3 Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
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.
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.
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.
20 #include "collision.h"
26 #include "clientenvironment.h"
28 #include "serverenvironment.h"
29 #include "serverobject.h"
30 #include "util/timetaker.h"
33 // float error is 10 - 9.96875 = 0.03125
34 //#define COLL_ZERO 0.032 // broken unit tests
38 struct NearbyCollisionInfo {
39 NearbyCollisionInfo(bool is_ul, bool is_obj, int bouncy,
40 const v3s16 &pos, const aabb3f &box) :
49 bool is_step_up = false;
58 // Checks for collision of a moving aabbox with a static aabbox
59 // Returns -1 if no collision, 0 if X collision, 1 if Y collision, 2 if Z collision
60 // The time after which the collision occurs is stored in dtime.
61 int axisAlignedCollision(
62 const aabb3f &staticbox, const aabb3f &movingbox,
63 const v3f &speed, f32 d, f32 *dtime)
65 //TimeTaker tt("axisAlignedCollision");
67 f32 xsize = (staticbox.MaxEdge.X - staticbox.MinEdge.X) - COLL_ZERO; // reduce box size for solve collision stuck (flying sand)
68 f32 ysize = (staticbox.MaxEdge.Y - staticbox.MinEdge.Y); // - COLL_ZERO; // Y - no sense for falling, but maybe try later
69 f32 zsize = (staticbox.MaxEdge.Z - staticbox.MinEdge.Z) - COLL_ZERO;
72 movingbox.MinEdge.X - staticbox.MinEdge.X,
73 movingbox.MinEdge.Y - staticbox.MinEdge.Y,
74 movingbox.MinEdge.Z - staticbox.MinEdge.Z,
75 movingbox.MaxEdge.X - staticbox.MinEdge.X,
76 movingbox.MaxEdge.Y - staticbox.MinEdge.Y,
77 movingbox.MaxEdge.Z - staticbox.MinEdge.Z
80 if(speed.X > 0) // Check for collision with X- plane
82 if (relbox.MaxEdge.X <= d) {
83 *dtime = -relbox.MaxEdge.X / speed.X;
84 if ((relbox.MinEdge.Y + speed.Y * (*dtime) < ysize) &&
85 (relbox.MaxEdge.Y + speed.Y * (*dtime) > COLL_ZERO) &&
86 (relbox.MinEdge.Z + speed.Z * (*dtime) < zsize) &&
87 (relbox.MaxEdge.Z + speed.Z * (*dtime) > COLL_ZERO))
90 else if(relbox.MinEdge.X > xsize)
95 else if(speed.X < 0) // Check for collision with X+ plane
97 if (relbox.MinEdge.X >= xsize - d) {
98 *dtime = (xsize - relbox.MinEdge.X) / speed.X;
99 if ((relbox.MinEdge.Y + speed.Y * (*dtime) < ysize) &&
100 (relbox.MaxEdge.Y + speed.Y * (*dtime) > COLL_ZERO) &&
101 (relbox.MinEdge.Z + speed.Z * (*dtime) < zsize) &&
102 (relbox.MaxEdge.Z + speed.Z * (*dtime) > COLL_ZERO))
105 else if(relbox.MaxEdge.X < 0)
113 if(speed.Y > 0) // Check for collision with Y- plane
115 if (relbox.MaxEdge.Y <= d) {
116 *dtime = -relbox.MaxEdge.Y / speed.Y;
117 if ((relbox.MinEdge.X + speed.X * (*dtime) < xsize) &&
118 (relbox.MaxEdge.X + speed.X * (*dtime) > COLL_ZERO) &&
119 (relbox.MinEdge.Z + speed.Z * (*dtime) < zsize) &&
120 (relbox.MaxEdge.Z + speed.Z * (*dtime) > COLL_ZERO))
123 else if(relbox.MinEdge.Y > ysize)
