From 36bec6e63dd64701c096e6964cbcd97804d6c234 Mon Sep 17 00:00:00 2001
From: Tnze <cjd001113@outlook.com>
Date: Mon, 2 Jan 2023 22:43:43 +0800
Subject: [PATCH] fix bitsPerBlock calculation bug in
 NewXXXXPaletteContainerWithData

---
 level/bitstorage.go | 10 ++++++++++
 level/palette.go    |  5 ++---
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/level/bitstorage.go b/level/bitstorage.go
index af84d7f..a22f1ea 100644
--- a/level/bitstorage.go
+++ b/level/bitstorage.go
@@ -67,6 +67,16 @@ func calcBitStorageSize(bits, length int) (size int) {
 	return (length + valuesPerLong - 1) / valuesPerLong
 }
 
+// calcBitsPerValue calculate when "longs" number of uint64 stores
+// "length" number of value, how many bits are used for each value.
+func calcBitsPerValue(length, longs int) (bits int) {
+	if longs == 0 || length == 0 {
+		return 0
+	}
+	valuePerLong := (length + longs - 1) / longs
+	return 64 / valuePerLong
+}
+
 type newBitStorageErr struct {
 	ArrlLen int
 	WantLen int
diff --git a/level/palette.go b/level/palette.go
index 99a98ac..7ad6cb5 100644
--- a/level/palette.go
+++ b/level/palette.go
@@ -2,7 +2,6 @@ package level
 
 import (
 	"io"
-	"math/bits"
 	"strconv"
 
 	"github.com/Tnze/go-mc/level/biome"
@@ -36,7 +35,7 @@ func NewStatesPaletteContainer(length int, defaultValue BlocksState) *PaletteCon
 
 func NewStatesPaletteContainerWithData(length int, data []uint64, pat []BlocksState) *PaletteContainer[BlocksState] {
 	var p palette[BlocksState]
-	n := bits.Len(uint(len(pat) - 1))
+	n := calcBitsPerValue(length, len(data))
 	switch n {
 	case 0:
 		p = &singleValuePalette[BlocksState]{pat[0]}
@@ -78,7 +77,7 @@ func NewBiomesPaletteContainer(length int, defaultValue BiomesState) *PaletteCon
 
 func NewBiomesPaletteContainerWithData(length int, data []uint64, pat []BiomesState) *PaletteContainer[BiomesState] {
 	var p palette[BiomesState]
-	n := bits.Len(uint(len(pat) - 1))
+	n := calcBitsPerValue(length, len(data))
 	switch n {
 	case 0:
 		p = &singleValuePalette[BiomesState]{pat[0]}