aboutsummaryrefslogtreecommitdiff
path: root/builtin/game/falling.lua
diff options
context:
space:
mode:
authorSmallJoker <SmallJoker@users.noreply.github.com>2018-07-01 12:31:28 +0200
committerGitHub <noreply@github.com>2018-07-01 12:31:28 +0200
commit6f22d14206824911b620ecec450689f84e6d278b (patch)
treefc639bddfc7e73e5479e6307d4e06039d94792fc /builtin/game/falling.lua
parent7d20ff47d7ce83825ccad81427fc8b45f80a2a2c (diff)
downloadminetest-6f22d14206824911b620ecec450689f84e6d278b.tar.gz
minetest-6f22d14206824911b620ecec450689f84e6d278b.tar.bz2
minetest-6f22d14206824911b620ecec450689f84e6d278b.zip
Make the server status message customizable (#7357)
Remove now redundant setting show_statusline_on_connect Improve documentation of `minetest.get_server_status`
Diffstat (limited to 'builtin/game/falling.lua')
0 files changed, 0 insertions, 0 deletions
128'>128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642
/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "collision.h"
#include "mapblock.h"
#include "map.h"
#include "nodedef.h"
#include "gamedef.h"
#include "log.h"
#include "environment.h"
#include "serverobject.h"
#include <vector>
#include <set>
#include "util/timetaker.h"
#include "main.h" // g_profiler
#include "profiler.h"

// float error is 10 - 9.96875 = 0.03125
//#define COLL_ZERO 0.032 // broken unit tests
#define COLL_ZERO 0

// Helper function:
// Checks for collision of a moving aabbox with a static aabbox
// Returns -1 if no collision, 0 if X collision, 1 if Y collision, 2 if Z collision
// The time after which the collision occurs is stored in dtime.
int axisAlignedCollision(
		const aabb3f &staticbox, const aabb3f &movingbox,
		const v3f &speed, f32 d, f32 &dtime)
{
	//TimeTaker tt("axisAlignedCollision");

	f32 xsize = (staticbox.MaxEdge.X - staticbox.MinEdge.X) - COLL_ZERO;     // reduce box size for solve collision stuck (flying sand)
	f32 ysize = (staticbox.MaxEdge.Y - staticbox.MinEdge.Y); // - COLL_ZERO; // Y - no sense for falling, but maybe try later
	f32 zsize = (staticbox.MaxEdge.Z - staticbox.MinEdge.Z) - COLL_ZERO;

	aabb3f relbox(
			movingbox.MinEdge.X - staticbox.MinEdge.X,
			movingbox.MinEdge.Y - staticbox.MinEdge.Y,
			movingbox.MinEdge.Z - staticbox.MinEdge.Z,
			movingbox.MaxEdge.X - staticbox.MinEdge.X,
			movingbox.MaxEdge.Y - staticbox.MinEdge.Y,
			movingbox.MaxEdge.Z - staticbox.MinEdge.Z
	);

	if(speed.X > 0) // Check for collision with X- plane
	{
		if(relbox.MaxEdge.X <= d)
		{
			dtime = - relbox.MaxEdge.X / speed.X;
			if((relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
					(relbox.MaxEdge.Y + speed.Y * dtime > COLL_ZERO) &&
					(relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
					(relbox.MaxEdge.Z + speed.Z * dtime > COLL_ZERO))
				return 0;
		}
		else if(relbox.MinEdge.X > xsize)
		{
			return -1;
		}
	}
	else if(speed.X < 0) // Check for collision with X+ plane
	{
		if(relbox.MinEdge.X >= xsize - d)
		{
			dtime = (xsize - relbox.MinEdge.X) / speed.X;
			if((relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
					(relbox.MaxEdge.Y + speed.Y * dtime > COLL_ZERO) &&
					(relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
					(relbox.MaxEdge.Z + speed.Z * dtime > COLL_ZERO))
				return 0;
		}
		else if(relbox.MaxEdge.X < 0)
		{
			return -1;
		}
	}

