 0, d = 0;
00975                                 double impulse = 0.0;
00976                                 float vrel_t_pre[3];
00977                                 float temp[3], spf;
00978         
00979                                 // calculate tangential velocity
00980                                 VECCOPY ( temp, collpair->normal );
00981                                 mul_v3_fl( temp, magrelVel );
00982                                 VECSUB ( vrel_t_pre, relativeVelocity, temp );
00983         
00984                                 // Decrease in magnitude of relative tangential velocity due to coulomb friction
00985                                 // in original formula "magrelVel" should be the "change of relative velocity in normal direction"
00986                                 magtangent = MIN2 ( clmd->coll_parms->friction * 0.01 * magrelVel,sqrt ( INPR ( vrel_t_pre,vrel_t_pre ) ) );
00987         
00988                                 // Apply friction impulse.
00989                                 if ( magtangent > ALMOST_ZERO )
00990                                 {
00991                                         normalize_v3( vrel_t_pre );
00992         
00993                                         impulse = magtangent; // 2.0 * 
00994                                         VECADDMUL ( cloth1->verts[collpair->collp].impulse, vrel_t_pre, impulse);
00995                                 }
00996         
00997                                 // Apply velocity stopping impulse
00998                                 // I_c = m * v_N / 2.0
00999                                 // no 2.0 * magrelVel normally, but looks nicer DG
01000                                 impulse =  magrelVel/2.0;
01001         
01002                                 VECADDMUL ( cloth1->verts[collpair->collp].impulse, collpair->normal, impulse);
01003                                 cloth1->verts[collpair->collp].impulse_count++;
01004         
01005                                 // Apply repulse impulse if distance too short
01006                                 // I_r = -min(dt*kd, m(0,1d/dt - v_n))
01007                                 spf = (float)clmd->sim_parms->stepsPerFrame / clmd->sim_parms->timescale;
01008         
01009                                 d = -collpair->distance;
01010                                 if ( ( magrelVel < 0.1*d*spf ) && ( d > ALMOST_ZERO ) )
01011                                 {
01012                                         repulse = MIN2 ( d*1.0/spf, 0.1*d*spf - magrelVel );
01013         
01014                                         // stay on the safe side and clamp repulse
01015                                         if ( impulse > ALMOST_ZERO )
01016                                                 repulse = MIN2 ( repulse, 5.0*impulse );
01017                                         repulse = MAX2 ( impulse, repulse );
01018         
01019                                         impulse = repulse / ( 5.0 ); // original 2.0 / 0.25
01020                                         VECADDMUL ( cloth1->verts[collpair->collp].impulse, collpair->normal, impulse);
01021                                 }
01022         
01023                                 result = 1;
01024                         }
01025                 } else {        
01026                         w1 = collpair->bary[0]; w2 = collpair->bary[1]; w3 = collpair->bary[2];                 
01027 
01028                         // Calculate relative "velocity".
01029                         collision_interpolateOnTriangle ( v1, cloth1->verts[collpair->ap1].tv, cloth1->verts[collpair->ap2].tv, cloth1->verts[collpair->ap3].tv, w1, w2, w3 );
01030         
01031                         VECSUB ( relativeVelocity, collmd->current_v[collpair->collp].co, v1);
01032                         
01033                         // Calculate the normal component of the relative velocity (actually only the magnitude - the direction is stored in 'normal').
01034                         magrelVel = INPR ( relativeVelocity, collpair->normal );
01035         
01036                         // If v_n_mag < 0 the edges are approaching each other.
01037                         if ( magrelVel > ALMOST_ZERO )
01038                         {
01039                                 // Calculate Impulse magnitude to stop all motion in normal direction.
01040                                 float magtangent = 0, repulse = 0, d = 0;
01041                                 double impulse = 0.0;
01042                                 float vrel_t_pre[3], pimpulse[3] = {0.0f, 0.0f, 0.0f};
01043                                 float temp[3], spf;
01044         
01045                                 // calculate tangential velocity
01046                                 VECCOPY ( temp, collpair->normal );
01047                                 mul_v3_fl( temp, magrelVel );
01048                                 VECSUB ( vrel_t_pre, relativeVelocity, temp );
01049         
01050                                 // Decrease in magnitude of relative tangential velocity due to coulomb friction
01051                                 // in original formula "magrelVel" should be the "change of relative velocity in normal direction"
01052                                 magtangent = MIN2 ( clmd->coll_parms->friction * 0.01 * magrelVel,sqrt ( INPR ( vrel_t_pre,vrel_t_pre ) ) );
01053         
01054                                 // Apply friction impulse.
01055                                 if ( magtangent > ALMOST_ZERO )
01056                                 {
01057                                         normalize_v3( vrel_t_pre );
01058         
01059                                         impulse = magtangent; // 2.0 * 
01060                                         VECADDMUL ( pimpulse, vrel_t_pre, impulse);
01061                                 }
01062         
01063                                 // Apply velocity stopping impulse
01064                                 // I_c = m * v_N / 2.0
01065                                 // no 2.0 * magrelVel normally, but looks nicer DG
01066                                 impulse =  magrelVel/2.0;
01067         
01068                                 VECADDMUL ( pimpulse, collpair->normal, impulse);
01069         
01070                                 // Apply repulse impulse if distance too short
01071                                 // I_r = -min(dt*kd, m(0,1d/dt - v_n))
01072                                 spf = (float)clmd->sim_parms->stepsPerFrame / clmd->sim_parms->timescale;
01073         
01074                                 d = -collpair->distance;
01075                                 if ( ( magrelVel < 0.1*d*spf ) && ( d > ALMOST_ZERO ) )
01076                                 {
01077                                         repulse = MIN2 ( d*1.0/spf, 0.1*d*spf - magrelVel );
01078         
01079                                         // stay on the safe side and clamp repulse
01080                                         if ( impulse > ALMOST_ZERO )
01081                                                 repulse = MIN2 ( repulse, 5.0*impulse );
01082                                         repulse = MAX2 ( impulse, repulse );
01083         
01084                                         impulse = repulse / ( 2.0 ); // original 2.0 / 0.25
01085                                         VECADDMUL ( pimpulse, collpair->normal, impulse);
01086                                 }
01087                                 
01088                                 if (w1 < 0.5) w1 *= 2.0;
01089                                 if (w2 < 0.5) w2 *= 2.0;
01090                                 if (w3 < 0.5) w3 *= 2.0;
01091                                 
01092                                 VECADDMUL(cloth1->verts[collpair->ap1].impulse, pimpulse, w1*2.0);
01093                                 VECADDMUL(cloth1->verts[collpair->ap2].impulse, pimpulse, w2*2.0);
01094                                 VECADDMUL(cloth1->verts[collpair->ap3].impulse, pimpulse, w3*2.0);;
01095                                 cloth1->verts[collpair->ap1].impulse_count++;
01096                                 cloth1->verts[collpair->ap2].impulse_count++;
01097                                 cloth1->verts[collpair->ap3].impulse_count++;
01098                                 
01099                                 result = 1;
01100                         }
01101                 }
01102         } 
01103         
01104         return result;
01105 }
01106 
01107 
01108 typedef struct tripairkey {
01109         int p, a1, a2, a3;
01110 } tripairkey;
01111 
01112 unsigned int tripair_hash(void *vkey)
01113 {
01114         tripairkey *key = vkey;
01115         int keys[4] = {key->p, key->a1, key->a2, key->a3};
01116         int i, j;
01117         
01118         for (i=0; i<4; i++) {
01119                 for (j=0; j<3; j++) {
01120                         if (keys[j] >= keys[j+1]) {
01121                                 SWAP(int, keys[j], keys[j+1]);
01122                         }
01123                 }
01124         }
01125         
01126         return keys[0]*101 + keys[1]*72 + keys[2]*53 + keys[3]*34;
01127 }
01128 
01129 int tripair_cmp(const void *va, const void *vb)
01130 {
01131         tripairkey *a = va, *b = vb;
01132         int keysa[4] = {a->p, a->a1, a->a2, a->a3};
01133         int keysb[4] = {b->p, b->a1, b->a2, b->a3};
01134         int i;
01135         
01136         for (i=0; i<4; i++) {
01137                 int j, ok=0;
01138                 for (j=0; j<4; j++) {
01139                         if (keysa[i] == keysa[j]) {
01140                                 ok = 1;
01141                                 break;
01142                         }
01143                 }
