Move PlayerSAO to dedicated files

4 files changed, 1021 insertions, 4 deletions

diff --git a/src/server/CMakeLists.txt b/src/server/CMakeLists.txt
index 9fa5ed9fa..26eaed5ac 100644
--- a/src/server/CMakeLists.txt
+++ b/src/server/CMakeLists.txt
@@ -1,6 +1,7 @@
 set(server_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/activeobjectmgr.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/mods.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/player_sao.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/serveractiveobject.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/unit_sao.cpp
 	PARENT_SCOPE)
diff --git a/src/server/player_sao.cpp b/src/server/player_sao.cpp
new file mode 100644
index 000000000..58fcea5fe
--- /dev/null
+++ b/src/server/player_sao.cpp
@@ -0,0 +1,695 @@
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+Copyright (C) 2013-2020 Minetest core developers & community
+
+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 "player_sao.h"
+#include "nodedef.h"
+#include "remoteplayer.h"
+#include "scripting_server.h"
+#include "server.h"
+#include "serverenvironment.h"
+
+PlayerSAO::PlayerSAO(ServerEnvironment *env_, RemotePlayer *player_, session_t peer_id_,
+		bool is_singleplayer):
+	UnitSAO(env_, v3f(0,0,0)),
+	m_player(player_),
+	m_peer_id(peer_id_),
+	m_is_singleplayer(is_singleplayer)
+{
+	SANITY_CHECK(m_peer_id != PEER_ID_INEXISTENT);
+
+	m_prop.hp_max = PLAYER_MAX_HP_DEFAULT;
+	m_prop.breath_max = PLAYER_MAX_BREATH_DEFAULT;
+	m_prop.physical = false;
+	m_prop.collisionbox = aabb3f(-0.3f, 0.0f, -0.3f, 0.3f, 1.77f, 0.3f);
+	m_prop.selectionbox = aabb3f(-0.3f, 0.0f, -0.3f, 0.3f, 1.77f, 0.3f);
+	m_prop.pointable = true;
+	// Start of default appearance, this should be overwritten by Lua
+	m_prop.visual = "upright_sprite";
+	m_prop.visual_size = v3f(1, 2, 1);
+	m_prop.textures.clear();
+	m_prop.textures.emplace_back("player.png");
+	m_prop.textures.emplace_back("player_back.png");
+	m_prop.colors.clear();
+	m_prop.colors.emplace_back(255, 255, 255, 255);
+	m_prop.spritediv = v2s16(1,1);
+	m_prop.eye_height = 1.625f;
+	// End of default appearance
+	m_prop.is_visible = true;
+	m_prop.backface_culling = false;
+	m_prop.makes_footstep_sound = true;
+	m_prop.stepheight = PLAYER_DEFAULT_STEPHEIGHT * BS;
+	m_hp = m_prop.hp_max;
+	m_breath = m_prop.breath_max;
+	// Disable zoom in survival mode using a value of 0
+	m_prop.zoom_fov = g_settings->getBool("creative_mode") ? 15.0f : 0.0f;
+
+	if (!g_settings->getBool("enable_damage"))
+		m_armor_groups["immortal"] = 1;
+}
+
+void PlayerSAO::finalize(RemotePlayer *player, const std::set<std::string> &privs)
+{
+	assert(player);
+	m_player = player;
+	m_privs = privs;
+}
+
+v3f PlayerSAO::getEyeOffset() const
+{
+	return v3f(0, BS * m_prop.eye_height, 0);
+}
+
+std::string PlayerSAO::getDescription()
+{
+	return std::string("player ") + m_player->getName();
+}
+
+// Called after id has been set and has been inserted in environment
+void PlayerSAO::addedToEnvironment(u32 dtime_s)
+{
+	ServerActiveObject::addedToEnvironment(dtime_s);
+	ServerActiveObject::setBasePosition(m_base_position);
+	m_player->setPlayerSAO(this);
+	m_player->setPeerId(m_peer_id);
+	m_last_good_position = m_base_position;
+}
+
+// Called before removing from environment
+void PlayerSAO::removingFromEnvironment()
+{
+	ServerActiveObject::removingFromEnvironment();
+	if (m_player->getPlayerSAO() == this) {
+		unlinkPlayerSessionAndSave();
+		for (u32 attached_particle_spawner : m_attached_particle_spawners) {
+			m_env->deleteParticleSpawner(attached_particle_spawner, false);
+		}
+	}
+}
+
+std::string PlayerSAO::getClientInitializationData(u16 protocol_version)
+{
+	std::ostringstream os(std::ios::binary);
+
+	// Protocol >= 15
+	writeU8(os, 1); // version
+	os << serializeString(m_player->getName()); // name
+	writeU8(os, 1); // is_player
+	writeS16(os, getId()); // id
+	writeV3F32(os, m_base_position);
+	writeV3F32(os, m_rotation);
+	writeU16(os, getHP());
+
+	std::ostringstream msg_os(std::ios::binary);
+	msg_os << serializeLongString(getPropertyPacket()); // message 1
+	msg_os << serializeLongString(generateUpdateArmorGroupsCommand()); // 2
+	msg_os << serializeLongString(generateUpdateAnimationCommand()); // 3
+	for (std::unordered_map<std::string, core::vector2d<v3f>>::const_iterator
+			ii = m_bone_position.begin(); ii != m_bone_position.end(); ++ii) {
+		msg_os << serializeLongString(generateUpdateBonePositionCommand((*ii).first,
+			(*ii).second.X, (*ii).second.Y)); // m_bone_position.size
+	}
+	msg_os << serializeLongString(generateUpdateAttachmentCommand()); // 4
+	msg_os << serializeLongString(generateUpdatePhysicsOverrideCommand()); // 5
+	// (AO_CMD_UPDATE_NAMETAG_ATTRIBUTES) : Deprecated, for backwards compatibility only.
