src/collision.cpp

   1 /*
   2 Minetest
   3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU Lesser General Public License as published by
   7 the Free Software Foundation; either version 2.1 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU Lesser General Public License for more details.
  14
  15 You should have received a copy of the GNU Lesser General Public License along
  16 with this program; if not, write to the Free Software Foundation, Inc.,
  17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #include "collision.h"
  21 #include "mapblock.h"
  22 #include "map.h"
  23 #include "nodedef.h"
  24 #include "gamedef.h"
  25 #include "log.h"
  26 #include "environment.h"
  27 #include "serverobject.h"
  28 #include <vector>
  29 #include <set>
  30 #include "util/timetaker.h"
  31 #include "main.h" // g_profiler
  32 #include "profiler.h"
  33
  34 // Helper function:
  35 // Checks for collision of a moving aabbox with a static aabbox
  36 // Returns -1 if no collision, 0 if X collision, 1 if Y collision, 2 if Z collision
  37 // The time after which the collision occurs is stored in dtime.
  38 int axisAlignedCollision(
  39                 const aabb3f &staticbox, const aabb3f &movingbox,
  40                 const v3f &speed, f32 d, f32 &dtime)
  41 {
  42         //TimeTaker tt("axisAlignedCollision");
  43
  44         f32 xsize = (staticbox.MaxEdge.X - staticbox.MinEdge.X);
  45         f32 ysize = (staticbox.MaxEdge.Y - staticbox.MinEdge.Y);
  46         f32 zsize = (staticbox.MaxEdge.Z - staticbox.MinEdge.Z);
  47
  48         aabb3f relbox(
  49                         movingbox.MinEdge.X - staticbox.MinEdge.X,
  50                         movingbox.MinEdge.Y - staticbox.MinEdge.Y,
  51                         movingbox.MinEdge.Z - staticbox.MinEdge.Z,
  52                         movingbox.MaxEdge.X - staticbox.MinEdge.X,
  53                         movingbox.MaxEdge.Y - staticbox.MinEdge.Y,
  54                         movingbox.MaxEdge.Z - staticbox.MinEdge.Z
  55         );
  56
  57         if(speed.X > 0) // Check for collision with X- plane
  58         {
  59                 if(relbox.MaxEdge.X <= d)
  60                 {
  61                         dtime = - relbox.MaxEdge.X / speed.X;
  62                         if((relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
  63                                         (relbox.MaxEdge.Y + speed.Y * dtime > 0) &&
  64                                         (relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
  65                                         (relbox.MaxEdge.Z + speed.Z * dtime > 0))
  66                                 return 0;
  67                 }
  68                 else if(relbox.MinEdge.X > xsize)
  69                 {
  70                         return -1;
  71                 }
  72         }
  73         else if(speed.X < 0) // Check for collision with X+ plane
  74         {
  75                 if(relbox.MinEdge.X >= xsize - d)
  76                 {
  77                         dtime = (xsize - relbox.MinEdge.X) / speed.X;
  78                         if((relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
  79                                         (relbox.MaxEdge.Y + speed.Y * dtime > 0) &&
  80                                         (relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
  81                                         (relbox.MaxEdge.Z + speed.Z * dtime > 0))
  82                                 return 0;
  83                 }
  84                 else if(relbox.MaxEdge.X < 0)
  85                 {
  86                         return -1;
  87                 }
  88         }
  89
  90         // NO else if here
  91
  92         if(speed.Y > 0) // Check for collision with Y- plane
  93         {
  94                 if(relbox.MaxEdge.Y <= d)
  95                 {
  96                         dtime = - relbox.MaxEdge.Y / speed.Y;
  97                         if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
  98                                         (relbox.MaxEdge.X + speed.X * dtime > 0) &&
  99                                         (relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
 100                                         (relbox.MaxEdge.Z + speed.Z * dtime > 0))
 101                                 return 1;
 102                 }
 103                 else if(relbox.MinEdge.Y > ysize)
 104                 {
 105                         return -1;
 106                 }
 107         }
 108         else if(speed.Y < 0) // Check for collision with Y+ plane
 109         {