01144                 if (!ok)
01145                         return -1;
01146         }
01147         
01148         return 0;
01149 }
01150 
01151 static void get_tripairkey(tripairkey *key, int p, int a1, int a2, int a3)
01152 {
01153         key->a1 = a1;
01154         key->a2 = a2;
01155         key->a3 = a3;
01156         key->p = p;
01157 }
01158 
01159 static int checkvisit(MemArena *arena, GHash *gh, int p, int a1, int a2, int a3)
01160 {
01161         tripairkey key, *key2;
01162         
01163         get_tripairkey(&key, p, a1, a2, a3);
01164         if (BLI_ghash_haskey(gh, &key))
01165                 return 1;
01166         
01167         key2 = BLI_memarena_alloc(arena, sizeof(*key2));
01168         *key2 = key;
01169         BLI_ghash_insert(gh, key2, NULL);
01170         
01171         return 0;
01172 }
01173 
01174 int cloth_point_tri_moving_v3v3_f(float v1[2][3], int i1, float v2[2][3], int i2,
01175                                    float v3[2][3],  int i3, float v4[2][3], int i4,
01176                                    float normal[3], float bary[3], float *t, 
01177                                                                    float *relnor, GHash *gh, MemArena *arena)
01178 {
01179         if (checkvisit(arena, gh, i1, i2, i3, i4))
01180                 return 0;
01181         
01182         return eltopo_point_tri_moving_v3v3_f(v1, i1, v2, i2, v3, i3, v4, i4, normal, bary, t, relnor);
01183 }
01184 
01185 static CollPair* cloth_collision ( ModifierData *md1, ModifierData *md2, BVHTreeOverlap *overlap, 
01186                                                                    CollPair *collpair, double dt, GHash *gh, MemArena *arena)
01187 {
01188         ClothModifierData *clmd = ( ClothModifierData * ) md1;
01189         CollisionModifierData *collmd = ( CollisionModifierData * ) md2;
01190         MFace *face1=NULL, *face2 = NULL;
01191         ClothVertex *verts1 = clmd->clothObject->verts;
01192         double distance = 0;
01193         float epsilon1 = clmd->coll_parms->epsilon;
01194         float epsilon2 = BLI_bvhtree_getepsilon ( collmd->bvhtree );
01195         float no[3], uv[3], t, relnor;
01196         int i, i1, i2, i3, i4, i5, i6;
01197         Cloth *cloth = clmd->clothObject;
01198         float n1[3], sdis, p[3], l, n2[3], off[3], v1[2][3], v2[2][3], v3[2][3], v4[2][3], v5[2][3], v6[2][3];
01199         int j, ret, bp1, bp2, bp3, ap1, ap2, ap3;
01200         
01201         face1 = & ( clmd->clothObject->mfaces[overlap->indexA] );
01202         face2 = & ( collmd->mfaces[overlap->indexB] );
01203 
01204         // check all 4 possible collisions
01205         for ( i = 0; i < 4; i++ )
01206         {
01207                 if ( i == 0 )
01208                 {
01209                         // fill faceA
01210                         ap1 = face1->v1;
01211                         ap2 = face1->v2;
01212                         ap3 = face1->v3;
01213 
01214                         // fill faceB
01215                         bp1 = face2->v1;
01216                         bp2 = face2->v2;
01217                         bp3 = face2->v3;
01218                 }
01219                 else if ( i == 1 )
01220                 {
01221                         if ( face1->v4 )
01222                         {
01223                                 // fill faceA
01224                                 ap1 = face1->v1;
01225                                 ap2 = face1->v3;
01226                                 ap3 = face1->v4;
01227 
01228                                 // fill faceB
01229                                 bp1 = face2->v1;
01230                                 bp2 = face2->v2;
01231                                 bp3 = face2->v3;
01232                         }
01233                         else {
01234                                 continue;
01235                         }
01236                 }
01237                 if ( i == 2 )
01238                 {
01239                         if ( face2->v4 )
01240                         {
01241                                 // fill faceA
01242                                 ap1 = face1->v1;
01243                                 ap2 = face1->v2;
01244                                 ap3 = face1->v3;
01245 
01246                                 // fill faceB
01247                                 bp1 = face2->v1;
01248                                 bp2 = face2->v3;
01249                                 bp3 = face2->v4;
01250                         }
01251                         else {
01252                                 continue;
01253                         }
01254                 }
01255                 else if ( i == 3 )
01256                 {
01257                         if ( face1->v4 && face2->v4 )
01258                         {
01259                                 // fill faceA
01260                                 ap1 = face1->v1;
01261                                 ap2 = face1->v3;
01262                                 ap3 = face1->v4;
01263 
01264                                 // fill faceB
01265                                 bp1 = face2->v1;
01266                                 bp2 = face2->v3;
01267                                 bp3 = face2->v4;
01268                         }
01269                         else {
01270                                 continue;
01271                         }
01272                 }
01273                 
01274                 copy_v3_v3(v1[0], cloth->verts[ap1].txold); 
01275                 copy_v3_v3(v1[1], cloth->verts[ap1].tx);
01276                 copy_v3_v3(v2[0], cloth->verts[ap2].txold);
01277                 copy_v3_v3(v2[1], cloth->verts[ap2].tx);
01278                 copy_v3_v3(v3[0], cloth->verts[ap3].txold);
01279                 copy_v3_v3(v3[1], cloth->verts[ap3].tx);
01280                 
01281                 copy_v3_v3(v4[0], collmd->current_x[bp1].co);
01282                 copy_v3_v3(v4[1], collmd->current_xnew[bp1].co);
01283                 copy_v3_v3(v5[0], collmd->current_x[bp2].co);
01284                 copy_v3_v3(v5[1], collmd->current_xnew[bp2].co);
01285                 copy_v3_v3(v6[0], collmd->current_x[bp3].co);
01286                 copy_v3_v3(v6[1], collmd->current_xnew[bp3].co);
01287                 
01288                 normal_tri_v3(n2, v4[1], v5[1], v6[1]);
01289                 
01290                 sdis = clmd->coll_parms->distance_repel + epsilon2 + FLT_EPSILON;
01291 
01292                 /*apply a repulsion force, to help the solver along*/
01293                 copy_v3_v3(off, n2);
01294                 negate_v3(off);
01295                 if (isect_ray_plane_v3(v1[1], off, v4[1], v5[1], v6[1], &l, 0)) {
01296                         if (l >= 0.0 && l < sdis) {
01297                                 mul_v3_fl(off, (l-sdis)*cloth->verts[ap1].mass*dt*clmd->coll_parms->repel_force*0.1);
01298 
01299                                 add_v3_v3(cloth->verts[ap1].tv, off);
01300                                 add_v3_v3(cloth->verts[ap2].tv, off);
01301                                 add_v3_v3(cloth->verts[ap3].tv, off);
01302                         }
01303                 }
01304 
01305                 /*offset new positions a bit, to account for margins*/
01306                 copy_v3_v3(off, n2);
01307                 mul_v3_fl(off,  epsilon1 + epsilon2 + ALMOST_ZERO);
01308                 add_v3_v3(v4[1], off); add_v3_v3(v5[1], off); add_v3_v3(v6[1], off);
01309                 
01310                 i1 = ap1; i2 = ap2; i3 = ap3;
01311                 i4 = bp1+cloth->numverts; i5 = bp2+cloth->numverts; i6 = bp3+cloth->numverts;
01312                 
01313                 for (j=0; j<6; j++) {
01314                         int collp;
01315 
01316                         switch (j) {
01317                         case 0:
01318                                 ret = cloth_point_tri_moving_v3v3_f(v1, i1, v4, i4, v5, i5, v6, i6, no, uv, &t, &relnor, gh, arena);
01319                                 collp = ap1;
01320                                 break;
01321                         case 1:
01322                                 collp = ap2;
01323                                 ret = cloth_point_tri_moving_v3v3_f(v2, i2, v4, i4, v5, i5, v6, i6, no, uv, &t, &relnor, gh, arena);
01324                                 break;
01325                         case 2:
01326                                 collp = ap3;
01327                                 ret = cloth_point_tri_moving_v3v3_f(v3, i3, v4, i4, v5, i5, v6, i6, no, uv, &t, &relnor, gh, arena);
01328                                 break;
01329                         case 3:
01330                                 collp = bp1;
01331                                 ret = cloth_point_tri_moving_v3v3_f(v4, i4, v1, i1, v2, i2, v3, i3, no, uv, &t, &relnor, gh, arena);
01332                                 break;
01333                         case 4:
01334                                 collp = bp2;                            
01335                                 ret = cloth_point_tri_moving_v3v3_f(v5, i5, v1, i1, v2, i2, v3, i3, no, uv, &t, &relnor, gh, arena);
01336                                 break;
01337                         case 5:
01338                                 collp = bp3;
01339                                 ret = cloth_point_tri_moving_v3v3_f(v6, i6, v1, i1, v2, i2, v3, i3, no, uv, &t, &relnor, gh, arena);
01340                                 break;
01341                         }
01342                         
01343                         /*cloth vert versus coll face*/
01344                         if (ret && j < 3) {
01345                                 collpair->bp1 = bp1; collpair->bp2 = bp2; collpair->bp3 = bp3;
01346                                 collpair->collp = collp;
