minetest/src/clientenvironment.cpp

/*
Minetest
Copyright (C) 2010-2017 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 "util/serialize.h"
#include "util/pointedthing.h"
#include "clientenvironment.h"
#include "clientsimpleobject.h"
#include "clientmap.h"
#include "scripting_client.h"
#include "mapblock_mesh.h"
#include "event.h"
#include "collision.h"
#include "profiler.h"
#include "raycast.h"
#include "voxelalgorithms.h"
#include "settings.h"
#include <algorithm>

/*
	ClientEnvironment
*/

ClientEnvironment::ClientEnvironment(ClientMap *map, scene::ISceneManager *smgr,
	ITextureSource *texturesource, Client *client,
	IrrlichtDevice *irr):
	Environment(client),
	m_map(map),
	m_smgr(smgr),
	m_texturesource(texturesource),
	m_client(client),
	m_irr(irr)
{
	char zero = 0;
	memset(attachement_parent_ids, zero, sizeof(attachement_parent_ids));
}

ClientEnvironment::~ClientEnvironment()
{
	// delete active objects
	for (ClientActiveObjectMap::iterator i = m_active_objects.begin();
			i != m_active_objects.end(); ++i) {
		delete i->second;
	}

	for(std::vector<ClientSimpleObject*>::iterator
		i = m_simple_objects.begin(); i != m_simple_objects.end(); ++i) {
		delete *i;
	}

	// Drop/delete map
	m_map->drop();

	delete m_local_player;
}

Map & ClientEnvironment::getMap()
{
	return *m_map;
}

ClientMap & ClientEnvironment::getClientMap()
{
	return *m_map;
}

void ClientEnvironment::setLocalPlayer(LocalPlayer *player)
{
	DSTACK(FUNCTION_NAME);
	/*
		It is a failure if already is a local player
	*/
	FATAL_ERROR_IF(m_local_player != NULL,
		"Local player already allocated");

	m_local_player = player;
}

void ClientEnvironment::step(float dtime)
{
	DSTACK(FUNCTION_NAME);

	/* Step time of day */
	stepTimeOfDay(dtime);

	// Get some settings
	bool fly_allowed = m_client->checkLocalPrivilege("fly");
	bool free_move = fly_allowed && g_settings->getBool("free_move");

	// Get local player
	LocalPlayer *lplayer = getLocalPlayer();
	assert(lplayer);
	// collision info queue
	std::vector<CollisionInfo> player_collisions;

	/*
		Get the speed the player is going
	*/
	bool is_climbing = lplayer->is_climbing;

	f32 player_speed = lplayer->getSpeed().getLength();

	/*
		Maximum position increment
	*/
	//f32 position_max_increment = 0.05*BS;
	f32 position_max_increment = 0.1*BS;

	// Maximum time increment (for collision detection etc)
	// time = distance / speed
	f32 dtime_max_increment = 1;
	if(player_speed > 0.001)
		dtime_max_increment = position_max_increment / player_speed;

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

	// Don't allow overly huge dtime
	if(dtime > 0.5)
		dtime = 0.5;

	f32 dtime_downcount = dtime;

	/*
		Stuff that has a maximum time increment
	*/

	u32 loopcount = 0;
	do
	{
		loopcount++;

		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;
		}

		/*
			Handle local player
		*/

		{
			// Apply physics
			if(!free_move && !is_climbing)
			{
				// Gravity
				v3f speed = lplayer->getSpeed();
				if(!lplayer->in_liquid)
					speed.Y -= lplayer->movement_gravity * lplayer->physics_override_gravity * dtime_part * 2;

				// Liquid floating / sinking
				if(lplayer->in_liquid && !lplayer->swimming_vertical)
					speed.Y -= lplayer->movement_liquid_sink * dtime_part * 2;

				// Liquid resistance
				if(lplayer->in_liquid_stable || lplayer->in_liquid)
				{
					// How much the node's viscosity blocks movement, ranges between 0 and 1
					// Should match the scale at which viscosity increase affects other liquid attributes
					const f32 viscosity_factor = 0.3;

					v3f d_wanted = -speed / lplayer->movement_liquid_fluidity;
					f32 dl = d_wanted.getLength();
					if(dl > lplayer->movement_liquid_fluidity_smooth)
						dl = lplayer->movement_liquid_fluidity_smooth;
					dl *= (lplayer->liquid_viscosity * viscosity_factor) + (1 - viscosity_factor);

					v3f d = d_wanted.normalize() * dl;
					speed += d;
				}

				lplayer->setSpeed(speed);
			}

			/*
				Move the lplayer.
				This also does collision detection.
			*/
			lplayer->move(dtime_part, this, position_max_increment,
				&player_collisions);
		}
	}
	while(dtime_downcount > 0.001);