	// NO else if here

	if(speed.Y > 0) // Check for collision with Y- plane
	{
		if(relbox.MaxEdge.Y <= d)
		{
			dtime = - relbox.MaxEdge.Y / speed.Y;
			if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
					(relbox.MaxEdge.X + speed.X * dtime > COLL_ZERO) &&
					(relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
					(relbox.MaxEdge.Z + speed.Z * dtime > COLL_ZERO))
				return 1;
		}
		else if(relbox.MinEdge.Y > ysize)
		{
			return -1;
		}
	}
	else if(speed.Y < 0) // Check for collision with Y+ plane
	{
		if(relbox.MinEdge.Y >= ysize - d)
		{
			dtime = (ysize - relbox.MinEdge.Y) / speed.Y;
			if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
					(relbox.MaxEdge.X + speed.X * dtime > COLL_ZERO) &&
					(relbox.MinEdge.Z + speed.Z * dtime < zsize) &&
					(relbox.MaxEdge.Z + speed.Z * dtime > COLL_ZERO))
				return 1;
		}
		else if(relbox.MaxEdge.Y < 0)
		{
			return -1;
		}
	}

	// NO else if here

	if(speed.Z > 0) // Check for collision with Z- plane
	{
		if(relbox.MaxEdge.Z <= d)
		{
			dtime = - relbox.MaxEdge.Z / speed.Z;
			if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
					(relbox.MaxEdge.X + speed.X * dtime > COLL_ZERO) &&
					(relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
					(relbox.MaxEdge.Y + speed.Y * dtime > COLL_ZERO))
				return 2;
		}
		//else if(relbox.MinEdge.Z > zsize)
		//{
		//	return -1;
		//}
	}
	else if(speed.Z < 0) // Check for collision with Z+ plane
	{
		if(relbox.MinEdge.Z >= zsize - d)
		{
			dtime = (zsize - relbox.MinEdge.Z) / speed.Z;
			if((relbox.MinEdge.X + speed.X * dtime < xsize) &&
					(relbox.MaxEdge.X + speed.X * dtime > COLL_ZERO) &&
					(relbox.MinEdge.Y + speed.Y * dtime < ysize) &&
					(relbox.MaxEdge.Y + speed.Y * dtime > COLL_ZERO))
				return 2;
		}
		//else if(relbox.MaxEdge.Z < 0)
		//{
		//	return -1;
		//}
	}

	return -1;
}

// Helper function:
// Checks if moving the movingbox up by the given distance would hit a ceiling.
bool wouldCollideWithCeiling(
		const std::vector<aabb3f> &staticboxes,
		const aabb3f &movingbox,
		f32 y_increase, f32 d)
{
	//TimeTaker tt("wouldCollideWithCeiling");

	assert(y_increase >= 0);

	for(std::vector<aabb3f>::const_iterator
			i = staticboxes.begin();
			i != staticboxes.end(); i++)
	{
		const aabb3f& staticbox = *i;
		if((movingbox.MaxEdge.Y - d <= staticbox.MinEdge.Y) &&
				(movingbox.MaxEdge.Y + y_increase > staticbox.MinEdge.Y) &&
				(movingbox.MinEdge.X < staticbox.MaxEdge.X) &&
				(movingbox.MaxEdge.X > staticbox.MinEdge.X) &&
				(movingbox.MinEdge.Z < staticbox.MaxEdge.Z) &&
				(movingbox.MaxEdge.Z > staticbox.MinEdge.Z))
			return true;
	}

	return false;
}


collisionMoveResult collisionMoveSimple(Environment *env, IGameDef *gamedef,
		f32 pos_max_d, const aabb3f &box_0,
		f32 stepheight, f32 dtime,
		v3f &pos_f, v3f &speed_f,
		v3f &accel_f,ActiveObject* self,
		bool collideWithObjects)
{
	Map *map = &env->getMap();
	//TimeTaker tt("collisionMoveSimple");
    ScopeProfiler sp(g_profiler, "collisionMoveSimple avg", SPT_AVG);

	collisionMoveResult result;

	/*
		Calculate new velocity
	*/
	if( dtime > 0.5 ) {
		infostream<<"collisionMoveSimple: WARNING: maximum step interval exceeded, lost movement details!"<<std::endl;
		dtime = 0.5;
	}
	speed_f += accel_f * dtime;

	// If there is no speed, there are no collisions
	if(speed_f.getLength() == 0)
		return result;

	// Limit speed for avoiding hangs
	speed_f.Y=rangelim(speed_f.Y,-5000,5000);
	speed_f.X=rangelim(speed_f.X,-5000,5000);
	speed_f.Z=rangelim(speed_f.Z,-5000,5000);