+	msg_os << serializeLongString(generateUpdateNametagAttributesCommand(m_prop.nametag_color)); // 6
+	int message_count = 6 + m_bone_position.size();
+	for (std::unordered_set<int>::const_iterator ii = m_attachment_child_ids.begin();
+			ii != m_attachment_child_ids.end(); ++ii) {
+		if (ServerActiveObject *obj = m_env->getActiveObject(*ii)) {
+			message_count++;
+			msg_os << serializeLongString(obj->generateUpdateInfantCommand(*ii, protocol_version));
+		}
+	}
+
+	writeU8(os, message_count);
+	os.write(msg_os.str().c_str(), msg_os.str().size());
+
+	// return result
+	return os.str();
+}
+
+void PlayerSAO::getStaticData(std::string * result) const
+{
+	FATAL_ERROR("Obsolete function");
+}
+
+void PlayerSAO::step(float dtime, bool send_recommended)
+{
+	if (!isImmortal() && m_drowning_interval.step(dtime, 2.0f)) {
+		// Get nose/mouth position, approximate with eye position
+		v3s16 p = floatToInt(getEyePosition(), BS);
+		MapNode n = m_env->getMap().getNode(p);
+		const ContentFeatures &c = m_env->getGameDef()->ndef()->get(n);
+		// If node generates drown
+		if (c.drowning > 0 && m_hp > 0) {
+			if (m_breath > 0)
+				setBreath(m_breath - 1);
+
+			// No more breath, damage player
+			if (m_breath == 0) {
+				PlayerHPChangeReason reason(PlayerHPChangeReason::DROWNING);
+				setHP(m_hp - c.drowning, reason);
+				m_env->getGameDef()->SendPlayerHPOrDie(this, reason);
+			}
+		}
+	}
+
+	if (m_breathing_interval.step(dtime, 0.5f) && !isImmortal()) {
+		// Get nose/mouth position, approximate with eye position
+		v3s16 p = floatToInt(getEyePosition(), BS);
+		MapNode n = m_env->getMap().getNode(p);
+		const ContentFeatures &c = m_env->getGameDef()->ndef()->get(n);
+		// If player is alive & not drowning & not in ignore & not immortal, breathe
+		if (m_breath < m_prop.breath_max && c.drowning == 0 &&
+				n.getContent() != CONTENT_IGNORE && m_hp > 0)
+			setBreath(m_breath + 1);
+	}
+
+	if (!isImmortal() && m_node_hurt_interval.step(dtime, 1.0f)) {
+		u32 damage_per_second = 0;
+		std::string nodename;
+		// Lowest and highest damage points are 0.1 within collisionbox
+		float dam_top = m_prop.collisionbox.MaxEdge.Y - 0.1f;
+
+		// Sequence of damage points, starting 0.1 above feet and progressing
+		// upwards in 1 node intervals, stopping below top damage point.
