From b80902ec100df275b217cea01e469b97648096d5 Mon Sep 17 00:00:00 2001
From: Gerrygames <gecam59@gmail.com>
Date: Wed, 22 Apr 2020 21:42:11 +0200
Subject: [PATCH] convert height maps, fix 1.16 chunk reading

---
 .../api/type/types/version/ChunkSectionType1_16.java   |  3 ++-
 .../protocol1_16to1_15_2/packets/WorldPackets.java     | 10 ++++++++++
 .../us/myles/ViaVersion/util/CompactArrayUtil.java     |  2 +-
 3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/common/src/main/java/us/myles/ViaVersion/api/type/types/version/ChunkSectionType1_16.java b/common/src/main/java/us/myles/ViaVersion/api/type/types/version/ChunkSectionType1_16.java
index 28a8ee2f8..f06c51e0f 100644
--- a/common/src/main/java/us/myles/ViaVersion/api/type/types/version/ChunkSectionType1_16.java
+++ b/common/src/main/java/us/myles/ViaVersion/api/type/types/version/ChunkSectionType1_16.java
@@ -34,7 +34,8 @@ public class ChunkSectionType1_16 extends Type<ChunkSection> {
         // Read blocks
         long[] blockData = new long[Type.VAR_INT.read(buffer)];
         if (blockData.length > 0) {
-            int expectedLength = (int) Math.ceil(ChunkSection.SIZE * bitsPerBlock / 64.0);
+            char valuesPerLong = (char) (64 / bitsPerBlock);
+            int expectedLength = (ChunkSection.SIZE + valuesPerLong - 1) / valuesPerLong;
             if (blockData.length != expectedLength) {
                 throw new IllegalStateException("Block data length (" + blockData.length + ") does not match expected length (" + expectedLength + ")! bitsPerBlock=" + bitsPerBlock + ", originalBitsPerBlock=" + originalBitsPerBlock);
             }
diff --git a/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_16to1_15_2/packets/WorldPackets.java b/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_16to1_15_2/packets/WorldPackets.java
index d57fa6c3a..9d183c50d 100644
--- a/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_16to1_15_2/packets/WorldPackets.java
+++ b/common/src/main/java/us/myles/ViaVersion/protocols/protocol1_16to1_15_2/packets/WorldPackets.java
@@ -2,6 +2,7 @@ package us.myles.ViaVersion.protocols.protocol1_16to1_15_2.packets;
 
 import com.github.steveice10.opennbt.tag.builtin.CompoundTag;
 import com.github.steveice10.opennbt.tag.builtin.IntArrayTag;
+import com.github.steveice10.opennbt.tag.builtin.LongArrayTag;
 import com.github.steveice10.opennbt.tag.builtin.StringTag;
 import com.github.steveice10.opennbt.tag.builtin.Tag;
 import us.myles.ViaVersion.api.minecraft.chunks.Chunk;
@@ -16,6 +17,7 @@ import us.myles.ViaVersion.protocols.protocol1_15to1_14_4.types.Chunk1_15Type;
 import us.myles.ViaVersion.protocols.protocol1_16to1_15_2.Protocol1_16To1_15_2;
 import us.myles.ViaVersion.protocols.protocol1_16to1_15_2.types.Chunk1_16Type;
 import us.myles.ViaVersion.protocols.protocol1_9_3to1_9_1_2.storage.ClientWorld;
+import us.myles.ViaVersion.util.CompactArrayUtil;
 
 import java.util.UUID;
 
@@ -82,6 +84,14 @@ public class WorldPackets {
                             blockEntity.put(skullOwnerTag);
                         }
                     }
+
+                    CompoundTag heightMaps = chunk.getHeightMap();
+                    for (String key : heightMaps.keySet()) {
+                        LongArrayTag heightMap = heightMaps.get(key);
+                        int[] heightMapData = new int[256];
+                        CompactArrayUtil.iterateCompactArray(9, heightMapData.length, heightMap.getValue(), (i, v) -> heightMapData[i] = v);
+                        heightMap.setValue(CompactArrayUtil.createCompactArrayWithPadding(9, heightMapData.length, i -> heightMapData[i]));
+                    }
                 });
             }
         });
diff --git a/common/src/main/java/us/myles/ViaVersion/util/CompactArrayUtil.java b/common/src/main/java/us/myles/ViaVersion/util/CompactArrayUtil.java
index 59d139e54..5bd476bc4 100644
--- a/common/src/main/java/us/myles/ViaVersion/util/CompactArrayUtil.java
+++ b/common/src/main/java/us/myles/ViaVersion/util/CompactArrayUtil.java
@@ -37,7 +37,7 @@ public class CompactArrayUtil {
         long divideMul = Integer.toUnsignedLong(MAGIC[magicIndex]);
         long divideAdd = Integer.toUnsignedLong(MAGIC[magicIndex + 1]);
         int divideShift = MAGIC[magicIndex + 2];
-        int size = (4096 + valuesPerLong - 1) / valuesPerLong;
+        int size = (entries + valuesPerLong - 1) / valuesPerLong;
 
         long[] data = new long[size];