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"
27 #include "client/clientenvironment.h"
28 #include "client/localplayer.h"
30 #include "serverenvironment.h"
31 #include "server/serveractiveobject.h"
32 #include "util/timetaker.h"
36 #warning "-ffast-math is known to cause bugs in collision code, do not use!"
39 struct NearbyCollisionInfo {
41 NearbyCollisionInfo(bool is_ul, int bouncy, const v3s16 &pos,
51 NearbyCollisionInfo(ActiveObject *obj, int bouncy,
59 inline bool isObject() const { return obj != nullptr; }
62 bool is_step_up = false;
70 // Truncate floating point numbers to specified number of decimal places
71 // in order to move all the floating point error to one side of the correct value
72 static inline f32 truncate(const f32 val, const f32 factor)
74 return truncf(val * factor) / factor;
77 static inline v3f truncate(const v3f& vec, const f32 factor)
80 truncate(vec.X, factor),
81 truncate(vec.Y, factor),
82 truncate(vec.Z, factor)
87 // Checks for collision of a moving aabbox with a static aabbox
88 // Returns -1 if no collision, 0 if X collision, 1 if Y collision, 2 if Z collision
89 // The time after which the collision occurs is stored in dtime.
90 CollisionAxis axisAlignedCollision(
91 const aabb3f &staticbox, const aabb3f &movingbox,
92 const v3f &speed, f32 *dtime)
94 //TimeTaker tt("axisAlignedCollision");
97 (movingbox.MaxEdge.X - movingbox.MinEdge.X) + (staticbox.MaxEdge.X - staticbox.MinEdge.X), // sum of the widths
98 (movingbox.MaxEdge.Y - movingbox.MinEdge.Y) + (staticbox.MaxEdge.Y - staticbox.MinEdge.Y),
99 (movingbox.MaxEdge.Z - movingbox.MinEdge.Z) + (staticbox.MaxEdge.Z - staticbox.MinEdge.Z),
100 std::max(movingbox.MaxEdge.X, staticbox.MaxEdge.X) - std::min(movingbox.MinEdge.X, staticbox.MinEdge.X), //outer bounding 'box' dimensions
101 std::max(movingbox.MaxEdge.Y, staticbox.MaxEdge.Y) - std::min(movingbox.MinEdge.Y, staticbox.MinEdge.Y),
102 std::max(movingbox.MaxEdge.Z, staticbox.MaxEdge.Z) - std::min(movingbox.MinEdge.Z, staticbox.MinEdge.Z)
105 const f32 dtime_max = *dtime;
106 f32 inner_margin; // the distance of clipping recovery
112 distance = relbox.MaxEdge.Y - relbox.MinEdge.Y;
113 *dtime = distance / std::abs(speed.Y);
114 time = std::max(*dtime, 0.0f);
116 if (*dtime <= dtime_max) {
117 inner_margin = std::max(-0.5f * (staticbox.MaxEdge.Y - staticbox.MinEdge.Y), -2.0f);
119 if ((speed.Y > 0 && staticbox.MinEdge.Y - movingbox.MaxEdge.Y > inner_margin) ||
120 (speed.Y < 0 && movingbox.MinEdge.Y - staticbox.MaxEdge.Y > inner_margin)) {
122 (std::max(movingbox.MaxEdge.X + speed.X * time, staticbox.MaxEdge.X)
123 - std::min(movingbox.MinEdge.X + speed.X * time, staticbox.MinEdge.X)
124 - relbox.MinEdge.X < 0) &&
125 (std::max(movingbox.MaxEdge.Z + speed.Z * time, staticbox.MaxEdge.Z)
126 - std::min(movingbox.MinEdge.Z + speed.Z * time, staticbox.MinEdge.Z)
127 - relbox.MinEdge.Z < 0)
129 return COLLISION_AXIS_Y;
133 return COLLISION_AXIS_NONE;
140 distance = relbox.MaxEdge.X - relbox.MinEdge.X;