128 else if(speed.Y < 0) // Check for collision with Y+ plane
130 if (relbox.MinEdge.Y >= ysize - d) {
131 *dtime = (ysize - relbox.MinEdge.Y) / speed.Y;
132 if ((relbox.MinEdge.X + speed.X * (*dtime) < xsize) &&
133 (relbox.MaxEdge.X + speed.X * (*dtime) > COLL_ZERO) &&
134 (relbox.MinEdge.Z + speed.Z * (*dtime) < zsize) &&
135 (relbox.MaxEdge.Z + speed.Z * (*dtime) > COLL_ZERO))
138 else if(relbox.MaxEdge.Y < 0)
146 if(speed.Z > 0) // Check for collision with Z- plane
148 if (relbox.MaxEdge.Z <= d) {
149 *dtime = -relbox.MaxEdge.Z / speed.Z;
150 if ((relbox.MinEdge.X + speed.X * (*dtime) < xsize) &&
151 (relbox.MaxEdge.X + speed.X * (*dtime) > COLL_ZERO) &&
152 (relbox.MinEdge.Y + speed.Y * (*dtime) < ysize) &&
153 (relbox.MaxEdge.Y + speed.Y * (*dtime) > COLL_ZERO))
156 //else if(relbox.MinEdge.Z > zsize)
161 else if(speed.Z < 0) // Check for collision with Z+ plane
163 if (relbox.MinEdge.Z >= zsize - d) {
164 *dtime = (zsize - relbox.MinEdge.Z) / speed.Z;
165 if ((relbox.MinEdge.X + speed.X * (*dtime) < xsize) &&
166 (relbox.MaxEdge.X + speed.X * (*dtime) > COLL_ZERO) &&
167 (relbox.MinEdge.Y + speed.Y * (*dtime) < ysize) &&
168 (relbox.MaxEdge.Y + speed.Y * (*dtime) > COLL_ZERO))
171 //else if(relbox.MaxEdge.Z < 0)
181 // Checks if moving the movingbox up by the given distance would hit a ceiling.
182 bool wouldCollideWithCeiling(
183 const std::vector<NearbyCollisionInfo> &cinfo,
184 const aabb3f &movingbox,
185 f32 y_increase, f32 d)
187 //TimeTaker tt("wouldCollideWithCeiling");
189 assert(y_increase >= 0); // pre-condition
191 for (std::vector<NearbyCollisionInfo>::const_iterator it = cinfo.begin();
192 it != cinfo.end(); ++it) {
193 const aabb3f &staticbox = it->box;
194 if ((movingbox.MaxEdge.Y - d <= staticbox.MinEdge.Y) &&
195 (movingbox.MaxEdge.Y + y_increase > staticbox.MinEdge.Y) &&
196 (movingbox.MinEdge.X < staticbox.MaxEdge.X) &&
197 (movingbox.MaxEdge.X > staticbox.MinEdge.X) &&
198 (movingbox.MinEdge.Z < staticbox.MaxEdge.Z) &&
199 (movingbox.MaxEdge.Z > staticbox.MinEdge.Z))
206 static inline void getNeighborConnectingFace(v3s16 p, INodeDefManager *nodedef,
207 Map *map, MapNode n, int v, int *neighbors)
209 MapNode n2 = map->getNodeNoEx(p);
210 if (nodedef->nodeboxConnects(n, n2, v))
214 collisionMoveResult collisionMoveSimple(Environment *env, IGameDef *gamedef,
215 f32 pos_max_d, const aabb3f &box_0,
216 f32 stepheight, f32 dtime,
217 v3f *pos_f, v3f *speed_f,
218 v3f accel_f, ActiveObject *self,
219 bool collideWithObjects)
221 static bool time_notification_done = false;
222 Map *map = &env->getMap();
223 //TimeTaker tt("collisionMoveSimple");
224 ScopeProfiler sp(g_profiler, "collisionMoveSimple avg", SPT_AVG);
226 collisionMoveResult result;
229 Calculate new velocity
232 if (!time_notification_done) {
233 time_notification_done = true;
234 infostream << "collisionMoveSimple: maximum step interval exceeded,"
