From faae40e0dc6efe07e8d39cef73fd441361e40fd0 Mon Sep 17 00:00:00 2001
From: bixilon <bixilon@bixilon.de>
Date: Fri, 5 Jun 2020 22:43:40 +0200
Subject: [PATCH] fix section counting in chunk bulk

---
 .../clientbound/play/PacketChunkBulk.java       |  2 +-
 .../java/de/bixilon/minosoft/util/BitByte.java  | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/main/java/de/bixilon/minosoft/protocol/packets/clientbound/play/PacketChunkBulk.java b/src/main/java/de/bixilon/minosoft/protocol/packets/clientbound/play/PacketChunkBulk.java
index cc3a747e6..a6048701f 100644
--- a/src/main/java/de/bixilon/minosoft/protocol/packets/clientbound/play/PacketChunkBulk.java
+++ b/src/main/java/de/bixilon/minosoft/protocol/packets/clientbound/play/PacketChunkBulk.java
@@ -42,7 +42,7 @@ public class PacketChunkBulk implements ClientboundPacket {
 
 
                     //chunk
-                    byte sections = (byte) Integer.bitCount(sectionBitMask);
+                    byte sections = BitByte.getBitCount(sectionBitMask);
                     int totalBytes = 4096 * sections; // 16 * 16 * 16 * sections; Section Width * Section Height * Section Width * sections
                     int halfBytes = totalBytes / 2; // half bytes
 
diff --git a/src/main/java/de/bixilon/minosoft/util/BitByte.java b/src/main/java/de/bixilon/minosoft/util/BitByte.java
index 83dbf08ad..43f6683c5 100644
--- a/src/main/java/de/bixilon/minosoft/util/BitByte.java
+++ b/src/main/java/de/bixilon/minosoft/util/BitByte.java
@@ -8,6 +8,13 @@ public class BitByte {
         return bitSet;
     }
 
+    public static boolean isBitSetShort(short in, int pos) {
+        boolean bitSet;
+        int mask = 1 << pos;
+        bitSet = ((in & mask) == mask);
+        return bitSet;
+    }
+
     public static byte getLow4Bits(byte input) {
         return (byte) (input & 0xF);
     }
@@ -16,4 +23,14 @@ public class BitByte {
         return (byte) ((input) >> 4 & 0xF);
     }
 
+    public static byte getBitCount(short input) {
+        byte ret = 0;
+        for (int i = 0; i < Short.BYTES * 8; i++) { // bytes to bits
+            if (isBitSetShort(input, i)) {
+                ret++;
+            }
+        }
+        return ret;
+    }
+
 }