linear palette

save/palette.go

@@ -0,0 +1,80 @@
+package save
+
+import (
+	"github.com/Tnze/go-mc/nbt"
+	pk "github.com/Tnze/go-mc/net/packet"
+	"io"
+)
+
+type BlockState interface {
+}
+
+type palette interface {
+	id(v BlockState) int
+	value(i int) BlockState
+	io.ReaderFrom
+	io.WriterTo
+	read(r nbt.DecoderReader) (int, error)
+}
+
+type linearPalette struct {
+	onResize func(n int, v BlockState) int
+	sToID    map[BlockState]int
+	idTos    map[int]BlockState
+	values   []BlockState
+	bits     int
+}
+
+func (l *linearPalette) id(v BlockState) int {
+	for i, t := range l.values {
+		if t == v {
+			return i
+		}
+	}
+	if cap(l.values)-len(l.values) > 0 {
+		l.values = append(l.values, v)
+		return len(l.values) - 1
+	}
+	return l.onResize(l.bits+1, v)
+}
+
+func (l *linearPalette) value(i int) BlockState {
+	if i >= 0 && i < len(l.values) {
+		return l.values[i]
+	}
+	return nil
+}
+
+func (l *linearPalette) ReadFrom(r io.Reader) (n int64, err error) {
+	var size, value pk.VarInt
+	if n, err = size.ReadFrom(r); err != nil {
+		return
+	}
+	for i := 0; i < int(size); i++ {
+		if nn, err := value.ReadFrom(r); err != nil {
+			return n + nn, err
+		} else {
+			n += nn
+		}
+		l.values[i] = l.idTos[int(value)]
+	}
+	return
+}
+
+func (l *linearPalette) WriteTo(w io.Writer) (n int64, err error) {
+	if n, err = pk.VarInt(len(l.values)).WriteTo(w); err != nil {
+		return
+	}
+	for _, v := range l.values {
+		if nn, err := pk.VarInt(l.sToID[v]).WriteTo(w); err != nil {
+			return n + nn, err
+		} else {
+			n += nn
+		}
+	}
+	return
+}
+
+func (l *linearPalette) read(r nbt.DecoderReader) (int, error) {
+	panic("not implemented yet")
+}