+		for (float dam_height = 0.1f; dam_height < dam_top; dam_height++) {
+			v3s16 p = floatToInt(m_base_position +
+				v3f(0.0f, dam_height * BS, 0.0f), BS);
+			MapNode n = m_env->getMap().getNode(p);
+			const ContentFeatures &c = m_env->getGameDef()->ndef()->get(n);
+			if (c.damage_per_second > damage_per_second) {
+				damage_per_second = c.damage_per_second;
+				nodename = c.name;
+			}
+		}
+
+		// Top damage point
+		v3s16 ptop = floatToInt(m_base_position +
+			v3f(0.0f, dam_top * BS, 0.0f), BS);
+		MapNode ntop = m_env->getMap().getNode(ptop);
+		const ContentFeatures &c = m_env->getGameDef()->ndef()->get(ntop);
+		if (c.damage_per_second > damage_per_second) {
+			damage_per_second = c.damage_per_second;
+			nodename = c.name;
+		}
+
+		if (damage_per_second != 0 && m_hp > 0) {
+			s32 newhp = (s32)m_hp - (s32)damage_per_second;
+			PlayerHPChangeReason reason(PlayerHPChangeReason::NODE_DAMAGE, nodename);
+			setHP(newhp, reason);
+			m_env->getGameDef()->SendPlayerHPOrDie(this, reason);
+		}
+	}
+
+	if (!m_properties_sent) {
+		m_properties_sent = true;
+		std::string str = getPropertyPacket();
+		// create message and add to list
+		ActiveObjectMessage aom(getId(), true, str);
+		m_messages_out.push(aom);
+		m_env->getScriptIface()->player_event(this, "properties_changed");
+	}
+
+	// If attached, check that our parent is still there. If it isn't, detach.
+	if (m_attachment_parent_id && !isAttached()) {
+		m_attachment_parent_id = 0;
+		m_attachment_bone = "";
+		m_attachment_position = v3f(0.0f, 0.0f, 0.0f);
+		m_attachment_rotation = v3f(0.0f, 0.0f, 0.0f);
+		setBasePosition(m_last_good_position);
+		m_env->getGameDef()->SendMovePlayer(m_peer_id);
+	}
+
+	//dstream<<"PlayerSAO::step: dtime: "<<dtime<<std::endl;
+
+	// Set lag pool maximums based on estimated lag
+	const float LAG_POOL_MIN = 5.0f;
+	float lag_pool_max = m_env->getMaxLagEstimate() * 2.0f;
+	if(lag_pool_max < LAG_POOL_MIN)
+		lag_pool_max = LAG_POOL_MIN;
+	m_dig_pool.setMax(lag_pool_max);
+	m_move_pool.setMax(lag_pool_max);
+
+	// Increment cheat prevention timers
+	m_dig_pool.add(dtime);
+	m_move_pool.add(dtime);
+	m_time_from_last_teleport += dtime;
+	m_time_from_last_punch += dtime;
+	m_nocheat_dig_time += dtime;
+	m_max_speed_override_time = MYMAX(m_max_speed_override_time - dtime, 0.0f);
+
+	// Each frame, parent position is copied if the object is attached,
+	// otherwise it's calculated normally.
+	// If the object gets detached this comes into effect automatically from
+	// the last known origin.
+	if (isAttached()) {
+		v3f pos = m_env->getActiveObject(m_attachment_parent_id)->getBasePosition();
+		m_last_good_position = pos;
+		setBasePosition(pos);
+	}
+
+	if (!send_recommended)
+		return;
+
+	if (m_position_not_sent) {
+		m_position_not_sent = false;
+		float update_interval = m_env->getSendRecommendedInterval();
+		v3f pos;
+		// When attached, the position is only sent to clients where the
+		// parent isn't known
+		if (isAttached())
+			pos = m_last_good_position;
+		else
+			pos = m_base_position;
+
+		std::string str = generateUpdatePositionCommand(
+			pos,
+			v3f(0.0f, 0.0f, 0.0f),
+			v3f(0.0f, 0.0f, 0.0f),
+			m_rotation,
+			true,
+			false,
+			update_interval
+		);
+		// create message and add to list
+		m_messages_out.emplace(getId(), false, str);
+	}
+
+	if (!m_armor_groups_sent) {
+		m_armor_groups_sent = true;
+		// create message and add to list
+		m_messages_out.emplace(getId(), true, generateUpdateArmorGroupsCommand());
+	}
+
+	if (!m_physics_override_sent) {
+		m_physics_override_sent = true;
+		// create message and add to list
+		m_messages_out.emplace(getId(), true, generateUpdatePhysicsOverrideCommand());
+	}
+
+	if (!m_animation_sent) {
+		m_animation_sent = true;
+		// create message and add to list