01347                                 
01348                                 copy_v3_v3(collpair->normal, no);
01349                                 mul_v3_v3fl(collpair->vector, collpair->normal, relnor);
01350                                 collpair->distance = relnor;
01351                                 collpair->time = t;
01352                                 
01353                                 copy_v3_v3(collpair->bary, uv);
01354                                 
01355                                 collpair->flag = COLLISION_USE_COLLFACE;
01356                                 collpair++;
01357                         } else if (ret && j >= 3) { /*coll vert versus cloth face*/
01358                                 collpair->ap1 = ap1; collpair->ap2 = ap2; collpair->ap3 = ap3;
01359                                 collpair->collp = collp;
01360                                 
01361                                 copy_v3_v3(collpair->normal, no);
01362                                 mul_v3_v3fl(collpair->vector, collpair->normal, relnor);
01363                                 collpair->distance = relnor;
01364                                 collpair->time = t;
01365                                 
01366                                 copy_v3_v3(collpair->bary, uv);
01367 
01368                                 collpair->flag = 0;
01369                                 collpair++;
01370                         }
01371                 }
01372         }
01373         
01374         return collpair;
01375 }
01376 
01377 static void machine_epsilon_offset(Cloth *cloth) {
01378         ClothVertex *cv;
01379         int i, j;
01380         
01381         cv = cloth->verts;
01382         for (i=0; i<cloth->numverts; i++, cv++) {
01383                 /*aggrevatingly enough, it's necassary to offset the coordinates
01384                  by a multiple of the 32-bit floating point epsilon when switching
01385                  into doubles*/
01386                 #define RNDSIGN (float)(-1*(BLI_rand()%2==0)|1)
01387                 for (j=0; j<3; j++) {
01388                         cv->tx[j] += FLT_EPSILON*30.0f*RNDSIGN;
01389                         cv->txold[j] += FLT_EPSILON*30.0f*RNDSIGN;
01390                         cv->tv[j] += FLT_EPSILON*30.0f*RNDSIGN;
01391                 }               
01392         }
01393 }
01394 
01395 #else /* !WITH_ELTOPO */
01396 
01397 //Determines collisions on overlap, collisions are written to collpair[i] and collision+number_collision_found is returned
01398 static CollPair* cloth_collision ( ModifierData *md1, ModifierData *md2, 
01399         BVHTreeOverlap *overlap, CollPair *collpair, float dt )
01400 {
01401         ClothModifierData *clmd = ( ClothModifierData * ) md1;
01402         CollisionModifierData *collmd = ( CollisionModifierData * ) md2;
01403         Cloth *cloth = clmd->clothObject;
01404         MFace *face1=NULL, *face2 = NULL;
01405 #ifdef USE_BULLET
01406         ClothVertex *verts1 = clmd->clothObject->verts;
01407 #endif
01408         double distance = 0;
01409         float epsilon1 = clmd->coll_parms->epsilon;
01410         float epsilon2 = BLI_bvhtree_getepsilon ( collmd->bvhtree );
01411         float n2[3], sdis, l;
01412         int i;
01413 
01414         face1 = & ( clmd->clothObject->mfaces[overlap->indexA] );
01415         face2 = & ( collmd->mfaces[overlap->indexB] );
01416 
01417         // check all 4 possible collisions
01418         for ( i = 0; i < 4; i++ )
01419         {
01420                 if ( i == 0 )
01421                 {
01422                         // fill faceA
01423                         collpair->ap1 = face1->v1;
01424                         collpair->ap2 = face1->v2;
01425                         collpair->ap3 = face1->v3;
01426 
01427                         // fill faceB
01428                         collpair->bp1 = face2->v1;
01429                         collpair->bp2 = face2->v2;
01430                         collpair->bp3 = face2->v3;
01431                 }
01432                 else if ( i == 1 )
01433                 {
01434                         if ( face1->v4 )
01435                         {
01436                                 // fill faceA
01437                                 collpair->ap1 = face1->v1;
01438                                 collpair->ap2 = face1->v4;
01439                                 collpair->ap3 = face1->v3;
01440 
01441                                 // fill faceB
01442                                 collpair->bp1 = face2->v1;
01443                                 collpair->bp2 = face2->v2;
01444                                 collpair->bp3 = face2->v3;
01445                         }
01446                         else
01447                                 i++;
01448                 }
01449                 if ( i == 2 )
01450                 {
01451                         if ( face2->v4 )
01452                         {
01453                                 // fill faceA
01454                                 collpair->ap1 = face1->v1;
01455                                 collpair->ap2 = face1->v2;
01456                                 collpair->ap3 = face1->v3;
01457 
01458                                 // fill faceB
01459                                 collpair->bp1 = face2->v1;
01460                                 collpair->bp2 = face2->v4;
01461                                 collpair->bp3 = face2->v3;
01462                         }
01463                         else
01464                                 break;
01465                 }
01466                 else if ( i == 3 )
01467                 {
01468                         if ( face1->v4 && face2->v4 )
01469                         {
01470                                 // fill faceA
01471                                 collpair->ap1 = face1->v1;
01472                                 collpair->ap2 = face1->v4;
01473                                 collpair->ap3 = face1->v3;
01474 
01475                                 // fill faceB
01476                                 collpair->bp1 = face2->v1;
01477                                 collpair->bp2 = face2->v4;
01478                                 collpair->bp3 = face2->v3;
01479                         }
01480                         else
01481                                 break;
01482                 }
01483                 
01484                 normal_tri_v3(n2, collmd->current_xnew[collpair->bp1].co, 
01485                         collmd->current_xnew[collpair->bp2].co, 
01486                         collmd->current_xnew[collpair->bp3].co);
01487                 
01488                 sdis = clmd->coll_parms->distance_repel + epsilon2 + FLT_EPSILON;
01489                 
01490                 /*apply a repulsion force, to help the solver along.
01491           this is kindof crude, it only tests one vert of the triangle*/
01492                 if (isect_ray_plane_v3(cloth->verts[collpair->ap1].tx, n2, collmd->current_xnew[collpair->bp1].co, 
01493                         collmd->current_xnew[collpair->bp2].co,
01494                         collmd->current_xnew[collpair->bp3].co, &l, 0))
01495                 {
01496                         if (l >= 0.0 && l < sdis) {
01497                                 mul_v3_fl(n2, (l-sdis)*cloth->verts[collpair->ap1].mass*dt*clmd->coll_parms->repel_force*0.1);
01498 
01499                                 add_v3_v3(cloth->verts[collpair->ap1].tv, n2);
01500                                 add_v3_v3(cloth->verts[collpair->ap2].tv, n2);
01501                                 add_v3_v3(cloth->verts[collpair->ap3].tv, n2);
01502                         }
01503                 }
01504                 
01505 #ifdef USE_BULLET
01506                 // calc distance + normal
01507                 distance = plNearestPoints (
01508                         verts1[collpair->ap1].txold, verts1[collpair->ap2].txold, verts1[collpair->ap3].txold, collmd->current_x[collpair->bp1].co, collmd->current_x[collpair->bp2].co, collmd->current_x[collpair->bp3].co, collpair->pa,collpair->pb,collpair->vector );
01509 #else
01510                 // just be sure that we don't add anything
01511                 distance = 2.0 * ( epsilon1 + epsilon2 + ALMOST_ZERO );
01512 #endif
01513 
01514                 if ( distance <= ( epsilon1 + epsilon2 + ALMOST_ZERO ) )
01515                 {
01516                         normalize_v3_v3( collpair->normal, collpair->vector );
01517 
01518                         collpair->distance = distance;
01519                         collpair->flag = 0;
01520                         collpair++;
01521                 }/*
01522                 else
01523                 {
01524                         float w1, w2, w3, u1, u2, u3;
01525                         float v1[3], v2[3], relativeVelocity[3];
01526 
01527                         // calc relative velocity
01528                         
01529                         // compute barycentric coordinates for both collision points
01530                         collision_compute_barycentric ( collpair->pa,
01531                         verts1[collpair->ap1].txold,
01532                         verts1[collpair->ap2].txold,
01533                         verts1[collpair->ap3].txold,
01534                         &w1, &w2, &w3 );
01535 
01536                         // was: txold
01537                         collision_compute_barycentric ( collpair->pb,
01538                         collmd->current_x[collpair->bp1].co,
01539                         collmd->current_x[collpair->bp2].co,
01540                         collmd->current_x[collpair->bp3].co,
01541                         &u1, &u2, &u3 );
01542 
01543                         // Calculate relative "velocity".