235 " lost movement details!"<<std::endl;
239 time_notification_done = false;
241 *speed_f += accel_f * dtime;
243 // If there is no speed, there are no collisions
244 if (speed_f->getLength() == 0)
247 // Limit speed for avoiding hangs
248 speed_f->Y = rangelim(speed_f->Y, -5000, 5000);
249 speed_f->X = rangelim(speed_f->X, -5000, 5000);
250 speed_f->Z = rangelim(speed_f->Z, -5000, 5000);
253 Collect node boxes in movement range
255 std::vector<NearbyCollisionInfo> cinfo;
257 //TimeTaker tt2("collisionMoveSimple collect boxes");
258 ScopeProfiler sp(g_profiler, "collisionMoveSimple collect boxes avg", SPT_AVG);
260 v3s16 oldpos_i = floatToInt(*pos_f, BS);
261 v3s16 newpos_i = floatToInt(*pos_f + *speed_f * dtime, BS);
262 s16 min_x = MYMIN(oldpos_i.X, newpos_i.X) + (box_0.MinEdge.X / BS) - 1;
263 s16 min_y = MYMIN(oldpos_i.Y, newpos_i.Y) + (box_0.MinEdge.Y / BS) - 1;
264 s16 min_z = MYMIN(oldpos_i.Z, newpos_i.Z) + (box_0.MinEdge.Z / BS) - 1;
265 s16 max_x = MYMAX(oldpos_i.X, newpos_i.X) + (box_0.MaxEdge.X / BS) + 1;
266 s16 max_y = MYMAX(oldpos_i.Y, newpos_i.Y) + (box_0.MaxEdge.Y / BS) + 1;
267 s16 max_z = MYMAX(oldpos_i.Z, newpos_i.Z) + (box_0.MaxEdge.Z / BS) + 1;
269 bool any_position_valid = false;
271 for(s16 x = min_x; x <= max_x; x++)
272 for(s16 y = min_y; y <= max_y; y++)
273 for(s16 z = min_z; z <= max_z; z++)
277 bool is_position_valid;
278 MapNode n = map->getNodeNoEx(p, &is_position_valid);
280 if (is_position_valid) {
281 // Object collides into walkable nodes
283 any_position_valid = true;
284 INodeDefManager *nodedef = gamedef->getNodeDefManager();
285 const ContentFeatures &f = nodedef->get(n);
286 if(f.walkable == false)
288 int n_bouncy_value = itemgroup_get(f.groups, "bouncy");
291 if (f.drawtype == NDT_NODEBOX && f.node_box.type == NODEBOX_CONNECTED) {
295 getNeighborConnectingFace(p2, nodedef, map, n, 1, &neighbors);
299 getNeighborConnectingFace(p2, nodedef, map, n, 2, &neighbors);
303 getNeighborConnectingFace(p2, nodedef, map, n, 4, &neighbors);
307 getNeighborConnectingFace(p2, nodedef, map, n, 8, &neighbors);
311 getNeighborConnectingFace(p2, nodedef, map, n, 16, &neighbors);
315 getNeighborConnectingFace(p2, nodedef, map, n, 32, &neighbors);
317 std::vector<aabb3f> nodeboxes;
318 n.getCollisionBoxes(gamedef->ndef(), &nodeboxes, neighbors);
319 for(std::vector<aabb3f>::iterator
320 i = nodeboxes.begin();
321 i != nodeboxes.end(); ++i)
324 box.MinEdge += v3f(x, y, z)*BS;
325 box.MaxEdge += v3f(x, y, z)*BS;
326 cinfo.push_back(NearbyCollisionInfo(false,
327 false, n_bouncy_value, p, box));
330 // Collide with unloaded nodes
331 aabb3f box = getNodeBox(p, BS);
332 cinfo.push_back(NearbyCollisionInfo(true, false, 0, p, box));
336 // Do not move if world has not loaded yet, since custom node boxes
337 // are not available for collision detection.
