Decompilation of Level::_playerChangeDimension()

Level.cpp

bool Level::_playerChangeDimension(Player* player, ChangeDimensionRequest& request)
{
	if(request.idk == 0)
	{
		Dimension* destination = createDimension(request.newDim);
		Dimension* currentDimension = getDimension(request.oldDim);
		player->field_3272 = 3;
		player->suspendRegion(); // VIRTUAL 215
		if(this->field_5440.field_12 == 0)
		{
			currentDimension->chunkSource->waitDiscardFinished(); // VIRTUAL 16
		}

		if(player->isLocalPlayer())
		{
			std::vector<BackgroundWorker*> workers = WorkerPool::getWorkersFor(0);
			for(BackgroundWorker* worker : workers)
			{
				worker->sync();
			}
		}

		this->field_5440.field_20 = this->field_5440.field_16;
		WorkerPool::getFor(4)->flush();
		RemovePlayerPacket _removeLocalPlayerPkt {2, 1, 0, player->getUniqueID(), player->field_3352}; // RakNetGUID

		/* Inform all server players that we are leaving, and vice-versa. */
		for(Player* p : this->_playerList) // 12
		{
			if(p != player && p->getDimensionId() == currentDimension)
			{
				RemovePlayerPacket _removeServerPlayerPkt {2, 1, 0, p->getUniqueID(), p->field_3352}; // RakNetGUID
				this->packetSender->send(player->field_3320, _removeServerPlayerPkt); // BatchedPacketSender, Level + 0x154
				this->packetSender->send(p->field_3320, _removeLocalPlayerPkt); // VIRTUAL 3
			}
		}

		/* Inform our player to remove all Entities from this dimension. */
		std::unordered_map<long, Entity*> _entities = currentDimension->getEntityIdMapConst();
		if(!_entities.empty())
		{
			for(auto i = _entities.begin(); i != _entities.end(); ++i)
			{
				Entity* e = i->second;
				RemoveEntityPacket _removeEntityPkt {2, 1, 0, e->getUniqueID()};
				this->packetSender->send(player->field_3320, _removeEntityPkt);
			}
		}

		/* Spawn a Nether Portal in the new Dimension, doesn't actually warp the player AFAIK */
		if(this->field_5440.field_12 == 0 && request.a)
		{
			Vec3 newDimensionPos = this->portalForcer->translatePosAcrossDimension(player->getPos(), request.oldDim, request.newDim); // 264
			BlockPos pos;

			if(this->portalForcer->findPortal(destination->getId(), newDimensionPos, 128, pos))
			{
				Vec3 portalPosition(pos);
				request.spawn.x = portalPosition.x;
				request.spawn.y = portalPosition.y;
				request.spawn.z = portalPosition.z;
			} else {
				request.spawn.x = newDimensionPos.x;
				request.spawn.y = newDimensionPos.y;
				request.spawn.z = newDimensionPos.z;
			}

			player->sendTelemetryPacket(TelemetryEventPacket(player, request.oldDim, request.newDim)); // VIRTUAL 253
		}

		/* Unload the current world */
		player->onPrepChangeDimension(); // VIRTUAL 216
		player->destroyRegion(); // VIRTUAL 214

		player->setPos(request.spawn); // VIRTUAL 6
		player->lerpTo(Vec3::ZERO, Vec2::ZERO, 0); // VIRTUAL 15

		if(this->field_5440.field_12 == 0)
		{
			ChangeDimensionPacket _changeDimensionPkt {2, 1, this->field_5440.field_12/*bool*/, request.newDim, request.spawn, request.b};
			this->packetSender->send(player->field_3320, _changeDimensionPkt);

			if(!player->isLocalPlayer())
			{
				player->field_3276 = 1; // true?
			}
		}

		player->field_3372 = 0;
		player->prepareRegion(destination->getChunkSource()); // VIRTUAL 213
		player->onDimensionChanged(); // VIRTUAL 217
		request.idk = 1;
	}

	if(request.idk == 1)
	{
		if(this->field_5440.field_12 == 0 && request.a)
		{
			if(!player->getRegion().hasChunksAt(BlockPos(player->x, player->y, player->z), 32))
			{
				return false;
			}

			player->trySendBatchPacket(1);
			this->portalForcer->force(*player);
			player->setPos(player->getPos());
			player->lerpTo(Vec3::ZERO, Vec2::ZERO, 0);

			this->packetSender->send(player->field_3320, MovePlayerPacket(*player, Player::PositionMode::ONE));
			request.a = 0; // false
		}