01544                         collision_interpolateOnTriangle ( v1, verts1[collpair->ap1].tv, verts1[collpair->ap2].tv, verts1[collpair->ap3].tv, w1, w2, w3 );
01545 
01546                         collision_interpolateOnTriangle ( v2, collmd->current_v[collpair->bp1].co, collmd->current_v[collpair->bp2].co, collmd->current_v[collpair->bp3].co, u1, u2, u3 );
01547 
01548                         VECSUB ( relativeVelocity, v2, v1 );
01549 
01550                         if(sqrt(INPR(relativeVelocity, relativeVelocity)) >= distance)
01551                         {
01552                                 // check for collision in the future
01553                                 collpair->flag |= COLLISION_IN_FUTURE;
01554                                 collpair++;
01555                         }
01556                 }*/
01557         }
01558         return collpair;
01559 }
01560 #endif /* WITH_ELTOPO */
01561 
01562 
01563 #if 0
01564 static int cloth_collision_response_moving( ClothModifierData *clmd, CollisionModifierData *collmd, CollPair *collpair, CollPair *collision_end )
01565 {
01566         int result = 0;
01567         Cloth *cloth1;
01568         float w1, w2, w3, u1, u2, u3;
01569         float v1[3], v2[3], relativeVelocity[3];
01570         float magrelVel;
01571 
01572         cloth1 = clmd->clothObject;
01573 
01574         for ( ; collpair != collision_end; collpair++ )
01575         {
01576                 // compute barycentric coordinates for both collision points
01577                 collision_compute_barycentric ( collpair->pa,
01578                         cloth1->verts[collpair->ap1].txold,
01579                         cloth1->verts[collpair->ap2].txold,
01580                         cloth1->verts[collpair->ap3].txold,
01581                         &w1, &w2, &w3 );
01582 
01583                 // was: txold
01584                 collision_compute_barycentric ( collpair->pb,
01585                         collmd->current_x[collpair->bp1].co,
01586                         collmd->current_x[collpair->bp2].co,
01587                         collmd->current_x[collpair->bp3].co,
01588                         &u1, &u2, &u3 );
01589 
01590                 // Calculate relative "velocity".
01591                 collision_interpolateOnTriangle ( v1, cloth1->verts[collpair->ap1].tv, cloth1->verts[collpair->ap2].tv, cloth1->verts[collpair->ap3].tv, w1, w2, w3 );
01592 
01593                 collision_interpolateOnTriangle ( v2, collmd->current_v[collpair->bp1].co, collmd->current_v[collpair->bp2].co, collmd->current_v[collpair->bp3].co, u1, u2, u3 );
01594 
01595                 VECSUB ( relativeVelocity, v2, v1 );
01596 
01597                 // Calculate the normal component of the relative velocity (actually only the magnitude - the direction is stored in 'normal').
01598                 magrelVel = INPR ( relativeVelocity, collpair->normal );
01599 
01600                 // printf("magrelVel: %f\n", magrelVel);
01601 
01602                 // Calculate masses of points.
01603                 // TODO
01604 
01605                 // If v_n_mag < 0 the edges are approaching each other.
01606                 if ( magrelVel > ALMOST_ZERO )
01607                 {
01608                         // Calculate Impulse magnitude to stop all motion in normal direction.
01609                         float magtangent = 0;
01610                         double impulse = 0.0;
01611                         float vrel_t_pre[3];
01612                         float temp[3];
01613 
01614                         // calculate tangential velocity
01615                         VECCOPY ( temp, collpair->normal );
01616                         mul_v3_fl( temp, magrelVel );
01617                         VECSUB ( vrel_t_pre, relativeVelocity, temp );
01618 
01619                         // Decrease in magnitude of relative tangential velocity due to coulomb friction
01620                         // in original formula "magrelVel" should be the "change of relative velocity in normal direction"
01621                         magtangent = MIN2 ( clmd->coll_parms->friction * 0.01 * magrelVel,sqrt ( INPR ( vrel_t_pre,vrel_t_pre ) ) );
01622 
01623                         // Apply friction impulse.
01624                         if ( magtangent > ALMOST_ZERO )
01625                         {
01626                                 normalize_v3( vrel_t_pre );
01627 
01628                                 impulse = 2.0 * magtangent / ( 1.0 + w1*w1 + w2*w2 + w3*w3 );
01629                                 VECADDMUL ( cloth1->verts[collpair->ap1].impulse, vrel_t_pre, w1 * impulse );
01630                                 VECADDMUL ( cloth1->verts[collpair->ap2].impulse, vrel_t_pre, w2 * impulse );
01631                                 VECADDMUL ( cloth1->verts[collpair->ap3].impulse, vrel_t_pre, w3 * impulse );
01632                         }
01633 
01634                         // Apply velocity stopping impulse
01635                         // I_c = m * v_N / 2.0
01636                         // no 2.0 * magrelVel normally, but looks nicer DG
01637                         impulse =  magrelVel / ( 1.0 + w1*w1 + w2*w2 + w3*w3 );
01638 
01639                         VECADDMUL ( cloth1->verts[collpair->ap1].impulse, collpair->normal, w1 * impulse );
01640                         cloth1->verts[collpair->ap1].impulse_count++;
01641 
01642                         VECADDMUL ( cloth1->verts[collpair->ap2].impulse, collpair->normal, w2 * impulse );
01643                         cloth1->verts[collpair->ap2].impulse_count++;
01644 
01645                         VECADDMUL ( cloth1->verts[collpair->ap3].impulse, collpair->normal, w3 * impulse );
01646                         cloth1->verts[collpair->ap3].impulse_count++;
01647 
01648                         // Apply repulse impulse if distance too short
01649                         // I_r = -min(dt*kd, m(0,1d/dt - v_n))
01650                         /*
01651                         d = clmd->coll_parms->epsilon*8.0/9.0 + epsilon2*8.0/9.0 - collpair->distance;
01652                         if ( ( magrelVel < 0.1*d*clmd->sim_parms->stepsPerFrame ) && ( d > ALMOST_ZERO ) )
01653                         {
01654                         repulse = MIN2 ( d*1.0/clmd->sim_parms->stepsPerFrame, 0.1*d*clmd->sim_parms->stepsPerFrame - magrelVel );
01655 
01656                         // stay on the safe side and clamp repulse
01657                         if ( impulse > ALMOST_ZERO )
01658                         repulse = MIN2 ( repulse, 5.0*impulse );
01659                         repulse = MAX2 ( impulse, repulse );
01660 
01661                         impulse = repulse / ( 1.0 + w1*w1 + w2*w2 + w3*w3 ); // original 2.0 / 0.25
01662                         VECADDMUL ( cloth1->verts[collpair->ap1].impulse, collpair->normal,  impulse );
01663                         VECADDMUL ( cloth1->verts[collpair->ap2].impulse, collpair->normal,  impulse );
01664                         VECADDMUL ( cloth1->verts[collpair->ap3].impulse, collpair->normal,  impulse );
01665                         }
01666                         */
01667                         result = 1;
01668                 }
01669         }
01670         return result;
01671 }
01672 #endif
01673 
01674 #if 0
01675 static float projectPointOntoLine(float *p, float *a, float *b) 
01676 {
01677         float ba[3], pa[3];
01678         VECSUB(ba, b, a);
01679         VECSUB(pa, p, a);
01680         return INPR(pa, ba) / INPR(ba, ba);
01681 }
01682 
01683 static void calculateEENormal(float *np1, float *np2, float *np3, float *np4,float *out_normal) 
01684 {
01685         float line1[3], line2[3];
01686         float length;
01687 
01688         VECSUB(line1, np2, np1);
01689         VECSUB(line2, np3, np1);
01690 
01691         // printf("l1: %f, l1: %f, l2: %f, l2: %f\n", line1[0], line1[1], line2[0], line2[1]);
01692 
01693         cross_v3_v3v3(out_normal, line1, line2);
01694 
01695         
01696 
01697         length = normalize_v3(out_normal);
01698         if (length <= FLT_EPSILON)
01699         { // lines are collinear
01700                 VECSUB(out_normal, np2, np1);
01701                 normalize_v3(out_normal);
01702         }
01703 }
01704 
01705 static void findClosestPointsEE(float *x1, float *x2, float *x3, float *x4, float *w1, float *w2)
01706 {
01707         float temp[3], temp2[3];
01708         
01709         double a, b, c, e, f; 
01710 
01711         VECSUB(temp, x2, x1);
01712         a = INPR(temp, temp);
01713 
01714         VECSUB(temp2, x4, x3);
01715         b = -INPR(temp, temp2);
01716 
01717         c = INPR(temp2, temp2);
01718 
01719         VECSUB(temp2, x3, x1);
01720         e = INPR(temp, temp2);
01721 
01722         VECSUB(temp, x4, x3);
01723         f = -INPR(temp, temp2);
01724 
01725         *w1 = (e * c - b * f) / (a * c - b * b);
01726         *w2 = (f - b * *w1) / c;
01727 
01728 }
01729 
01730 // calculates the distance of 2 edges
01731 static float edgedge_distance(float np11[3], float np12[3], float np21[3], float np22[3], float *out_a1, float *out_a2, float *out_normal)
01732 {
01733         float line1[3], line2[3], cross[3];
01734         float length;
