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- /*
- 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 <cmath>
- #include "mapblock.h"
- #include "map.h"
- #include "nodedef.h"
- #include "gamedef.h"
- #ifndef SERVER
- #include "client/clientenvironment.h"
- #include "client/localplayer.h"
- #endif
- #include "serverenvironment.h"
- #include "server/serveractiveobject.h"
- #include "util/timetaker.h"
- #include "profiler.h"
- #ifdef __FAST_MATH__
- #warning "-ffast-math is known to cause bugs in collision code, do not use!"
- #endif
- namespace {
- struct NearbyCollisionInfo {
- // node
- NearbyCollisionInfo(bool is_ul, int bouncy, v3s16 pos, const aabb3f &box) :
- obj(nullptr),
- box(box),
- position(pos),
- bouncy(bouncy),
- is_unloaded(is_ul),
- is_step_up(false)
- {}
- // object
- NearbyCollisionInfo(ActiveObject *obj, int bouncy, const aabb3f &box) :
- obj(obj),
- box(box),
- bouncy(bouncy),
- is_unloaded(false),
- is_step_up(false)
- {}
- inline bool isObject() const { return obj != nullptr; }
- ActiveObject *obj;
- aabb3f box;
- v3s16 position;
- u8 bouncy;
- // bitfield to save space
- bool is_unloaded:1, is_step_up:1;
- };
- // Helper functions:
- // Truncate floating point numbers to specified number of decimal places
- // in order to move all the floating point error to one side of the correct value
- inline f32 truncate(const f32 val, const f32 factor)
- {
- return truncf(val * factor) / factor;
- }
- inline v3f truncate(const v3f vec, const f32 factor)
- {
- return v3f(
- truncate(vec.X, factor),
- truncate(vec.Y, factor),
- truncate(vec.Z, factor)
- );
- }
- }
- // 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.
- CollisionAxis axisAlignedCollision(
- const aabb3f &staticbox, const aabb3f &movingbox,
- const v3f speed, f32 *dtime)
- {
- //TimeTaker tt("axisAlignedCollision");
- aabb3f relbox(
- (movingbox.MaxEdge.X - movingbox.MinEdge.X) + (staticbox.MaxEdge.X - staticbox.MinEdge.X), // sum of the widths
- (movingbox.MaxEdge.Y - movingbox.MinEdge.Y) + (staticbox.MaxEdge.Y - staticbox.MinEdge.Y),
- (movingbox.MaxEdge.Z - movingbox.MinEdge.Z) + (staticbox.MaxEdge.Z - staticbox.MinEdge.Z),
- std::max(movingbox.MaxEdge.X, staticbox.MaxEdge.X) - std::min(movingbox.MinEdge.X, staticbox.MinEdge.X), //outer bounding 'box' dimensions
- std::max(movingbox.MaxEdge.Y, staticbox.MaxEdge.Y) - std::min(movingbox.MinEdge.Y, staticbox.MinEdge.Y),
- std::max(movingbox.MaxEdge.Z, staticbox.MaxEdge.Z) - std::min(movingbox.MinEdge.Z, staticbox.MinEdge.Z)
- );
- const f32 dtime_max = *dtime;
- f32 inner_margin; // the distance of clipping recovery
- f32 distance;
- f32 time;
- if (speed.Y) {