 110                 if(relbox.MinEdge.Y >= ysize - d)
 111                 {
 112                         dtime = (ysize - relbox.MinEdge.Y) / speed.Y;
 113                         if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
 114                                         (relbox.MaxEdge.X + speed.X * dtime > 0) &&
 115                                         (relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
 116                                         (relbox.MaxEdge.Z + speed.Z * dtime > 0))
 117                                 return 1;
 118                 }
 119                 else if(relbox.MaxEdge.Y < 0)
 120                 {
 121                         return -1;
 122                 }
 123         }
 124
 125         // NO else if here
 126
 127         if(speed.Z > 0) // Check for collision with Z- plane
 128         {
 129                 if(relbox.MaxEdge.Z <= d)
 130                 {
 131                         dtime = - relbox.MaxEdge.Z / speed.Z;
 132                         if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
 133                                         (relbox.MaxEdge.X + speed.X * dtime > 0) &&
 134                                         (relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
 135                                         (relbox.MaxEdge.Y + speed.Y * dtime > 0))
 136                                 return 2;
 137                 }
 138                 //else if(relbox.MinEdge.Z > zsize)
 139                 //{
 140                 //      return -1;
 141                 //}
 142         }
 143         else if(speed.Z < 0) // Check for collision with Z+ plane
 144         {
 145                 if(relbox.MinEdge.Z >= zsize - d)
 146                 {
 147                         dtime = (zsize - relbox.MinEdge.Z) / speed.Z;
 148                         if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
 149                                         (relbox.MaxEdge.X + speed.X * dtime > 0) &&
 150                                         (relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
 151                                         (relbox.MaxEdge.Y + speed.Y * dtime > 0))
 152                                 return 2;
 153                 }
 154                 //else if(relbox.MaxEdge.Z < 0)
 155                 //{
 156                 //      return -1;
 157                 //}
 158         }
 159
 160         return -1;
 161 }
 162
 163 // Helper function:
 164 // Checks if moving the movingbox up by the given distance would hit a ceiling.
 165 bool wouldCollideWithCeiling(
 166                 const std::vector<aabb3f> &staticboxes,
 167                 const aabb3f &movingbox,
 168                 f32 y_increase, f32 d)
 169 {
 170         //TimeTaker tt("wouldCollideWithCeiling");
 171
 172         assert(y_increase >= 0);
 173
 174         for(std::vector<aabb3f>::const_iterator
 175                         i = staticboxes.begin();
 176                         i != staticboxes.end(); i++)
 177         {
 178                 const aabb3f& staticbox = *i;
 179                 if((movingbox.MaxEdge.Y - d <= staticbox.MinEdge.Y) &&
 180                                 (movingbox.MaxEdge.Y + y_increase > staticbox.MinEdge.Y) &&
 181                                 (movingbox.MinEdge.X < staticbox.MaxEdge.X) &&
 182                                 (movingbox.MaxEdge.X > staticbox.MinEdge.X) &&
 183                                 (movingbox.MinEdge.Z < staticbox.MaxEdge.Z) &&
 184                                 (movingbox.MaxEdge.Z > staticbox.MinEdge.Z))
 185                         return true;
 186         }
 187
 188         return false;
 189 }
 190
 191
 192 collisionMoveResult collisionMoveSimple(Environment *env, IGameDef *gamedef,
 193                 f32 pos_max_d, const aabb3f &box_0,
 194                 f32 stepheight, f32 dtime,
 195                 v3f &pos_f, v3f &speed_f, v3f &accel_f)
 196 {
 197         Map *map = &env->getMap();
 198         //TimeTaker tt("collisionMoveSimple");
 199     ScopeProfiler sp(g_profiler, "collisionMoveSimple avg", SPT_AVG);
 200
 201         collisionMoveResult result;
 202
 203         /*
 204                 Calculate new velocity
 205         */
 206         if( dtime > 0.5 ) {
 207                 infostream<<"collisionMoveSimple: WARNING: maximum step interval exceeded, lost movement details!"<<std::endl;
 208                 dtime = 0.5;
 209         }
 210         speed_f += accel_f * dtime;
 211
 212     // If there is no speed, there are no collisions
 213         if(speed_f.getLength() == 0)