	//std::cout<<"Looped "<<loopcount<<" times."<<std::endl;

	for(std::vector<CollisionInfo>::iterator i = player_collisions.begin();
		i != player_collisions.end(); ++i) {
		CollisionInfo &info = *i;
		v3f speed_diff = info.new_speed - info.old_speed;;
		// Handle only fall damage
		// (because otherwise walking against something in fast_move kills you)
		if(speed_diff.Y < 0 || info.old_speed.Y >= 0)
			continue;
		// Get rid of other components
		speed_diff.X = 0;
		speed_diff.Z = 0;
		f32 pre_factor = 1; // 1 hp per node/s
		f32 tolerance = BS*14; // 5 without damage
		f32 post_factor = 1; // 1 hp per node/s
		if(info.type == COLLISION_NODE)
		{
			const ContentFeatures &f = m_client->ndef()->
				get(m_map->getNodeNoEx(info.node_p));
			// Determine fall damage multiplier
			int addp = itemgroup_get(f.groups, "fall_damage_add_percent");
			pre_factor = 1.0 + (float)addp/100.0;
		}
		float speed = pre_factor * speed_diff.getLength();
		if (speed > tolerance) {
			f32 damage_f = (speed - tolerance) / BS * post_factor;
			u8 damage = (u8)MYMIN(damage_f + 0.5, 255);
			if (damage != 0) {
				damageLocalPlayer(damage, true);
				MtEvent *e = new SimpleTriggerEvent("PlayerFallingDamage");
				m_client->event()->put(e);
			}
		}
	}

	if (m_client->moddingEnabled()) {
		m_script->environment_step(dtime);
	}

	// Protocol v29 make this behaviour obsolete
	if (getGameDef()->getProtoVersion() < 29) {
		if (m_lava_hurt_interval.step(dtime, 1.0)) {
			v3f pf = lplayer->getPosition();

			// Feet, middle and head
			v3s16 p1 = floatToInt(pf + v3f(0, BS * 0.1, 0), BS);
			MapNode n1 = m_map->getNodeNoEx(p1);
			v3s16 p2 = floatToInt(pf + v3f(0, BS * 0.8, 0), BS);
			MapNode n2 = m_map->getNodeNoEx(p2);
			v3s16 p3 = floatToInt(pf + v3f(0, BS * 1.6, 0), BS);
			MapNode n3 = m_map->getNodeNoEx(p3);

			u32 damage_per_second = 0;
			damage_per_second = MYMAX(damage_per_second,
				m_client->ndef()->get(n1).damage_per_second);
			damage_per_second = MYMAX(damage_per_second,
				m_client->ndef()->get(n2).damage_per_second);
			damage_per_second = MYMAX(damage_per_second,
				m_client->ndef()->get(n3).damage_per_second);

			if (damage_per_second != 0)
				damageLocalPlayer(damage_per_second, true);
		}

		/*
			Drowning
		*/
		if (m_drowning_interval.step(dtime, 2.0)) {
			v3f pf = lplayer->getPosition();

			// head
			v3s16 p = floatToInt(pf + v3f(0, BS * 1.6, 0), BS);
			MapNode n = m_map->getNodeNoEx(p);
			ContentFeatures c = m_client->ndef()->get(n);
			u8 drowning_damage = c.drowning;
			if (drowning_damage > 0 && lplayer->hp > 0) {
				u16 breath = lplayer->getBreath();
				if (breath > 10) {
					breath = 11;
				}
				if (breath > 0) {
					breath -= 1;
				}
				lplayer->setBreath(breath);
				updateLocalPlayerBreath(breath);
			}

			if (lplayer->getBreath() == 0 && drowning_damage > 0) {
				damageLocalPlayer(drowning_damage, true);
			}
		}
		if (m_breathing_interval.step(dtime, 0.5)) {
			v3f pf = lplayer->getPosition();