	/*
		Collect node boxes in movement range
	*/
	std::vector<aabb3f> cboxes;
	std::vector<bool> is_unloaded;
	std::vector<bool> is_step_up;
	std::vector<bool> is_object;
	std::vector<int> bouncy_values;
	std::vector<v3s16> node_positions;
	{
	//TimeTaker tt2("collisionMoveSimple collect boxes");
    ScopeProfiler sp(g_profiler, "collisionMoveSimple collect boxes avg", SPT_AVG);

	v3s16 oldpos_i = floatToInt(pos_f, BS);
	v3s16 newpos_i = floatToInt(pos_f + speed_f * dtime, BS);
	s16 min_x = MYMIN(oldpos_i.X, newpos_i.X) + (box_0.MinEdge.X / BS) - 1;
	s16 min_y = MYMIN(oldpos_i.Y, newpos_i.Y) + (box_0.MinEdge.Y / BS) - 1;
	s16 min_z = MYMIN(oldpos_i.Z, newpos_i.Z) + (box_0.MinEdge.Z / BS) - 1;
	s16 max_x = MYMAX(oldpos_i.X, newpos_i.X) + (box_0.MaxEdge.X / BS) + 1;
	s16 max_y = MYMAX(oldpos_i.Y, newpos_i.Y) + (box_0.MaxEdge.Y / BS) + 1;
	s16 max_z = MYMAX(oldpos_i.Z, newpos_i.Z) + (box_0.MaxEdge.Z / BS) + 1;

	for(s16 x = min_x; x <= max_x; x++)
	for(s16 y = min_y; y <= max_y; y++)
	for(s16 z = min_z; z <= max_z; z++)
	{
		v3s16 p(x,y,z);

		bool is_position_valid;
		MapNode n = map->getNodeNoEx(p, &is_position_valid);

		if (is_position_valid) {
			// Object collides into walkable nodes

			const ContentFeatures &f = gamedef->getNodeDefManager()->get(n);
			if(f.walkable == false)
				continue;
			int n_bouncy_value = itemgroup_get(f.groups, "bouncy");

			std::vector<aabb3f> nodeboxes = n.getCollisionBoxes(gamedef->ndef());
			for(std::vector<aabb3f>::iterator
					i = nodeboxes.begin();
					i != nodeboxes.end(); i++)
			{
				aabb3f box = *i;
				box.MinEdge += v3f(x, y, z)*BS;
				box.MaxEdge += v3f(x, y, z)*BS;
				cboxes.push_back(box);
				is_unloaded.push_back(false);
				is_step_up.push_back(false);
				bouncy_values.push_back(n_bouncy_value);
				node_positions.push_back(p);
				is_object.push_back(false);
			}
		}
		else {
			// Collide with unloaded nodes
			aabb3f box = getNodeBox(p, BS);
			cboxes.push_back(box);
			is_unloaded.push_back(true);
			is_step_up.push_back(false);
			bouncy_values.push_back(0);
			node_positions.push_back(p);
			is_object.push_back(false);
		}
	}
	} // tt2

	if(collideWithObjects)
	{
		ScopeProfiler sp(g_profiler, "collisionMoveSimple objects avg", SPT_AVG);
		//TimeTaker tt3("collisionMoveSimple collect object boxes");

		/* add object boxes to cboxes */


		std::list<ActiveObject*> objects;
#ifndef SERVER
		ClientEnvironment *c_env = dynamic_cast<ClientEnvironment*>(env);
		if (c_env != 0)
		{
			f32 distance = speed_f.getLength();
			std::vector<DistanceSortedActiveObject> clientobjects;
			c_env->getActiveObjects(pos_f,distance * 1.5,clientobjects);
			for (size_t i=0; i < clientobjects.size(); i++)
			{
				if ((self == 0) || (self != clientobjects[i].obj)) {
					objects.push_back((ActiveObject*)clientobjects[i].obj);
				}
			}
		}
		else
#endif
		{
			ServerEnvironment *s_env = dynamic_cast<ServerEnvironment*>(env);
			if (s_env != 0)
			{
				f32 distance = speed_f.getLength();
				std::set<u16> s_objects = s_env->getObjectsInsideRadius(pos_f,distance * 1.5);
				for (std::set<u16>::iterator iter = s_objects.begin(); iter != s_objects.end(); iter++)
				{
					ServerActiveObject *current = s_env->getActiveObject(*iter);
					if ((self == 0) || (self != current)) {
						objects.push_back((ActiveObject*)current);
					}
				}
			}
		}

		for (std::list<ActiveObject*>::const_iterator iter = objects.begin();iter != objects.end(); ++iter)
		{
			ActiveObject *object = *iter;

			if (object != NULL)
			{
				aabb3f object_collisionbox;
				if (object->getCollisionBox(&object_collisionbox) &&
						object->collideWithObjects())
				{
					cboxes.push_back(object_collisionbox);
					is_unloaded.push_back(false);
					is_step_up.push_back(false);
					bouncy_values.push_back(0);
					node_positions.push_back(v3s16(0,0,0));
					is_object.push_back(true);
				}
			}
		}
	} //tt3

	assert(cboxes.size() == is_unloaded.size());
	assert(cboxes.size() == is_step_up.size());
	assert(cboxes.size() == bouncy_values.size());
	assert(cboxes.size() == node_positions.size());
	assert(cboxes.size() == is_object.size());