+		m_messages_out.emplace(getId(), true, generateUpdateAnimationCommand());
+	}
+
+	if (!m_bone_position_sent) {
+		m_bone_position_sent = true;
+		for (std::unordered_map<std::string, core::vector2d<v3f>>::const_iterator
+				ii = m_bone_position.begin(); ii != m_bone_position.end(); ++ii) {
+			std::string str = generateUpdateBonePositionCommand((*ii).first,
+					(*ii).second.X, (*ii).second.Y);
+			// create message and add to list
+			m_messages_out.emplace(getId(), true, str);
+		}
+	}
+
+	if (!m_attachment_sent) {
+		m_attachment_sent = true;
+		std::string str = generateUpdateAttachmentCommand();
+		// create message and add to list
+		ActiveObjectMessage aom(getId(), true, str);
+		m_messages_out.push(aom);
+	}
+}
+
+std::string PlayerSAO::generateUpdatePhysicsOverrideCommand() const
+{
+	std::ostringstream os(std::ios::binary);
+	// command
+	writeU8(os, AO_CMD_SET_PHYSICS_OVERRIDE);
+	// parameters
+	writeF32(os, m_physics_override_speed);
+	writeF32(os, m_physics_override_jump);
+	writeF32(os, m_physics_override_gravity);
+	// these are sent inverted so we get true when the server sends nothing
+	writeU8(os, !m_physics_override_sneak);
+	writeU8(os, !m_physics_override_sneak_glitch);
+	writeU8(os, !m_physics_override_new_move);
+	return os.str();
+}
+
+void PlayerSAO::setBasePosition(const v3f &position)
+{
+	if (m_player && position != m_base_position)
+		m_player->setDirty(true);
+
+	// This needs to be ran for attachments too
+	ServerActiveObject::setBasePosition(position);
+
+	// Updating is not wanted/required for player migration
+	if (m_env) {
+		m_position_not_sent = true;
+	}
+}
+
+void PlayerSAO::setPos(const v3f &pos)
+{
+	if(isAttached())
+		return;
+
+	// Send mapblock of target location
+	v3s16 blockpos = v3s16(pos.X / MAP_BLOCKSIZE, pos.Y / MAP_BLOCKSIZE, pos.Z / MAP_BLOCKSIZE);
+	m_env->getGameDef()->SendBlock(m_peer_id, blockpos);
+
+	setBasePosition(pos);
+	// Movement caused by this command is always valid
+	m_last_good_position = pos;
+	m_move_pool.empty();
+	m_time_from_last_teleport = 0.0;
+	m_env->getGameDef()->SendMovePlayer(m_peer_id);
+}
+
+void PlayerSAO::moveTo(v3f pos, bool continuous)
+{
+	if(isAttached())
+		return;
+
+	setBasePosition(pos);
+	// Movement caused by this command is always valid
+	m_last_good_position = pos;
+	m_move_pool.empty();
+	m_time_from_last_teleport = 0.0;
+	m_env->getGameDef()->SendMovePlayer(m_peer_id);
+}
+
+void PlayerSAO::setPlayerYaw(const float yaw)
+{
+	v3f rotation(0, yaw, 0);
+	if (m_player && yaw != m_rotation.Y)
+		m_player->setDirty(true);
+
+	// Set player model yaw, not look view
+	UnitSAO::setRotation(rotation);
+}
+
+void PlayerSAO::setFov(const float fov)
+{
+	if (m_player && fov != m_fov)
+		m_player->setDirty(true);
+
+	m_fov = fov;
+}
+
+void PlayerSAO::setWantedRange(const s16 range)
+{
+	if (m_player && range != m_wanted_range)
+		m_player->setDirty(true);
+
+	m_wanted_range = range;
+}
+
+void PlayerSAO::setPlayerYawAndSend(const float yaw)
+{
+	setPlayerYaw(yaw);
+	m_env->getGameDef()->SendMovePlayer(m_peer_id);
+}
+
+void PlayerSAO::setLookPitch(const float pitch)
+{
+	if (m_player && pitch != m_pitch)
+		m_player->setDirty(true);
+
+	m_pitch = pitch;
+}
+
+void PlayerSAO::setLookPitchAndSend(const float pitch)
+{
+	setLookPitch(pitch);
+	m_env->getGameDef()->SendMovePlayer(m_peer_id);
+}
+
+u16 PlayerSAO::punch(v3f dir,
+	const ToolCapabilities *toolcap,
+	ServerActiveObject *puncher,
+	float time_from_last_punch)
+{
+	if (!toolcap)
+		return 0;
+
+	FATAL_ERROR_IF(!puncher, "Punch action called without SAO");
+
+	// No effect if PvP disabled or if immortal
+	if (isImmortal() || !g_settings->getBool("enable_pvp")) {
+		if (puncher->getType() == ACTIVEOBJECT_TYPE_PLAYER) {
+			// create message and add to list
+			sendPunchCommand();
+			return 0;
+		}
+	}
+