141 *dtime = distance / std::abs(speed.X);
142 time = std::max(*dtime, 0.0f);
144 if (*dtime <= dtime_max) {
145 inner_margin = std::max(-0.5f * (staticbox.MaxEdge.X - staticbox.MinEdge.X), -2.0f);
147 if ((speed.X > 0 && staticbox.MinEdge.X - movingbox.MaxEdge.X > inner_margin) ||
148 (speed.X < 0 && movingbox.MinEdge.X - staticbox.MaxEdge.X > inner_margin)) {
150 (std::max(movingbox.MaxEdge.Y + speed.Y * time, staticbox.MaxEdge.Y)
151 - std::min(movingbox.MinEdge.Y + speed.Y * time, staticbox.MinEdge.Y)
152 - relbox.MinEdge.Y < 0) &&
153 (std::max(movingbox.MaxEdge.Z + speed.Z * time, staticbox.MaxEdge.Z)
154 - std::min(movingbox.MinEdge.Z + speed.Z * time, staticbox.MinEdge.Z)
155 - relbox.MinEdge.Z < 0)
157 return COLLISION_AXIS_X;
160 return COLLISION_AXIS_NONE;
167 distance = relbox.MaxEdge.Z - relbox.MinEdge.Z;
168 *dtime = distance / std::abs(speed.Z);
169 time = std::max(*dtime, 0.0f);
171 if (*dtime <= dtime_max) {
172 inner_margin = std::max(-0.5f * (staticbox.MaxEdge.Z - staticbox.MinEdge.Z), -2.0f);
174 if ((speed.Z > 0 && staticbox.MinEdge.Z - movingbox.MaxEdge.Z > inner_margin) ||
175 (speed.Z < 0 && movingbox.MinEdge.Z - staticbox.MaxEdge.Z > inner_margin)) {
177 (std::max(movingbox.MaxEdge.X + speed.X * time, staticbox.MaxEdge.X)
178 - std::min(movingbox.MinEdge.X + speed.X * time, staticbox.MinEdge.X)
179 - relbox.MinEdge.X < 0) &&
180 (std::max(movingbox.MaxEdge.Y + speed.Y * time, staticbox.MaxEdge.Y)
181 - std::min(movingbox.MinEdge.Y + speed.Y * time, staticbox.MinEdge.Y)
182 - relbox.MinEdge.Y < 0)
184 return COLLISION_AXIS_Z;
189 return COLLISION_AXIS_NONE;
193 // Checks if moving the movingbox up by the given distance would hit a ceiling.
194 bool wouldCollideWithCeiling(
195 const std::vector<NearbyCollisionInfo> &cinfo,
196 const aabb3f &movingbox,
197 f32 y_increase, f32 d)
199 //TimeTaker tt("wouldCollideWithCeiling");
201 assert(y_increase >= 0); // pre-condition
203 for (const auto &it : cinfo) {
204 const aabb3f &staticbox = it.box;
205 if ((movingbox.MaxEdge.Y - d <= staticbox.MinEdge.Y) &&
206 (movingbox.MaxEdge.Y + y_increase > staticbox.MinEdge.Y) &&
207 (movingbox.MinEdge.X < staticbox.MaxEdge.X) &&
208 (movingbox.MaxEdge.X > staticbox.MinEdge.X) &&
209 (movingbox.MinEdge.Z < staticbox.MaxEdge.Z) &&
210 (movingbox.MaxEdge.Z > staticbox.MinEdge.Z))
217 static inline void getNeighborConnectingFace(const v3s16 &p,
218 const NodeDefManager *nodedef, Map *map, MapNode n, int v, int *neighbors)
220 MapNode n2 = map->getNode(p);
221 if (nodedef->nodeboxConnects(n, n2, v))
225 collisionMoveResult collisionMoveSimple(Environment *env, IGameDef *gamedef,
226 f32 pos_max_d, const aabb3f &box_0,
227 f32 stepheight, f32 dtime,
228 v3f *pos_f, v3f *speed_f,
229 v3f accel_f, ActiveObject *self,
230 bool collideWithObjects)
232 static bool time_notification_done = false;
233 Map *map = &env->getMap();
235 ScopeProfiler sp(g_profiler, "collisionMoveSimple()", SPT_AVG);
237 collisionMoveResult result;
240 Calculate new velocity
243 if (!time_notification_done) {