01735         float temp[3], temp2[3];
01736         float dist_a1, dist_a2;
01737         
01738         VECSUB(line1, np12, np11);
01739         VECSUB(line2, np22, np21);
01740 
01741         cross_v3_v3v3(cross, line1, line2);
01742         length = INPR(cross, cross);
01743 
01744         if (length < FLT_EPSILON) 
01745         {
01746                 *out_a2 = projectPointOntoLine(np11, np21, np22);
01747                 if ((*out_a2 >= -FLT_EPSILON) && (*out_a2 <= 1.0 + FLT_EPSILON)) 
01748                 {
01749                         *out_a1 = 0;
01750                         calculateEENormal(np11, np12, np21, np22, out_normal);
01751                         VECSUB(temp, np22, np21);
01752                         mul_v3_fl(temp, *out_a2);
01753                         VECADD(temp2, temp, np21);
01754                         VECADD(temp2, temp2, np11);
01755                         return INPR(temp2, temp2);
01756                 }
01757 
01758                 CLAMP(*out_a2, 0.0, 1.0);
01759                 if (*out_a2 > .5) 
01760                 { // == 1.0
01761                         *out_a1 = projectPointOntoLine(np22, np11, np12);
01762                         if ((*out_a1 >= -FLT_EPSILON) && (*out_a1 <= 1.0 + FLT_EPSILON)) 
01763                         {
01764                                 calculateEENormal(np11, np12, np21, np22, out_normal);
01765 
01766                                 // return (np22 - (np11 + (np12 - np11) * out_a1)).lengthSquared();
01767                                 VECSUB(temp, np12, np11);
01768                                 mul_v3_fl(temp, *out_a1);
01769                                 VECADD(temp2, temp, np11);
01770                                 VECSUB(temp2, np22, temp2);
01771                                 return INPR(temp2, temp2);
01772                         }
01773                 } 
01774                 else 
01775                 { // == 0.0
01776                         *out_a1 = projectPointOntoLine(np21, np11, np12);
01777                         if ((*out_a1 >= -FLT_EPSILON) && (*out_a1 <= 1.0 + FLT_EPSILON)) 
01778                         {
01779                                 calculateEENormal(np11, np11, np21, np22, out_normal);
01780 
01781                                 // return (np21 - (np11 + (np12 - np11) * out_a1)).lengthSquared();
01782                                 VECSUB(temp, np12, np11);
01783                                 mul_v3_fl(temp, *out_a1);
01784                                 VECADD(temp2, temp, np11);
01785                                 VECSUB(temp2, np21, temp2);
01786                                 return INPR(temp2, temp2);
01787                         }
01788                 }
01789 
01790                 CLAMP(*out_a1, 0.0, 1.0);
01791                 calculateEENormal(np11, np12, np21, np22, out_normal);
01792                 if(*out_a1 > .5)
01793                 {
01794                         if(*out_a2 > .5)
01795                         {
01796                                 VECSUB(temp, np12, np22);
01797                         }
01798                         else
01799                         {
01800                                 VECSUB(temp, np12, np21);
01801                         }
01802                 }
01803                 else
01804                 {
01805                         if(*out_a2 > .5)
01806                         {
01807                                 VECSUB(temp, np11, np22);
01808                         }
01809                         else
01810                         {
01811                                 VECSUB(temp, np11, np21);
01812                         }
01813                 }
01814 
01815                 return INPR(temp, temp);
01816         }
01817         else
01818         {
01819                 
01820                 // If the lines aren't parallel (but coplanar) they have to intersect
01821 
01822                 findClosestPointsEE(np11, np12, np21, np22, out_a1, out_a2);
01823 
01824                 // If both points are on the finite edges, we're done.
01825                 if (*out_a1 >= 0.0 && *out_a1 <= 1.0 && *out_a2 >= 0.0 && *out_a2 <= 1.0) 
01826                 {
01827                         float p1[3], p2[3];
01828                         
01829                         // p1= np11 + (np12 - np11) * out_a1;
01830                         VECSUB(temp, np12, np11);
01831                         mul_v3_fl(temp, *out_a1);
01832                         VECADD(p1, np11, temp);
01833                         
01834                         // p2 = np21 + (np22 - np21) * out_a2;
01835                         VECSUB(temp, np22, np21);
01836                         mul_v3_fl(temp, *out_a2);
01837                         VECADD(p2, np21, temp);
01838 
01839                         calculateEENormal(np11, np12, np21, np22, out_normal);
01840                         VECSUB(temp, p1, p2);
01841                         return INPR(temp, temp);
01842                 }
01843 
01844                 
01845                 /*
01846                 * Clamp both points to the finite edges.
01847                 * The one that moves most during clamping is one part of the solution.
01848                 */
01849                 dist_a1 = *out_a1;
01850                 CLAMP(dist_a1, 0.0, 1.0);
01851                 dist_a2 = *out_a2;
01852                 CLAMP(dist_a2, 0.0, 1.0);
01853 
01854                 // Now project the "most clamped" point on the other line.
01855                 if (dist_a1 > dist_a2) 
01856                 { 
01857                         /* keep out_a1 */
01858                         float p1[3];
01859 
01860                         // p1 = np11 + (np12 - np11) * out_a1;
01861                         VECSUB(temp, np12, np11);
01862                         mul_v3_fl(temp, *out_a1);
01863                         VECADD(p1, np11, temp);
01864 
01865                         *out_a2 = projectPointOntoLine(p1, np21, np22);
01866                         CLAMP(*out_a2, 0.0, 1.0);
01867 
01868                         calculateEENormal(np11, np12, np21, np22, out_normal);
01869 
01870                         // return (p1 - (np21 + (np22 - np21) * out_a2)).lengthSquared();
01871                         VECSUB(temp, np22, np21);
01872                         mul_v3_fl(temp, *out_a2);
01873                         VECADD(temp, temp, np21);
01874                         VECSUB(temp, p1, temp);
01875                         return INPR(temp, temp);
01876                 } 
01877                 else 
01878                 {       
01879                         /* keep out_a2 */
01880                         float p2[3];
01881                         
01882                         // p2 = np21 + (np22 - np21) * out_a2;
01883                         VECSUB(temp, np22, np21);
01884                         mul_v3_fl(temp, *out_a2);
01885                         VECADD(p2, np21, temp);
01886 
01887                         *out_a1 = projectPointOntoLine(p2, np11, np12);
01888                         CLAMP(*out_a1, 0.0, 1.0);
01889 
01890                         calculateEENormal(np11, np12, np21, np22, out_normal);
01891                         
01892                         // return ((np11 + (np12 - np11) * out_a1) - p2).lengthSquared();
01893                         VECSUB(temp, np12, np11);
01894                         mul_v3_fl(temp, *out_a1);
01895                         VECADD(temp, temp, np11);
01896                         VECSUB(temp, temp, p2);
01897                         return INPR(temp, temp);
01898                 }
01899         }
01900         
01901         printf("Error in edgedge_distance: end of function\n");
01902         return 0;
01903 }
01904 
01905 static int cloth_collision_moving_edges ( ClothModifierData *clmd, CollisionModifierData *collmd, CollPair *collpair )
01906 {
01907         EdgeCollPair edgecollpair;
01908         Cloth *cloth1=NULL;
01909         ClothVertex *verts1=NULL;
01910         unsigned int i = 0, k = 0;
01911         int numsolutions = 0;
01912         double x1[3], v1[3], x2[3], v2[3], x3[3], v3[3];
01913         double solution[3], solution2[3];
01914         MVert *verts2 = collmd->current_x; // old x
01915         MVert *velocity2 = collmd->current_v; // velocity
01916         float distance = 0;
01917         float triA[3][3], triB[3][3];
01918         int result = 0;
01919 
01920         cloth1 = clmd->clothObject;
01921         verts1 = cloth1->verts;
01922 
01923         for(i = 0; i < 9; i++)
01924         {
01925                 // 9 edge - edge possibilities
01926 
01927                 if(i == 0) // cloth edge: 1-2; coll edge: 1-2
01928                 {
01929                         edgecollpair.p11 = collpair->ap1;
01930                         edgecollpair.p12 = collpair->ap2;
01931 
01932                         edgecollpair.p21 = collpair->bp1;
01933                         edgecollpair.p22 = collpair->bp2;
01934                 }
01935                 else if(i == 1) // cloth edge: 1-2; coll edge: 2-3
01936                 {
01937                         edgecollpair.p11 = collpair->ap1;
01938                         edgecollpair.p12 = collpair->ap2;