+	s32 old_hp = getHP();
+	HitParams hitparams = getHitParams(m_armor_groups, toolcap,
+			time_from_last_punch);
+
+	PlayerSAO *playersao = m_player->getPlayerSAO();
+
+	bool damage_handled = m_env->getScriptIface()->on_punchplayer(playersao,
+				puncher, time_from_last_punch, toolcap, dir,
+				hitparams.hp);
+
+	if (!damage_handled) {
+		setHP((s32)getHP() - (s32)hitparams.hp,
+				PlayerHPChangeReason(PlayerHPChangeReason::PLAYER_PUNCH, puncher));
+	} else { // override client prediction
+		if (puncher->getType() == ACTIVEOBJECT_TYPE_PLAYER) {
+			// create message and add to list
+			sendPunchCommand();
+		}
+	}
+
+	actionstream << puncher->getDescription() << " (id=" << puncher->getId() <<
+		", hp=" << puncher->getHP() << ") punched " <<
+		getDescription() << " (id=" << m_id << ", hp=" << m_hp <<
+		"), damage=" << (old_hp - (s32)getHP()) <<
+		(damage_handled ? " (handled by Lua)" : "") << std::endl;
+
+	return hitparams.wear;
+}
+
+void PlayerSAO::setHP(s32 hp, const PlayerHPChangeReason &reason)
+{
+	s32 oldhp = m_hp;
+
+	hp = rangelim(hp, 0, m_prop.hp_max);
+
+	if (oldhp != hp) {
+		s32 hp_change = m_env->getScriptIface()->on_player_hpchange(this, hp - oldhp, reason);
+		if (hp_change == 0)
+			return;
+
+		hp = rangelim(oldhp + hp_change, 0, m_prop.hp_max);
+	}
+
+	if (hp < oldhp && isImmortal())
+		return;
+
+	m_hp = hp;
+
+	// Update properties on death
+	if ((hp == 0) != (oldhp == 0))
+		m_properties_sent = false;
+}
+
+void PlayerSAO::setBreath(const u16 breath, bool send)
+{
+	if (m_player && breath != m_breath)
+		m_player->setDirty(true);
+
+	m_breath = rangelim(breath, 0, m_prop.breath_max);
+
+	if (send)
+		m_env->getGameDef()->SendPlayerBreath(this);
+}
+
+Inventory *PlayerSAO::getInventory() const
+{
+	return m_player ? &m_player->inventory : nullptr;
+}
+
+InventoryLocation PlayerSAO::getInventoryLocation() const
+{
+	InventoryLocation loc;
+	loc.setPlayer(m_player->getName());
+	return loc;
+}
+
+u16 PlayerSAO::getWieldIndex() const
+{
+	return m_player->getWieldIndex();
+}
+
+ItemStack PlayerSAO::getWieldedItem(ItemStack *selected, ItemStack *hand) const
+{
+	return m_player->getWieldedItem(selected, hand);
+}
+
+bool PlayerSAO::setWieldedItem(const ItemStack &item)
+{
+	InventoryList *mlist = m_player->inventory.getList(getWieldList());
+	if (mlist) {
+		mlist->changeItem(m_player->getWieldIndex(), item);
+		return true;
+	}
+	return false;
+}
+
+void PlayerSAO::disconnected()
+{
+	m_peer_id = PEER_ID_INEXISTENT;
+	m_pending_removal = true;
+}
+
+void PlayerSAO::unlinkPlayerSessionAndSave()
+{
+	assert(m_player->getPlayerSAO() == this);
+	m_player->setPeerId(PEER_ID_INEXISTENT);
+	m_env->savePlayer(m_player);
+	m_player->setPlayerSAO(NULL);
+	m_env->removePlayer(m_player);
+}
+
+std::string PlayerSAO::getPropertyPacket()
+{
+	m_prop.is_visible = (true);
+	return generateSetPropertiesCommand(m_prop);
+}
+
+void PlayerSAO::setMaxSpeedOverride(const v3f &vel)
+{
+	if (m_max_speed_override_time == 0.0f)
+		m_max_speed_override = vel;
+	else
+		m_max_speed_override += vel;
+	if (m_player) {
+		float accel = MYMIN(m_player->movement_acceleration_default,
+				m_player->movement_acceleration_air);
+		m_max_speed_override_time = m_max_speed_override.getLength() / accel / BS;
+	}
+}
+
+bool PlayerSAO::checkMovementCheat()
+{
+	if (isAttached() || m_is_singleplayer ||
+			g_settings->getBool("disable_anticheat")) {
+		m_last_good_position = m_base_position;
+		return false;
+	}
+
+	bool cheated = false;
+	/*
+		Check player movements
+
+		NOTE: Actually the server should handle player physics like the
+		client does and compare player's position to what is calculated
+		on our side. This is required when eg. players fly due to an
+		explosion. Altough a node-based alternative might be possible
+		too, and much more lightweight.
