Add support for dimension ranges and network hashes

mapping/block.go

@@ -21,6 +21,8 @@ type Block interface {
 	DowngradeBlockActorData(map[string]any)
 	// UpgradeBlockActorData upgrades the input sub chunk to the latest block actor.
 	UpgradeBlockActorData(map[string]any)
+	HashToRuntimeID(hash uint32) (rid uint32, ok bool)
+	RuntimeIDToHash(rid uint32) (hash uint32, ok bool)
 	// Adjust adjusts the latest mappings to account for custom states.
 	Adjust([]protocol.BlockEntry)
 	Air() uint32
@@ -41,6 +43,9 @@ type DefaultBlockMapping struct {
 
 	// infoUpdateRID is the runtime ID of the info_update block in the latest version of the game.
 	infoUpdateBlockRID uint32
+
+	networkhashToRids map[uint32]uint32
+	ridsToNetworkhash map[uint32]uint32
 }
 
 func NewBlockMapping(raw []byte) *DefaultBlockMapping {
@@ -51,6 +56,8 @@ func NewBlockMapping(raw []byte) *DefaultBlockMapping {
 	runtimeIDToState := make(map[uint32]blockupgrader.BlockState)
 	var airRID *uint32
 	var infoUpdateBlockRID *uint32
+	networkhashToRids := make(map[uint32]uint32)
+	ridsToNetworkhash := make(map[uint32]uint32)
 
 	var s blockupgrader.BlockState
 	for {
@@ -67,8 +74,11 @@ func NewBlockMapping(raw []byte) *DefaultBlockMapping {
 			infoUpdateBlockRID = &rid
 		}
 
-		stateRuntimeIDs[internal.HashState(blockupgrader.Upgrade(s))] = rid
+		upgradedStates := blockupgrader.Upgrade(s)
+		stateRuntimeIDs[internal.HashState(upgradedStates)] = rid
 		runtimeIDToState[rid] = s
+		networkhashToRids[networkBlockHash(upgradedStates.Name, upgradedStates.Properties)] = rid
+		ridsToNetworkhash[rid] = networkBlockHash(s.Name, s.Properties)
 	}
 	if airRID == nil {
 		panic("couldn't find air")
@@ -83,6 +93,8 @@ func NewBlockMapping(raw []byte) *DefaultBlockMapping {
 		runtimeIDToState:   runtimeIDToState,
 		airRID:             *airRID,
 		infoUpdateBlockRID: *infoUpdateBlockRID,
+		networkhashToRids:  networkhashToRids,
+		ridsToNetworkhash:  ridsToNetworkhash,
 	}
 }
 
@@ -114,6 +126,16 @@ func (m *DefaultBlockMapping) UpgradeBlockActorData(actorData map[string]any) {
 	}
 }
 
+func (m *DefaultBlockMapping) RuntimeIDToHash(rid uint32) (uint32, bool) {
+	hash, found := m.ridsToNetworkhash[rid]
+	return hash, found
+}
+
+func (m *DefaultBlockMapping) HashToRuntimeID(hash uint32) (uint32, bool) {
+	rid, found := m.networkhashToRids[hash]
+	return rid, found
+}
+
 func (m *DefaultBlockMapping) Adjust(entries []protocol.BlockEntry) {
 	if len(entries) == 0 {
 		return

mapping/network_block_hash.go

@@ -0,0 +1,97 @@
+package mapping
+
+import (
+	"encoding/binary"
+	"hash/fnv"
+	"sort"
+	"strings"
+)
+
+var bufNetworkhash []byte = make([]byte, 0xff)
+
+func networkBlockHash(name string, properties map[string]any) uint32 {
+	if name == "minecraft:unknown" {
+		return 0xfffffffe // -2
+	}
+
+	keys := make([]string, 0, len(properties))
+	for k := range properties {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	bufNetworkhash = bufNetworkhash[:0]
+	var data = bufNetworkhash
+	writeString := func(str string) {
+		data = binary.LittleEndian.AppendUint16(data, uint16(len(str)))
+		data = append(data, []byte(str)...)
+	}
+
+	data = append(data, 10) // compound
+	data = append(data, 0)
+	data = append(data, 0)
+
+	data = append(data, 8) // string
+	writeString("name")
+	writeString(name)
+
+	data = append(data, 10) // compound
+	writeString("states")
+	for _, k := range keys {
+		v := properties[k]
+		switch v := v.(type) {
+		case string:
+			data = append(data, 8) // string
+			writeString(k)
+			writeString(v)
+
+		case uint8:
+			data = append(data, 1) // tagByte
+			writeString(k)
+			data = append(data, byte(v))
+		case int8:
+			data = append(data, 1) // tagByte
+			writeString(k)
+			data = append(data, byte(v))
+		case bool:
+			b := 0
+			if v {
+				b = 1
+			}
+			data = append(data, 1) // tagByte
+			writeString(k)
+			data = append(data, byte(b))
+
+		case uint16:
+			data = append(data, 2) // tagInt16
+			writeString(k)
+			data = binary.LittleEndian.AppendUint16(data, uint16(v))
+		case int16:
+			data = append(data, 2) // tagInt16
+			writeString(k)
+			data = binary.LittleEndian.AppendUint16(data, uint16(v))
+
+		case uint32:
+			data = append(data, 3) // tagInt32
+			writeString(k)
+			data = binary.LittleEndian.AppendUint32(data, uint32(v))
+		case int32:
+			data = append(data, 3) // tagInt32
+			writeString(k)
+			data = binary.LittleEndian.AppendUint32(data, uint32(v))
+		default:
+			panic("unhandled nbt type")
+		}
+	}
+	data = append(data, 0) // end
+	data = append(data, 0) // end
+
+	h := fnv.New32a()
+	h.Write(data)
+	return h.Sum32()
+}
+
+func splitNamespace(identifier string) (ns, name string) {
+	ns_name := strings.Split(identifier, ":")
+	return ns_name[0], ns_name[len(ns_name)-1]
+}