244 time_notification_done = true;
245 infostream << "collisionMoveSimple: maximum step interval exceeded,"
246 " lost movement details!"<<std::endl;
250 time_notification_done = false;
252 *speed_f += accel_f * dtime;
254 // If there is no speed, there are no collisions
255 if (speed_f->getLength() == 0)
258 // Limit speed for avoiding hangs
259 speed_f->Y = rangelim(speed_f->Y, -5000, 5000);
260 speed_f->X = rangelim(speed_f->X, -5000, 5000);
261 speed_f->Z = rangelim(speed_f->Z, -5000, 5000);
263 *speed_f = truncate(*speed_f, 10000.0f);
266 Collect node boxes in movement range
268 std::vector<NearbyCollisionInfo> cinfo;
270 //TimeTaker tt2("collisionMoveSimple collect boxes");
271 ScopeProfiler sp2(g_profiler, "collisionMoveSimple(): collect boxes", SPT_AVG);
273 v3f newpos_f = *pos_f + *speed_f * dtime;
275 MYMIN(pos_f->X, newpos_f.X),
276 MYMIN(pos_f->Y, newpos_f.Y) + 0.01f * BS, // bias rounding, player often at +/-n.5
277 MYMIN(pos_f->Z, newpos_f.Z)
280 MYMAX(pos_f->X, newpos_f.X),
281 MYMAX(pos_f->Y, newpos_f.Y),
282 MYMAX(pos_f->Z, newpos_f.Z)
284 v3s16 min = floatToInt(minpos_f + box_0.MinEdge, BS) - v3s16(1, 1, 1);
285 v3s16 max = floatToInt(maxpos_f + box_0.MaxEdge, BS) + v3s16(1, 1, 1);
287 bool any_position_valid = false;
290 for (p.X = min.X; p.X <= max.X; p.X++)
291 for (p.Y = min.Y; p.Y <= max.Y; p.Y++)
292 for (p.Z = min.Z; p.Z <= max.Z; p.Z++) {
293 bool is_position_valid;
294 MapNode n = map->getNode(p, &is_position_valid);
296 if (is_position_valid && n.getContent() != CONTENT_IGNORE) {
297 // Object collides into walkable nodes
299 any_position_valid = true;
300 const NodeDefManager *nodedef = gamedef->getNodeDefManager();
301 const ContentFeatures &f = nodedef->get(n);
306 int n_bouncy_value = itemgroup_get(f.groups, "bouncy");
309 if (f.drawtype == NDT_NODEBOX &&
310 f.node_box.type == NODEBOX_CONNECTED) {
314 getNeighborConnectingFace(p2, nodedef, map, n, 1, &neighbors);
318 getNeighborConnectingFace(p2, nodedef, map, n, 2, &neighbors);
322 getNeighborConnectingFace(p2, nodedef, map, n, 4, &neighbors);
326 getNeighborConnectingFace(p2, nodedef, map, n, 8, &neighbors);
330 getNeighborConnectingFace(p2, nodedef, map, n, 16, &neighbors);
334 getNeighborConnectingFace(p2, nodedef, map, n, 32, &neighbors);
336 std::vector<aabb3f> nodeboxes;
337 n.getCollisionBoxes(gamedef->ndef(), &nodeboxes, neighbors);
339 // Calculate float position only once
340 v3f posf = intToFloat(p, BS);
341 for (auto box : nodeboxes) {
344 cinfo.emplace_back(false, n_bouncy_value, p, box);
347 // Collide with unloaded nodes (position invalid) and loaded
348 // CONTENT_IGNORE nodes (position valid)
349 aabb3f box = getNodeBox(p, BS);
350 cinfo.emplace_back(true, 0, p, box);
354 // Do not move if world has not loaded yet, since custom node boxes
355 // are not available for collision detection.
356 // This also intentionally occurs in the case of the object being positioned
357 // solely on loaded CONTENT_IGNORE nodes, no matter where they come from.