338 if (!any_position_valid) {
339 *speed_f = v3f(0, 0, 0);
345 if(collideWithObjects)
347 ScopeProfiler sp(g_profiler, "collisionMoveSimple objects avg", SPT_AVG);
348 //TimeTaker tt3("collisionMoveSimple collect object boxes");
350 /* add object boxes to cinfo */
352 std::vector<ActiveObject*> objects;
354 ClientEnvironment *c_env = dynamic_cast<ClientEnvironment*>(env);
356 f32 distance = speed_f->getLength();
357 std::vector<DistanceSortedActiveObject> clientobjects;
358 c_env->getActiveObjects(*pos_f, distance * 1.5, clientobjects);
359 for (size_t i=0; i < clientobjects.size(); i++) {
360 if ((self == 0) || (self != clientobjects[i].obj)) {
361 objects.push_back((ActiveObject*)clientobjects[i].obj);
368 ServerEnvironment *s_env = dynamic_cast<ServerEnvironment*>(env);
370 f32 distance = speed_f->getLength();
371 std::vector<u16> s_objects;
372 s_env->getObjectsInsideRadius(s_objects, *pos_f, distance * 1.5);
373 for (std::vector<u16>::iterator iter = s_objects.begin(); iter != s_objects.end(); ++iter) {
374 ServerActiveObject *current = s_env->getActiveObject(*iter);
375 if ((self == 0) || (self != current)) {
376 objects.push_back((ActiveObject*)current);
382 for (std::vector<ActiveObject*>::const_iterator iter = objects.begin();
383 iter != objects.end(); ++iter) {
384 ActiveObject *object = *iter;
386 if (object != NULL) {
387 aabb3f object_collisionbox;
388 if (object->getCollisionBox(&object_collisionbox) &&
389 object->collideWithObjects()) {
390 cinfo.push_back(NearbyCollisionInfo(false, true, 0, v3s16(), object_collisionbox));
401 Collision uncertainty radius
402 Make it a bit larger than the maximum distance of movement
404 f32 d = pos_max_d * 1.1;
405 // A fairly large value in here makes moving smoother
408 // This should always apply, otherwise there are glitches
409 assert(d > pos_max_d); // invariant
413 while(dtime > BS * 1e-10) {
414 //TimeTaker tt3("collisionMoveSimple dtime loop");
415 ScopeProfiler sp(g_profiler, "collisionMoveSimple dtime loop avg", SPT_AVG);
417 // Avoid infinite loop
419 if (loopcount >= 100) {
420 warningstream << "collisionMoveSimple: Loop count exceeded, aborting to avoid infiniite loop" << std::endl;
424 aabb3f movingbox = box_0;
425 movingbox.MinEdge += *pos_f;
426 movingbox.MaxEdge += *pos_f;
428 int nearest_collided = -1;
429 f32 nearest_dtime = dtime;
430 int nearest_boxindex = -1;
433 Go through every nodebox, find nearest collision
435 for (u32 boxindex = 0; boxindex < cinfo.size(); boxindex++) {
436 NearbyCollisionInfo box_info = cinfo[boxindex];
437 // Ignore if already stepped up this nodebox.
438 if (box_info.is_step_up)
441 // Find nearest collision of the two boxes (raytracing-like)
443 int collided = axisAlignedCollision(box_info.box,
444 movingbox, *speed_f, d, &dtime_tmp);
446 if (collided == -1 || dtime_tmp >= nearest_dtime)
449 nearest_dtime = dtime_tmp;
450 nearest_collided = collided;
451 nearest_boxindex = boxindex;
454 if (nearest_collided == -1) {
455 // No collision with any collision box.