+	*/
+
+	float override_max_H, override_max_V;
+	if (m_max_speed_override_time > 0.0f) {
+		override_max_H = MYMAX(fabs(m_max_speed_override.X), fabs(m_max_speed_override.Z));
+		override_max_V = fabs(m_max_speed_override.Y);
+	} else {
+		override_max_H = override_max_V = 0.0f;
+	}
+
+	float player_max_walk = 0; // horizontal movement
+	float player_max_jump = 0; // vertical upwards movement
+
+	if (m_privs.count("fast") != 0)
+		player_max_walk = m_player->movement_speed_fast; // Fast speed
+	else
+		player_max_walk = m_player->movement_speed_walk; // Normal speed
+	player_max_walk *= m_physics_override_speed;
+	player_max_walk = MYMAX(player_max_walk, override_max_H);
+
+	player_max_jump = m_player->movement_speed_jump * m_physics_override_jump;
+	// FIXME: Bouncy nodes cause practically unbound increase in Y speed,
+	//        until this can be verified correctly, tolerate higher jumping speeds
+	player_max_jump *= 2.0;
+	player_max_jump = MYMAX(player_max_jump, override_max_V);
+
+	// Don't divide by zero!
+	if (player_max_walk < 0.0001f)
+		player_max_walk = 0.0001f;
+	if (player_max_jump < 0.0001f)
+		player_max_jump = 0.0001f;
+
+	v3f diff = (m_base_position - m_last_good_position);
+	float d_vert = diff.Y;
+	diff.Y = 0;
+	float d_horiz = diff.getLength();
+	float required_time = d_horiz / player_max_walk;
+
+	// FIXME: Checking downwards movement is not easily possible currently,
+	//        the server could calculate speed differences to examine the gravity
+	if (d_vert > 0) {
+		// In certain cases (water, ladders) walking speed is applied vertically
+		float s = MYMAX(player_max_jump, player_max_walk);
+		required_time = MYMAX(required_time, d_vert / s);
+	}
+
+	if (m_move_pool.grab(required_time)) {
+		m_last_good_position = m_base_position;
+	} else {
+		const float LAG_POOL_MIN = 5.0;
+		float lag_pool_max = m_env->getMaxLagEstimate() * 2.0;
+		lag_pool_max = MYMAX(lag_pool_max, LAG_POOL_MIN);
+		if (m_time_from_last_teleport > lag_pool_max) {
+			actionstream << "Player " << m_player->getName()
+					<< " moved too fast; resetting position"
+					<< std::endl;
+			cheated = true;
+		}
+		setBasePosition(m_last_good_position);
+	}
+	return cheated;
+}
+
+bool PlayerSAO::getCollisionBox(aabb3f *toset) const
+{
+	//update collision box
+	toset->MinEdge = m_prop.collisionbox.MinEdge * BS;
+	toset->MaxEdge = m_prop.collisionbox.MaxEdge * BS;
+
+	toset->MinEdge += m_base_position;
+	toset->MaxEdge += m_base_position;
+	return true;
+}
+
+bool PlayerSAO::getSelectionBox(aabb3f *toset) const
+{
+	if (!m_prop.is_visible || !m_prop.pointable) {
+		return false;
+	}
+
+	toset->MinEdge = m_prop.selectionbox.MinEdge * BS;
+	toset->MaxEdge = m_prop.selectionbox.MaxEdge * BS;
+
+	return true;
+}
+
+float PlayerSAO::getZoomFOV() const
+{
+	return m_prop.zoom_fov;
+}
diff --git a/src/server/player_sao.h b/src/server/player_sao.h
new file mode 100644
index 000000000..ce1cb1677
--- /dev/null
+++ b/src/server/player_sao.h
@@ -0,0 +1,325 @@
+
+/*
+Minetest
+Copyright (C) 2010-2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+Copyright (C) 2013-2020 Minetest core developers & community
+
+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 "constants.h"
+#include "network/networkprotocol.h"
+#include "unit_sao.h"
+#include "util/numeric.h"
+
+/*
+	PlayerSAO needs some internals exposed.