358 if (!any_position_valid) {
359 *speed_f = v3f(0, 0, 0);
365 if(collideWithObjects)
367 /* add object boxes to cinfo */
369 std::vector<ActiveObject*> objects;
371 ClientEnvironment *c_env = dynamic_cast<ClientEnvironment*>(env);
373 // Calculate distance by speed, add own extent and 1.5m of tolerance
374 f32 distance = speed_f->getLength() * dtime +
375 box_0.getExtent().getLength() + 1.5f * BS;
376 std::vector<DistanceSortedActiveObject> clientobjects;
377 c_env->getActiveObjects(*pos_f, distance, clientobjects);
379 for (auto &clientobject : clientobjects) {
380 // Do collide with everything but itself and the parent CAO
381 if (!self || (self != clientobject.obj &&
382 self != clientobject.obj->getParent())) {
383 objects.push_back((ActiveObject*) clientobject.obj);
390 ServerEnvironment *s_env = dynamic_cast<ServerEnvironment*>(env);
392 // Calculate distance by speed, add own extent and 1.5m of tolerance
393 f32 distance = speed_f->getLength() * dtime +
394 box_0.getExtent().getLength() + 1.5f * BS;
396 // search for objects which are not us, or we are not its parent
397 // we directly use the callback to populate the result to prevent
398 // a useless result loop here
399 auto include_obj_cb = [self, &objects] (ServerActiveObject *obj) {
400 if (!obj->isGone() &&
401 (!self || (self != obj && self != obj->getParent()))) {
402 objects.push_back((ActiveObject *)obj);
407 std::vector<ServerActiveObject *> s_objects;
408 s_env->getObjectsInsideRadius(s_objects, *pos_f, distance, include_obj_cb);
412 for (std::vector<ActiveObject*>::const_iterator iter = objects.begin();
413 iter != objects.end(); ++iter) {
414 ActiveObject *object = *iter;
416 if (object && object->collideWithObjects()) {
417 aabb3f object_collisionbox;
418 if (object->getCollisionBox(&object_collisionbox))
419 cinfo.emplace_back(object, 0, object_collisionbox);
424 LocalPlayer *lplayer = c_env->getLocalPlayer();
425 if (lplayer->getParent() == nullptr) {
426 aabb3f lplayer_collisionbox = lplayer->getCollisionbox();
427 v3f lplayer_pos = lplayer->getPosition();
428 lplayer_collisionbox.MinEdge += lplayer_pos;
429 lplayer_collisionbox.MaxEdge += lplayer_pos;
430 ActiveObject *obj = (ActiveObject*) lplayer->getCAO();
431 cinfo.emplace_back(obj, 0, lplayer_collisionbox);
445 while(dtime > BS * 1e-10f) {
446 // Avoid infinite loop
448 if (loopcount >= 100) {
449 warningstream << "collisionMoveSimple: Loop count exceeded, aborting to avoid infiniite loop" << std::endl;
453 aabb3f movingbox = box_0;
454 movingbox.MinEdge += *pos_f;
455 movingbox.MaxEdge += *pos_f;
457 CollisionAxis nearest_collided = COLLISION_AXIS_NONE;
458 f32 nearest_dtime = dtime;
459 int nearest_boxindex = -1;
462 Go through every nodebox, find nearest collision
464 for (u32 boxindex = 0; boxindex < cinfo.size(); boxindex++) {
465 const NearbyCollisionInfo &box_info = cinfo[boxindex];
466 // Ignore if already stepped up this nodebox.
467 if (box_info.is_step_up)
470 // Find nearest collision of the two boxes (raytracing-like)
471 f32 dtime_tmp = nearest_dtime;
472 CollisionAxis collided = axisAlignedCollision(box_info.box,
473 movingbox, *speed_f, &dtime_tmp);
475 if (collided == -1 || dtime_tmp >= nearest_dtime)
478 nearest_dtime = dtime_tmp;
479 nearest_collided = collided;
480 nearest_boxindex = boxindex;
483 if (nearest_collided == COLLISION_AXIS_NONE) {
484 // No collision with any collision box.
485 *pos_f += truncate(*speed_f * dtime, 100.0f);
486 dtime = 0; // Set to 0 to avoid "infinite" loop due to small FP numbers
488 // Otherwise, a collision occurred.