 214                 return result;
 215
 216         /*
 217                 Collect node boxes in movement range
 218         */
 219         std::vector<aabb3f> cboxes;
 220         std::vector<bool> is_unloaded;
 221         std::vector<bool> is_step_up;
 222         std::vector<bool> is_object;
 223         std::vector<int> bouncy_values;
 224         std::vector<v3s16> node_positions;
 225         {
 226         //TimeTaker tt2("collisionMoveSimple collect boxes");
 227     ScopeProfiler sp(g_profiler, "collisionMoveSimple collect boxes avg", SPT_AVG);
 228
 229         v3s16 oldpos_i = floatToInt(pos_f, BS);
 230         v3s16 newpos_i = floatToInt(pos_f + speed_f * dtime, BS);
 231         s16 min_x = MYMIN(oldpos_i.X, newpos_i.X) + (box_0.MinEdge.X / BS) - 1;
 232         s16 min_y = MYMIN(oldpos_i.Y, newpos_i.Y) + (box_0.MinEdge.Y / BS) - 1;
 233         s16 min_z = MYMIN(oldpos_i.Z, newpos_i.Z) + (box_0.MinEdge.Z / BS) - 1;
 234         s16 max_x = MYMAX(oldpos_i.X, newpos_i.X) + (box_0.MaxEdge.X / BS) + 1;
 235         s16 max_y = MYMAX(oldpos_i.Y, newpos_i.Y) + (box_0.MaxEdge.Y / BS) + 1;
 236         s16 max_z = MYMAX(oldpos_i.Z, newpos_i.Z) + (box_0.MaxEdge.Z / BS) + 1;
 237
 238         for(s16 x = min_x; x <= max_x; x++)
 239         for(s16 y = min_y; y <= max_y; y++)
 240         for(s16 z = min_z; z <= max_z; z++)
 241         {
 242                 v3s16 p(x,y,z);
 243                 try{
 244                         // Object collides into walkable nodes
 245                         MapNode n = map->getNode(p);
 246                         const ContentFeatures &f = gamedef->getNodeDefManager()->get(n);
 247                         if(f.walkable == false)
 248                                 continue;
 249                         int n_bouncy_value = itemgroup_get(f.groups, "bouncy");
 250
 251                         std::vector<aabb3f> nodeboxes = n.getNodeBoxes(gamedef->ndef());
 252                         for(std::vector<aabb3f>::iterator
 253                                         i = nodeboxes.begin();
 254                                         i != nodeboxes.end(); i++)
 255                         {
 256                                 aabb3f box = *i;
 257                                 box.MinEdge += v3f(x, y, z)*BS;
 258                                 box.MaxEdge += v3f(x, y, z)*BS;
 259                                 cboxes.push_back(box);
 260                                 is_unloaded.push_back(false);
 261                                 is_step_up.push_back(false);
 262                                 bouncy_values.push_back(n_bouncy_value);
 263                                 node_positions.push_back(p);
 264                                 is_object.push_back(false);
 265                         }
 266                 }
 267                 catch(InvalidPositionException &e)
 268                 {
 269                         // Collide with unloaded nodes
 270                         aabb3f box = getNodeBox(p, BS);
 271                         cboxes.push_back(box);
 272                         is_unloaded.push_back(true);
 273                         is_step_up.push_back(false);
 274                         bouncy_values.push_back(0);
 275                         node_positions.push_back(p);
 276                         is_object.push_back(false);
 277                 }
 278         }
 279         } // tt2
 280
 281         {
 282                 ScopeProfiler sp(g_profiler, "collisionMoveSimple objects avg", SPT_AVG);
 283                 //TimeTaker tt3("collisionMoveSimple collect object boxes");
 284
 285                 /* add object boxes to cboxes */
 286
 287
 288                 std::list<ActiveObject*> objects;
 289 #ifndef SERVER
 290                 ClientEnvironment *c_env = dynamic_cast<ClientEnvironment*>(env);
 291                 if (c_env != 0)
 292                 {
 293                         f32 distance = speed_f.getLength();
 294                         std::vector<DistanceSortedActiveObject> clientobjects;
 295                         c_env->getActiveObjects(pos_f,distance * 1.5,clientobjects);
 296                         for (int i=0; i < clientobjects.size(); i++)
 297                         {
 298                                 objects.push_back((ActiveObject*)clientobjects[i].obj);
 299                         }
 300                 }
 301                 else
 302 #endif
 303                 {
 304                         ServerEnvironment *s_env = dynamic_cast<ServerEnvironment*>(env);
 305                         if (s_env != 0)
 306                         {