		Vec3 playerPos = player->getPos();
		if(!player->getRegion().hasChunksAt(BlockPos({playerPos.x - 16.0F, playerPos.y - 16.0F, playerPos.z - 16.0F}), BlockPos({playerPos.x + 16.0F, playerPos.y + 16.0F, playerPos.z + 16.0F})))
		{
			return false;
		}

		std::unique_ptr<AddEntityPacket> _localPlayerAddPkt = player->getAddPacket(); // VIRTUAL 19

		for(Player* p : this->_playerList)
		{
			if(p != player && p->getDimensionId() == currentDimension)
			{
				std::unique_ptr<AddEntityPacket> _serverPlayerAddPkt = p->getAddPacket();
				if(_serverPlayerAddPkt)
				{
					this->packetSender->send(player->field_3320, _serverPlayerAddPkt);
				}
				this->packetSender->send(p->field_3320, _localPlayerAddPkt);

				if(p->getArmorTypeHash() != NULL) // VIRTUAL 185
				{
					MobArmorEquipmentPacket _serverPlayerArmorPkt(*p);
					this->packetSender->send(player->field_3320, _serverPlayerArmorPkt);
				}

				if(player->getArmorTypeHash() != NULL)
				{
					MobArmorEquipmentPacket _localPlayerArmorPkt(*player);
					this->packetSender->send(p->field_3320, _localPlayerArmorPkt);
				}
			}
		}

		std::unordered_map<long, Entity*> _entitiesNew = this->getDimension(request.newDim)->getEntityIdMapConst();
		if(!_entitiesNew.empty())
		{
			for(auto i = _entitiesNew.begin(); i != _entitiesNew.end(); ++i)
			{
				Entity* e = i->second;
				std::unique_ptr<AddEntityPacket> _entityAddPkt = e->getAddPacket();
				if(_entityAddPkt)
				{
					this->packetSender->send(player->field_3320, *_entityAddPkt.get());
				}

				if(EntityClassTree::isMob(*e))
				{
					if(e->getArmorTypeHash() != NULL)
					{
						MobArmorEquipmentPacket _entityArmorPkt(*entity);
						this->packetSender->send(player->field_3320, _entityArmorPkt);
					}

					if(e->getCarriedItem()) // VIRTUAL 156
					{
						ItemInstance _heldItem(e->getCarriedItem());
						MobEquipmentPacket _entityHeldItemPkt {2, 1, 0, e->getUniqueID(), _heldItem, false, false, false};
						this->packetSender->send(player->field_3320, _entityHeldItemPkt);
						if(_heldItem.userData) // CompoundTag
						{
							delete _heldItem.userData;
						}
					}
				}
			}
		}

		if(!request.b)
		{
			if(this->field_5440.field_12 != 0)
			{
				this->packetSender->send({2, 1, 0, 0, 0, 0, 0, 14, player->getUniqueID()}); // PlayerActionPacket
			}

			player->field_3272 = 0;
		}
		else
		{
			request.idk = 2;
		}
	}

	if(request.idk == 2)
	{
		if(player->field_3480 == 0)
		{
			return false;
		}

		player->field_3272 = 0;
		player->respawn(); // VIRTUAL 222

		this->packetSender->send(player->field_3320, {2, 1, 0, player->getUniqueID(), player->getPos(), player->getRotation(), player->headRotation/*360*/, true, player->field_281}); // MovePlayerPacket
	
		return player->field_3480;
	}

	return false;
}

Wow I didn't understand anything