- distance = relbox.MaxEdge.Y - relbox.MinEdge.Y;
- *dtime = distance / std::abs(speed.Y);
- time = std::max(*dtime, 0.0f);
- if (*dtime <= dtime_max) {
- inner_margin = std::max(-0.5f * (staticbox.MaxEdge.Y - staticbox.MinEdge.Y), -2.0f);
- if ((speed.Y > 0 && staticbox.MinEdge.Y - movingbox.MaxEdge.Y > inner_margin) ||
- (speed.Y < 0 && movingbox.MinEdge.Y - staticbox.MaxEdge.Y > inner_margin)) {
- if (
- (std::max(movingbox.MaxEdge.X + speed.X * time, staticbox.MaxEdge.X)
- - std::min(movingbox.MinEdge.X + speed.X * time, staticbox.MinEdge.X)
- - relbox.MinEdge.X < 0) &&
- (std::max(movingbox.MaxEdge.Z + speed.Z * time, staticbox.MaxEdge.Z)
- - std::min(movingbox.MinEdge.Z + speed.Z * time, staticbox.MinEdge.Z)
- - relbox.MinEdge.Z < 0)
- )
- return COLLISION_AXIS_Y;
- }
- }
- else {
- return COLLISION_AXIS_NONE;
- }
- }
- // NO else if here
- if (speed.X) {
- distance = relbox.MaxEdge.X - relbox.MinEdge.X;
- *dtime = distance / std::abs(speed.X);
- time = std::max(*dtime, 0.0f);
- if (*dtime <= dtime_max) {
- inner_margin = std::max(-0.5f * (staticbox.MaxEdge.X - staticbox.MinEdge.X), -2.0f);
- if ((speed.X > 0 && staticbox.MinEdge.X - movingbox.MaxEdge.X > inner_margin) ||
- (speed.X < 0 && movingbox.MinEdge.X - staticbox.MaxEdge.X > inner_margin)) {
- if (
- (std::max(movingbox.MaxEdge.Y + speed.Y * time, staticbox.MaxEdge.Y)
- - std::min(movingbox.MinEdge.Y + speed.Y * time, staticbox.MinEdge.Y)
- - relbox.MinEdge.Y < 0) &&
- (std::max(movingbox.MaxEdge.Z + speed.Z * time, staticbox.MaxEdge.Z)
- - std::min(movingbox.MinEdge.Z + speed.Z * time, staticbox.MinEdge.Z)
- - relbox.MinEdge.Z < 0)
- )
- return COLLISION_AXIS_X;
- }
- } else {
- return COLLISION_AXIS_NONE;
- }
- }
- // NO else if here
- if (speed.Z) {
- distance = relbox.MaxEdge.Z - relbox.MinEdge.Z;
- *dtime = distance / std::abs(speed.Z);
- time = std::max(*dtime, 0.0f);
- if (*dtime <= dtime_max) {
- inner_margin = std::max(-0.5f * (staticbox.MaxEdge.Z - staticbox.MinEdge.Z), -2.0f);
- if ((speed.Z > 0 && staticbox.MinEdge.Z - movingbox.MaxEdge.Z > inner_margin) ||
- (speed.Z < 0 && movingbox.MinEdge.Z - staticbox.MaxEdge.Z > inner_margin)) {
- if (
- (std::max(movingbox.MaxEdge.X + speed.X * time, staticbox.MaxEdge.X)
- - std::min(movingbox.MinEdge.X + speed.X * time, staticbox.MinEdge.X)
- - relbox.MinEdge.X < 0) &&
- (std::max(movingbox.MaxEdge.Y + speed.Y * time, staticbox.MaxEdge.Y)
- - std::min(movingbox.MinEdge.Y + speed.Y * time, staticbox.MinEdge.Y)
- - relbox.MinEdge.Y < 0)
- )
- return COLLISION_AXIS_Z;
- }
- }
- }
- return COLLISION_AXIS_NONE;
- }
- // Helper function:
- // Checks if moving the movingbox up by the given distance would hit a ceiling.