 307                                 f32 distance = speed_f.getLength();
 308                                 std::set<u16> s_objects = s_env->getObjectsInsideRadius(pos_f,distance * 1.5);
 309                                 for (std::set<u16>::iterator iter = s_objects.begin(); iter != s_objects.end(); iter++)
 310                                 {
 311                                         ServerActiveObject *current = s_env->getActiveObject(*iter);
 312                                         objects.push_back((ActiveObject*)current);
 313                                 }
 314                         }
 315                 }
 316
 317                 for (std::list<ActiveObject*>::const_iterator iter = objects.begin();iter != objects.end(); ++iter)
 318                 {
 319                         ActiveObject *object = *iter;
 320
 321                         if (object != NULL)
 322                         {
 323                                 aabb3f object_collisionbox;
 324                                 if (object->getCollisionBox(&object_collisionbox))
 325                                 {
 326                                         cboxes.push_back(object_collisionbox);
 327                                         is_unloaded.push_back(false);
 328                                         is_step_up.push_back(false);
 329                                         bouncy_values.push_back(0);
 330                                         node_positions.push_back(v3s16(0,0,0));
 331                                         is_object.push_back(true);
 332                                 }
 333                         }
 334                 }
 335         } //tt3
 336
 337         assert(cboxes.size() == is_unloaded.size());
 338         assert(cboxes.size() == is_step_up.size());
 339         assert(cboxes.size() == bouncy_values.size());
 340         assert(cboxes.size() == node_positions.size());
 341         assert(cboxes.size() == is_object.size());
 342
 343         /*
 344                 Collision detection
 345         */
 346
 347         /*
 348                 Collision uncertainty radius
 349                 Make it a bit larger than the maximum distance of movement
 350         */
 351         f32 d = pos_max_d * 1.1;
 352         // A fairly large value in here makes moving smoother
 353         //f32 d = 0.15*BS;
 354
 355         // This should always apply, otherwise there are glitches
 356         assert(d > pos_max_d);
 357
 358         int loopcount = 0;
 359
 360         while(dtime > BS*1e-10)
 361         {
 362                 //TimeTaker tt3("collisionMoveSimple dtime loop");
 363         ScopeProfiler sp(g_profiler, "collisionMoveSimple dtime loop avg", SPT_AVG);
 364
 365                 // Avoid infinite loop
 366                 loopcount++;
 367                 if(loopcount >= 100)
 368                 {
 369                         infostream<<"collisionMoveSimple: WARNING: Loop count exceeded, aborting to avoid infiniite loop"<<std::endl;
 370                         dtime = 0;
 371                         break;
 372                 }
 373
 374                 aabb3f movingbox = box_0;
 375                 movingbox.MinEdge += pos_f;
 376                 movingbox.MaxEdge += pos_f;
 377
 378                 int nearest_collided = -1;
 379                 f32 nearest_dtime = dtime;
 380                 u32 nearest_boxindex = -1;
 381
 382                 /*
 383                         Go through every nodebox, find nearest collision
 384                 */
 385                 for(u32 boxindex = 0; boxindex < cboxes.size(); boxindex++)
 386                 {
 387                         // Ignore if already stepped up this nodebox.
 388                         if(is_step_up[boxindex])
 389                                 continue;
 390
 391                         // Find nearest collision of the two boxes (raytracing-like)
 392                         f32 dtime_tmp;
 393                         int collided = axisAlignedCollision(
 394                                         cboxes[boxindex], movingbox, speed_f, d, dtime_tmp);
 395
 396                         if(collided == -1 || dtime_tmp >= nearest_dtime)
 397                                 continue;
 398
 399                         nearest_dtime = dtime_tmp;
 400                         nearest_collided = collided;
 401                         nearest_boxindex = boxindex;
 402                 }
 403
 404                 if(nearest_collided == -1)
 405                 {
 406                         // No collision with any collision box.
