save.py

import nbtlib as nbt
import base36

import chunk

class Save:
	def __init__(self, world, path = "save"):
		self.world = world
		self.path = path
	
	def chunk_position_to_path(self, chunk_position):
		x, y, z = chunk_position

		chunk_path = '/'.join((self.path,
			base36.dumps(x % 64), base36.dumps(z % 64),
			f"c.{base36.dumps(x)}.{base36.dumps(z)}.dat"))
		
		return chunk_path

	def load_chunk(self, chunk_position):
		# load the chunk file
		
		chunk_path = self.chunk_position_to_path(chunk_position)

		try:
			chunk_blocks = nbt.load(chunk_path)["Level"]["Blocks"]
		
		except FileNotFoundError:
			return

		# create chunk and fill it with the blocks from our chunk file

		self.world.chunks[chunk_position] = chunk.Chunk(self.world, chunk_position)

		for x in range(chunk.CHUNK_WIDTH):
			for y in range(chunk.CHUNK_HEIGHT):
				for z in range(chunk.CHUNK_LENGTH):
					self.world.chunks[chunk_position].blocks[x][y][z] = chunk_blocks[
						x * chunk.CHUNK_LENGTH * chunk.CHUNK_HEIGHT +
						z * chunk.CHUNK_HEIGHT +
						y]

	def save_chunk(self, chunk_position):
		x, y, z = chunk_position
		
		# try to load the chunk file
		# if it doesn't exist, create a new one

		chunk_path = self.chunk_position_to_path(chunk_position)

		try:
			chunk_data = nbt.load(chunk_path)
		
		except FileNotFoundError:
			chunk_data = nbt.File({"": nbt.Compound({"Level": nbt.Compound()})})
			
			chunk_data["Level"]["xPos"] = x
			chunk_data["Level"]["zPos"] = z

		# fill the chunk file with the blocks from our chunk

		chunk_blocks = nbt.ByteArray([0] * (chunk.CHUNK_WIDTH * chunk.CHUNK_HEIGHT * chunk.CHUNK_LENGTH))

		for x in range(chunk.CHUNK_WIDTH):
			for y in range(chunk.CHUNK_HEIGHT):
				for z in range(chunk.CHUNK_LENGTH):
					chunk_blocks[
						x * chunk.CHUNK_LENGTH * chunk.CHUNK_HEIGHT +
						z * chunk.CHUNK_HEIGHT +
						y] = self.world.chunks[chunk_position].blocks[x][y][z]
		
		# save the chunk file

		chunk_data["Level"]["Blocks"] = chunk_blocks
		chunk_data.save(chunk_path, gzipped = True)

	def load(self):
		# for x in range(-16, 15):
		# 	for y in range(-15, 16):
		# 		self.load_chunk((x, 0, y))

		# for x in range(-4, 4):
		# 	for y in range(-4, 4):
		# 		self.load_chunk((x, 0, y))

		for x in range(-1, 1):
			for y in range(-1, 1):
				self.load_chunk((x, 0, y))
	
	def save(self):
		for chunk_position in self.world.chunks:
			if chunk_position[1] != 0: # reject all chunks above and below the world limit
				continue
		
			chunk = self.world.chunks[chunk_position]

			if chunk.modified:
				self.save_chunk(chunk_position)
				chunk.modified = False