From ff83b42132d107b7721b7e505bb3edb4a15dface Mon Sep 17 00:00:00 2001
From: Leijurv <leijurv@gmail.com>
Date: Tue, 28 Aug 2018 13:58:36 -0700
Subject: [PATCH] fix heightMap bug

---
 src/main/java/baritone/chunk/ChunkPacker.java | 20 +++++++++----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/main/java/baritone/chunk/ChunkPacker.java b/src/main/java/baritone/chunk/ChunkPacker.java
index 6bac5529..3cd0b415 100644
--- a/src/main/java/baritone/chunk/ChunkPacker.java
+++ b/src/main/java/baritone/chunk/ChunkPacker.java
@@ -22,8 +22,6 @@ import baritone.utils.Helper;
 import baritone.utils.pathing.PathingBlockType;
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockAir;
-import net.minecraft.block.BlockDoublePlant;
-import net.minecraft.block.BlockTallGrass;
 import net.minecraft.block.state.IBlockState;
 import net.minecraft.init.Blocks;
 import net.minecraft.util.ResourceLocation;
@@ -69,17 +67,17 @@ public final class ChunkPacker implements Helper {
         //System.out.println("Chunk packing took " + (end - start) + "ms for " + chunk.x + "," + chunk.z);
         String[] blockNames = new String[256];
         for (int z = 0; z < 16; z++) {
+            outerLoop:
             for (int x = 0; x < 16; x++) {
-                int height = chunk.getHeightValue(x, z);
-                IBlockState blockState = chunk.getBlockState(x, height, z);
-                for (int y = height; y > 0; y--) {
-                    blockState = chunk.getBlockState(x, y, z);
-                    if (getPathingBlockType(blockState.getBlock()) != PathingBlockType.AIR) {
-                        break;
+                for (int y = 255; y >= 0; y--) {
+                    int index = CachedChunk.getPositionIndex(x, y, z);
+                    if (!bitSet.get(index) && !bitSet.get(index + 1)) {
+                        String name = blockToString(chunk.getBlockState(x, y, z).getBlock());
+                        blockNames[z << 4 | x] = name;
+                        continue outerLoop;
                     }
                 }
-                String name = blockToString(blockState.getBlock());
-                blockNames[z << 4 | x] = name;
+                blockNames[z << 4 | x] = "air";
             }
         }
         CachedChunk cached = new CachedChunk(chunk.x, chunk.z, bitSet, blockNames, specialBlocks);
@@ -116,7 +114,7 @@ public final class ChunkPacker implements Helper {
         // however, this failed in the nether when you were near a nether fortress
         // because fences check their adjacent blocks in the world for their fence connection status to determine AABB shape
         // this caused a nullpointerexception when we saved chunks on unload, because they were unable to check their neighbors
-        if (block instanceof BlockAir || block instanceof BlockTallGrass || block instanceof BlockDoublePlant) {
+        if (block instanceof BlockAir) {
             return PathingBlockType.AIR;
         }