01939 
01940                         edgecollpair.p21 = collpair->bp2;
01941                         edgecollpair.p22 = collpair->bp3;
01942                 }
01943                 else if(i == 2) // cloth edge: 1-2; coll edge: 1-3
01944                 {
01945                         edgecollpair.p11 = collpair->ap1;
01946                         edgecollpair.p12 = collpair->ap2;
01947 
01948                         edgecollpair.p21 = collpair->bp1;
01949                         edgecollpair.p22 = collpair->bp3;
01950                 }
01951                 else if(i == 3) // cloth edge: 2-3; coll edge: 1-2
01952                 {
01953                         edgecollpair.p11 = collpair->ap2;
01954                         edgecollpair.p12 = collpair->ap3;
01955 
01956                         edgecollpair.p21 = collpair->bp1;
01957                         edgecollpair.p22 = collpair->bp2;
01958                 }
01959                 else if(i == 4) // cloth edge: 2-3; coll edge: 2-3
01960                 {
01961                         edgecollpair.p11 = collpair->ap2;
01962                         edgecollpair.p12 = collpair->ap3;
01963 
01964                         edgecollpair.p21 = collpair->bp2;
01965                         edgecollpair.p22 = collpair->bp3;
01966                 }
01967                 else if(i == 5) // cloth edge: 2-3; coll edge: 1-3
01968                 {
01969                         edgecollpair.p11 = collpair->ap2;
01970                         edgecollpair.p12 = collpair->ap3;
01971 
01972                         edgecollpair.p21 = collpair->bp1;
01973                         edgecollpair.p22 = collpair->bp3;
01974                 }
01975                 else if(i ==6) // cloth edge: 1-3; coll edge: 1-2
01976                 {
01977                         edgecollpair.p11 = collpair->ap1;
01978                         edgecollpair.p12 = collpair->ap3;
01979 
01980                         edgecollpair.p21 = collpair->bp1;
01981                         edgecollpair.p22 = collpair->bp2;
01982                 }
01983                 else if(i ==7) // cloth edge: 1-3; coll edge: 2-3
01984                 {
01985                         edgecollpair.p11 = collpair->ap1;
01986                         edgecollpair.p12 = collpair->ap3;
01987 
01988                         edgecollpair.p21 = collpair->bp2;
01989                         edgecollpair.p22 = collpair->bp3;
01990                 }
01991                 else if(i == 8) // cloth edge: 1-3; coll edge: 1-3
01992                 {
01993                         edgecollpair.p11 = collpair->ap1;
01994                         edgecollpair.p12 = collpair->ap3;
01995 
01996                         edgecollpair.p21 = collpair->bp1;
01997                         edgecollpair.p22 = collpair->bp3;
01998                 }
01999                 /*
02000                 if((edgecollpair.p11 == 3) && (edgecollpair.p12 == 16))
02001                         printf("Ahier!\n");
02002                 if((edgecollpair.p11 == 16) && (edgecollpair.p12 == 3))
02003                         printf("Ahier!\n");
02004                 */
02005 
02006                 // if ( !cloth_are_edges_adjacent ( clmd, collmd, &edgecollpair ) )
02007                 {
02008                         // always put coll points in p21/p22
02009                         VECSUB ( x1, verts1[edgecollpair.p12].txold, verts1[edgecollpair.p11].txold );
02010                         VECSUB ( v1, verts1[edgecollpair.p12].tv, verts1[edgecollpair.p11].tv );
02011 
02012                         VECSUB ( x2, verts2[edgecollpair.p21].co, verts1[edgecollpair.p11].txold );
02013                         VECSUB ( v2, velocity2[edgecollpair.p21].co, verts1[edgecollpair.p11].tv );
02014 
02015                         VECSUB ( x3, verts2[edgecollpair.p22].co, verts1[edgecollpair.p11].txold );
02016                         VECSUB ( v3, velocity2[edgecollpair.p22].co, verts1[edgecollpair.p11].tv );
02017 
02018                         numsolutions = cloth_get_collision_time ( x1, v1, x2, v2, x3, v3, solution );
02019 
02020                         if((edgecollpair.p11 == 3 && edgecollpair.p12==16)|| (edgecollpair.p11==16 && edgecollpair.p12==3))
02021                         {
02022                                 if(edgecollpair.p21==6 || edgecollpair.p22 == 6)
02023                                 {
02024                                         printf("dist: %f, sol[k]: %lf, sol2[k]: %lf\n", distance, solution[k], solution2[k]);
02025                                         printf("a1: %f, a2: %f, b1: %f, b2: %f\n", x1[0], x2[0], x3[0], v1[0]);
02026                                         printf("b21: %d, b22: %d\n", edgecollpair.p21, edgecollpair.p22);
02027                                 }
02028                         }
02029 
02030                         for ( k = 0; k < numsolutions; k++ )
02031                         {
02032                                 // printf("sol %d: %lf\n", k, solution[k]);
02033                                 if ( ( solution[k] >= ALMOST_ZERO ) && ( solution[k] <= 1.0 ) && ( solution[k] >  ALMOST_ZERO))
02034                                 {
02035                                         float a,b;
02036                                         float out_normal[3];
02037                                         float distance;
02038                                         float impulse = 0;
02039                                         float I_mag;
02040 
02041                                         // move verts
02042                                         VECADDS(triA[0], verts1[edgecollpair.p11].txold, verts1[edgecollpair.p11].tv, solution[k]);
02043                                         VECADDS(triA[1], verts1[edgecollpair.p12].txold, verts1[edgecollpair.p12].tv, solution[k]);
02044 
02045                                         VECADDS(triB[0], collmd->current_x[edgecollpair.p21].co, collmd->current_v[edgecollpair.p21].co, solution[k]);
02046                                         VECADDS(triB[1], collmd->current_x[edgecollpair.p22].co, collmd->current_v[edgecollpair.p22].co, solution[k]);
02047 
02048                                         // TODO: check for collisions
02049                                         distance = edgedge_distance(triA[0], triA[1], triB[0], triB[1], &a, &b, out_normal);
02050                                         
02051                                         if ((distance <= clmd->coll_parms->epsilon + BLI_bvhtree_getepsilon ( collmd->bvhtree ) + ALMOST_ZERO) && (INPR(out_normal, out_normal) > 0))
02052                                         {
02053                                                 float vrel_1_to_2[3], temp[3], temp2[3], out_normalVelocity;
02054                                                 float desiredVn;
02055 
02056                                                 VECCOPY(vrel_1_to_2, verts1[edgecollpair.p11].tv);
02057                                                 mul_v3_fl(vrel_1_to_2, 1.0 - a);
02058                                                 VECCOPY(temp, verts1[edgecollpair.p12].tv);
02059                                                 mul_v3_fl(temp, a);
02060 
02061                                                 VECADD(vrel_1_to_2, vrel_1_to_2, temp);
02062 
02063                                                 VECCOPY(temp, verts1[edgecollpair.p21].tv);
02064                                                 mul_v3_fl(temp, 1.0 - b);
02065                                                 VECCOPY(temp2, verts1[edgecollpair.p22].tv);
02066                                                 mul_v3_fl(temp2, b);
02067                                                 VECADD(temp, temp, temp2);
02068 
02069                                                 VECSUB(vrel_1_to_2, vrel_1_to_2, temp);
02070 
02071                                                 out_normalVelocity = INPR(vrel_1_to_2, out_normal);
02072 /*
02073                                                 // this correction results in wrong normals sometimes?
02074                                                 if(out_normalVelocity < 0.0)
02075                                                 {
02076                                                         out_normalVelocity*= -1.0;
02077                                                         negate_v3(out_normal);
02078                                                 }
02079 */
02080                                                 /* Inelastic repulsion impulse. */
02081 
02082                                                 // Calculate which normal velocity we need. 
02083                                                 desiredVn = (out_normalVelocity * (float)solution[k] - (.1 * (clmd->coll_parms->epsilon + BLI_bvhtree_getepsilon ( collmd->bvhtree )) - sqrt(distance)) - ALMOST_ZERO);
02084 
02085                                                 // Now calculate what impulse we need to reach that velocity. 
02086                                                 I_mag = (out_normalVelocity - desiredVn) / 2.0; // / (1/m1 + 1/m2);
02087 
02088                                                 // Finally apply that impulse. 