 407                         pos_f += speed_f * dtime;
 408                         dtime = 0;  // Set to 0 to avoid "infinite" loop due to small FP numbers
 409                 }
 410                 else
 411                 {
 412                         // Otherwise, a collision occurred.
 413
 414                         const aabb3f& cbox = cboxes[nearest_boxindex];
 415
 416                         // Check for stairs.
 417                         bool step_up = (nearest_collided != 1) && // must not be Y direction
 418                                         (movingbox.MinEdge.Y < cbox.MaxEdge.Y) &&
 419                                         (movingbox.MinEdge.Y + stepheight > cbox.MaxEdge.Y) &&
 420                                         (!wouldCollideWithCeiling(cboxes, movingbox,
 421                                                         cbox.MaxEdge.Y - movingbox.MinEdge.Y,
 422                                                         d));
 423
 424                         // Get bounce multiplier
 425                         bool bouncy = (bouncy_values[nearest_boxindex] >= 1);
 426                         float bounce = -(float)bouncy_values[nearest_boxindex] / 100.0;
 427
 428                         // Move to the point of collision and reduce dtime by nearest_dtime
 429                         if(nearest_dtime < 0)
 430                         {
 431                                 // Handle negative nearest_dtime (can be caused by the d allowance)
 432                                 if(!step_up)
 433                                 {
 434                                         if(nearest_collided == 0)
 435                                                 pos_f.X += speed_f.X * nearest_dtime;
 436                                         if(nearest_collided == 1)
 437                                                 pos_f.Y += speed_f.Y * nearest_dtime;
 438                                         if(nearest_collided == 2)
 439                                                 pos_f.Z += speed_f.Z * nearest_dtime;
 440                                 }
 441                         }
 442                         else
 443                         {
 444                                 pos_f += speed_f * nearest_dtime;
 445                                 dtime -= nearest_dtime;
 446                         }
 447
 448                         bool is_collision = true;
 449                         if(is_unloaded[nearest_boxindex])
 450                                 is_collision = false;
 451
 452                         CollisionInfo info;
 453                         if (is_object[nearest_boxindex]) {
 454                                 info.type = COLLISION_OBJECT;
 455                         }
 456                         else
 457                                 info.type = COLLISION_NODE;
 458                         info.node_p = node_positions[nearest_boxindex];
 459                         info.bouncy = bouncy;
 460                         info.old_speed = speed_f;
 461
 462                         // Set the speed component that caused the collision to zero
 463                         if(step_up)
 464                         {
 465                                 // Special case: Handle stairs
 466                                 is_step_up[nearest_boxindex] = true;
 467                                 is_collision = false;
 468                         }
 469                         else if(nearest_collided == 0) // X
 470                         {
 471                                 if(fabs(speed_f.X) > BS*3)
 472                                         speed_f.X *= bounce;
 473                                 else
 474                                         speed_f.X = 0;
 475                                 result.collides = true;
 476                                 result.collides_xz = true;
 477                         }
 478                         else if(nearest_collided == 1) // Y
 479                         {
 480                                 if(fabs(speed_f.Y) > BS*3)
 481                                         speed_f.Y *= bounce;
 482                                 else
 483                                         speed_f.Y = 0;
 484                                 result.collides = true;
 485                         }
 486                         else if(nearest_collided == 2) // Z
 487                         {
 488                                 if(fabs(speed_f.Z) > BS*3)
 489                                         speed_f.Z *= bounce;
 490                                 else
 491                                         speed_f.Z = 0;
 492                                 result.collides = true;
 493                                 result.collides_xz = true;
 494                         }
 495
 496                         info.new_speed = speed_f;
 497                         if(info.new_speed.getDistanceFrom(info.old_speed) < 0.1*BS)
 498                                 is_collision = false;
 499
 500                         if(is_collision){
 501                                 result.collisions.push_back(info);
