up3

server/world/block_state.go

@@ -0,0 +1,116 @@
+package world
+
+import (
+	"bytes"
+	_ "embed"
+	"fmt"
+	"maps"
+	"math"
+	"slices"
+	"strings"
+	"unsafe"
+
+	"github.com/sandertv/gophertunnel/minecraft/nbt"
+)
+
+var (
+	//go:embed block_states.nbt
+	blockStateData []byte
+)
+
+func init() {
+	dec := nbt.NewDecoder(bytes.NewBuffer(blockStateData))
+
+	// Register all block states present in the block_states.nbt file. These are all possible options registered
+	// blocks may encode to.
+	for {
+		var s BlockState
+		if err := dec.Decode(&s); err != nil {
+			break
+		}
+		DefaultBlockRegistry.RegisterBlockState(s)
+	}
+}
+
+// BlockState holds a combination of a name and properties, together with a version.
+type BlockState struct {
+	Name       string         `nbt:"name"`
+	Properties map[string]any `nbt:"states"`
+	Version    int32          `nbt:"version"`
+}
+
+// unknownBlock represents a block that has not yet been implemented. It is used for registering block
+// states that haven't yet been added.
+type unknownBlock struct {
+	BlockState
+	data map[string]any
+}
+
+// EncodeBlock ...
+func (b unknownBlock) EncodeBlock() (string, map[string]any) {
+	return b.Name, b.Properties
+}
+
+// Model ...
+func (unknownBlock) Model() BlockModel {
+	return unknownModel{}
+}
+
+// Hash ...
+func (b unknownBlock) Hash() (uint64, uint64) {
+	return 0, math.MaxUint64
+}
+
+// EncodeNBT ...
+func (b unknownBlock) EncodeNBT() map[string]any {
+	return maps.Clone(b.data)
+}
+
+// DecodeNBT ...
+func (b unknownBlock) DecodeNBT(data map[string]any) any {
+	b.data = maps.Clone(data)
+	return b
+}
+
+// stateHash is a struct that may be used as a map key for block states. It contains the name of the block state
+// and an encoded version of the properties.
+type stateHash struct {
+	name, properties string
+}
+
+// hashProperties produces a hash for the block properties held by the BlockState.
+func hashProperties(properties map[string]any) string {
+	if properties == nil {
+		return ""
+	}
+	keys := make([]string, 0, len(properties))
+	for k := range properties {
+		keys = append(keys, k)
+	}
+	slices.Sort(keys)
+
+	var b strings.Builder
+	for _, k := range keys {
+		switch v := properties[k].(type) {
+		case bool:
+			if v {
+				b.WriteByte(1)
+			} else {
+				b.WriteByte(0)
+			}
+		case uint8:
+			b.WriteByte(v)
+		case int32:
+			a := *(*[4]byte)(unsafe.Pointer(&v))
+			b.Write(a[:])
+		case string:
+			b.WriteString(v)
+		default:
+			// If block encoding is broken, we want to find out as soon as possible. This saves a lot of time
+			// debugging in-game.
+			panic(fmt.Sprintf("invalid block property type %T for property %v", v, k))
+		}
+	}
+
+	return b.String()
+}