Refactor: Add StartServer and ServeClient functions, improve palette unpacking with new helpers, and simplify the proxy example

examples/chunks/main.go

@@ -10,7 +10,13 @@ import (
 	"github.com/admin-else/queser"
 )
 
-func UnpackIndirectPalette(r io.Reader, bitsPerEntry uint8, numberOfEntries int) (err error) {
+const (
+	BlocksPerChunkSection = 4096
+	BiomesPerChunkSection = 64
+	SectionsPerChunk      = 24
+)
+
+func UnpackArrayPalette(r io.Reader, bitsPerEntry uint8, numberOfEntries int) (data []int32, err error) {
 	var palletLen queser.VarInt
 	palletLen, err = palletLen.Decode(r)
 	if err != nil {
@@ -25,50 +31,130 @@ func UnpackIndirectPalette(r io.Reader, bitsPerEntry uint8, numberOfEntries int)
 		}
 		pallet = append(pallet, int32(entry))
 	}
+	data, err = UnpackLongData(r, bitsPerEntry, numberOfEntries)
+	for i, b := range data {
+		data[i] = pallet[b] // maybe check bounds?
+	}
+
+	return
+}
+
+func UnpackLongData(r io.Reader, bitsPerEntry uint8, numberOfEntries int) (data []int32, err error) {
 	entriesPerLong := int(64 / bitsPerEntry)
 	numberOfLongs := int(math.Ceil(float64(numberOfEntries) / float64(entriesPerLong)))
-	var data []uint64
+	var dataL []uint64
 	for range numberOfLongs {
 		var entry uint64
 		err = binary.Read(r, binary.BigEndian, &entry)
 		if err != nil {
 			return
 		}
-		data = append(data, entry)
+		dataL = append(dataL, entry)
 	}
-	fmt.Println(data)
+
+	data = LongsToData(dataL, int32(numberOfEntries), int32(bitsPerEntry))
 	return
 }
 
-func GetBit(data []uint64, index, bpe int32) uint64 {
-	// net.minecraft.util.collection.PackedIntegerArray
-	return 1
+func UnpackSingleValuePalette(r io.Reader, numberOfEntries int) (data []int32, err error) {
+	entry, err := queser.VarInt(0).Decode(r)
+	if err != nil {
+		return
+	}
+	data = make([]int32, numberOfEntries)
+	for i := range data {
+		data[i] = int32(entry)
+	}
+	return
 }
 
-func UnpackPalette(r io.Reader, numberOfEntries int) (err error) {
+func LongsToData(data []uint64, n, bpe int32) (ret []int32) {
+	mask := (uint64(1) << uint32(bpe)) - 1
+	elementsPerLong := 64 / bpe
+
+	ret = make([]int32, n)
+	for i := range n {
+		ret[i] = int32((data[i/elementsPerLong] >> ((i % elementsPerLong) * bpe)) & mask)
+	}
+	return
+}
+
+func UnpackBlockData(r io.Reader) (blocks [BlocksPerChunkSection]int32, err error) {
 	var bitsPerEntry uint8
 	err = binary.Read(r, binary.BigEndian, &bitsPerEntry)
 	if err != nil {
 		return
 	}
-	err = UnpackIndirectPalette(r, bitsPerEntry, numberOfEntries)
+	var blocksSlice []int32
+	fmt.Println("blocks bpe", bitsPerEntry)
+	switch bitsPerEntry {
+	case 0:
+		blocksSlice, err = UnpackSingleValuePalette(r, BlocksPerChunkSection)
+	case 1, 2, 3, 4:
+		blocksSlice, err = UnpackArrayPalette(r, bitsPerEntry, BlocksPerChunkSection)
+	case 5, 6, 7, 8:
+		panic("unimplemented")
+	default:
+		blocksSlice, err = UnpackLongData(r, bitsPerEntry, BlocksPerChunkSection)
+	}
+	blocks = [BlocksPerChunkSection]int32(blocksSlice)
 	return
 }
 
-func UnpackSection(r io.Reader) (err error) {
+func UnpackBiomeData(r io.Reader) (biomes [BiomesPerChunkSection]int32, err error) {
+	// net.minecraft.world.chunk.PaletteProvider#forBiomes
+	var bitsPerEntry uint8
+	err = binary.Read(r, binary.BigEndian, &bitsPerEntry)
+	if err != nil {
+		return
+	}
+	var biomesSlice []int32
+	fmt.Println("biome bpe", bitsPerEntry)
+	switch bitsPerEntry {
+	case 0:
+		biomesSlice, err = UnpackSingleValuePalette(r, BiomesPerChunkSection)
+	case 1, 2, 3:
+		biomesSlice, err = UnpackArrayPalette(r, bitsPerEntry, BiomesPerChunkSection)
+	default:
+		biomesSlice, err = UnpackLongData(r, bitsPerEntry, BiomesPerChunkSection)
+	}
+	if err != nil {
+		return
+	}
+	biomes = [BiomesPerChunkSection]int32(biomesSlice)
+	return
+}
+
+type ChunkSection struct {
+	BlockData [BlocksPerChunkSection]int32
+	BiomeData [BiomesPerChunkSection]int32
+}
+
+func UnpackSection(r io.Reader) (s ChunkSection, err error) {
 	var blockCount int16
 	err = binary.Read(r, binary.BigEndian, &blockCount)
 	if err != nil {
 		return
 	}
-	err = UnpackPalette(r, 4096) // 4096 is the number of blocks in a chunk
+	s.BlockData, err = UnpackBlockData(r)
+	if err != nil {
+		return
+	}
+	s.BiomeData, err = UnpackBiomeData(r)
+	if err != nil {
+		return
+	}
+
 	return
 }
 
 func mainE() (err error) {
 	fmt.Println(packet.X*16, packet.Z*16)
 	b := bytes.NewBuffer(packet.ChunkData.Val)
-	err = UnpackSection(b)
+	sections := make([]ChunkSection, SectionsPerChunk)
+	for i := range sections {
+		sections[i], err = UnpackSection(b)
+	}
 	return
 }