+*/
+
+class LagPool
+{
+	float m_pool = 15.0f;
+	float m_max = 15.0f;
+public:
+	LagPool() = default;
+
+	void setMax(float new_max)
+	{
+		m_max = new_max;
+		if(m_pool > new_max)
+			m_pool = new_max;
+	}
+
+	void add(float dtime)
+	{
+		m_pool -= dtime;
+		if(m_pool < 0)
+			m_pool = 0;
+	}
+
+	void empty()
+	{
+		m_pool = m_max;
+	}
+
+	bool grab(float dtime)
+	{
+		if(dtime <= 0)
+			return true;
+		if(m_pool + dtime > m_max)
+			return false;
+		m_pool += dtime;
+		return true;
+	}
+};
+
+class RemotePlayer;
+
+class PlayerSAO : public UnitSAO
+{
+public:
+	PlayerSAO(ServerEnvironment *env_, RemotePlayer *player_, session_t peer_id_,
+			bool is_singleplayer);
+
+	ActiveObjectType getType() const
+	{ return ACTIVEOBJECT_TYPE_PLAYER; }
+	ActiveObjectType getSendType() const
+	{ return ACTIVEOBJECT_TYPE_GENERIC; }
+	std::string getDescription();
+
+	/*
+		Active object <-> environment interface
+	*/
+
+	void addedToEnvironment(u32 dtime_s);
+	void removingFromEnvironment();
+	bool isStaticAllowed() const { return false; }
+	std::string getClientInitializationData(u16 protocol_version);
+	void getStaticData(std::string *result) const;
+	void step(float dtime, bool send_recommended);
+	void setBasePosition(const v3f &position);
+	void setPos(const v3f &pos);
+	void moveTo(v3f pos, bool continuous);
+	void setPlayerYaw(const float yaw);
+	// Data should not be sent at player initialization
+	void setPlayerYawAndSend(const float yaw);
+	void setLookPitch(const float pitch);
+	// Data should not be sent at player initialization
+	void setLookPitchAndSend(const float pitch);
+	f32 getLookPitch() const { return m_pitch; }
+	f32 getRadLookPitch() const { return m_pitch * core::DEGTORAD; }
+	// Deprecated
+	f32 getRadLookPitchDep() const { return -1.0 * m_pitch * core::DEGTORAD; }
+	void setFov(const float pitch);
+	f32 getFov() const { return m_fov; }
+	void setWantedRange(const s16 range);
+	s16 getWantedRange() const { return m_wanted_range; }
+
+	/*
+		Interaction interface
+	*/
+
+	u16 punch(v3f dir,
+		const ToolCapabilities *toolcap,
+		ServerActiveObject *puncher,
+		float time_from_last_punch);
+	void rightClick(ServerActiveObject *clicker) {}
+	void setHP(s32 hp, const PlayerHPChangeReason &reason);
+	void setHPRaw(u16 hp) { m_hp = hp; }
+	s16 readDamage();
+	u16 getBreath() const { return m_breath; }
+	void setBreath(const u16 breath, bool send = true);
+
+	/*
+		Inventory interface
+	*/
+	Inventory *getInventory() const;
+	InventoryLocation getInventoryLocation() const;
+	void setInventoryModified() {}
+	std::string getWieldList() const { return "main"; }
+	u16 getWieldIndex() const;
+	ItemStack getWieldedItem(ItemStack *selected, ItemStack *hand = nullptr) const;
+	bool setWieldedItem(const ItemStack &item);
+
+	/*
+		PlayerSAO-specific
+	*/
+
+	void disconnected();
+
+	RemotePlayer *getPlayer() { return m_player; }
+	session_t getPeerID() const { return m_peer_id; }
+
+	// Cheat prevention
+
+	v3f getLastGoodPosition() const
+	{
+		return m_last_good_position;
+	}
+	float resetTimeFromLastPunch()
+	{
+		float r = m_time_from_last_punch;
+		m_time_from_last_punch = 0.0;
+		return r;
+	}
+	void noCheatDigStart(const v3s16 &p)
+	{
+		m_nocheat_dig_pos = p;
+		m_nocheat_dig_time = 0;
+	}
+	v3s16 getNoCheatDigPos()
+	{
+		return m_nocheat_dig_pos;
+	}
+	float getNoCheatDigTime()
+	{
+		return m_nocheat_dig_time;
+	}
+	void noCheatDigEnd()
+	{
+		m_nocheat_dig_pos = v3s16(32767, 32767, 32767);
+	}
+	LagPool& getDigPool()
+	{
+		return m_dig_pool;
+	}
+	void setMaxSpeedOverride(const v3f &vel);
+	// Returns true if cheated
+	bool checkMovementCheat();
+
+	// Other
+
+	void updatePrivileges(const std::set<std::string> &privs,
+			bool is_singleplayer)