			// head
			v3s16 p = floatToInt(pf + v3f(0, BS * 1.6, 0), BS);
			MapNode n = m_map->getNodeNoEx(p);
			ContentFeatures c = m_client->ndef()->get(n);
			if (!lplayer->hp) {
				lplayer->setBreath(11);
			} else if (c.drowning == 0) {
				u16 breath = lplayer->getBreath();
				if (breath <= 10) {
					breath += 1;
					lplayer->setBreath(breath);
					updateLocalPlayerBreath(breath);
				}
			}
		}
	}

	// Update lighting on local player (used for wield item)
	u32 day_night_ratio = getDayNightRatio();
	{
		// Get node at head

		// On InvalidPositionException, use this as default
		// (day: LIGHT_SUN, night: 0)
		MapNode node_at_lplayer(CONTENT_AIR, 0x0f, 0);

		v3s16 p = lplayer->getLightPosition();
		node_at_lplayer = m_map->getNodeNoEx(p);

		u16 light = getInteriorLight(node_at_lplayer, 0, m_client->ndef());
		final_color_blend(&lplayer->light_color, light, day_night_ratio);
	}

	/*
		Step active objects and update lighting of them
	*/

	g_profiler->avg("CEnv: num of objects", m_active_objects.size());
	bool update_lighting = m_active_object_light_update_interval.step(dtime, 0.21);
	for (ClientActiveObjectMap::iterator i = m_active_objects.begin();
			i != m_active_objects.end(); ++i) {
		ClientActiveObject* obj = i->second;
		// Step object
		obj->step(dtime, this);

		if(update_lighting)
		{
			// Update lighting
			u8 light = 0;
			bool pos_ok;

			// Get node at head
			v3s16 p = obj->getLightPosition();
			MapNode n = m_map->getNodeNoEx(p, &pos_ok);
			if (pos_ok)
				light = n.getLightBlend(day_night_ratio, m_client->ndef());
			else
				light = blend_light(day_night_ratio, LIGHT_SUN, 0);

			obj->updateLight(light);
		}
	}

	/*
		Step and handle simple objects
	*/
	g_profiler->avg("CEnv: num of simple objects", m_simple_objects.size());
	for(std::vector<ClientSimpleObject*>::iterator
		i = m_simple_objects.begin(); i != m_simple_objects.end();) {
		std::vector<ClientSimpleObject*>::iterator cur = i;
		ClientSimpleObject *simple = *cur;

		simple->step(dtime);
		if(simple->m_to_be_removed) {
			delete simple;
			i = m_simple_objects.erase(cur);
		}
		else {
			++i;
		}
	}
}

void ClientEnvironment::addSimpleObject(ClientSimpleObject *simple)
{
	m_simple_objects.push_back(simple);
}

GenericCAO* ClientEnvironment::getGenericCAO(u16 id)
{
	ClientActiveObject *obj = getActiveObject(id);
	if (obj && obj->getType() == ACTIVEOBJECT_TYPE_GENERIC)
		return (GenericCAO*) obj;
	else
		return NULL;
}

ClientActiveObject* ClientEnvironment::getActiveObject(u16 id)
{
	ClientActiveObjectMap::iterator n = m_active_objects.find(id);
	if (n == m_active_objects.end())
		return NULL;
	return n->second;
}

bool isFreeClientActiveObjectId(const u16 id,
	ClientActiveObjectMap &objects)
{
	if(id == 0)
		return false;

	return objects.find(id) == objects.end();
}

u16 getFreeClientActiveObjectId(ClientActiveObjectMap &objects)
{
	//try to reuse id's as late as possible
	static u16 last_used_id = 0;
	u16 startid = last_used_id;
	for(;;) {
		last_used_id ++;
		if (isFreeClientActiveObjectId(last_used_id, objects))
			return last_used_id;

		if (last_used_id == startid)
			return 0;
	}
}

u16 ClientEnvironment::addActiveObject(ClientActiveObject *object)
{
	assert(object); // Pre-condition
	if(object->getId() == 0)
	{
		u16 new_id = getFreeClientActiveObjectId(m_active_objects);
		if(new_id == 0)
		{
			infostream<<"ClientEnvironment::addActiveObject(): "
				<<"no free ids available"<<std::endl;
			delete object;
			return 0;
		}
		object->setId(new_id);
	}
	if (!isFreeClientActiveObjectId(object->getId(), m_active_objects)) {
		infostream<<"ClientEnvironment::addActiveObject(): "
			<<"id is not free ("<<object->getId()<<")"<<std::endl;
		delete object;
		return 0;
	}
	infostream<<"ClientEnvironment::addActiveObject(): "
		<<"added (id="<<object->getId()<<")"<<std::endl;
	m_active_objects[object->getId()] = object;
	object->addToScene(m_smgr, m_texturesource, m_irr);
	{ // Update lighting immediately
		u8 light = 0;
		bool pos_ok;