489 NearbyCollisionInfo &nearest_info = cinfo[nearest_boxindex];
490 const aabb3f& cbox = nearest_info.box;
492 //movingbox except moved to the horizontal position it would be after step up
493 aabb3f stepbox = movingbox;
494 stepbox.MinEdge.X += speed_f->X * dtime;
495 stepbox.MinEdge.Z += speed_f->Z * dtime;
496 stepbox.MaxEdge.X += speed_f->X * dtime;
497 stepbox.MaxEdge.Z += speed_f->Z * dtime;
499 bool step_up = (nearest_collided != COLLISION_AXIS_Y) && // must not be Y direction
500 (movingbox.MinEdge.Y < cbox.MaxEdge.Y) &&
501 (movingbox.MinEdge.Y + stepheight > cbox.MaxEdge.Y) &&
502 (!wouldCollideWithCeiling(cinfo, stepbox,
503 cbox.MaxEdge.Y - movingbox.MinEdge.Y,
506 // Get bounce multiplier
507 float bounce = -(float)nearest_info.bouncy / 100.0f;
509 // Move to the point of collision and reduce dtime by nearest_dtime
510 if (nearest_dtime < 0) {
511 // Handle negative nearest_dtime
513 if (nearest_collided == COLLISION_AXIS_X)
514 pos_f->X += speed_f->X * nearest_dtime;
515 if (nearest_collided == COLLISION_AXIS_Y)
516 pos_f->Y += speed_f->Y * nearest_dtime;
517 if (nearest_collided == COLLISION_AXIS_Z)
518 pos_f->Z += speed_f->Z * nearest_dtime;
521 *pos_f += truncate(*speed_f * nearest_dtime, 100.0f);
522 dtime -= nearest_dtime;
525 bool is_collision = true;
526 if (nearest_info.is_unloaded)
527 is_collision = false;
530 if (nearest_info.isObject())
531 info.type = COLLISION_OBJECT;
533 info.type = COLLISION_NODE;
535 info.node_p = nearest_info.position;
536 info.object = nearest_info.obj;
537 info.old_speed = *speed_f;
538 info.plane = nearest_collided;
540 // Set the speed component that caused the collision to zero
542 // Special case: Handle stairs
543 nearest_info.is_step_up = true;
544 is_collision = false;
545 } else if (nearest_collided == COLLISION_AXIS_X) {
546 if (fabs(speed_f->X) > BS * 3)
547 speed_f->X *= bounce;
550 result.collides = true;
551 } else if (nearest_collided == COLLISION_AXIS_Y) {
552 if(fabs(speed_f->Y) > BS * 3)
553 speed_f->Y *= bounce;
556 result.collides = true;
557 } else if (nearest_collided == COLLISION_AXIS_Z) {
558 if (fabs(speed_f->Z) > BS * 3)
559 speed_f->Z *= bounce;
562 result.collides = true;
565 info.new_speed = *speed_f;
566 if (info.new_speed.getDistanceFrom(info.old_speed) < 0.1f * BS)
567 is_collision = false;
570 info.axis = nearest_collided;
571 result.collisions.push_back(info);
577 Final touches: Check if standing on ground, step up stairs.
580 box.MinEdge += *pos_f;
581 box.MaxEdge += *pos_f;
582 for (const auto &box_info : cinfo) {
583 const aabb3f &cbox = box_info.box;
586 See if the object is touching ground.
588 Object touches ground if object's minimum Y is near node's
589 maximum Y and object's X-Z-area overlaps with the node's
593 if (cbox.MaxEdge.X - d > box.MinEdge.X && cbox.MinEdge.X + d < box.MaxEdge.X &&
594 cbox.MaxEdge.Z - d > box.MinEdge.Z &&
595 cbox.MinEdge.Z + d < box.MaxEdge.Z) {
596 if (box_info.is_step_up) {
597 pos_f->Y += cbox.MaxEdge.Y - box.MinEdge.Y;
599 box.MinEdge += *pos_f;
600 box.MaxEdge += *pos_f;
602 if (std::fabs(cbox.MaxEdge.Y - box.MinEdge.Y) < 0.05f) {
603 result.touching_ground = true;
605 if (box_info.isObject())
606 result.standing_on_object = true;