456 *pos_f += *speed_f * dtime;
457 dtime = 0; // Set to 0 to avoid "infinite" loop due to small FP numbers
459 // Otherwise, a collision occurred.
460 NearbyCollisionInfo &nearest_info = cinfo[nearest_boxindex];
461 const aabb3f& cbox = nearest_info.box;
463 bool step_up = (nearest_collided != 1) && // must not be Y direction
464 (movingbox.MinEdge.Y < cbox.MaxEdge.Y) &&
465 (movingbox.MinEdge.Y + stepheight > cbox.MaxEdge.Y) &&
466 (!wouldCollideWithCeiling(cinfo, movingbox,
467 cbox.MaxEdge.Y - movingbox.MinEdge.Y,
470 // Get bounce multiplier
471 float bounce = -(float)nearest_info.bouncy / 100.0;
473 // Move to the point of collision and reduce dtime by nearest_dtime
474 if (nearest_dtime < 0) {
475 // Handle negative nearest_dtime (can be caused by the d allowance)
477 if (nearest_collided == 0)
478 pos_f->X += speed_f->X * nearest_dtime;
479 if (nearest_collided == 1)
480 pos_f->Y += speed_f->Y * nearest_dtime;
481 if (nearest_collided == 2)
482 pos_f->Z += speed_f->Z * nearest_dtime;
485 *pos_f += *speed_f * nearest_dtime;
486 dtime -= nearest_dtime;
489 bool is_collision = true;
490 if (nearest_info.is_unloaded)
491 is_collision = false;
494 if (nearest_info.is_object)
495 info.type = COLLISION_OBJECT;
497 info.type = COLLISION_NODE;
499 info.node_p = nearest_info.position;
500 info.old_speed = *speed_f;
502 // Set the speed component that caused the collision to zero
504 // Special case: Handle stairs
505 nearest_info.is_step_up = true;
506 is_collision = false;
507 } else if (nearest_collided == 0) { // X
508 if (fabs(speed_f->X) > BS * 3)
509 speed_f->X *= bounce;
512 result.collides = true;
513 } else if (nearest_collided == 1) { // Y
514 if(fabs(speed_f->Y) > BS * 3)
515 speed_f->Y *= bounce;
518 result.collides = true;
519 } else if (nearest_collided == 2) { // Z
520 if (fabs(speed_f->Z) > BS * 3)
521 speed_f->Z *= bounce;
524 result.collides = true;
527 info.new_speed = *speed_f;
528 if (info.new_speed.getDistanceFrom(info.old_speed) < 0.1 * BS)
529 is_collision = false;
532 result.collisions.push_back(info);
538 Final touches: Check if standing on ground, step up stairs.
541 box.MinEdge += *pos_f;
542 box.MaxEdge += *pos_f;
543 for (u32 boxindex = 0; boxindex < cinfo.size(); boxindex++) {
544 NearbyCollisionInfo &box_info = cinfo[boxindex];
545 const aabb3f &cbox = box_info.box;
548 See if the object is touching ground.
550 Object touches ground if object's minimum Y is near node's
551 maximum Y and object's X-Z-area overlaps with the node's
554 Use 0.15*BS so that it is easier to get on a node.
556 if (cbox.MaxEdge.X - d > box.MinEdge.X && cbox.MinEdge.X + d < box.MaxEdge.X &&
557 cbox.MaxEdge.Z - d > box.MinEdge.Z &&
558 cbox.MinEdge.Z + d < box.MaxEdge.Z) {
559 if (box_info.is_step_up) {
560 pos_f->Y += cbox.MaxEdge.Y - box.MinEdge.Y;
562 box.MinEdge += *pos_f;
563 box.MaxEdge += *pos_f;
565 if (fabs(cbox.MaxEdge.Y - box.MinEdge.Y) < 0.15 * BS) {
566 result.touching_ground = true;
568 if (box_info.is_object)
569 result.standing_on_object = true;