		// Get node at head
		v3s16 p = object->getLightPosition();
		MapNode n = m_map->getNodeNoEx(p, &pos_ok);
		if (pos_ok)
			light = n.getLightBlend(getDayNightRatio(), m_client->ndef());
		else
			light = blend_light(getDayNightRatio(), LIGHT_SUN, 0);

		object->updateLight(light);
	}
	return object->getId();
}

void ClientEnvironment::addActiveObject(u16 id, u8 type,
	const std::string &init_data)
{
	ClientActiveObject* obj =
		ClientActiveObject::create((ActiveObjectType) type, m_client, this);
	if(obj == NULL)
	{
		infostream<<"ClientEnvironment::addActiveObject(): "
			<<"id="<<id<<" type="<<type<<": Couldn't create object"
			<<std::endl;
		return;
	}

	obj->setId(id);

	try
	{
		obj->initialize(init_data);
	}
	catch(SerializationError &e)
	{
		errorstream<<"ClientEnvironment::addActiveObject():"
			<<" id="<<id<<" type="<<type
			<<": SerializationError in initialize(): "
			<<e.what()
			<<": init_data="<<serializeJsonString(init_data)
			<<std::endl;
	}

	addActiveObject(obj);
}

void ClientEnvironment::removeActiveObject(u16 id)
{
	verbosestream<<"ClientEnvironment::removeActiveObject(): "
		<<"id="<<id<<std::endl;
	ClientActiveObject* obj = getActiveObject(id);
	if (obj == NULL) {
		infostream<<"ClientEnvironment::removeActiveObject(): "
			<<"id="<<id<<" not found"<<std::endl;
		return;
	}
	obj->removeFromScene(true);
	delete obj;
	m_active_objects.erase(id);
}

void ClientEnvironment::processActiveObjectMessage(u16 id, const std::string &data)
{
	ClientActiveObject *obj = getActiveObject(id);
	if (obj == NULL) {
		infostream << "ClientEnvironment::processActiveObjectMessage():"
			<< " got message for id=" << id << ", which doesn't exist."
			<< std::endl;
		return;
	}

	try {
		obj->processMessage(data);
	} catch (SerializationError &e) {
		errorstream<<"ClientEnvironment::processActiveObjectMessage():"
			<< " id=" << id << " type=" << obj->getType()
			<< " SerializationError in processMessage(): " << e.what()
			<< std::endl;
	}
}

/*
	Callbacks for activeobjects
*/

void ClientEnvironment::damageLocalPlayer(u8 damage, bool handle_hp)
{
	LocalPlayer *lplayer = getLocalPlayer();
	assert(lplayer);

	if (handle_hp) {
		if (lplayer->hp > damage)
			lplayer->hp -= damage;
		else
			lplayer->hp = 0;
	}

	ClientEnvEvent event;
	event.type = CEE_PLAYER_DAMAGE;
	event.player_damage.amount = damage;
	event.player_damage.send_to_server = handle_hp;
	m_client_event_queue.push(event);
}

void ClientEnvironment::updateLocalPlayerBreath(u16 breath)
{
	ClientEnvEvent event;
	event.type = CEE_PLAYER_BREATH;
	event.player_breath.amount = breath;
	m_client_event_queue.push(event);
}

/*
	Client likes to call these
*/

void ClientEnvironment::getActiveObjects(v3f origin, f32 max_d,
	std::vector<DistanceSortedActiveObject> &dest)
{
	for (ClientActiveObjectMap::iterator i = m_active_objects.begin();
			i != m_active_objects.end(); ++i) {
		ClientActiveObject* obj = i->second;

		f32 d = (obj->getPosition() - origin).getLength();

		if(d > max_d)
			continue;

