support block state & nbt improvement

level/block/block.go

@@ -1,28 +1,62 @@
 package block
 
+import (
+	"bytes"
+	"compress/zlib"
+	_ "embed"
+	"fmt"
+
+	"github.com/Tnze/go-mc/nbt"
+)
+
 type Block interface {
 	ID() string
 }
 
+// This file stores all possible block states into a TAG_List with zlib compressed.
+//go:embed block_states.nbt
+var blockStates []byte
+
 var toStateID = make(map[Block]int)
 var fromStateID []Block
-var fromID = make(map[string]Block)
 
 func init() {
-	//regState := func(s Block) {
-	//	if _, ok := toStateID[s]; ok {
-	//		panic(fmt.Errorf("state %#v already exist", s))
-	//	}
-	//	toStateID[s] = len(fromStateID)
-	//	fromStateID = append(fromStateID, s)
-	//}
-	//regBlock := func(b Block) {
-	//	fromID[b.ID()] = b
-	//	b.forEachState(regState)
-	//}
-	//regBlock(Air{})
+	regState := func(s Block) {
+		if _, ok := toStateID[s]; ok {
+			panic(fmt.Errorf("state %#v already exist", s))
+		}
+		toStateID[s] = len(fromStateID)
+		fromStateID = append(fromStateID, s)
+	}
+	var states []struct {
+		Name       string
+		Properties nbt.RawMessage
+	}
+	// decompress
+	z, err := zlib.NewReader(bytes.NewReader(blockStates))
+	if err != nil {
+		panic(err)
+	}
+	// decode all states
+	if _, err = nbt.NewDecoder(z).Decode(&states); err != nil {
+		panic(err)
+	}
+	for _, state := range states {
+		block := fromID[state.Name]
+		if state.Properties.Type != nbt.TagEnd {
+			err := state.Properties.Unmarshal(&block)
+			if err != nil {
+				panic(err)
+			}
+		}
+		regState(block)
+	}
 }
 
-func NewFromStateID(stateID int) Block {
+func FromStateID(stateID int) Block {
 	return fromStateID[stateID]
 }
+
+func ToStateID(b Block) int {
+	return toStateID[b]
+}