- bool wouldCollideWithCeiling(
- const std::vector<NearbyCollisionInfo> &cinfo,
- const aabb3f &movingbox,
- f32 y_increase, f32 d)
- {
- //TimeTaker tt("wouldCollideWithCeiling");
- assert(y_increase >= 0); // pre-condition
- for (const auto &it : cinfo) {
- const aabb3f &staticbox = it.box;
- 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;
- }
- static inline void getNeighborConnectingFace(const v3s16 &p,
- const NodeDefManager *nodedef, Map *map, MapNode n, int v, int *neighbors)
- {
- MapNode n2 = map->getNode(p);
- if (nodedef->nodeboxConnects(n, n2, v))
- *neighbors |= v;
- }
- 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)
- {
- #define PROFILER_NAME(text) (s_env ? ("Server: " text) : ("Client: " text))
- static bool time_notification_done = false;
- Map *map = &env->getMap();
- ServerEnvironment *s_env = dynamic_cast<ServerEnvironment*>(env);
- ScopeProfiler sp(g_profiler, PROFILER_NAME("collisionMoveSimple()"), SPT_AVG, PRECISION_MICRO);
- collisionMoveResult result;
- /*
- Calculate new velocity
- */
- if (dtime > DTIME_LIMIT) {
- if (!time_notification_done) {
- time_notification_done = true;
- warningstream << "collisionMoveSimple: maximum step interval exceeded,"
- " lost movement details!"<<std::endl;
- }
- dtime = DTIME_LIMIT;
- } else {
- time_notification_done = false;
- }
- v3f dpos_f = (*speed_f + accel_f * 0.5f * dtime) * dtime;
- v3f newpos_f = *pos_f + dpos_f;
- *speed_f += accel_f * dtime;
- // If the object is static, there are no collisions
- if (dpos_f == v3f())
- 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);
- *speed_f = truncate(*speed_f, 10000.0f);
- /*
- Collect node boxes in movement range
- */
- // cached allocation
- thread_local std::vector<NearbyCollisionInfo> cinfo;
- cinfo.clear();
- {
- v3f minpos_f(
- MYMIN(pos_f->X, newpos_f.X),
- MYMIN(pos_f->Y, newpos_f.Y) + 0.01f * BS, // bias rounding, player often at +/-n.5
- MYMIN(pos_f->Z, newpos_f.Z)
- );
- v3f maxpos_f(
- MYMAX(pos_f->X, newpos_f.X),
- MYMAX(pos_f->Y, newpos_f.Y),
- MYMAX(pos_f->Z, newpos_f.Z)
- );
- v3s16 min = floatToInt(minpos_f + box_0.MinEdge, BS) - v3s16(1, 1, 1);
- v3s16 max = floatToInt(maxpos_f + box_0.MaxEdge, BS) + v3s16(1, 1, 1);
- const auto *nodedef = gamedef->getNodeDefManager();
- bool any_position_valid = false;
- thread_local std::vector<aabb3f> nodeboxes;
- v3s16 p;
- for (p.Z = min.Z; p.Z <= max.Z; p.Z++)
- for (p.Y = min.Y; p.Y <= max.Y; p.Y++)
- for (p.X = min.X; p.X <= max.X; p.X++) {
- bool is_position_valid;
- MapNode n = map->getNode(p, &is_position_valid);
- if (is_position_valid && n.getContent() != CONTENT_IGNORE) {
- // Object collides into walkable nodes
- any_position_valid = true;
- const ContentFeatures &f = nodedef->get(n);
- if (!f.walkable)
- continue;
- // Negative bouncy may have a meaning, but we need +value here.
- int n_bouncy_value = abs(itemgroup_get(f.groups, "bouncy"));
- u8 neighbors = n.getNeighbors(p, map);
- nodeboxes.clear();
- n.getCollisionBoxes(nodedef, &nodeboxes, neighbors);
- // Calculate float position only once
- v3f posf = intToFloat(p, BS);
- for (auto box : nodeboxes) {
- box.MinEdge += posf;
- box.MaxEdge += posf;
- cinfo.emplace_back(false, n_bouncy_value, p, box);
- }
- } else {
- // Collide with unloaded nodes (position invalid) and loaded
- // CONTENT_IGNORE nodes (position valid)
- aabb3f box = getNodeBox(p, BS);
- cinfo.emplace_back(true, 0, p, box);
- }
- }
- // Do not move if world has not loaded yet, since custom node boxes
- // are not available for collision detection.
- // This also intentionally occurs in the case of the object being positioned
- // solely on loaded CONTENT_IGNORE nodes, no matter where they come from.