		DistanceSortedActiveObject dso(obj, d);

		dest.push_back(dso);
	}
}

ClientEnvEvent ClientEnvironment::getClientEnvEvent()
{
	FATAL_ERROR_IF(m_client_event_queue.empty(),
			"ClientEnvironment::getClientEnvEvent(): queue is empty");

	ClientEnvEvent event = m_client_event_queue.front();
	m_client_event_queue.pop();
	return event;
}

ClientActiveObject * ClientEnvironment::getSelectedActiveObject(
	const core::line3d<f32> &shootline_on_map, v3f *intersection_point,
	v3s16 *intersection_normal)
{
	std::vector<DistanceSortedActiveObject> objects;
	getActiveObjects(shootline_on_map.start,
		shootline_on_map.getLength() + 3, objects);
	const v3f line_vector = shootline_on_map.getVector();

	// Sort them.
	// After this, the closest object is the first in the array.
	std::sort(objects.begin(), objects.end());

	/* Because objects can have different nodebox sizes,
	 * the object whose center is the nearest isn't necessarily
	 * the closest one. If an object is found, don't stop
	 * immediately. */

	f32 d_min = shootline_on_map.getLength();
	ClientActiveObject *nearest_obj = NULL;
	for (u32 i = 0; i < objects.size(); i++) {
		ClientActiveObject *obj = objects[i].obj;

		aabb3f *selection_box = obj->getSelectionBox();
		if (selection_box == NULL)
			continue;

		v3f pos = obj->getPosition();

		aabb3f offsetted_box(selection_box->MinEdge + pos,
			selection_box->MaxEdge + pos);

		if (offsetted_box.getCenter().getDistanceFrom(
			shootline_on_map.start) > d_min + 9.6f*BS) {
			// Probably there is no active object that has bigger nodebox than
			// (-5.5,-5.5,-5.5,5.5,5.5,5.5)
			// 9.6 > 5.5*sqrt(3)
			break;
		}

		v3f current_intersection;
		v3s16 current_normal;
		if (boxLineCollision(offsetted_box, shootline_on_map.start, line_vector,
			&current_intersection, &current_normal)) {
			f32 d_current = current_intersection.getDistanceFrom(
				shootline_on_map.start);
			if (d_current <= d_min) {
				d_min = d_current;
				nearest_obj = obj;
				*intersection_point = current_intersection;
				*intersection_normal = current_normal;
			}
		}
	}

	return nearest_obj;
}

/*
	Check if a node is pointable
*/
static inline bool isPointableNode(const MapNode &n,
	INodeDefManager *ndef, bool liquids_pointable)
{
	const ContentFeatures &features = ndef->get(n);
	return features.pointable ||
		(liquids_pointable && features.isLiquid());
}

PointedThing ClientEnvironment::getPointedThing(
	core::line3d<f32> shootline,
	bool liquids_pointable,
	bool look_for_object)
{
	PointedThing result;

	INodeDefManager *nodedef = m_map->getNodeDefManager();

	core::aabbox3d<s16> maximal_exceed = nodedef->getSelectionBoxIntUnion();
	// The code needs to search these nodes
	core::aabbox3d<s16> search_range(-maximal_exceed.MaxEdge,
		-maximal_exceed.MinEdge);
	// If a node is found, there might be a larger node behind.
	// To find it, we have to go further.
	s16 maximal_overcheck =
		std::max(abs(search_range.MinEdge.X), abs(search_range.MaxEdge.X))
			+ std::max(abs(search_range.MinEdge.Y), abs(search_range.MaxEdge.Y))
			+ std::max(abs(search_range.MinEdge.Z), abs(search_range.MaxEdge.Z));

	const v3f original_vector = shootline.getVector();
	const f32 original_length = original_vector.getLength();

	f32 min_distance = original_length;

	// First try to find an active object
	if (look_for_object) {
		ClientActiveObject *selected_object = getSelectedActiveObject(
			shootline, &result.intersection_point,
			&result.intersection_normal);

		if (selected_object != NULL) {
			min_distance =
				(result.intersection_point - shootline.start).getLength();

			result.type = POINTEDTHING_OBJECT;
			result.object_id = selected_object->getId();
		}
	}

	// Reduce shootline
	if (original_length > 0) {
		shootline.end = shootline.start
			+ shootline.getVector() / original_length * min_distance;
	}

	// Try to find a node that is closer than the selected active
	// object (if it exists).