 502                         }
 503                 }
 504         }
 505
 506         /*
 507                 Final touches: Check if standing on ground, step up stairs.
 508         */
 509         aabb3f box = box_0;
 510         box.MinEdge += pos_f;
 511         box.MaxEdge += pos_f;
 512         for(u32 boxindex = 0; boxindex < cboxes.size(); boxindex++)
 513         {
 514                 const aabb3f& cbox = cboxes[boxindex];
 515
 516                 /*
 517                         See if the object is touching ground.
 518
 519                         Object touches ground if object's minimum Y is near node's
 520                         maximum Y and object's X-Z-area overlaps with the node's
 521                         X-Z-area.
 522
 523                         Use 0.15*BS so that it is easier to get on a node.
 524                 */
 525                 if(
 526                                 cbox.MaxEdge.X-d > box.MinEdge.X &&
 527                                 cbox.MinEdge.X+d < box.MaxEdge.X &&
 528                                 cbox.MaxEdge.Z-d > box.MinEdge.Z &&
 529                                 cbox.MinEdge.Z+d < box.MaxEdge.Z
 530                 ){
 531                         if(is_step_up[boxindex])
 532                         {
 533                                 pos_f.Y += (cbox.MaxEdge.Y - box.MinEdge.Y);
 534                                 box = box_0;
 535                                 box.MinEdge += pos_f;
 536                                 box.MaxEdge += pos_f;
 537                         }
 538                         if(fabs(cbox.MaxEdge.Y-box.MinEdge.Y) < 0.15*BS)
 539                         {
 540                                 result.touching_ground = true;
 541                                 if(is_unloaded[boxindex])
 542                                         result.standing_on_unloaded = true;
 543                         }
 544                 }
 545         }
 546
 547         return result;
 548 }
 549
 550 #if 0
 551 // This doesn't seem to work and isn't used
 552 collisionMoveResult collisionMovePrecise(Map *map, IGameDef *gamedef,
 553                 f32 pos_max_d, const aabb3f &box_0,
 554                 f32 stepheight, f32 dtime,
 555                 v3f &pos_f, v3f &speed_f, v3f &accel_f)
 556 {
 557         //TimeTaker tt("collisionMovePrecise");
 558     ScopeProfiler sp(g_profiler, "collisionMovePrecise avg", SPT_AVG);
 559
 560         collisionMoveResult final_result;
 561
 562         // If there is no speed, there are no collisions
 563         if(speed_f.getLength() == 0)
 564                 return final_result;
 565
 566         // Don't allow overly huge dtime
 567         if(dtime > 2.0)
 568                 dtime = 2.0;
 569
 570         f32 dtime_downcount = dtime;
 571
 572         u32 loopcount = 0;
 573         do
 574         {
 575                 loopcount++;
 576
 577                 // Maximum time increment (for collision detection etc)
 578                 // time = distance / speed
 579                 f32 dtime_max_increment = 1.0;
 580                 if(speed_f.getLength() != 0)
 581                         dtime_max_increment = pos_max_d / speed_f.getLength();
 582
 583                 // Maximum time increment is 10ms or lower
 584                 if(dtime_max_increment > 0.01)
 585                         dtime_max_increment = 0.01;
 586
 587                 f32 dtime_part;
 588                 if(dtime_downcount > dtime_max_increment)
 589                 {
 590                         dtime_part = dtime_max_increment;
 591                         dtime_downcount -= dtime_part;
 592                 }
 593                 else
 594                 {
 595                         dtime_part = dtime_downcount;
 596                         /*
 597                                 Setting this to 0 (no -=dtime_part) disables an infinite loop
 598                                 when dtime_part is so small that dtime_downcount -= dtime_part
 599                                 does nothing
 600                         */
 601                         dtime_downcount = 0;
 602                 }
 603
 604                 collisionMoveResult result = collisionMoveSimple(map, gamedef,
 605                                 pos_max_d, box_0, stepheight, dtime_part,
 606                                 pos_f, speed_f, accel_f);
 607
 608                 if(result.touching_ground)
 609                         final_result.touching_ground = true;
 610                 if(result.collides)
 611                         final_result.collides = true;
 612                 if(result.collides_xz)
 613                         final_result.collides_xz = true;
 614                 if(result.standing_on_unloaded)
 615                         final_result.standing_on_unloaded = true;
 616         }
 617         while(dtime_downcount > 0.001);
 618
 619         return final_result;
 620 }
 621 #endif