02089                                                 impulse = (2.0 * -I_mag) / (a*a + (1.0-a)*(1.0-a) + b*b + (1.0-b)*(1.0-b));
02090 
02091                                                 VECADDMUL ( verts1[edgecollpair.p11].impulse, out_normal, (1.0-a) * impulse );
02092                                                 verts1[edgecollpair.p11].impulse_count++;
02093 
02094                                                 VECADDMUL ( verts1[edgecollpair.p12].impulse, out_normal, a * impulse );
02095                                                 verts1[edgecollpair.p12].impulse_count++;
02096 
02097                                                 // return true;
02098                                                 result = 1;
02099                                                 break;
02100                                         }
02101                                         else
02102                                         {
02103                                                 // missing from collision.hpp
02104                                         }
02105                                         // mintime = MIN2(mintime, (float)solution[k]);
02106 
02107                                         break;
02108                                 }
02109                         }
02110                 }
02111         }
02112         return result;
02113 }
02114 
02115 static int cloth_collision_moving ( ClothModifierData *clmd, CollisionModifierData *collmd, CollPair *collpair, CollPair *collision_end )
02116 {
02117         Cloth *cloth1;
02118         cloth1 = clmd->clothObject;
02119 
02120         for ( ; collpair != collision_end; collpair++ )
02121         {
02122                 // only handle moving collisions here
02123                 if (!( collpair->flag & COLLISION_IN_FUTURE ))
02124                         continue;
02125 
02126                 cloth_collision_moving_edges ( clmd, collmd, collpair);
02127                 // cloth_collision_moving_tris ( clmd, collmd, collpair);
02128         }
02129 
02130         return 1;
02131 }
02132 #endif
02133 
02134 static void add_collision_object(Object ***objs, unsigned int *numobj, unsigned int *maxobj, Object *ob, Object *self, int level)
02135 {
02136         CollisionModifierData *cmd= NULL;
02137 
02138         if(ob == self)
02139                 return;
02140 
02141         /* only get objects with collision modifier */
02142         if(ob->pd && ob->pd->deflect)
02143                 cmd= (CollisionModifierData *)modifiers_findByType(ob, eModifierType_Collision);
02144         
02145         if(cmd) {       
02146                 /* extend array */
02147                 if(*numobj >= *maxobj) {
02148                         *maxobj *= 2;
02149                         *objs= MEM_reallocN(*objs, sizeof(Object*)*(*maxobj));
02150                 }
02151                 
02152                 (*objs)[*numobj] = ob;
02153                 (*numobj)++;
02154         }
02155 
02156         /* objects in dupli groups, one level only for now */
02157         if(ob->dup_group && level == 0) {
02158                 GroupObject *go;
02159                 Group *group= ob->dup_group;
02160 
02161                 /* add objects */
02162                 for(go= group->gobject.first; go; go= go->next)
02163                         add_collision_object(objs, numobj, maxobj, go->ob, self, level+1);
02164         }       
02165 }
02166 
02167 // return all collision objects in scene
02168 // collision object will exclude self 
02169 Object **get_collisionobjects(Scene *scene, Object *self, Group *group, unsigned int *numcollobj)
02170 {
02171         Base *base;
02172         Object **objs;
02173         GroupObject *go;
02174         unsigned int numobj= 0, maxobj= 100;
02175         
02176         objs= MEM_callocN(sizeof(Object *)*maxobj, "CollisionObjectsArray");
02177 
02178         /* gather all collision objects */
02179         if(group) {
02180                 /* use specified group */
02181                 for(go= group->gobject.first; go; go= go->next)
02182                         add_collision_object(&objs, &numobj, &maxobj, go->ob, self, 0);
02183         }
02184         else {
02185                 Scene *sce_iter;
02186                 /* add objects in same layer in scene */
02187                 for(SETLOOPER(scene, sce_iter, base)) {
02188                         if(base->lay & self->lay)
02189                                 add_collision_object(&objs, &numobj, &maxobj, base->object, self, 0);
02190 
02191                 }
02192         }
02193 
02194         *numcollobj= numobj;
02195 
02196         return objs;
02197 }
02198 
02199 static void add_collider_cache_object(ListBase **objs, Object *ob, Object *self, int level)
02200 {
02201         CollisionModifierData *cmd= NULL;
02202         ColliderCache *col;
02203 
02204         if(ob == self)
02205                 return;
02206 
02207         if(ob->pd && ob->pd->deflect)
02208                 cmd =(CollisionModifierData *)modifiers_findByType(ob, eModifierType_Collision);
02209         
02210         if(cmd && cmd->bvhtree) {       
02211                 if(*objs == NULL)
02212                         *objs = MEM_callocN(sizeof(ListBase), "ColliderCache array");
02213 
02214                 col = MEM_callocN(sizeof(ColliderCache), "ColliderCache");
02215                 col->ob = ob;
02216                 col->collmd = cmd;
02217                 /* make sure collider is properly set up */
02218                 collision_move_object(cmd, 1.0, 0.0);
02219                 BLI_addtail(*objs, col);
02220         }
02221 
02222         /* objects in dupli groups, one level only for now */
02223         if(ob->dup_group && level == 0) {
02224                 GroupObject *go;
02225                 Group *group= ob->dup_group;
02226 
02227                 /* add objects */
02228                 for(go= group->gobject.first; go; go= go->next)
02229                         add_collider_cache_object(objs, go->ob, self, level+1);
02230         }
02231 }
02232 
02233 ListBase *get_collider_cache(Scene *scene, Object *self, Group *group)
02234 {
02235         GroupObject *go;
02236         ListBase *objs= NULL;
02237         
02238         /* add object in same layer in scene */
02239         if(group) {
02240                 for(go= group->gobject.first; go; go= go->next)
02241                         add_collider_cache_object(&objs, go->ob, self, 0);
02242         }
02243         else {
02244                 Scene *sce_iter;
02245                 Base *base;
02246 
02247                 /* add objects in same layer in scene */
02248                 for(SETLOOPER(scene, sce_iter, base)) {
02249                         if(!self || (base->lay & self->lay))
02250                                 add_collider_cache_object(&objs, base->object, self, 0);
02251 
02252                 }
02253         }
02254 
02255         return objs;
02256 }
02257 
02258 void free_collider_cache(ListBase **colliders)
02259 {
02260         if(*colliders) {
02261                 BLI_freelistN(*colliders);
02262                 MEM_freeN(*colliders);
02263                 *colliders = NULL;
02264         }
02265 }
02266 
02267 
02268 static void cloth_bvh_objcollisions_nearcheck ( ClothModifierData * clmd, CollisionModifierData *collmd,
02269         CollPair **collisions, CollPair **collisions_index, int numresult, BVHTreeOverlap *overlap, double dt)
02270 {
02271         int i;
02272 #ifdef WITH_ELTOPO
02273         GHash *visithash = BLI_ghash_new(edgepair_hash, edgepair_cmp, "visthash, collision.c");
02274         GHash *tri_visithash = BLI_ghash_new(tripair_hash, tripair_cmp, "tri_visthash, collision.c");
02275         MemArena *arena = BLI_memarena_new(1<<16, "edge hash arena, collision.c");
02276 #endif
02277         
02278         *collisions = ( CollPair* ) MEM_mallocN ( sizeof ( CollPair ) * numresult * 64, "collision array" ); //*4 since cloth_collision_static can return more than 1 collision
02279         *collisions_index = *collisions;
02280         
02281 #ifdef WITH_ELTOPO
02282         machine_epsilon_offset(clmd->clothObject);
02283 
02284         for ( i = 0; i < numresult; i++ )
02285         {
02286                 *collisions_index = cloth_collision ( ( ModifierData * ) clmd, ( ModifierData * ) collmd,
02287                                                                                           overlap+i, *collisions_index, dt, tri_visithash, arena );
02288         }
02289 
02290         for ( i = 0; i < numresult; i++ )
02291         {
02292                 *collisions_index = cloth_edge_collision ( ( ModifierData * ) clmd, ( ModifierData * ) collmd,
02293                                                                                                    overlap+i, *collisions_index, visithash, arena );
02294         }
02295         BLI_ghash_free(visithash, NULL, NULL);
02296         BLI_ghash_free(tri_visithash, NULL, NULL);
02297         BLI_memarena_free(arena);
02298 #else /* WITH_ELTOPO */
02299         for ( i = 0; i < numresult; i++ )
02300         {
02301                 *collisions_index = cloth_collision ( ( ModifierData * ) clmd, ( ModifierData * ) collmd,
02302                                                                                           overlap+i, *collisions_index, dt );
02303         }
02304 #endif /* WITH_ELTOPO */
02305 
02306 }
02307 
02308 static int cloth_bvh_objcollisions_resolve ( ClothModifierData * clmd, CollisionModifierData *collmd, CollPair *collisions, CollPair *collisions_index)
02309 {
02310         Cloth *cloth = clmd->clothObject;
02311         int i=0, j = 0, /*numfaces = 0,*/ numverts = 0;
02312         ClothVertex *verts = NULL;
02313         int ret = 0;
02314         int result = 0;
02315         float tnull[3] = {0,0,0};
02316         
02317         /*numfaces = clmd->clothObject->numfaces;*/ /*UNUSED*/
02318         numverts = clmd->clothObject->numverts;
02319  
02320         verts = cloth->verts;
02321         
02322         // process all collisions (calculate impulses, TODO: also repulses if distance too short)
02323         result = 1;
02324         for ( j = 0; j < 5; j++ ) // 5 is just a value that ensures convergence
02325         {
02326                 result = 0;
02327 
02328                 if ( collmd->bvhtree )
02329                 {
02330 #ifdef WITH_ELTOPO
02331                         result += cloth_collision_response_moving(clmd, collmd, collisions, collisions_index);
02332                         result += cloth_edge_collision_response_moving(clmd, collmd, collisions, collisions_index);
02333 #else
02334                         result += cloth_collision_response_static ( clmd, collmd, collisions, collisions_index );
02335 #endif
02336 #ifdef WITH_ELTOPO
02337                         {
02338 #else
02339                         // apply impulses in parallel
02340                         if ( result )
02341                         {
02342 #endif
02343                                 for ( i = 0; i < numverts; i++ )
02344                                 {
02345                                         // calculate "velocities" (just xnew = xold + v; no dt in v)
02346                                         if ( verts[i].impulse_count )
02347                                         {
02348                                                 VECADDMUL ( verts[i].tv, verts[i].impulse, 1.0f / verts[i].impulse_count );
02349                                                 VECCOPY ( verts[i].impulse, tnull );
02350                                                 verts[i].impulse_count = 0;
02351 
02352                                                 ret++;
02353                                         }
02354                                 }
02355                         }