	/*
		Collision detection
	*/

	/*
		Collision uncertainty radius
		Make it a bit larger than the maximum distance of movement
	*/
	f32 d = pos_max_d * 1.1;
	// A fairly large value in here makes moving smoother
	//f32 d = 0.15*BS;

	// This should always apply, otherwise there are glitches
	assert(d > pos_max_d);

	int loopcount = 0;

	while(dtime > BS*1e-10)
	{
		//TimeTaker tt3("collisionMoveSimple dtime loop");
        ScopeProfiler sp(g_profiler, "collisionMoveSimple dtime loop avg", SPT_AVG);

		// Avoid infinite loop
		loopcount++;
		if(loopcount >= 100)
		{
			infostream<<"collisionMoveSimple: WARNING: Loop count exceeded, aborting to avoid infiniite loop"<<std::endl;
			dtime = 0;
			break;
		}

		aabb3f movingbox = box_0;
		movingbox.MinEdge += pos_f;
		movingbox.MaxEdge += pos_f;

		int nearest_collided = -1;
		f32 nearest_dtime = dtime;
		u32 nearest_boxindex = -1;

		/*
			Go through every nodebox, find nearest collision
		*/
		for(u32 boxindex = 0; boxindex < cboxes.size(); boxindex++)
		{
			// Ignore if already stepped up this nodebox.
			if(is_step_up[boxindex])
				continue;

			// Find nearest collision of the two boxes (raytracing-like)
			f32 dtime_tmp;
			int collided = axisAlignedCollision(
					cboxes[boxindex], movingbox, speed_f, d, dtime_tmp);

			if(collided == -1 || dtime_tmp >= nearest_dtime)
				continue;

			nearest_dtime = dtime_tmp;
			nearest_collided = collided;
			nearest_boxindex = boxindex;
		}

		if(nearest_collided == -1)
		{
			// No collision with any collision box.
			pos_f += speed_f * dtime;
			dtime = 0;  // Set to 0 to avoid "infinite" loop due to small FP numbers
		}
		else
		{
			// Otherwise, a collision occurred.

			const aabb3f& cbox = cboxes[nearest_boxindex];

			// Check for stairs.
			bool step_up = (nearest_collided != 1) && // must not be Y direction
					(movingbox.MinEdge.Y < cbox.MaxEdge.Y) &&
					(movingbox.MinEdge.Y + stepheight > cbox.MaxEdge.Y) &&
					(!wouldCollideWithCeiling(cboxes, movingbox,
							cbox.MaxEdge.Y - movingbox.MinEdge.Y,
							d));

			// Get bounce multiplier
			bool bouncy = (bouncy_values[nearest_boxindex] >= 1);
			float bounce = -(float)bouncy_values[nearest_boxindex] / 100.0;

			// Move to the point of collision and reduce dtime by nearest_dtime
			if(nearest_dtime < 0)
			{
				// Handle negative nearest_dtime (can be caused by the d allowance)
				if(!step_up)
				{
					if(nearest_collided == 0)
						pos_f.X += speed_f.X * nearest_dtime;
					if(nearest_collided == 1)
						pos_f.Y += speed_f.Y * nearest_dtime;
					if(nearest_collided == 2)
						pos_f.Z += speed_f.Z * nearest_dtime;
				}
			}
			else
			{
				pos_f += speed_f * nearest_dtime;
				dtime -= nearest_dtime;
			}
			
			bool is_collision = true;
			if(is_unloaded[nearest_boxindex])
				is_collision = false;

			CollisionInfo info;
			if (is_object[nearest_boxindex]) {
				info.type = COLLISION_OBJECT;
			}
			else {
				info.type = COLLISION_NODE;
			}
			info.node_p = node_positions[nearest_boxindex];
			info.bouncy = bouncy;
			info.old_speed = speed_f;