- if (!any_position_valid) {
- *speed_f = v3f(0, 0, 0);
- return result;
- }
- }
- /*
- Collect object boxes in movement range
- */
- auto process_object = [] (ActiveObject *object) {
- if (object && object->collideWithObjects()) {
- aabb3f box;
- if (object->getCollisionBox(&box))
- cinfo.emplace_back(object, 0, box);
- }
- };
- if (collideWithObjects) {
- // Calculate distance by speed, add own extent and 1.5m of tolerance
- const f32 distance = speed_f->getLength() * dtime +
- box_0.getExtent().getLength() + 1.5f * BS;
- #ifndef SERVER
- ClientEnvironment *c_env = dynamic_cast<ClientEnvironment*>(env);
- if (c_env) {
- std::vector<DistanceSortedActiveObject> clientobjects;
- c_env->getActiveObjects(*pos_f, distance, clientobjects);
- for (auto &clientobject : clientobjects) {
- // Do collide with everything but itself and the parent CAO
- if (!self || (self != clientobject.obj &&
- self != clientobject.obj->getParent())) {
- process_object(clientobject.obj);
- }
- }
- // add collision with local player
- LocalPlayer *lplayer = c_env->getLocalPlayer();
- if (lplayer->getParent() == nullptr) {
- aabb3f lplayer_collisionbox = lplayer->getCollisionbox();
- v3f lplayer_pos = lplayer->getPosition();
- lplayer_collisionbox.MinEdge += lplayer_pos;
- lplayer_collisionbox.MaxEdge += lplayer_pos;
- auto *obj = (ActiveObject*) lplayer->getCAO();
- cinfo.emplace_back(obj, 0, lplayer_collisionbox);
- }
- }
- else
- #endif
- if (s_env) {
- // search for objects which are not us, or we are not its parent.
- // we directly process the object in this callback to avoid useless
- // looping afterwards.
- auto include_obj_cb = [self, &process_object] (ServerActiveObject *obj) {
- if (!obj->isGone() &&
- (!self || (self != obj && self != obj->getParent()))) {
- process_object(obj);
- }
- return false;
- };
- // nothing is put into this vector
- std::vector<ServerActiveObject*> s_objects;
- s_env->getObjectsInsideRadius(s_objects, *pos_f, distance, include_obj_cb);
- }
- }
- /*
- Collision detection
- */
- f32 d = 0.0f;
- int loopcount = 0;
- while(dtime > BS * 1e-10f) {
- // Avoid infinite loop
- loopcount++;
- if (loopcount >= 100) {
- warningstream << "collisionMoveSimple: Loop count exceeded, aborting to avoid infiniite loop" << std::endl;
- break;
- }
- aabb3f movingbox = box_0;
- movingbox.MinEdge += *pos_f;
- movingbox.MaxEdge += *pos_f;
- CollisionAxis nearest_collided = COLLISION_AXIS_NONE;
- f32 nearest_dtime = dtime;
- int nearest_boxindex = -1;
- /*
- Go through every nodebox, find nearest collision
- */
- for (u32 boxindex = 0; boxindex < cinfo.size(); boxindex++) {
- const NearbyCollisionInfo &box_info = cinfo[boxindex];
- // Ignore if already stepped up this nodebox.
- if (box_info.is_step_up)
- continue;
- // Find nearest collision of the two boxes (raytracing-like)
- f32 dtime_tmp = nearest_dtime;
- CollisionAxis collided = axisAlignedCollision(box_info.box,
- movingbox, *speed_f, &dtime_tmp);
- if (collided == -1 || dtime_tmp >= nearest_dtime)
- continue;
- nearest_dtime = dtime_tmp;
- nearest_collided = collided;
- nearest_boxindex = boxindex;
- }
- if (nearest_collided == COLLISION_AXIS_NONE) {
- // No collision with any collision box.
- *pos_f += truncate(*speed_f * dtime, 100.0f);
- dtime = 0; // Set to 0 to avoid "infinite" loop due to small FP numbers
- } else {
- // Otherwise, a collision occurred.