02356                 }
02357         }
02358         return ret;
02359 }
02360 
02361 // cloth - object collisions
02362 int cloth_bvh_objcollision (Object *ob, ClothModifierData * clmd, float step, float dt )
02363 {
02364         Cloth *cloth= clmd->clothObject;
02365         BVHTree *cloth_bvh= cloth->bvhtree;
02366         unsigned int i=0, numfaces = 0, numverts = 0, k, l, j;
02367         int rounds = 0; // result counts applied collisions; ic is for debug output;
02368         ClothVertex *verts = NULL;
02369         int ret = 0, ret2 = 0;
02370         Object **collobjs = NULL;
02371         unsigned int numcollobj = 0;
02372 
02373         if ((clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_COLLOBJ) || cloth_bvh==NULL)
02374                 return 0;
02375         
02376         verts = cloth->verts;
02377         numfaces = cloth->numfaces;
02378         numverts = cloth->numverts;
02379 
02381         // static collisions
02383 
02384         // update cloth bvh
02385         bvhtree_update_from_cloth ( clmd, 1 ); // 0 means STATIC, 1 means MOVING (see later in this function)
02386         bvhselftree_update_from_cloth ( clmd, 0 ); // 0 means STATIC, 1 means MOVING (see later in this function)
02387         
02388         collobjs = get_collisionobjects(clmd->scene, ob, clmd->coll_parms->group, &numcollobj);
02389         
02390         if(!collobjs)
02391                 return 0;
02392 
02393         do
02394         {
02395                 CollPair **collisions, **collisions_index;
02396                 
02397                 ret2 = 0;
02398 
02399                 collisions = MEM_callocN(sizeof(CollPair *) *numcollobj , "CollPair");
02400                 collisions_index = MEM_callocN(sizeof(CollPair *) *numcollobj , "CollPair");
02401                 
02402                 // check all collision objects
02403                 for(i = 0; i < numcollobj; i++)
02404                 {
02405                         Object *collob= collobjs[i];
02406                         CollisionModifierData *collmd = (CollisionModifierData*)modifiers_findByType(collob, eModifierType_Collision);
02407                         BVHTreeOverlap *overlap = NULL;
02408                         unsigned int result = 0;
02409                         
02410                         if(!collmd->bvhtree)
02411                                 continue;
02412                         
02413                         /* move object to position (step) in time */
02414                         
02415                         collision_move_object ( collmd, step + dt, step );
02416                         
02417                         /* search for overlapping collision pairs */
02418                         overlap = BLI_bvhtree_overlap ( cloth_bvh, collmd->bvhtree, &result );
02419                                 
02420                         // go to next object if no overlap is there
02421                         if( result && overlap ) {
02422                                 /* check if collisions really happen (costly near check) */
02423                                 cloth_bvh_objcollisions_nearcheck ( clmd, collmd, &collisions[i], 
02424                                         &collisions_index[i], result, overlap, dt/(float)clmd->coll_parms->loop_count);
02425                         
02426                                 // resolve nearby collisions
02427                                 ret += cloth_bvh_objcollisions_resolve ( clmd, collmd, collisions[i],  collisions_index[i]);
02428                                 ret2 += ret;
02429                         }
02430 
02431                         if ( overlap )
02432                                 MEM_freeN ( overlap );
02433                 }
02434                 rounds++;
02435                 
02436                 for(i = 0; i < numcollobj; i++)
02437                 {
02438                         if ( collisions[i] ) MEM_freeN ( collisions[i] );
02439                 }
02440                         
02441                 MEM_freeN(collisions);
02442                 MEM_freeN(collisions_index);
02443 
02445                 // update positions
02446                 // this is needed for bvh_calc_DOP_hull_moving() [kdop.c]
02448 
02449                 // verts come from clmd
02450                 for ( i = 0; i < numverts; i++ )
02451                 {
02452                         if ( clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL )
02453                         {
02454                                 if ( verts [i].flags & CLOTH_VERT_FLAG_PINNED )
02455                                 {
02456                                         continue;
02457                                 }
02458                         }
02459 
02460                         VECADD ( verts[i].tx, verts[i].txold, verts[i].tv );
02461                 }
02463                 
02464                 
02466                 // Test on *simple* selfcollisions
02468                 if ( clmd->coll_parms->flags & CLOTH_COLLSETTINGS_FLAG_SELF )
02469                 {
02470                         for(l = 0; l < (unsigned int)clmd->coll_parms->self_loop_count; l++)
02471                         {
02472                                 // TODO: add coll quality rounds again
02473                                 BVHTreeOverlap *overlap = NULL;
02474                                 unsigned int result = 0;
02475         
02476                                 // collisions = 1;
02477                                 verts = cloth->verts; // needed for openMP
02478         
02479                                 numfaces = cloth->numfaces;
02480                                 numverts = cloth->numverts;
02481         
02482                                 verts = cloth->verts;
02483         
02484                                 if ( cloth->bvhselftree )
02485                                 {
02486                                         // search for overlapping collision pairs 
02487                                         overlap = BLI_bvhtree_overlap ( cloth->bvhselftree, cloth->bvhselftree, &result );
02488         
02489         // #pragma omp parallel for private(k, i, j) schedule(static)
02490                                         for ( k = 0; k < result; k++ )
02491                                         {
02492                                                 float temp[3];
02493                                                 float length = 0;
02494                                                 float mindistance;
02495         
02496                                                 i = overlap[k].indexA;
02497                                                 j = overlap[k].indexB;
02498         
02499                                                 mindistance = clmd->coll_parms->selfepsilon* ( cloth->verts[i].avg_spring_len + cloth->verts[j].avg_spring_len );
02500         
02501                                                 if ( clmd->sim_parms->flags & CLOTH_SIMSETTINGS_FLAG_GOAL )
02502                                                 {
02503                                                         if ( ( cloth->verts [i].flags & CLOTH_VERT_FLAG_PINNED )
02504                                                                                 && ( cloth->verts [j].flags & CLOTH_VERT_FLAG_PINNED ) )
02505                                                         {
02506                                                                 continue;
02507                                                         }
02508                                                 }
02509         
02510                                                 VECSUB ( temp, verts[i].tx, verts[j].tx );
02511         
02512                                                 if ( ( ABS ( temp[0] ) > mindistance ) || ( ABS ( temp[1] ) > mindistance ) || ( ABS ( temp[2] ) > mindistance ) ) continue;
02513         
02514                                                 // check for adjacent points (i must be smaller j)
02515                                                 if ( BLI_edgehash_haskey ( cloth->edgehash, MIN2(i, j), MAX2(i, j) ) )
02516                                                 {
02517                                                         continue;
02518                                                 }
02519         
02520                                                 length = normalize_v3( temp );
02521         
02522                                                 if ( length < mindistance )
02523                                                 {
02524                                                         float correction = mindistance - length;
02525         
02526                                                         if ( cloth->verts [i].flags & CLOTH_VERT_FLAG_PINNED )
02527                                                         {
02528                                                                 mul_v3_fl( temp, -correction );
02529                                                                 VECADD ( verts[j].tx, verts[j].tx, temp );
02530                                                         }
02531                                                         else if ( cloth->verts [j].flags & CLOTH_VERT_FLAG_PINNED )
02532                                                         {
02533                                                                 mul_v3_fl( temp, correction );
02534                                                                 VECADD ( verts[i].tx, verts[i].tx, temp );
02535                                                         }
02536                                                         else
02537                                                         {
02538                                                                 mul_v3_fl( temp, -correction*0.5 );
02539                                                                 VECADD ( verts[j].tx, verts[j].tx, temp );
02540         
02541                                                                 VECSUB ( verts[i].tx, verts[i].tx, temp );
02542                                                         }
02543                                                         ret = 1;
02544                                                         ret2 += ret;
02545                                                 }
02546                                                 else
02547                                                 {
02548                                                         // check for approximated time collisions
02549                                                 }
02550                                         }
02551         
02552                                         if ( overlap )
02553                                                 MEM_freeN ( overlap );
02554         
02555                                 }
02556                         }
02558 
02560                         // SELFCOLLISIONS: update velocities
02562                         if ( ret2 )
02563                         {
02564                                 for ( i = 0; i < cloth->numverts; i++ )
02565                                 {
02566                                         if ( ! ( verts [i].flags & CLOTH_VERT_FLAG_PINNED ) )
02567                                         {
02568                                                 VECSUB ( verts[i].tv, verts[i].tx, verts[i].txold );
02569                                         }
02570                                 }
02571                         }
02573                 }
02574         }
02575         while ( ret2 && ( clmd->coll_parms->loop_count>rounds ) );
02576         
02577         if(collobjs)
02578                 MEM_freeN(collobjs);
02579 
02580         return 1|MIN2 ( ret, 1 );
02581 }