			// Set the speed component that caused the collision to zero
			if(step_up)
			{
				// Special case: Handle stairs
				is_step_up[nearest_boxindex] = true;
				is_collision = false;
			}
			else if(nearest_collided == 0) // X
			{
				if(fabs(speed_f.X) > BS*3)
					speed_f.X *= bounce;
				else
					speed_f.X = 0;
				result.collides = true;
				result.collides_xz = true;
			}
			else if(nearest_collided == 1) // Y
			{
				if(fabs(speed_f.Y) > BS*3)
					speed_f.Y *= bounce;
				else
					speed_f.Y = 0;
				result.collides = true;
			}
			else if(nearest_collided == 2) // Z
			{
				if(fabs(speed_f.Z) > BS*3)
					speed_f.Z *= bounce;
				else
					speed_f.Z = 0;
				result.collides = true;
				result.collides_xz = true;
			}

			info.new_speed = speed_f;
			if(info.new_speed.getDistanceFrom(info.old_speed) < 0.1*BS)
				is_collision = false;

			if(is_collision){
				result.collisions.push_back(info);
			}
		}
	}

	/*
		Final touches: Check if standing on ground, step up stairs.
	*/
	aabb3f box = box_0;
	box.MinEdge += pos_f;
	box.MaxEdge += pos_f;
	for(u32 boxindex = 0; boxindex < cboxes.size(); boxindex++)
	{
		const aabb3f& cbox = cboxes[boxindex];

		/*
			See if the object is touching ground.

			Object touches ground if object's minimum Y is near node's
			maximum Y and object's X-Z-area overlaps with the node's
			X-Z-area.

			Use 0.15*BS so that it is easier to get on a node.
		*/
		if(
				cbox.MaxEdge.X-d > box.MinEdge.X &&
				cbox.MinEdge.X+d < box.MaxEdge.X &&
				cbox.MaxEdge.Z-d > box.MinEdge.Z &&
				cbox.MinEdge.Z+d < box.MaxEdge.Z
		){
			if(is_step_up[boxindex])
			{
				pos_f.Y += (cbox.MaxEdge.Y - box.MinEdge.Y);
				box = box_0;
				box.MinEdge += pos_f;
				box.MaxEdge += pos_f;
			}
			if(fabs(cbox.MaxEdge.Y-box.MinEdge.Y) < 0.15*BS)
			{
				result.touching_ground = true;
				if(is_unloaded[boxindex])
					result.standing_on_unloaded = true;
			}
		}
	}

	return result;
}

#if 0
// This doesn't seem to work and isn't used
collisionMoveResult collisionMovePrecise(Map *map, IGameDef *gamedef,
		f32 pos_max_d, const aabb3f &box_0,
		f32 stepheight, f32 dtime,
		v3f &pos_f, v3f &speed_f, v3f &accel_f)
{
	//TimeTaker tt("collisionMovePrecise");
    ScopeProfiler sp(g_profiler, "collisionMovePrecise avg", SPT_AVG);
	
	collisionMoveResult final_result;

	// If there is no speed, there are no collisions
	if(speed_f.getLength() == 0)
		return final_result;

	// Don't allow overly huge dtime
	if(dtime > 2.0)
		dtime = 2.0;

	f32 dtime_downcount = dtime;

	u32 loopcount = 0;
	do
	{
		loopcount++;

		// Maximum time increment (for collision detection etc)
		// time = distance / speed
		f32 dtime_max_increment = 1.0;
		if(speed_f.getLength() != 0)
			dtime_max_increment = pos_max_d / speed_f.getLength();

		// Maximum time increment is 10ms or lower
		if(dtime_max_increment > 0.01)
			dtime_max_increment = 0.01;

		f32 dtime_part;
		if(dtime_downcount > dtime_max_increment)
		{
			dtime_part = dtime_max_increment;
			dtime_downcount -= dtime_part;
		}
		else
		{
			dtime_part = dtime_downcount;
			/*
				Setting this to 0 (no -=dtime_part) disables an infinite loop
				when dtime_part is so small that dtime_downcount -= dtime_part
				does nothing
			*/
			dtime_downcount = 0;
		}

		collisionMoveResult result = collisionMoveSimple(map, gamedef,
				pos_max_d, box_0, stepheight, dtime_part,
				pos_f, speed_f, accel_f);

		if(result.touching_ground)
			final_result.touching_ground = true;
		if(result.collides)
			final_result.collides = true;
		if(result.collides_xz)
			final_result.collides_xz = true;
		if(result.standing_on_unloaded)
			final_result.standing_on_unloaded = true;
	}
	while(dtime_downcount > 0.001);

	return final_result;
}
#endif