+	{
+		m_privs = privs;
+		m_is_singleplayer = is_singleplayer;
+	}
+
+	bool getCollisionBox(aabb3f *toset) const;
+	bool getSelectionBox(aabb3f *toset) const;
+	bool collideWithObjects() const { return true; }
+
+	void finalize(RemotePlayer *player, const std::set<std::string> &privs);
+
+	v3f getEyePosition() const { return m_base_position + getEyeOffset(); }
+	v3f getEyeOffset() const;
+	float getZoomFOV() const;
+
+	inline Metadata &getMeta() { return m_meta; }
+
+private:
+	std::string getPropertyPacket();
+	void unlinkPlayerSessionAndSave();
+	std::string generateUpdatePhysicsOverrideCommand() const;
+
+	RemotePlayer *m_player = nullptr;
+	session_t m_peer_id = 0;
+
+	// Cheat prevention
+	LagPool m_dig_pool;
+	LagPool m_move_pool;
+	v3f m_last_good_position;
+	float m_time_from_last_teleport = 0.0f;
+	float m_time_from_last_punch = 0.0f;
+	v3s16 m_nocheat_dig_pos = v3s16(32767, 32767, 32767);
+	float m_nocheat_dig_time = 0.0f;
+	float m_max_speed_override_time = 0.0f;
+	v3f m_max_speed_override = v3f(0.0f, 0.0f, 0.0f);
+
+	// Timers
+	IntervalLimiter m_breathing_interval;
+	IntervalLimiter m_drowning_interval;
+	IntervalLimiter m_node_hurt_interval;
+
+	bool m_position_not_sent = false;
+
+	// Cached privileges for enforcement
+	std::set<std::string> m_privs;
+	bool m_is_singleplayer;
+
+	u16 m_breath = PLAYER_MAX_BREATH_DEFAULT;
+	f32 m_pitch = 0.0f;
+	f32 m_fov = 0.0f;
+	s16 m_wanted_range = 0.0f;
+
+	Metadata m_meta;
+public:
+	float m_physics_override_speed = 1.0f;
+	float m_physics_override_jump = 1.0f;
+	float m_physics_override_gravity = 1.0f;
+	bool m_physics_override_sneak = true;
+	bool m_physics_override_sneak_glitch = false;
+	bool m_physics_override_new_move = true;
+	bool m_physics_override_sent = false;
+};
+
+
+struct PlayerHPChangeReason {
+	enum Type : u8 {
+		SET_HP,
+		PLAYER_PUNCH,
+		FALL,
+		NODE_DAMAGE,
+		DROWNING,
+		RESPAWN
+	};
+
+	Type type = SET_HP;
+	bool from_mod = false;
+	int lua_reference = -1;
+
+	// For PLAYER_PUNCH
+	ServerActiveObject *object = nullptr;
+	// For NODE_DAMAGE
+	std::string node;
+
+	inline bool hasLuaReference() const
+	{
+		return lua_reference >= 0;
+	}
+
+	bool setTypeFromString(const std::string &typestr)
+	{
+		if (typestr == "set_hp")
+			type = SET_HP;
+		else if (typestr == "punch")
+			type = PLAYER_PUNCH;
+		else if (typestr == "fall")
+			type = FALL;
+		else if (typestr == "node_damage")
+			type = NODE_DAMAGE;
+		else if (typestr == "drown")
+			type = DROWNING;
+		else if (typestr == "respawn")
+			type = RESPAWN;
+		else
+			return false;
+
+		return true;
+	}
+
+	std::string getTypeAsString() const
+	{
+		switch (type) {
+		case PlayerHPChangeReason::SET_HP:
+			return "set_hp";
+		case PlayerHPChangeReason::PLAYER_PUNCH:
+			return "punch";
+		case PlayerHPChangeReason::FALL:
+			return "fall";
+		case PlayerHPChangeReason::NODE_DAMAGE:
+			return "node_damage";
+		case PlayerHPChangeReason::DROWNING:
+			return "drown";
+		case PlayerHPChangeReason::RESPAWN:
+			return "respawn";
+		default:
+			return "?";
+		}
+	}
+
+	PlayerHPChangeReason(Type type):
+			type(type)
+	{}
+
+	PlayerHPChangeReason(Type type, ServerActiveObject *object):
+			type(type), object(object)
+	{}
+
+	PlayerHPChangeReason(Type type, std::string node):
+			type(type), node(node)
+	{}
+};
diff --git a/src/server/unit_sao.cpp b/src/server/unit_sao.cpp
index b30b7a76b..74b0508b8 100644
--- a/src/server/unit_sao.cpp
+++ b/src/server/unit_sao.cpp
@@ -22,10 +22,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "scripting_server.h"
 #include "serverenvironment.h"
 
-/*
-	UnitSAO
- */
-
 UnitSAO::UnitSAO(ServerEnvironment *env, v3f pos) : ServerActiveObject(env, pos)
 {
 	// Initialize something to armor groups