- NearbyCollisionInfo &nearest_info = cinfo[nearest_boxindex];
- const aabb3f& cbox = nearest_info.box;
- //movingbox except moved to the horizontal position it would be after step up
- aabb3f stepbox = movingbox;
- stepbox.MinEdge.X += speed_f->X * dtime;
- stepbox.MinEdge.Z += speed_f->Z * dtime;
- stepbox.MaxEdge.X += speed_f->X * dtime;
- stepbox.MaxEdge.Z += speed_f->Z * dtime;
- // Check for stairs.
- bool step_up = (nearest_collided != COLLISION_AXIS_Y) && // must not be Y direction
- (movingbox.MinEdge.Y < cbox.MaxEdge.Y) &&
- (movingbox.MinEdge.Y + stepheight > cbox.MaxEdge.Y) &&
- (!wouldCollideWithCeiling(cinfo, stepbox,
- cbox.MaxEdge.Y - movingbox.MinEdge.Y,
- d));
- // Get bounce multiplier
- float bounce = -(float)nearest_info.bouncy / 100.0f;
- // Move to the point of collision and reduce dtime by nearest_dtime
- if (nearest_dtime < 0) {
- // Handle negative nearest_dtime
- if (!step_up) {
- if (nearest_collided == COLLISION_AXIS_X)
- pos_f->X += speed_f->X * nearest_dtime;
- if (nearest_collided == COLLISION_AXIS_Y)
- pos_f->Y += speed_f->Y * nearest_dtime;
- if (nearest_collided == COLLISION_AXIS_Z)
- pos_f->Z += speed_f->Z * nearest_dtime;
- }
- } else {
- *pos_f += truncate(*speed_f * nearest_dtime, 100.0f);
- dtime -= nearest_dtime;
- }
- bool is_collision = true;
- if (nearest_info.is_unloaded)
- is_collision = false;
- CollisionInfo info;
- if (nearest_info.isObject())
- info.type = COLLISION_OBJECT;
- else
- info.type = COLLISION_NODE;
- info.node_p = nearest_info.position;
- info.object = nearest_info.obj;
- info.old_speed = *speed_f;
- info.plane = nearest_collided;
- // Set the speed component that caused the collision to zero
- if (step_up) {
- // Special case: Handle stairs
- nearest_info.is_step_up = true;
- is_collision = false;
- } else if (nearest_collided == COLLISION_AXIS_X) {
- if (fabs(speed_f->X) > BS * 3)
- speed_f->X *= bounce;
- else
- speed_f->X = 0;
- result.collides = true;
- } else if (nearest_collided == COLLISION_AXIS_Y) {
- if(fabs(speed_f->Y) > BS * 3)
- speed_f->Y *= bounce;
- else
- speed_f->Y = 0;
- result.collides = true;
- } else if (nearest_collided == COLLISION_AXIS_Z) {
- if (fabs(speed_f->Z) > BS * 3)
- speed_f->Z *= bounce;
- else
- speed_f->Z = 0;
- result.collides = true;
- }
- info.new_speed = *speed_f;
- if (info.new_speed.getDistanceFrom(info.old_speed) < 0.1f * BS)
- is_collision = false;
- if (is_collision) {
- info.axis = nearest_collided;
- result.collisions.push_back(std::move(info));
- }
- }
- }
- /*
- Final touches: Check if standing on ground, step up stairs.
- */
- aabb3f box = box_0;
- box.MinEdge += *pos_f;
- box.MaxEdge += *pos_f;
- for (const auto &box_info : cinfo) {
- const aabb3f &cbox = box_info.box;
- /*
- 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.
- */
- 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 (box_info.is_step_up) {
- pos_f->Y += cbox.MaxEdge.Y - box.MinEdge.Y;
- box = box_0;
- box.MinEdge += *pos_f;
- box.MaxEdge += *pos_f;
- }
- if (std::fabs(cbox.MaxEdge.Y - box.MinEdge.Y) < 0.05f) {
- result.touching_ground = true;
- if (box_info.isObject())
- result.standing_on_object = true;
- }
- }
- }
- return result;
- }
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