	voxalgo::VoxelLineIterator iterator(shootline.start / BS,
		shootline.getVector() / BS);
	v3s16 oldnode = iterator.m_current_node_pos;
	// Indicates that a node was found.
	bool is_node_found = false;
	// If a node is found, it is possible that there's a node
	// behind it with a large nodebox, so continue the search.
	u16 node_foundcounter = 0;
	// If a node is found, this is the center of the
	// first nodebox the shootline meets.
	v3f found_boxcenter(0, 0, 0);
	// The untested nodes are in this range.
	core::aabbox3d<s16> new_nodes;
	while (true) {
		// Test the nodes around the current node in search_range.
		new_nodes = search_range;
		new_nodes.MinEdge += iterator.m_current_node_pos;
		new_nodes.MaxEdge += iterator.m_current_node_pos;

		// Only check new nodes
		v3s16 delta = iterator.m_current_node_pos - oldnode;
		if (delta.X > 0)
			new_nodes.MinEdge.X = new_nodes.MaxEdge.X;
		else if (delta.X < 0)
			new_nodes.MaxEdge.X = new_nodes.MinEdge.X;
		else if (delta.Y > 0)
			new_nodes.MinEdge.Y = new_nodes.MaxEdge.Y;
		else if (delta.Y < 0)
			new_nodes.MaxEdge.Y = new_nodes.MinEdge.Y;
		else if (delta.Z > 0)
			new_nodes.MinEdge.Z = new_nodes.MaxEdge.Z;
		else if (delta.Z < 0)
			new_nodes.MaxEdge.Z = new_nodes.MinEdge.Z;

		// For each untested node
		for (s16 x = new_nodes.MinEdge.X; x <= new_nodes.MaxEdge.X; x++) {
			for (s16 y = new_nodes.MinEdge.Y; y <= new_nodes.MaxEdge.Y; y++) {
				for (s16 z = new_nodes.MinEdge.Z; z <= new_nodes.MaxEdge.Z; z++) {
					MapNode n;
					v3s16 np(x, y, z);
					bool is_valid_position;

					n = m_map->getNodeNoEx(np, &is_valid_position);
					if (!(is_valid_position &&
						isPointableNode(n, nodedef, liquids_pointable))) {
						continue;
					}
					std::vector<aabb3f> boxes;
					n.getSelectionBoxes(nodedef, &boxes,
						n.getNeighbors(np, m_map));

					v3f npf = intToFloat(np, BS);
					for (std::vector<aabb3f>::const_iterator i = boxes.begin();
						i != boxes.end(); ++i) {
						aabb3f box = *i;
						box.MinEdge += npf;
						box.MaxEdge += npf;
						v3f intersection_point;
						v3s16 intersection_normal;
						if (!boxLineCollision(box, shootline.start, shootline.getVector(),
							&intersection_point, &intersection_normal)) {
							continue;
						}
						f32 distance = (intersection_point - shootline.start).getLength();
						if (distance >= min_distance) {
							continue;
						}
						result.type = POINTEDTHING_NODE;
						result.node_undersurface = np;
						result.intersection_point = intersection_point;
						result.intersection_normal = intersection_normal;
						found_boxcenter = box.getCenter();
						min_distance = distance;
						is_node_found = true;
					}
				}
			}
		}
		if (is_node_found) {
			node_foundcounter++;
			if (node_foundcounter > maximal_overcheck) {
				break;
			}
		}
		// Next node
		if (iterator.hasNext()) {
			oldnode = iterator.m_current_node_pos;
			iterator.next();
		} else {
			break;
		}
	}

	if (is_node_found) {
		// Set undersurface and abovesurface nodes
		f32 d = 0.002 * BS;
		v3f fake_intersection = result.intersection_point;
		// Move intersection towards its source block.
		if (fake_intersection.X < found_boxcenter.X)
			fake_intersection.X += d;
		else
			fake_intersection.X -= d;

		if (fake_intersection.Y < found_boxcenter.Y)
			fake_intersection.Y += d;
		else
			fake_intersection.Y -= d;

		if (fake_intersection.Z < found_boxcenter.Z)
			fake_intersection.Z += d;
		else
			fake_intersection.Z -= d;

		result.node_real_undersurface = floatToInt(fake_intersection, BS);
		result.node_abovesurface = result.node_real_undersurface
			+ result.intersection_normal;
	}
	return result;
}